Effects of different concentrations of hydrogen peroxide on the color stability of various esthetic restorative materials in vitro

Abstract

Purpose: The aim of this in vitro study was to determine the color changes of four different restorative materials after exposing these materials to two different bleaching agents. Materials and Methods: In this study, bleaching agents were applied to a low-fusing porcelain (VITA VM9), heat-pressed glass ceramics (IPS Empress Esthetic), and two types of composites (Clearfil Majesty Esthetic and Clearfil Photo Posterior). Twenty disc-shaped specimens were fabricated (with a diameter of 10 mm and a thickness of 2 mm) from each material ( n 0 = 10). The initial color changes were measured using a spectrophotometer. The first set of specimens were bleached with 10% hydrogen peroxide (HP) for 1 h daily for 10 days. Another set of specimens were bleached with 40% HP bleaching gel for two consecutive applications for 20 min each. The data were analyzed statistically by using two-way analysis of variance (ANOVA) and post hoc Tamhane's T2 tests ( P Results: The mean color change value (Δ E ) for Clearfil Majesty Esthetic was significantly higher than the value for VITA VM9 groups, treated with the 10% HP. In addition, the values for Clearfil Photo Posterior were significantly higher than the values for Clearfil Majesty Esthetic, IPS Empress Esthetic, and VITA VM9 groups treated with the 40% HP ( P P Conclusion: The effects of bleaching agents should be known and applied consciously when restorative materials (especially polymer-containing restorative materials) are present.