Effect of Bleaching on the Microhardness and Modulus of Elasticity of ACTIVA BioACTIVE – RESTORATIVE: An In Vitro Study

Abstract

Aim: Bleaching is reported to have a deleterious effect on the physical properties of composite material. There is a lack of studies evaluating the effect of bleaching on ACTIVA BioACTIVE – RESTORATIVE. The aim of this study was to evaluate the effects of bleaching on the microhardness and modulus of elasticity of ACTIVA BioACTIVE – RESTORATIVE. Materials and methods: In this in vitro study, the effect of bleaching on two restorative materials was tested. The two restorative materials ACTIVA BioACTIVE – RESTORATIVE and 3M Filtek Z350 Xt were subjected to bleaching with two concentrations of carbamide peroxide (15% and 35%). Measurements of Microhardness and Modulus of elasticity were recorded before and after the bleaching procedure. Data were checked for normality using the Shapiro–Wilk test. Unpaired t test was applied to compare mean of different variables across groups ( p < .0001). Results: The microhardness and modulus of elasticity was higher among the 3M Filtek Z350 Xt group when compared to ACTIVA BioACTIVE – RESTORATIVE. Approximately 35% carbamide peroxide showed the least values when compared to 15% carbamide peroxide. Conclusion: Within the limitation of this study it can be concluded that 15% and 35% carbamide peroxide significantly decreased the Microhardness and Modulus of Elasticity of ACTIVA BioACTIVE – RESTORATIVE and 3M Filtek Z350 Xt. The deleterious effect was concentration dependent as more effect was noted with 35% Carbamide Peroxide. Therefore, patients have to be advised that the existing composite restoration might become softer after bleaching.