"Comparative evaluation of effect of toothbrush-dentifrice abrasion on surface roughness of resin composites with different filler loading:" An in vitro study

Objectives: This in vitro study evaluated the effect of toothbrush-dentifrice abrasion on the surface roughness of two restorative posterior resin composites, Filtek Z250 and Z350 after simulated toothbrushing twice daily for a period of 3 months. Methods: All the specimens were polished and cleaned and surface topography was evaluated by Veeco di CP-II Atomic Force Microscope (AFM) at six different points; similarly, these specimens were again subjected to evaluation after simulated toothbrushing using dentifrice. The surface roughness evaluation was done for AFM images using software made available and the factor measured were average roughness (Ra) and maximum peak to valley distance R(p v). Data were normally distributed as tested using the Shapiro-Wilk W-test (P > 0.05). Therefore, analysis was performed using the parametric tests, i.e., independent "t"-test (for comparing two groups). The level of statistical significance was set at P < 0.05. Results: The mean change in Ra and the mean change in Rp-v for Z350 were less as compared to Z250, and this difference was statistically significant. Conclusions: Within the limitation of the present study, it can be concluded that toothbrushing increased the roughness in Z250 in comparison to Z350.