Evaluation of Discoloration Removal by Polishing Resin Composites Submitted to Staining in Different Drink Solutions.

The aim of this study was to evaluate the discoloration effects of water, cola-based soft drink, coffee, and wine on resin composites used in restorative dentistry and the possibility of removing the stain with chair side manual polishing. The A2 shade of three materials was tested. Disc specimens were prepared. A spectrophotometer was used to measure the baseline CIE-Lab color parameters of each material (n=10) 24 hours after sample preparation. Samples were then immersed in a cola-based soft drink, coffee, or wine for 1 hour every day, for 30 days. For the remaining hours, the specimens were stored in distilled water. In the control group, the specimens were immersed in water for the whole period. The color differences (ΔE) were calculated after 7 and 30 days of storage, and after polishing with coarse Sof-Lex discs, and analyzed by two-way ANOVA with repeated measures and Tukey's HSD test (α=0.05). Luna presented higher ΔE values (3.41) (a) followed by Durafill (2.82) (b) and Herculite (2.24) (c) . For the drink solutions, ΔE values were higher for wine (4.40) (a) followed by coffee (2.59) (b) and for cola-based soft drink (2.23) (c) and water (2.13) (c) which were statistically similar. For time, ΔE values were higher for 30 days (3.97) (a) and then for 7 days (2.48) (b) and after polishing (2.04) (c) . The results indicate that color stability is material dependent. The types of drinks that patients consume also influence the color stability of restorative materials.