Effect of bleaching gels on the surface roughness, hardness, and micromorphology of composites.

This study sought to evaluate the effect of three bleaching gels on the surface roughness, hardness, and morphology of resin-based composites basically designed for posterior and anterior use. The application of the bleaching agents tested had no statistically significant effect on the surface roughness or hardness of the composites tested. With both unbleached and bleached samples, the posterior composite was significantly harder than the anterior composite while the roughness was not significantly different (p > 0.06).