Saturday, September 07, 2013

Longitudinal evaluation of simulated toothbrushing on the roughness and optical stability of microfilled, microhybrid and nanofilled resin-based composites

Abstract

Objectives

The aim of this study was to evaluate the influence of simulated toothbrushing over ten weeks on the roughness and optical stability (color, translucency and gloss) of microfilled–Mf (Durafil VS), microhybrid - Mh (Empress Direct) and nanofilled–Nf (Z 350) resin-based composites (RBC).

Methods

The roughness, color, translucency and gloss of each RBC were measured before and after storage in distilled water (DW) and propionic acid (PA) for ten weeks. The specimens were removed from the media each week, submitted to toothbrushing simulation and the properties measured. The obtained data were analyzed using a multifactor analysis of variance (MANOVA) and Tukey's HSD test (α = 0.05).

Results

The roughness significantly increased after ten weeks for the three RBCs (p < 0.05), with the final values of roughness presenting no statistical differences among them (p > 0.05). Only Mf and Nf immersed in DW and Mh immersed in PA presented a change in color after ten weeks (p < 0.05), although the change in color was lower after immersion in PA for the three RBCs (p < 0.05). None of the RBCs presented significant changes in translucency after ten weeks (p > 0.05). Only Mh immersed in DW presented gloss stability after ten weeks (p > 0.05).

Conclusions

Toothbrushing increased the roughness and diminished the gloss of the three RBCs. The translucency was not influenced by the toothbrushing. The immersion in propionic acid produced lower alterations in color than did immersion in distilled water.
Clinical Significance: In general, the three RBCs presented similar optical behaviors after toothbrushing over ten weeks. Thus, it is possible that anterior restorations produced with these materials will not present perceptible differences over time.

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