In vitro assessment of color changes of clear orthodontic elastomeric module materials after exposure to high-pigment beverages

Abstract

BackgroundAesthetic elastomeric modules are subject to staining as a result of exposure to foods and beverages that can cause staining. The objective of this study was to assess, in vitro, color changes of clear orthodontic elastomeric module materials exposed to different staining beverages. MethodsSamples of four brands of clear orthodontic elastomeric modules (Morelli, TP Orthodontics, RMO, and GAC) were immersed for 15 minutes, three times weekly, in four beverages that can cause staining: coffee, cola, black tea, and red wine. Between sessions, samples were stored in artificial saliva at 37°C. Color changes were assessed after 4 weeks using the yellowness index (YI) (ASTM International D-6290/E-313-10 standard practices), calculated according to the Comission Internationale de l'Eclairage L*a*b* system with the aid of a spectrophotometer (range 0 to 100, with higher values indicating more yellowness). YI results were analyzed using ANOVA and the Tukey multiple comparisons test. ResultsDifferent degrees of discoloration were observed across the brands, despite the similarity of chemical structures. Coffee caused the most severe color change (mean ± SD YI 56.1 ± 0.79), followed by red wine (38.0 ± 0.78) and black tea (31.9 ± 0.63); these differences were significant. The GAC modules were the least affected by yellowness, whereas Morelli showed the highest degree of discoloration. Conclusion(s)The intake of foods and beverages with a high pigment content can cause discoloration of clear orthodontic elastomeric modules and thus lead to aesthetic complaints. Our findings can help practitioners select the most appropriate brand of elastomeric modules according to the dietary habits of each patient.