Alaa.doc J Bagh College Dentistry Vol. 27(2), June 2015 Effect of the Pedodontics, Orthodontics and Preventive Dentistry136 Effect of different staining materials on color stability of sapphire brackets bonded with different types of light cure orthodontic adhesives (An in vitro study) Alaa Faleh Albo Hassan, B.D.S. (1) Nidhal H. Ghaib, B.D.S., M.Sc. (2) ABSTRACT Background: The demand for better esthetic during orthodontic treatment has increased nowadays, so orthodontists starting using esthetic arch wires, brackets and ligatures.Tooth colored brackets were introduced in different types of materials. Sapphire ceramic brackets are one type of esthetic brackets and their color stability remains the main concern for the clinicians and patients at the same time . The present study design to evaluate the effect of three different staining materials (pepsi, black tea and cigarette smoke) on the stainability of sapphire ceramic brackets bonded with three types of light cure orthodontic adhesives which include: Resilience, Enlight and Transbond. Materials and Methods: The sample consisted of three hundred sixty sapphire brackets. The brackets were divided according to bonding materials into three groups each group consist of one hundred twenty brackets, then each subgroup farther subdivided into four groups according to the material they were immersed (distilled water, black tea, Pepsi and cigarette smoke) with thirty brackets each, then Each group with ten brackets farther subdivided according to time interval of immersion in each media into three groups one day, seven days and fourteen days at 37°C in the incubator.A UV-Visible spectrophotometer (Shimadzu, UV -1800) was used to perform a light absorption test. Results: ANOVA and LSD post Hoc tests were used to identify the significant effects of the staining materials at a significance level P ≤ 0.05.It was found that the immersion time gradually influenced the color stability of the adhesive materials with sapphire brackets with the highest activity observed at fourteen days interval. The brackets bonded with Resilience light cure adhesive are the most type affected by staining materials, then followed by the brackets bonded with Transbond and finally the brackets bonded with Enlight light cure adhesive. For the staining materials it was found that the cigarette smoke is the most powerful staining material, followed by tea and finally pepsi. Conclusions: From the above result we can conclude that the type of adhesive must take in consideration when the esthetic brackets have been used. Key words: Sapphire brackets, color stability, staining materials. (J Bagh Coll Dentistry 2015; 27(2):136-141). INTRODUCTION In modern society, the esthetic aspect of orthodontic therapy is becoming increasingly important because of the growing number of adult patients. Ceramic brackets have been developed to improve esthetics during orthodontic treatment (1,2). All currently available ceramic brackets are composed of aluminum oxide and because of their distinct differences during fabrication, two types of ceramic brackets are available, namely the polycrystalline alumina which are binders to thermally fuse the particles together, and the single crystal alumina or monocrystalline alumina or sapphire brackets which are milled from single crystals of sapphire (monocrystalline) using diamond tools (3-6). Color stability is considered an important factor in the success of an esthetic treatment Several factors influence the color stability of contemporary light activated materials, such as the photo initiator system, the resin matrix, the light-curing unit used for polymerization, and the irradiation times (7). (1) Master Student, Department of Orthodontics, College of Dentistry, University of Baghdad. (2) Professor, Department of Orthodontics, College of Dentistry, University of Baghdad. However, the optical properties of dental composite resins change because of polymerization, and the extent of change is influenced by the brand and shade of resin composites and the wavelength of curing lights (8,9). Composite resin discoloration is multifactorial, including factors such as intrinsic discoloration and extrinsic staining. Cigarette smoke, Tea, and pepsi are the most materials used among Iraqi people that have a potential staining ability. Therefore, it is important to assess the effect of these materials on the sapphire ceramic brackets. MATERIALS AND METHOD For this study 360 PERFECT CLEAR sapphire brackets (HUBIT/Korea) for maxillary central incisors on the right side were used, Roth type, slot 0.018” x 0.022”. Three types of light cure orthodontic adhesive were used in this studyEnlight light cure orthodontic adhesive (Ormco / Italy), Transbond TM XT light cure orthodontic adhesive (3M Unitek /USA) and Resilience® Light Cure orthodontic Adhesive System (Orthotechnology/ USA) fig. (1). Black J Bagh College Dentistry Vol. 27(2), June 2015 Effect of the Pedodontics, Orthodontics and Preventive Dentistry137 tea (AHMAD TEA, England), pepsi (Baghdad Company, Iraq), cigarette (Gauloises Blondes, European Union) and distilled water (control media) used as the staining materials. Figure 1: Bonding materials used in the present study. Sample organization The sample composed of 360 sapphire brackets were used in testing the staining effect of black tea, Pepsi and cigarette smoke. The brackets were divided according to bonding materials into three groups each group consist of 120 brackets: 1. Brackets bonded with Enlight Light-Cure orthodontic adhesive composite. 