Effect of In-Office Bleaching Agents on Three Different Esthetic Restorative Materials: An In Vitro Study

Abstract

Objective: The purpose of this study was to evaluate the effect of two hydrogen peroxide concentrations, commonly used in In-Office bleaching, on the surface roughness and color change of different esthetic restorative materials. Materials and Methods: Sixty disc samples (10 mm in diameter and 2 mm in thickness) of the different restorative materials used were constructed following the manufacturers’ instructions. Samples were classified into three main groups (n=20) according to the type of restorative material: Group1: Microhybrid composite Filtek P90 Silorane, Group 2: IPS emax Press and Group 3: Vitadur Alpha porcelain. Each of the three groups was divided into two subgroups (n=10) (a and b) according to the type of bleaching agent used (Opalesence Xtra Boost 35% hydrogen peroxide (HP) and Zoom 2 25% HP respectively). Samples of subgroups were further divided into two equal divisions (n=5) according to the type of test performed (Roughness testing and Color assessment). Each sample was assessed for surface roughness and color change before bleaching so that each sample served as its own control. Surface roughness was examined using Environmental scanning electronic microscope (ESEM). Color measurements were made with spectrophotometer using CIELAB color scale. One sample from each subgroup was examined to confirm their crystalline phase before and after bleaching using X-Ray Diffraction. Results were statistically analyzed. Results: Significant differences in Ra values were observed between the unbleached and bleached samples, as well as between subgroups treated with Opalesence Xtra Boost and those treated with Zoom 2. The two bleaching agents had statistically significant effect on the color of restorative materials (P<0.05). Moreover, the color change was found to be significantly higher for the restorative materials treated with Opalesence Xtra Boost compared to Zoom 2, regarding their mean ΔE values. Conclusion: Highly concentrated in-office bleaching systems adversely affected the surface roughness and color of Filtek P90 Silorane, IPS e-max Press and Vitadur Alpha porcelain.