Effect of hydrogen peroxide on color and whiteness of resin‐based composites

OBJECTIVE: To evaluate the influence of a 35% hydrogen peroxide gel on color and whiteness changes of resin-based composites (RBC). MATERIALS AND METHODS: Discs (n = 10; shade A3.5 enamel; and 8 mm diameter and 2 mm thick) were fabricated from three RBC (DF- Durafill, Heraeus Kulzer; ED- IPS Empress Direct, Ivoclar Vivadent; and AP- Amelogen Plus, Ultradent Products). Three subgroups were obtained for each RBC: before bleaching (T0 ) and after first (T1 ) and second (T2 ) bleaching applications. A dental spectrophotometer (VITA Easyshade, Vita Zahnfabrik) was used to obtain CIELAB color coordinates and whiteness index for dentistry (WID ) in all periods. CIELAB ( ΔEab* ) and CIEDE2000 (ΔE00 ) color differences were also obtained. Perceptibility (PT) and acceptability (AT) thresholds were used to analyze values of ΔEab* , ΔE00 , and ΔWID . Two-way analysis of variance (ANOVA; for L*, a*, b*, and WID ) and one-way ANOVA and Tukey tests (for ΔEab* and ΔE00 ) were used to analyzed the results (α = 0.05). RESULTS: L* and WID values from all RBC did not change after bleaching applications (T1 and T2 ) (P > .05). There were no significant differences in color differences ( ΔEab* and ΔE00 ) among all RBC evaluated after bleaching applications (T1 -T0 and T2 -T0 ; P > .05). Regardless of the RBC, mean values of ΔE00 between all different periods were always below 50%:50% PT value. CONCLUSIONS: The 35% hydrogen peroxide bleaching gel influences on color and whiteness of resin-based composites. However, color changes were not clinically perceived and whiteness variations were clinically acceptable. CLINICAL SIGNIFICANCE: Patients should be advised that existing composite restorations might not match the natural tooth color after bleaching, and their replacement may be required.