Influence of a Bleaching Agent on the Color Stability of Indirect Composite Resins Immersed in Dyes

Abstract

This study aimed to evaluate the effect of a bleaching agent on the color of extrinsically pigmented indirect composite resins. Samples of five resins (Adoro, Resilab, Cristobal, Sinfony, Epricord) were manufactured and divided into five groups: red wine, coffee, orange juice, Coca-Cola, and artificial saliva (control). The stained samples were immersed in a 38% hydrogen peroxide solution for 30 min per week, over three weeks. Color readings were performed at the initial state (L0), after 21 days of dye immersion (ΔE1, L1), and after 7 (ΔE2, L2), 14 (ΔE3, L3), and 21 days (ΔE4, L4) of bleach immersion. Data were subjected to ANOVA and Tukey’s honestly significant difference (HSD) test (α = 0.05). The color alteration was greater in ΔE1, regardless of color solution, indicating extrinsic pigmentation. The Resilab group exhibited greater ΔE1 values than the other resins. The bleaching agent promoted bleaching action on the surfaces of the materials studied, removing the previously impregnated pigments.