J Bagh College Dentistry Vol. 29(3), September 2017 Color Stability of Pedodontics, Orthodontics and Preventive Dentistry 100 Color Stability of Different Aesthetic Arch-wires after Immersion into Different Types of Mouthwashes (In Vitro Study) Lubna Maky Hussein, B.D.S. (a) Nidhal H. Ghaib, B.D.S., M.Sc. (b) ABSTRAC Background: Because of the demands for aesthetic orthodontic appliances have increased, aesthetic archwires have been widely used to meet patient's aesthetic needs. The color stability of aesthetic archwires is clinically important, any staining or discoloration will affect patient’s acceptance and satisfaction. This study was designed to evaluate the color stability of different types of aesthetic archwires after immersion into different types of mouth washes. Materials and methods: Four brands of nickel titanium coated aesthetic arch wires: Epoxy coated (Orthotechnology and G&H) and Teflon coated (Dany and Hubit) were evaluated after 1 week, 3 weeks and 6 weeks of immersion into two types of mouthwashes (Listerine with alcohol and Listerine without alcohol). Color change measurements were performed by using spectrophotometer VITA Easyshade Compact according to the commission Internationale de I’Eclairage L*a*b* color space system. Results: The results of this study showed that there were highly significant differences in color change values among all brands of aesthetic archwires at various immersion media. On the other hand, a significant difference was found between Dany and Orthotechnology aesthetic archwires at 1 week immersion in distilled water. Listerine with alcohol mouthwash produced more color changes of aesthetic archwires and color change value increases with the time of immersion. Conclusions: All brands of aesthetic archwires showed different degrees of color changes but most of these changes were not visible or clinically acceptable. Key words: Color stability, aesthetic archwires, mouthwash. (J Bagh Coll Dentistry 2017; 29(3):100-105) INTRODUCTION Aesthetic, is one of major concerns during orthodontic treatment. The great demand for better aesthetics has led manufacturers to develop appliances which combine both acceptable aesthetics for the patient and adequate technical performance for the clinician. There are many aesthetic brackets and archwires in the markets when compared to mid-1990s (1-3). Most of the orthodontic appliance components are metallic and silver in color. By the introduction of aesthetic brackets made of ceramic or composite, which become more popular, the aesthetic problem is partially solved, but the archwires are still made of metals such as titanium molybdenum alloy, nickel-titanium or stainless steel. Lately, coated metallic and fiber-reinforced archwires have been introduced to overcome this aesthetic problem. Fiber-reinforced arch wires are experimental and not universally commercial available, there are good anticipations from them for the future (2,4,5). Materials used in archwire coatings are colored polymers or inorganic materials like polytetrafluoroethylene (Teflon), epoxy-resin, parylene-polymer, synthetic fluoride resins or less (a) Master student, Department of Orthodontics, College of Dentistry, University of Baghdad. (b)Professor, Department of Orthodontics, College of Dentistry, University of Baghdad. commonly palladium coverings to produce aesthetic archwires which simulate the color of teeth (2,6). The color stability of aesthetic archwires is clinically important during orthodontic treatment. Ideally, the color of aesthetic archwires should match that of natural teeth and aesthetic brackets, but the color of natural teeth varies according to color measurement protocol, race, age and gender (3,4). However, some authors have suggested that the color of coated archwires tends to change over time and the coating splits during use in the mouth exposing the underlying metal (7). There are internal and external causes of discoloration of aesthetic arch wires. External discoloration may be caused by food dyes and colored mouth rinses, the type of coating material and its surface roughness play important roles in the extent of the discoloration. The