J Bagh College Dentistry Vol. 29(1), March 2017 The effect Oral and maxillofacial Surgery and Periodontics 111 The Effect Of Treatment Protocol and Implant Dimensions on Primary Stability Utilizing Resonance Frequency Analysis Thair Abdul Lateef, B.D.S., H.D.D., F.I.B.M.S. (1) ABSTRACT Background: According to Branemark’s protocol, the waiting period between tooth extraction and implant placement is 6–8 months; this is the late placement technique. Achieving and maintaining implant stability are prerequisites for a dental implant to be successful. Resonance Frequency Analysis (RFA) is a noninvasive diagnostic method that measures implant stability. The aim of this study was to investigate the influence of treatment protocol and implant dimensions on primary implant stability utilizing RFA. Materials and methods: This study included 63 Iraqi patients (37 male, 26 female; ranging 22-66 years). According to treatment protocol, the sample was divided into 2 groups; A (delayed) & B (immediate). Dental implants were inserted and the implant stability quotient (ISQ) measures for primary stability documented by Osstell device. Results: For both groups fixtures introduced in the mandible showed a higher stability (74 and 71.85) respectively and was lower in maxilla. The mean primary stability of group A was 70.21 (ranged from 51-83), while for group B was 68.55 (46.5-81). Conclusion: primary stability influencing osseointegration and subsequent long term success. It was higher in association with delayed implant placement, mandible, and increased implant diameters. Keywords: Primary stability, immediate implant, ISQ. .(J Bagh Coll Dentistry 2017; 29(1):111-116). INTRODUCTION According to Branemark’s protocol, the waiting period between tooth extraction and implant placement is 6–8 months; this is the late placement technique. Series of biological processes such as bone resorption (vertically and horizontally), gingival collapse and migratory movements of the adjacent teeth to the extraction space occur during this period. Other concerns about this protocol include the increased time of edentulism, longer treatment time and additional surgical procedure. In 1993 Wilson and Weber used the terms immediate, recent, delayed and mature, to describe the timing of implant placement after tooth extraction or the extraction socket’s healing process (1). Some scholars proposed immediate implant technique, namely extracting the worthless remnant root and immediately embedding implant in situ at the same time. The clinical effect of this technique is accepted well (2). Implants placed immediately into extraction sockets have been shown to have a high rate of clinical success (3). Achieving and maintaining implant stability are prerequisites for a dental implant to be successful. Implant stability can be defined as (1) Assistant professor. Department of Oral and Maxillofacial Surgery.Baghdad. Iraq e-mail: d.thair_61@yahoo.com the absence of clinical mobility, which is also the suggested definition of osseointegration. Primary implant stability at placement is a mechanical phenomenon that is related to the local bone quality and quantity, the type of implant and placement technique used (4). Successful osseointegration is prerequisite for functional dental implants and primary implant stability is a prerequisite for successful osseointegration (4). Primary implant stability is widely regarded as the central determinant of implant osseointegration success; how it is measured and quantified is not viewed with similar universal acceptance. Clinical investigations involving large numbers of patients are vitally important to defining objective measures of primary implant stability related to dental implant success and the variables that modify success (5). The methods to determine implant stability clinically are clinical perception, percussion test, and reverse torque test, cutting torque resistance analysis, periotest and RFA (4). Resonance Frequency Analysis (RFA) It is a noninvasive diagnostic method that measures implant