Objective: To assess the influence of polishing techniques on surface roughness and color changing of composite resin subjected to three different staining.
Methods: Four polishing techniques were tested (T0: Mylar matrix – control; T1: aluminum oxide discs; T2: felt disc + diamond paste; T3: aluminum oxide discs + felt disc + diamond paste) on specimens made of nanofilled composite resin (Filtek Supreme XT, 3M ESPE). The specimens were randomly assessed into 12 experimental groups (n=4) according to: (i) polishing techniques, (ii) staining (distilled water, coffee, or cigarette). The mean roughness (Ra) was evaluated under Atomic Force Microscopy (AFM), on the contact mode. The color change was examined by spectrophotometer after the polishing procedures and 30 days of staining. The data was submitted to Linear Correlation test, 2-way ANOVA followed by Tukeyxs Test, at P=.05.
Results: The order of surface roughness after polishing was: T3>T1=T2>T0. After staining the mean roughness increased with T0 and decreased with T3. The peak of color changing was obtained with T0 and cigarette. There was not correlation between surface roughness and color changing (r=.015).
Conclusion: The association of aluminum oxide discs, felt disc and diamond paste promoted the highest surface roughness. All staining types, mainly the cigarette, resulted in perceptive color changing, independently of polishing technique. Supported by CAPES grant#1578-08-1