amount of color change can be influenced by a number of factors, such as oral hygiene and water absorption (8). This study was designed to evaluate the color stability of different types of aesthetic archwires after immersion into different types of mouth washes. J Bagh College Dentistry Vol. 29(3), September 2017 Color Stability of Pedodontics, Orthodontics and Preventive Dentistry 101 MATERIALS AND METHODS The Samples Preparation The samples consisted of maxillary nickel titanium coated aesthetic archwires (0.018 *0.025 inch) with different coating materials and from different companies, they were: Epoxy coated (Orthotechnology Company / U.S.A. and G & H Company/ U.S.A.) and Teflon coated (Dany Company/Korea and Hubit Company/Korea). Thirty six samples (nine samples from each Company) were prepared; each sample was made by cutting the preformed archwires into two halves, then putting ten halves of the aesthetic archwires segments together and uniting their free ends firstly by the light cure composite resin (Fig. 1), because it set quickly so it becomes easier to use the ethyl cyanoacrylate (super glue) to get more fixation, therefore; the sample resembles a strip (Fig. 2) (9,10). The ethyl cyanoacrylate can tolerate the humidity so the samples stay as strips in the mouthwashes during the testing time. The coating surface of each wire segment was facing into the same direction so that the color could be measured properly. Fig. 1: Uniting the ten halves of the coated archwires segments together by light cure composite resin Fig. 2: Sample from each Company resembles a strip The Samples Grouping The samples were grouped according to different time intervals which are: 1 week, 3 weeks and 6 weeks. For each time interval each group contains four strips, one strip from each Company as follow: - Distilled water as a control group - Listerine with alcohol - Listerine without alcohol Listerine Mouthwashes Preparation Two types of Listerine mouth washes (Listerine with alcohol and Listerine without alcohol Johnson & Johnson, UK.) used in this study were ready made solution. Equal amounts of mouth washes (500ml) were poured in covered containers to be ready for the designed procedure. Color Measurements The color measurement of each sample was performed by using a spectrophotometer VITA Easyshade Compact (VITA Zahnfabrik, Bad Sackingen, Germany) (Fig. 3). Fig. 3: Spectrophotometer VITA Easyshade Compact After numbering the samples of each Company from 1 to 4; 1 for Dany Company, 2 for Hubit Company, 3 for Orthotechnology Company and 4 for G&H Company by permanent marker that couldn’t be removed by the mouth washes, they were incubated in distilled water at 37°C for 24 hours, baseline measurements (T0) were done. Then, the samples were divided into three main groups according to the immersion media (distilled water as a control media, Listerine with alcohol and Listerine without alcohol) and immersed in separate containers for 30 seconds twice daily, according to the manufacturer's instructions. During immersion, the samples were incubated at 37°C. After that the samples were stored in distilled water in the incubator at 37°C which is the temperature of the human body. Color change measurements were calculated after 1 week (T1), 3 weeks (T2), and 6 weeks (T3). Before each color measurement, the samples were removed from the mouthwashes and rinsed with distilled water for 5 minutes. Excess water was removed by tissue papers and the samples were allowed to dry (4). The samples were fixed and stabilized on white card boards (11). Before performing the color measurements, the (4 strips; 1 strip from each company) J Bagh College Dentistry Vol. 29(3), September 2017 Color Stability of Pedodontics, Orthodontics and Preventive Dentistry 102 spectrophotometer VITA Easyshade Compact was adjusted and calibrated according to the manufacturer’s instructions and it was hold by a special holder and keep the tip of it perpendicular and in contact with archwires surface using ruler as a guide (Fig. 4) (5,11). Fig. 4: The tip of VITA Easyshade Compact was perpendicular and in contact with archwires surface The color measurements