stability and bone density at various time points using vibration and structural principle analysis. Two commercially devices have been developed to assess implant stability. The original (electrical) method uses a direct connection (wire) between the transducer and the resonance frequency analyzer. The second method uses magnetic frequencies between transducer and resonance frequency analyzer. J Bagh College Dentistry Vol. 29(1), March 2017 The effect Oral and maxillofacial Surgery and Periodontics 112 The new magnetic RFA device has a transducer, a metallic rod with a magnet on top, which is screwed onto an implant or abutment. The electronic device and the magnetic device are capable of measuring similar changes; however the magnetic device results in higher implant stability quotient (ISQ) value when measuring the stability of nonsubmerged dental implant (4). The ISQ is a measure of interfacial stiffness presented by the implant bone interface. ISQ- based evaluations of primary implant stability have inferred that a number of variables affect stability. Such variables include the following: (1) bone quality, (2) implant site (anatomic position), (3) age, (4) gender, (5) smoking status, (6) periodontal status, (7) implant diameter, (8) implant length and (9) implant design (5). The present study was performed to investigate the influence of certain variables (treatment protocol and implant dimensions) on primary implant stability utilizing RFA test. MATERIALS AND METHODS In the period between October 2015 and June 2016, this study was conducted in the Implantology Unit at the Department of Oral & Maxillofacial Surgery, College of Dentistry, University of Baghdad, Iraq. Sixty three patients participated in this clinical prospective study (37 male, 26 female; ranging 22-66 years) needed one or more dental implant were selected. The whole sample was divided into 2 groups: 1- Group A: dental implants placed with the delayed protocol (at least 6 months after tooth extraction). 2- Group B: dental implants placed with immediate post extraction protocol. An informed written consent was secured from all patients using their data for research purposes. A number of exposure variables were evaluated in multivariate analyses including age, gender, implant dimensions and location. Inclusion criteria 1- Fair oral hygiene. 2- Implants to be placed at least 6 months after teeth extraction and/or immediate post extraction placement of hopeless teeth or retained roots. 3- Patients age > 18 years. 4- Sufficient bone width and height to accommodate conventional implant therapy without alveolar bone augmentation. Exclusion Criteria 1- Poor oral hygiene. 2- Smoking more than 20 cigarettes/day and excessive alcohol consumption. 3- High degree of bruxism. 4- Any systemic chronic disease affecting bone healing potential (localized radiotherapy of the oral cavity, antitumor chemotherapy, liver pathologies, immunosuppressed status, and current corticosteroid therapy, inflammatory and autoimmune disease of the oral cavity). 5- Current pregnancy. Preoperative clinical and radiographical examination following detailed previous medical and dental history was taken for each patient using a special form of case sheet for the implant center. For radiological assessment, Orthopantomogram (OPG) was made for each candidate, (Fig 1). Surgical procedure For both groups treatment began for both groups with local anesthesia xylocaine/adrenaline 2% which was induced by block or infiltration technique. After elevation of mucoperiosteal flap, all implants were inserted according to a strict protocol that followed the manufacturer's instructions. For group B, immediate extraction of hopeless teeth/retained roots was performed as atraumatically as possible prior to implant installation, (Fig 2). Sutures were removed 10 days after surgery. For both groups, 150 implants (Dentium, Korea) were installed. With 100 implants for group A and 50 for group B. The actual ISQ (implant stability quotient) were collected for both groups with the aid of