2. Brackets bonded with Transbond TM XT light cure orthodontic adhesive composite. 3. Brackets bonded with Resilience® light cure orthodontic adhesive composite. Then each subgroup farther subdivided into four groups according to the media they were immersed (distilled water as control group, black tea, Pepsi and cigarette smoke) with 30 brackets each, then Each group (with 10 brackets)farther subdivided according to time interval of immersion in each media into three groups (1day,7days and14days ) Bonding procedure A small amount of the adhesive paste was applied onto bracket base , then by using a clamping tweezer the bracket was placed lightly onto glass slide mounted on the table of surveyor (Dentaurum, Germany) covered by celluloid strip to facilitate detachment of the bracket - adhesive complex with a recovery of the set material Then a constant load was placed on the bracket for 10 seconds (by fixing the 200 gm load on the upper part of the vertical arm of the surveyor, and fixing the analyzing rod in the lower part of the vertical arm of the surveyor and put it in contact with the bonded bracket), to ensure that each bracket was seated under an equal force and to ensure a uniform thickness of the adhesive. Then any excess adhesive material was removed from around the bracket base with a sharp hand scaler without disturbing the seated bracket. After that the bracket adhesive was photopolymerized with a light-curing unit (Blue LEX LD-109, Taiwan); the light guide of curing light unit was directed toward the bracket, the light shined through the bracket for 5 ,10, 20 seconds for Transbond TM XT, Enlight, Resilience® adhesive pastes respectively .The bonded brackets were allowed to bench set for 24 hrs. To ensure complete polymerization of adhesive material, after setting; the celluloid strips were removed and the resultant bracket bonded adhesive were flat surfaces. Smoke Chamber The smoke chamber was a plastic container allowing cigarette smoke to enter from one end of the chamber , by a rubber tube that fit the cigarette, the rubber tube positioned to provide a uniform distribution of the entering cigarette smoke, and leave from the other end, by a portable suction device (saliva ejector) (HOO3-C, china) fitted that caused a negative pressure to aspirate the smoke released by the cigarette, thereby leading to impregnation of the brackets with the substances contained in the smoke, for the purpose of reproducing in vitro the conditions of a smoker’s oral cavity, for equal exposure of all brackets to cigarette smoke. The brackets were ligated with stainless steel ligature wires and putted into a chamber by fixing onto a supporting stainless steel holder that would allow the samples to remain in the same vertical position, so that the greater part of their surface would be exposed to the cigarette smokefig (2). Figure 2: Smoking equipment used in the study. J Bagh College Dentistry Vol. 27(2), June 2015 Effect of the Pedodontics, Orthodontics and Preventive Dentistry138 Staining procedure: v Preparation of staining solutions : ¸ Tea: The tea solution was prepared by immersing 5 teabags in 500 ml of boiling distilled water for 10 minutes ¸ Pepsi : New cans of Pepsi were used for each day. v Immersion in the staining solutions Each bracket was stored in a solution in inert plastic containers and labeled with sticky labels and stored at 37°C in the incubator,all solutions were regularly renewed after every 24 hours of storage. The total storage period was 14 days ¸ Cigarette For each bracket, 20 cigarettes were used for each day and each cigarette was burned in a standard time of 10 min in a total period of 14 days ,After exposure to every 20 cigarette the brackets were cleaned by ultrasonic cleaner(VGT- 1740QT, china) to eliminate excesses of substances from the smoke adhered to the bracket surfaces After this, the bracket putted back into its respective container containing distilled water and stored at 37°C in the incubator( Memmert, Germany) until the next time it was exposed to smoke Spectrophotometric analysis The color change readings were made using a