Abstract

With the growing awareness of esthetics, the use of bleaching agents are on the increase. Bleaching agents intended to be used at home affects the existing restorations. The aim of the present study was to evaluate the effect of bleaching with carbamide peroxide agents at concentrations 10 and 22% on the microhardness and shear bond strength of composites and compomers. For microhardness and shear bond strength evaluation, samples of both composite and compomer restorative materials were subdivided into control group (stored in artificial saliva), Experimental groups bleached with 10% CP and those bleached with 22% carbamide peroxide. Following 2 weeks of bleaching treatment, Vickers’s hardness number was noted for each test specimen using a microhardness meter. For shear bond strength evaluation, the specimens were subjected to shear test under Instron universal testing machine. One way Analysis of Variance (ANOVA) was used for multiple group comparisons followed by Tukey’s test for pair wise comparison. Bleaching with carbamide ceroxide at concentrations 10 and 22% caused reduction in hardness of composite restorative materials. However bond strength of both composite and a compomer restorative material was not affected following bleaching treatment. Hence it can be deduced that bleaching caused reduction in hardness of composite restorative materials.

Key words: Carbamide peroxide, bleaching, restoration, bonding, microhardness, composite resins, compomer.