RFA (resonance frequency analysis) using Osstell device (Goteborg, Sweden) with maximum insertion torque values of 35 N/cm during low speed insertion by means of a transducer attached to implant body (smart peg) and readings for the primary stability were scored, Fig 4. ISQ values were considered as follows: low (0-50), medium (51-70) and high (71-100). Patients instructed to take the following drug regimen: Amoxicillin 500 mg + metronidazole 250 mg + Paracetamol 500 mg /thrice daily for 5 days postoperatively. Fig 1: Diagnostic preoperative OPG revealed hopeless tooth No.8. J Bagh College Dentistry Vol. 29(1), March 2017 The effect Oral and maxillofacial Surgery and Periodontics 113 Fig 2: A. Atraumatic extraction of hopeless tooth No. 8 presented with severe periodontitis prior to immediate implant placement. B. Installation of dental implant into the socket of the extracted tooth. Statistical analysis Two independent sample t-test, paired t-test and Pearson correlation (R) were the statistical method used to analyze the data. The level of significance tested according to the P-value, were: P>0.05 (Not significant), P<0.05 (Significant), P<0.01 (Highly significant). The analyses were accomplished using computer software program: Statistical Package for Social Sciences (SPSS version 18). RESULTS The mean primary stability of group A was 70.21 (ranged from 51-83), while for group B was 68.55 (46.5-81). High ISQ values (>70) observed in 57% of dental implants placed in group A; however it was less for group B which recorded 42%. The 5th decade of life (40-49 years) was the dominant one for both groups, group A occupied (35.13%) and group B (30.77%). The prominent sex in this study were females (37 patients, 58.73%), while males attended with less number (26 patients, 41.27%) as clarified in table 1. Regarding treatment protocol and site of placement: the mean primary stability for the group A was 70.21 ISQ, in which the anterior mandible recorded the highest value 75.5 ISQ, while the stability in anterior maxilla was the lowest 65.5 ISQ. On the other hand; for group B, the mean stability was lower than group A which was 68.55 ISQ, with predominance for the posterior mandible 76.37 ISQ, with also the least figures reported in anterior maxilla. For both groups fixtures introduced in the mandible showed a higher stability (74 and 71.85) respectively and was lower in maxilla. All these data exemplified in table 2. Table 1: Age and sex distribution. Table 2: Primary implant stability in relation to treatment protocol and site of placement. Place ment protoc ol Jaw site Primar y stabilit y (mean ISQ) Mandible Maxilla Group A (100 fixture s) Anterio r 3 (3%) 30 (30%) 70.21 Primary ISQ 75.5 65.5 Posterio r 31 (31%) 36 (36%) Primary ISQ 72.5 67.37 Mean ISQ 74 66.43 Group B (50 fixture s) Mandible Maxilla 68.55 Anterio r 3 (6%) 67.33 32 (64%) 61.04 Posterio r 2 (4%) 76.37 13 (26%) 69.46 Mean ISQ 71.85 65.25 paired t-test showed significant difference in the ISQ value between the Group A (0.000) and Group B (0.003) (P<0.05), Pearson correlation showed direct proportional relationship between Group A & B (0.9 & 0.3) respectively, which indicates higher primary stability in Group A, table 3 explains statistical results (Table 3). In Dentium system different implant dimensions utilized for this research. The highest stability regarding implant diameter registered with the widest diameter in group A (4.8 mm) in which the mean stability was 75.75 ISQ. While; the lowest figures noted with the narrowest diameter in this system (3.4 mm) which was 62.70, With the mean for all diameters 69.63. Sex Delayed (Group A) Immediate (Group B) Total Female 22 (34.92%) 15 (23.81%) 37 (58.73%) Male 15 (23.81%) 11 (17.46%) 26 (41.27%) BB J Bagh College Dentistry Vol. 29(1), March 2017 The effect Oral and maxillofacial Surgery and Periodontics 114 For group B (4.8 mm) diameter was not applied, as the highest stability reported with (4.3 mm) 70.66 ISQ, while; the lowest was with (3.8 mm) 59.68 ISQ, with the mean for all diameters 64.19 ISQ. These are demonstrated in table 4 and mean stability regarding the diameters was also higher in delayed protocol, Fig 3. 