spectrophotometer, Uv-Visible Spectrophotometer (Shimadzu, UV-1800, Japan), with wavelength range 200-800 ŋm with double beam analytical holders. To allow the standard positioning of the brackets during the reading, the bracket of each group and subgroup positioned on black rectangular cardboard segments (40×15×0.2 mm) with a central window at (17 mm) from the bottom to be in the way of the light beam of the spectrophotometer. Before the readings, each bracket was taken out of the immersion media and washed by ultrasonic cleaner for one minute and properly dried on paper towels (10-12). Before color reading the spectrophotometer was calibrated by opening the chamber and putting two black card boards without window on the two analytical beam holders and then the chamber closed and the device given the order auto zero to eliminate the effect of the black card board After that the chamber of the spectrophotometer was opened and the bracket was positioned in a standardized upright position with the black card board fig.(3), then the chamber is closed and the machine is given the order to start scanning starting from 800ŋm wavelength in the infra-red zone to 200ŋm Wavelength in the UV zone passing through the entire visible spectrum. The results appear as a graph from which the amount of light absorption is plotted as a graph and the amount of absorbed light at a specific wavelength was obtained. For all the samples the light absorption at 345ŋm wavelength visible light was obtained and used in the later statistical analysis. Figure 3: The bracket positioned on the analytical beam holder of the spectrophotometer and the blank on the other analytical beam holder. Statistical analysis Data were collected and analyzed using SPSS (statistical package of social science) software version 15 for windows XP Chicago, USA. The following statistics were used: A- Descriptive statistic: including mean, standard deviation, statistical tables and graphical presentation by bar charts. B- Inferential statistics 1- One way analysis of variance test (ANOVA) was used to examine anysignificant difference between more than two groups. 2- LSD test was used to find any statistical significant difference between any two groups. P value of more than 0.05 was regarded as statistically insignificant as follows: NS Non-significant p>0.05 S Significant 0.05≥p>0.01 HS Highly significant p≤0.01 RESULTS Comparison between adhesive materials The amount of incremental increase in light absorption by sapphire brackets bonded with Resilience, Enlight and Transbond adhesives when immersed in staining materials at three time intervals was shown in table 1 and table 2. J Bagh College Dentistry Vol. 27(2), June 2015 Effect of the Pedodontics, Orthodontics and Preventive Dentistry139 Table 1: Descriptive statistics and adhesive difference in each duration for Pepsi, Tea and Cigarette smoke by ANOVA test. Media Duration Adhesives Descriptive statistics Comparison (d.f.=29) Mean S.D. F-test p-value Pe ps i - D .W . 1 day Resilience -0.001 0.001 0.040 0.961 (NS) Enlight -0.001 0.001 Transbond -0.001 0.002 7 days Resilience 0.005 0.001 31.695 0.000 (HS) Enlight 0.001 0.000 Transbond 0.002 0.001 14 days Resilience 0.009 0.001 104.871 0.000 (HS) Enlight 0.002 0.001 Transbond 0.006 0.001 T ea - D .W . 1 day Resilience 0.015 0.001 575.446 0.000 (HS) Enlight 0.004 0.001 Transbond 0.005 0.000 7 days Resilience 0.021 0.001 425.474 0.000 (HS) Enlight 0.008 0.001 Transbond 0.011 0.001 14 days Resilience 0.028 0.001 197.129 0.000 (HS) Enlight 0.015 0.002 Transbond 0.020 0.002 C ig ar et te S m ok e - D .W . 1 day Resilience 0.021 0.001 128.885 0.000 (HS) Enlight 0.011 0.001 Transbond 0.016 0.002 7 days Resilience 0.039 0.001 840.875 0.000 (HS) Enlight 0.021 0.001 Transbond 0.028 0.001 14 days Resilience 0.049 0.001 1324.121 0.000 (HS) Enlight 0.025 0.001 Transbond 0.038 0.001 Table 2: Difference between the different adhesives for light absorption after immersion in Pepsi, Tea and Cigarette smoke by LSD test Media Duration Adhesives Mean Difference p-value P ep si - D .W . 7 days Resilience Enlight 0.004 0.000 (HS) Transbond 0.003 0.000 (HS) Enlight Transbond -0.001 0.013 (S) 14 days Resilience Enlight 0.007 0.000 (HS) Transbond 0.003 0.000 (HS) Enlight Transbond -0.004 0.000 (HS) T ea - D .W . 1 day Resilience Enlight 0.012 0.000 (HS) Transbond 0.010 0.000 (HS) Enlight Transbond -0.001 0.001 (HS) 7 days Resilience Enlight 0.013 0.000 (HS) Transbond 0.010 0.000 (HS) Enlight Transbond -0.003 0.000 (HS) 14 days Resilience Enlight 0.013 0.000 (HS) Transbond 0.009 0.000 (HS) Enlight Transbond -0.004 0.000 (HS) C ig ar et te S m ok e - D .W . 