Effect of Whitening Toothpastes on Composite Resins Surface

Objectives: To evaluate the influence of simulated brushing with whitening and regular toothpastes on color variation (ΔE), surface roughness (Ra) and microhardness (KHN) of composite resins.
Methods: One hundred disks of each composite resin were made: Filtek Z350 (3M ESPE) and Grandio SO (VOCO Heraus). Each group was divided into 5 subgroups: AS - (control I) immersed in artificial saliva, CS - (control II) immersed in coffee solution, LW - brushing with Colgate Luminous White (Colgate-Palmolive); OD - brushing with Oral B 3D White (Procter & Gamble) and SP- brushing with Sensodyne Total Protection (GlaxoSmithKline). Brushing was performed for 30 days, daily (120 cycles/day/200g weight) after immersion in coffee solution for 10 min. Initial and final (after 30 days) ΔE, Ra and KHN data were recorded. ANOVA, Tukey (5%), T-student and Dunn statistical tests were used to analyze the data obtained.
Results: The lowest color variation mean values for the composite resin Filtek ​​ were presented by groups AS and OD and the highest by group SP. For the composite resin Grandio SO, the lowest values were presented by group AS and the highest by groups SP and CS. Both resins showed similar values for Ra, with the highest mean values presented by groups AS and CS and the lowest by groups OD and SP. KHN highest mean values were presented by Grandio SO for all experimental conditions; with groups LW and SP showing a decrease in KHN after the 30 day treatment. For Filtek groups SP and OD showed a decrease in KHN.
Conclusions: Simulated brushing with the toothpastes evaluated showed influence on color, surface roughness and hardness of composite resins previously pigmented by coffee, but the alteration depended of the type of resin and toothpaste used.