were taken from twelve reference points which located at different distances from the beginning of the coating material and these points were recognized by permanent marker at the posterior surface of the sample. Five measurements of each reference point were performed and the average was calculated (4,5,9). Color changes were characterized using the Commission Internationale de l’Eclairage L*a*b* color space system (CIE L*a*b*), it depends on the following coordinates: L* describes lightness with values from 0 (black) to 100 (white), a* describes the red/green coordinate, with +a* indicating red and -a* indicating green and b* describes the yellow/blue coordinate, with +b* indicating yellow and -b* indicating blue (4,12-14). Total color change Δ E* value was measured by this equation: ΔE* = (ΔL*2 + Δa*2 + Δb*2)1/2 (4,14), where ΔL*, Δa* and Δb* are differences in L*, a* and b* values between baseline measurement (T0) and measurement after immersion at each time interval (T1, T2, T3) as follows: Δ L* = L2 _ L1 Δ a * = a 2 – a1 Δ b* = b2 – b1 Then relate the ΔE* values to the clinical environment by converting the data to National Bureau of Standards (NBS) units (9,14,15) as follow: NBS units = Δ E* × 0.92 Statistical Analyses Data were collected and analyzed using SPSS (statistical package of social science) software version 19.The following statistics were used: A- Descriptive Statistics: including mean, standard deviation (S.D.), minimum (Min.) and maximum (Max.) values. B- Inferential Statistics: including: 1. One-way ANOVA test: was used to compare the ΔE* value (color change) among the different media and wire brands. 2. Tukey’s honestly significant difference test (HSD): was performed to test any statistically significant difference in ΔE* value (color change) between any two groups. In the statistical evaluation, the following levels of significance were used as follow: NS Non-significant p>0.05 S Significant 0.05≥p>0.01 HS Highly significant p≤0.01 RESULTS Table (1) showed total color changes (ΔE* values) and National Bureau of Standards (NBS) units of the aesthetic archwires at different time intervals of immersion in various media. It was found that Hubit aesthetic archwires were the least color stable while Orthotechnology aesthetic archwires were the most color stable. Listerine with alcohol caused more color changes of aesthetic archwires than Listerine without alcohol and color change value increases with the time of immersion. Although all tested aesthetic archwires showed color changes among all immersion media at different time intervals but not all these color changes are clinically important. From clinical point of view, color changes can be expressed according to ΔE* values and NBS units, there were color changes not appreciable by the human eye (Δ E* < l, trace and slight color change) While clinically acceptable color changes which appreciable by skillful operator (3.3 > Δ E* > l, slight and noticeable color change). But clinically unacceptable color changes which appreciable by non-skilled persons (Δ E* > 3.3, appreciable color change) (9,14-16). Table (2) and (3) showed ANOVA test and Tukey HSD test results. It was found that there were highly significant differences in color changes (ΔE* values) among all aesthetic archwires brands in all immersion media at different time intervals. J Bagh College Dentistry Vol. 29(3), September 2017 Color Stability of Pedodontics, Orthodontics and Preventive Dentistry 103 On the other hand, a significant difference was found between Dany and Orthotechnology aesthetic archwires at 1 week immersion in distilled water. Table 1: Descriptive statistics of ΔE* values and National Bureau of Standards (NBS) units of aesthetic arch wires in various immersion media at differenttime intervals. Companies Media Duration N Mean S.D. Min. Max. NBS unit Color change Dany Distilled water 1 week 12 0.141 0.002 0.138 0.146 0.12972 Trace 3 weeks 12 0.273 0.003 0.268 0.277 0.25116 Trace 6 weeks 12 0.286 0.001 0.284 0.289 0.26312 Trace Listerine with alcohol 1 week 12 0.539 0.004 0.534 0.546 0.49588 Trace 3 weeks 12 1.014 0.008 1.010 1.040 0.93288 Slight 6 weeks 12 