Surface roughness of different dental materials before and after simulated toothbrushing in vitro

This study measured the effect of toothbrushing with a slurry of toothpaste on different dental materials that have been optimally polished. Specimens (n=8) of 21 dental materials, 16 resin composites, 1 amalgam and 4 ceramic materials, were subjected to 36,000 cycles (approximately five hours) of circular toothbrushing with a force of 1.7 N and a slurry of toothpaste (RDA 75) in a device for simulated toothbrushing. The unpolished enamel and dentin of extracted anterior teeth were used as a control. The mean roughness (Ra) was measured with an optical sensor (FRT MicroProf) before and after toothbrushing. To compare the roughness of the different materials, ANOVA with a post hoc Tukey B test was applied (p<0.05). Among the resin composites, the hybrid composites showed the greatest increase in mean roughness, while the microfilled composites and the compomer Compoglass F demonstrated the lowest increase. No statistically significant difference in roughness was found before and after simulated toothbrushing for the Amalcap amalgam, Esthet-X resin composite, TPH Spectrum resin composite, d.SIGN ceramic and the experimental ceramic. The other ceramic materials and dentin and enamel specimens showed a statistically significant decrease in mean roughness after simulated toothbrushing. Glazed Empress demonstrated a statistically significant higher initial roughness than polished Empress. For resin composites, no correlation was found between the mean particle size and mean roughness after simulated toothbrushing.