Effect of proxide bleaching systems on the marginal integrity and surface hardness of composite restorations
Abstract
Peroxide bleaching systems may affect resin composite restorations through their strong oxidative effect. The objective was to investigate the influence of bleaching systems on long-term stability of marginal integrity of composite restorations and composite surface resistance.
Class V cavities were prepared at the enamel-dentine junction and filled using a total-etch adhesive system Gluma Comfort Bond (n=36) and self-etching adhesive iBond (n=36) in combination with the microhybrid resin composite material Charisma. The peroxide bleaching gel Opalescence PF 20% (20 wt. % carbamide peroxide) was applied 25 times on the restorations.
The control groups were exposed to distilled water for 24 hours and two months before a microleakage test was performed. Composite hardness was characterized after 0, 2, 7, 14 and 25 applications of the gel and compared with the control group (each n=5) exposed to distilled water for two months.
Surface morphology was evaluated using scanning elec