1.536 0.002 1.532 1.539 1.41312 Slight Listerine without alcohol 1 week 12 0.323 0.003 0.320 0.329 0.29716 Trace 3 weeks 12 0.494 0.002 0.490 0.498 0.45448 Trace 6 weeks 12 0.896 0.002 0.892 0.899 0.82432 Slight Hubit Distilled water 1 week 12 0.342 0.003 0.338 0.347 0.31464 Trace 3 weeks 12 0.697 0.002 0.693 0.699 0.64124 Slight 6 weeks 12 0.726 0.004 0.719 0.730 0.66792 Slight Listerine with alcohol 1 week 12 1.396 0.004 1.389 1.399 1.28432 Slight 3 weeks 12 2.132 0.002 2.128 2.135 1.96144 Noticeable 6 weeks 12 3.358 0.002 3.354 3.360 3.08936 Appreciable Listerine without alcohol 1 week 12 0.852 0.002 0.849 0.856 0.78384 Slight 3 weeks 12 1.244 0.003 1.240 1.249 1.14448 Slight 6 weeks 12 2.266 0.003 2.260 2.270 2.08472 Noticeable Ortho technology Distilled water 1 week 12 0.123 0.003 0.118 0.127 0.11316 Trace 3 weeks 12 0.213 0.002 0.210 0.217 0.19596 Trace 6 weeks 12 0.253 0.038 0.200 0.300 0.23276 Trace Listerine with alcohol 1 week 12 0.637 0.003 0.630 0.643 0.58604 Slight 3 weeks 12 1.065 0.031 1.010 1.100 0.9798 Slight 6 weeks 12 1.804 0.002 1.801 1.808 1.65968 Noticeable Listerine without alcohol 1 week 12 0.242 0.002 0.238 0.246 0.22264 Trace 3 weeks 12 0.341 0.003 0.337 0.346 0.31372 Trace 6 weeks 12 0.748 0.005 0.740 0.755 0.68816 Slight G&H Distilled water 1 week 12 0.313 0.029 0.280 0.380 0.28796 Trace 3 weeks 12 0.456 0.004 0.450 0.461 0.41952 Trace 6 weeks 12 0.491 0.003 0.488 0.496 0.45172 Trace Listerine with alcohol 1 week 12 1.310 0.054 1.200 1.390 1.2052 Slight 3 weeks 12 1.841 0.004 1.836 1.850 1.69372 Noticeable 6 weeks 12 2.882 0.003 2.879 2.887 2.65144 Noticeable Listerine without alcohol 1 week 12 0.703 0.003 0.700 0.710 0.64676 Slight 3 weeks 12 0.813 0.003 0.810 0.818 0.74796 Slight 6 weeks 12 1.246 0.004 1.240 1.252 1.14632 Slight Table 2: ANOVA test and Tukey HSD test results of aesthetic arch wires and the effect of aesthetic arch wires brand. Duration Media F-test p-value Tukey HSD test Dany vs. Hubit Dany vs. Orthotec Dany vs. G&H Hubit vs. Orthotec Hubit vs. G&H Orthotec vs. G&H 1 week Distilled water 722.576 0.000(HS) 0.000(HS) 0.017(S) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) Listerine with alcohol 1007032.162 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) Listerine without alcohol 131963.910 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 3 weeks Distilled water 72137.972 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) Listerine with alcohol 722497.476 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) Listerine without alcohol 262314.062 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 6 weeks Distilled water 1580.672 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) Listerine with alcohol 1125902.728 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) Listerine without alcohol 417999.534 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) J Bagh College Dentistry Vol. 29(3), September 2017 Color Stability of Pedodontics, Orthodontics and Preventive Dentistry 104 Table 3: ANOVA test and Tukey HSD test results of aesthetic arch wires and the effect of various immersion media. Companies Duration F-test p-value Tukey HSD test Control vs. Lis A Control vs. Lis W Lis A vs. Lis W Dany 1 week 3103525.149 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 3 weeks 1585764.170 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 6 weeks 7821098.786 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) Hubit 1 week 3718981.182 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 3 weeks 5787882.082 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 6 weeks 6349430.423 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) Ortho technology 1 week 723610.659 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 3 weeks 64977.088 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 6 weeks 87695.362 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) G&H 1 week 17658.179 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 3 weeks 1882589.490 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) 6 weeks 5123299.815 0.000(HS) 0.000(HS) 0.000(HS) 0.000(HS) *Lis. A (Listerine with alcohol), *Lis. W (Listerine without