The effect of immediate and delayed polishing on the color stability of a composite resin.

Polishing techniques are known to enhance the longevity and appearance of composite resin restorations. However, the influence of the timing of polishing on the final results of a restoration is not well documented. The aim of this study was to determine the effect of immediate and delayed polishing on the color stability of a composite resin. Sixty composite resin specimens were fabricated and randomly divided into 2 groups according to immersion solutions: group 1, deionized water (control); and group 2, coffee (as staining solution). The groups were further divided according to polishing time periods (immediate, 1 day, 7 days, 14 days, and 21 days). The polishing was performed by 1 calibrated operator using a sequence of aluminum oxide discs with different granulations. Color measurements were assessed at baseline and after a 48-hour immersion in the assigned medium by a reflection spectrophotometer, according to CIE Lab* parameters. The data were submitted to an analysis of variance (ANOVA) and the post hoc Tukey test at a significance level of 0.05. The ANOVA showed that the immersion solutions had a statistically significant difference (α = 0.05) on color stability. The composite resin color stability was not influenced by the timing of polishing, and all subgroups showed clinically unacceptable discoloration after exposure to coffee. Thus, with regard to color stability, the timing of final polishing may be established according to the preferences of the clinician.