0 10 20 30 40 50 60 70 80 90 100 Mean ISQ ISQ & implant length ISQ & implant diameter Group A Group B Fig 3: Variables distribution. Table 3: Statistical results. Sample size Mean ISQ (placement protocol) Mean ISQ (length) Mean ISQ (diameter) t-test Sig R P-value Group A (100) 70.21 73.78 75.75 0.000 0.05 0.9 0.8 Group B (50) 68.55 63.85 70.66 0.003 0.05 0.3 0.5 Table 4: The effect of implant diameter on mean stability for both delayed and immediate placement. Protocol & ISQ Implant diameter (No. & %) Group A- (69.63) ISQ 3.4 mm 3.8 mm 4.3 mm 4.8 mm 3410 ► 10 (10%) 3412 ► 20 (20%) 3414 ► 3 (3%) 3808 ► 4 (4%) 3810 ► 11 (11%) 3812 ► 18 (18%) 3814 ► 4 (4%) 4308 ► 4 (4%) 4310 ► 16 (16%) 4312 ► 6 (6%) 4808 ► 2 (2%) 4810 ► 1 (1%) 4812 ► 1 (1%) Mean stability 62.70 70.06 70.03 75.75 Group B- (64.19) ISQ 3412 ► 6 (12%) 3414 ► 7 (14%) 3812 ► 10 (20%) 3814 ► 24 (48%) 4310 ► 1 (2%) 4312 ► 2 (4%) --------- Mean stability 62.23 59.68 70.66 In a correlation to the implant length for group A: the highest stability recorded with the length (14 mm) 73.78 ISQ and the lowest with (8 mm) 67.70 ISQ. While; for group B, the highest figure 81 ISQ was with (10 mm, insignificant) since single fixture is inserted. The lowest reported with (14 mm), however, most fixtures fall under the category of this length (31 dental implants) with 63.85 ISQ as shown in table 5. Fig 4: ISQ primary stability measurement for tooth site No. 12 with the aid of Osstell device. J Bagh College Dentistry Vol. 29(1), March 2017 The effect Oral and maxillofacial Surgery and Periodontics 115 Table 5: The effect of implant length on mean stability for both delayed and immediate placement. Treatment protocol Implant length (No. & %) 14 mm % 12 mm % 10 mm % 8 mm % Group A- (69.95) ISQ 3414 ► 3 3814 ► 4 7% 3412 ► 20 3812 ► 18 4312 ► 6 4812 ► 1 45% 3410 ► 10 3810 ► 11 4310 ► 16 4810 ► 1 38% 3808 ► 4 4308 ► 4 4808 ► 2 10% Mean stability 73.78 68.05 70.30 67.70 Group B- (69.67) ISQ 3414 ►7 3814►24 31 (62%) 3412►6 3812►10 4312►2 18 (36%) 4310►1 1 (2%) ---------- Mean stability 63.85 64.16 81 (insignificant) DISCUSSION The primary stability is considered to be as the password for osseointegration. Gaining good primary stability is of paramount importance for successful osseointegration and subsequently achieving the main goal of dental implant placement from the functional and esthetic points of view which is the long term success. An objective precise measurement for primary stability is the RFA seems to be the most indicative. This study tried to analyze the influence of some important variables on the primary stability, those are treatment protocol (delayed vs immediate), site of fixture in the jaws and dental implant dimensions (diameter vs length). The 5th decade of life (40-49 years) was the prominent one in this study (21 patients, 33.33%), this is logic in the country since the general impression on patient compliance is poor for patients with teeth loss, not seeking for treatment at early time, also most of patients who ask for immediate implant placement presented with symptomless retained roots. Females occupied the first place 37 (58.73%) with female: male ratio 37:26 (1.4:1). Since most of fixtures for both groups introduced in the anterior region of maxilla and mandible (esthetic zone) about 33.3% for the group A and 70% for the group B (immediate placement), this is may be due to the willing desire in women for perfect esthetic more than males confirmed by (Al Garni et al. 2012) (6). In general the primary stability in group A (70.21 ISQ) was better than group B (68.55ISQ) and this may be related to the available amount of bone surrounding dental implant which is better with the delayed protocol than immediate postextraction implantation that is usually associated with alveolar defects and profound gaps between implant body and alveolar socket walls. This study revealed that the mean primary stability in the mandible