alcohol). DISCUSSION The color stability of aesthetic archwires is an important factor in the success of an aesthetic orthodontic treatment, but the color of these archwires tends to change overtime (7). The sensitivity of the human eye in observing small color differences is limited and the interpretation of visual color comparisons is subjective. Instrumental measurements minimize the subjective interpretation of visual color comparisons, therefore; spectrophotometer is used instead of visual evaluation (4,5). Recently, VITA Easyshade Compact is one of the latest spectrophotometers which available for clinical use. This instrument is small, wireless, easy to handle and allow an improved understanding of color perception and its correlation with clinical aspects (13). Color changes were characterized using the Commission Internationale de l’Eclairage L*a*b* color space system (CIE L*a*b*) which is one of the most popular and universally used system for dentistry and many authors used this system to evaluate the perceptibility of color differences (4,12-14). Many authors had used ΔE* values to evaluate the perceptibility of color differences (18,19). However, it is noteworthy that the criteria for perceptibility used by each author were somewhat different. To overcome these differences and disagreements in the criteria, the National Bureau of Standards (NBS) system is frequently used to define the degree of color difference (Δ E* value) according to the clinical significance (9,14,15). Water absorption, absorption or adsorption of colorants from mouthwashes may be the causes of color changes of aesthetic archwires that is in agreement with other findings (17-19). Moreover, color changes of aesthetic archwires may be related to presence of alcohol and pH level of the tested mouthwashes, it was found that low pH level and high alcohol concentration of mouthwashes may affect the surface integrity by softening the coating material and cause discoloration, this comes in agreement with other researches (20,21). In conclusion; although all brands of aesthetic archwires showed color changes at variable degrees but most of these changes were not visible or clinically acceptable. REFERENCES 1. Russell JS. Current products and practice: Aesthetic orthodontic brackets. J Orthod 2005; 32(2): 146-63. 2. Kaphoor AA, Sundareswaran S. Aesthetic nickel titanium wires- How much do they deliver? Eur J Orthod 2012; 34(5): 603-9. 3. Aksakalli S, Malkoc S. Aesthetic orthodontic arch wires: Literature review. J Orthod Res 2013; 1(1): 2- 4. 4. da Silva DL, Mattos CT, de Araujo MV, de Oliveira Ruellas AC. 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Asmussen E. Softening of BISGMA-based polymers by ethanol and by organic acids of plaque. Scand J Dent Res 1984; 92: 257-61 . الخالصة إن األستقرار اللوني .لمطالب المرضىتلبيةً واسع نطاق علىعلى أجهزة تقويم األسنان التجميلية ,أُستُخدمت أسالك التقويم التجميلية نتيجة الطلب المتزايد الخلفیة: من مختلفة نوا أل ياالستقراراللون لتقييم ت هذه الدراسةصمم .ألسالك التقويم التجميلية مهم سريرياً, فأي تصبغ أوتغير لوني سيؤثر على رضا وقناعة المريض غسوالت الفم. من مختلفة أنوا فيها غمر بعدأسالك التقويم التجميلية (Danyوالمغلفة بالتفلون G&H)و (Orthotechnologyالمغلفة باأليبوكسي :أربع ماركات من أسالك النيكل تيتانيوم التجميلية المغلفة تقييمتم : رقالموادوالط وقد أجريت قياسات حول(غسوالت الفم )ليسترين مع الكحول و ليستيرين بدون ك بعد أسبو واحد وثالثة أسابيع ثم ستة اسابيع من الغمر في نوعين من (Hubitو .وفقاً للمنظمة العالمية لألضاءة (VITA Easyshade Compactجهاز فحص الطيف اللوني )التغير اللوني بأستخدام بيئات الغمر.من مختلفأسالك التقويم التجميلية في وجود أختالفات معنوية كبيرة في قيم التغير اللوني بين جميع ماركات أظهرت نتائج هذه الدراسة لقد النتائج: خالل فترة الغمر ألسبو واحد في الماء Orthotechnology)وشركة ) (Dany)الجانب االخر, ُوِجد أختالف معنوي بين أسالك التقويم التجميلية لشركة . لتغير اللوني تزداد بزيادة فترة الغمرإن قيمة اكما ألسالك التقويم التجميليةوقد أنتج غسول الفم ليستيرين مع الكحول تغيرات لونية أكثر المقطر .مقبولة سريرياً أوهذه التغيرات كانت غير مرئية معظمأسالك التقويم التجميلية تغيرات لونية بدرجات مختلفة ولكن ماركات أظهرت جميع االستنتاجات: سالك التقويم التجميلية ,غسول الفم.أ األستقرار اللوني, :المفتاحیة الكلمات