1 day Resilience Enlight 0.010 0.000 (HS) Transbond 0.005 0.000 (HS) Enlight Transbond -0.005 0.000 (HS) 7 days Resilience Enlight 0.019 0.000 (HS) Transbond 0.011 0.000 (HS) Enlight Transbond -0.007 0.000 (HS) 14 days Resilience Enlight 0.024 0.000 (HS) Transbond 0.011 0.000 (HS) Enlight Transbond -0.013 0.000 (HS) J Bagh College Dentistry Vol. 27(2), June 2015 Effect of the Pedodontics, Orthodontics and Preventive Dentistry140 DISCUSSION It has been shown that the brand, the solution and storage time influence the degree of color change of the materials and this is coming in agreement with Villalta et al. (13). According to Villalta et al. (13) and Soares et al. (14) , the staining capacity of the composite resin is related to extrinsic factors, such as the pigment agent is subjected to, andto intrinsic factors, such as loading particles and resinous matrix. The structure of the composite resin and the characteristics of its particles have a direct impact on its susceptibility to staining by external agents. All types of adhesives tested in the present study stained by the staining media but with different extent, the Enlight stained less than Resilience and Transbond and the Transbond less than Resilience. There is a correlation between discoloration and the filler component in resin composites, the higher contents of the filler in dental Composites resulted in lesser discoloration than lower filled polymers , So a possible reason for the better color stability of Enlight adhesive could be the elevated filler content of approximately70-80 percent by weight, while for Resilience adhesive the filler content approximately 41 percent by weight and this is coming in agreement with(15-19), while For Transbond adhesive the filler content of approximately70-80 percent by weight(as Enlight adhesive) but it contain silane treated silica and silane treated quartz as a filler which explain the more stainability of this adhesive than Enlight adhesive, It has been suggested that silanization of filler particles plays an important role in discoloration. This is due to the fact that silane has high water absorption levels and this is coming in agreement with (20). Every component of resin may be implicated in discoloration. It has been shown that the resin matrix plays a major part in the color stability of composites and water sorption rate is of particular importance (21-23). It was found that incorporation of greater amounts of TEGDMA resulted in an increase in water uptake in Bis-GMA based resins; Kalachandra (24) and Mazato et al. (25) reported that this was due to increased surface hydrophilicity. Hydrophilic groups such as the ethoxy group in TEGDMA are thought to show affinity with water molecule by hydrogen bonding to oxygen (26), which may explain the better color stability of Enlight adhesive. From this study we can conclude that: 1. The color of sapphire brackets bonded with any type of the three adhesive materials significantly became darker with increased immersion time in the staining media from 1 day to 14 days. 2. 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J Dent Res 1995; 74:1597–601. الخالصة استخدام االسالك التجمیلیة والحاصرات التجمیلیة باالضافة الى البدء ب لقد ازدادت الحاجة الى استعمال االجھزة التقویمیة التجمیلیة في ھذه االیام مما دفع مقومي االسنان الى:الخلفیة .االشرطة المطاطیة التجمیلیة ھي نوع من انواع الحاصرات التقویمیة التجمیلیة ویبقى )Sapphire(الخزفیة والحاصرات التقویمیة ,الحاصرات التقویمیة الشبیھة بلون االسنان انتجت من انواع مختلفة من المواد .استقرار لونھا ھو الشغل الشاغل لالطباء والمرضى على حد سواء المرتبطة مع ثالث )Sapphire(الخزفیة الحاصرات التقویمیة تلوینعلى قابلیة ) الببسي ودخان السجائر,الشاي االسود(مختلفة ھي ملونةمواد اجریت ھذه الدراسة لتقییم تأثیر ثالثة ).Resilience, Enlight and Transbond(من المواد الالصقة الضوئیة التصلب ھي انواع تم تقسیم ھذه الحاصرات وفقا لمواد الربط الى ثالث مجموعات رئیسیة تتكون كل مجموعة من مائة , ن حاصرة تقویمیة یاقوتیة تكونت ھذه الدراسة من ثالثمائة وستو:المواد والطرق صرة لكل منھم ثم كل بواقع ثالثون حا) الببسي ودخان السجائر,الشاي االسود ,الماء المقطر(وعشرون حاصرة تقویمیة وثم قسمت كل مجموعة الى اربع مجامیع فرعیة وفقا لمواد الغمر . باستعمال الحاضن م37في درجة حرارة ) سبعة ایام واربعة عشر یوما, یوم واحد( مجموعة الى عشرة حاصرات حسب الفترة الزمنیة للغمر .الجراء اختبار امتصاص الضوء (Shimadzu, UV -1800)تم استخدام االشعة الطیفیة المرئیة فوق البنفسجیة .P ≤ 0.05 لتحدید تأثیر المواد الملونة عند مستوى داللة ) LSDو ANOVA (العملیة االحصائیة واستخدمت:النتائج .ًااربعة عشر یوموقد لوحظ اعلى نشاط في الفترة الزمنیة ) Sapphire(وقد وجد ان وقت الغمر یؤثر تدریجیًا على االستقرار اللوني للمواد الالصقة مع الحاصرات التقویمیة ان وجد وقد.Enlightالالصقالحاصرات المثبتھ ب واخیرًا Transbondالالصقثم تلیھا المثبتھ بًا ھي االكثر تلون Resilienceلتقویمیة المثبتھ بالالصق الضوئي التصلب الحاصرات ا .دخان السجائر ھو اقوى المواد الملونة یلیھا الشاي االسود واخیرا الببسي .لنتائج اعاله ان نوعیة المواد الالصقة یجب ان تؤخذ بنظر االعتبار عند استخدام الحاصرات التقویمیة التجمیلیةنستطیع ان نستخلص من ا:االستنتاجات .المواد الملونة,االستقرار اللوني,الحاصرات الیاقوتیة:الكلمات المفتاحیة