Color stability of resin composites for orthodontic attachments: an in vitro study

ABSTRACT Objective: The aim of the present study was to evaluate the color stability of Filtek Z350 XT, Filtek Z250 XT, Z100 resin composites and Transbond XT orthodontic resin, all used in orthodontic attachments, when immersed in popular beverages. Methods: Thirty disk-shaped specimens of each resin composite (2 x 5mm) were manufactured and randomly divided into six groups according to immersion solutions: coffee, red wine, white wine, regular beer, dark beer and deionized water (control). The specimens were fully immersed in each of the solutions for six days at 37°C, representing approximately six months of consumption. The color measurements were evaluated by a reflection spectrophotometer, at baseline (before immersion) and after staining. L*a*b* coordinates were measured and the color change (ΔE00) was calculated using the CIEDE2000 formula. The data were analyzed by ANOVA/Tukey tests at a significance level of 0.05. Results: The resin composites immersed in white wine and regular beer showed either imperceptible or clinically acceptable ΔE00, and no difference from the control group (p= 0.4449 and p= 0.467 respectively). Immersion in coffee and red wine were considered clinically unacceptable and were significantly different from the control group (p= 0.0028 and p= 0.0475 respectively). Conclusion: Based on the results of the present study, the consumption of coffee and red wine may cause color change of the resin composite attachments above the visual acceptability threshold, and impair aesthetics during treatment.

摘要
目的：本研究旨在评估正畸附件常用的Filtek Z350 XT、Filtek Z250 XT、Z100复合树脂以及Transbond XT正畸树脂，在浸泡于常见饮品后的色泽稳定性。
方法：每种复合树脂制备30个盘状试样（尺寸为2×5mm），并根据浸泡溶液随机分为6组：咖啡、红酒、白酒、普通啤酒、黑啤以及去离子水（对照组）。将试样完全浸没于各溶液中，于37℃下浸泡6天，模拟约6个月的日常饮用时长。采用反射式分光光度计在基线（浸泡前）及染色后进行色泽测量，记录L*a*b*色度坐标，并通过CIEDE2000色差公式计算色差值（ΔE00）。采用单因素方差分析（ANOVA）与Tukey多重比较检验进行数据分析，显著性水平设定为0.05。
结果：经白酒与普通啤酒浸泡的复合树脂试样，其ΔE00值均无法被肉眼察觉或临床可接受，且与对照组无统计学差异（分别为p=0.4449与p=0.467）。经咖啡与红酒浸泡的试样，色差值则被认为临床不可接受，且与对照组存在显著统计学差异（分别为p=0.0028与p=0.0475）。
结论：基于本研究结果，咖啡与红酒的摄入可能导致复合树脂正畸附件的色变超过视觉可接受阈值，从而在正畸治疗过程中损害美观效果。