Method:
75 cylindrical specimens were prepared for 5 different composite (Filtek P60, Filtek Z250, Quadrant LC, Grandio and Filtek Supreme) (n=15). Each group of the 5 composite specimens was divided into 3 subgroups (n=5) according to the bleaching agents Opalescence PF, Vivastyle, Nite White). An additional specimen from each group was served as a control group. Bleaching agents were applied for 8 hours/day for 14 days respectively. Roughness measurements were made with a profilometer, at repeated intervals of 24 hours, 48 hours, 1, and 2 weeks. CIE Lab* color coordinates was obtained using a spectrophotometer. Data were analyzed with 2-way analysis of variance and Tukey’s Honestly Significant Difference (HSD) test (α = 0.05).
Result: Surface roughness values increased significantly during the first 2 weeks (P < 0.001) for all bleaching groups of each restorative material. The lowest color difference was observed in the groups Opalescence PF, while the highest color difference was observed in Vivastyle, and Nite White. When comparing the five different restorative materials, no significant difference was observed between Filtek P60 and Filtek Z250, and these materials demonstrated significantly less color change than Quadrant LC and the nanohybrid materials (Grandio, Filtek Supreme).
Conclusion: The posterior (Filtek P60) and universal (Filtek Z250) composite resin restorative materials were found to be less stainable than the nanohybrid and universal (Quadrant LC) composite resins.