was good for both groups A and B 74 ISQ and 71.85 ISQ respectively, this greatly related to the density of mandible which is better in all sites than the maxilla, here the maxilla showed medium stability for both functional zones 66.43 ISQ, 65.25 ISQ respectively. Fyhrie, 2004 stated that bone density of the mandible found to be 4% higher than maxilla and decreases progressively as to go posteriorly (7). Best stability observed with the bigger dental implant diameter that is the best was with (Ø4.8 mm) implants 75.75 ISQ, followed by (Ø4.3 mm and Ø3.8 mm) 70.03 and 70.06 ISQ respectively. The least stability reported with the delayed protocol was with the narrowest conventional diameters Ø3.4 mm (62.70 ISQ), as this is supported by many researchers as (Barikani, 2013) (8). On the other hand with immediate placement the figures was unreliable with Ø3.8 mm recorded the least stability 59.68 ISQ, higher stability registered with Ø4.3 mm (few number 3) and Ø3.4 mm. With immediate treatment many factors affecting the measurement as the socket wall gaps created after extraction or bone defects as dehiscence or fenestration. The length of dental implant has an influence on stability in group A. The stability was higher with 14 mm length dental implants (73.78 ISQ) and the least was with 8 mm. However this is not the case in immediate placement in which the dominant length was 14 mm (62%) but the lowest stability recorded 63.85 ISQ, however, clinically all implants had reasonable stability obtained by over-drilling procedure 2-3 mm beyond the depth of the socket walls. CONCLUSION The primary stability is of eminent influence on osseointegration and subsequent long term success. It was higher in association with J Bagh College Dentistry Vol. 29(1), March 2017 The effect Oral and maxillofacial Surgery and Periodontics 116 delayed implant placement, mandible, and increased implant diameters. REFERENCES: 1. Mainetti T, Lang NP, Bengazi F, Favero V, Soto Cantero L, Botticelli D. Sequential healing at implants installed immediately into extraction sockets. An experimental study in dogs. Clin Oral Implants Res. 27. 2016. 130–138. 2. S. S. Soydan, S. Cubuk, Y. Oguz, S. Uckan: Are success and survival rates of early implant placement higher than immediate implant placement? Int J Oral Maxillofac Surg. 2013. 42: 511–515. 3. Jinghui Zhao, Yanmin Zhou, Xiaolin Sun, Wang Yue, A lan, Gao Donghui, Liu Yuyan. Clinical Study of Delayed Immediate Implant. International Conference on Human Health and Biomedical Engineering August, 2011.19-22. 4. Nedir R, Bischof M, Szmukler-Moncler S, Bernard JP, Samson J. Predicting osseointegration by means of implant primary stability. Clin Oral Implants Res 2004. 15:520-528. 5. Gaurang Mistry, Omkar Shetty, Shreya Shetty, Raghuwar D Singh: Measuring implant stability: A review of different methods. J Dent Implants | Jul - Dec 2014. (2): 165-169. 6. Al Garni, B., Pani, S.C., AlMaaz, A., Al Qeshtaini, E., Abu-Haimed, H., and Sharif, K. Factors affecting the willingness to pay for implants: A study of patients in Riyadh. Dent Res J, 9(6): 2012.719-724. 7. Fyhrie, D.B. Summary-measuring "bone quality". Journal of musculoskeletal & neuronal interactions, 2004.5(4): 318-320. 8. Barikani, H., Rashtak, S., Akbari, S., Badri, S., Daneshparvar, N., and Rokn, A. The effect of implant length and diameter on the primary stability in different bone types. J Dent (Tehran, Iran), 10(5). 2013: 449-455. الخالصة اشهر: وهذا هو الوضع المتأخر للزرعة. الحصول وتحقيق ثبات 8-6استنادا الى مبدأ برينمارك, فان وقت االنتظار بين قلع السن ووضع الزرعة هو المقدمة: هي طريقة جيدة لقياس ثبات الزرعة.الغاية من هذه الدراسة هو فحص تأثير مبدأ وضع الزرعة RFAالزرعة هي اهم االهداف المطلوبة لنجاح الزرعة.جهاز ال . RFAوابعادها على ثبات الزرعة االولي بواسطة ال تين: سنة(. حسب توقيت العالج, قسمت العينة الى مجموع 66-66اناث, بين 66ذكور, 63مريض عراقي ) 66تتضمن الدراسة المواد وطرق العمل: مجموعة أ )المتأخر( و مجموعة ب )اآلني(. ادخلت الزرعات وقيست الثباتية االولية للزرعة بواسطة جهاز االوستيل. 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