Effect of surface sealant and repolishing procedures on the color of composite resin exposed to cigarette smoke.

This study evaluated the effect of cigarette smoke on the color of composite resins, with and without the application of a surface sealant and before and after the restorative material was repolished. Twenty composite resin specimens were divided into two groups (n = 10); one of which received a surface sealant. Both groups were exposed daily to the smoke of 20 cigarettes. Color analyses were performed using a spectrophotometer at different intervals: prior to cigarette smoke exposure (baseline), 21 days after cigarette smoke exposure, and after the specimens were repolished using aluminum oxide discs. Cigarette smoke caused a decrease in lightness (L*), especially in samples that received the sealant (p = 0.014). At 21 days, there was an increase in yellow pigment for both groups, with higher values (p = 0.00001) and predominant red pigmentation in the samples that received sealant. An increase in lightness and a decrease in yellow pigments (p < 0.05) were reported in both groups after repolishing. Cigarette smoke significantly altered the color of the composite resin (DeltaE > or = 10.34), especially in the specimens that received the sealant. In this study, the sealant tested intensified cigarette staining, and although repolishing decreased surface pigmentation, it was unable to restore the original color of the composite resin.