The Effect of Home-Bleaching Agents on Surface Roughness of Restorative Materials - Abstract
Aim: The purpose of this study was to evaluate the effect of two home-bleaching agents (10 and 20% carbamide peroxide) on the surface roughness of four tooth-colored restorative materials over time.
Methods: Four tooth-colored restorative materials, a compomer (Compoglass F - IvoclarVivadent) and three composite resins (Filtek Z250 - 3M ESPE, Filtek Supreme XT - 3M ESPE, Grandio - Voco) were tested in this study. Two commercial home bleaching agents (Opalescence - Ultradent Products Inc.) 10% and 20% carbamide peroxide were selected. Thirty cylindrical specimen of each restorative material were fabricated, randomly divided into 3 groups and treated as follows: Group A stored in distilled water, Group B bleached with 10% carbamide peroxide seven hours/day and Group C bleached with 20% carbamide peroxide seven hours/day. All treatment was conducted at 37oC and fresh gel applied and rinsed off daily for six weeks. For the bleached groups the specimens were stored in distilled water at 37oC during the hiatus periods. Surface roughness measurements (Ra, ?m) were made after 24h and repeated every week of exposure for six weeks using a profilometer. Data were analyzed using ANOVA and Tukey’s test at a level of significance of a=0.05.
Results: Specimens from control groups showed no significant alteration during all test periods while for exposure to 10% carbamide peroxide only compomer presented significant increase in surface roughness after 6 weeks (p<0.05). For 20% carbamide peroxide surface roughness mean values were significantly increased after six weeks for all restorative materials (p<0.05).
Conclusions: The effect of bleaching on surface roughness of restorative materials was material and time depended. Bleaching procedures should not be carried out when toothcolored restorations are presented. Otherwise, the restorations may need to be repeated.