Whitening toothpastes effect on nanoparticle resin composite roughness after a brushing challenge: An in vitro study

BACKGROUND: Nowadays, the use of whitening toothpastes is a common habit, especially among young adults, due to aesthetic appeal. On the other hand, little is known regarding the effects of brushing with those newly dentifrices on wear properties of resin composites. MATERIAL AND METHODS: Thirty specimens of nanoparticle composite resin were fabricated and stored in distilled water for 24 h at 370C. After this, the roughness analysis was performed and submitted to the simulated brushing technique using three types of toothpastes: conventional (GI), and two with whitening effect (GII and GIII) for a period of 15 days, with 2 brushing sessions per day for 2 minutes each. The final surface roughness was analyzed after completing all the brushing cycles and stereoscopic images were taken for each group. The data was analyzed by one-way ANOVA and Tukey-test post hoc for intergroup comparison and the T-test for dependent samples as well (α = 0.05). RESULTS: However showing an increase of roughness for all groups after the brushing cycles (p = 0.01), no statistically significant differences among the groups after simulated brushing was verified (p = 0.17). Yet, just some cracks of the stereoscopic images were shown, demonstrating no distinct visual effects among the studied groups. CONCLUSIONS: After simulated brushing with the whitening toothpastes, similar degree of roughness was verified on the composite resin tested. Key words:Composite resin, toothpastes, whitening.