Effect of whitening mouthrinses on color change, whiteness change, surface roughness, and hardness of stained resin composites.

Purpose: To evaluate the effect of whitening mouthrinses on the color change, whiteness change, surface roughness, and hardness of stained resin composites after different immersion times.

Methods: Three different resin composites (Estelite Σ Quick, G-Aenial Anterior, Omnichroma) were used to prepare a total of 90 samples (30 samples from each resin composite). The samples were kept in coffee for 12 days, then divided into three subgroups (Control, Crest 3D White, and Listerine Advanced White; n=10 each). Color change (ΔE₀₀) and whiteness change (ΔWID) were evaluated at time intervals of 0-24 hours (T0-T1), 0-72 hours (T0-T2), and 24-72 hours (T1-T2). Surface roughness and hardness values were evaluated at T0, T1, and T2 after immersion in mouthrinses. Two-way ANOVA (for color and whiteness changes) and generalized linear model (for surface roughness and hardness) were used for data analyses (P< 0.05).

Results: Omnichroma had the highest value for color change with Crest 3D White during T0-T1 and T0-T2. Crest 3D White showed better color changes than Listerine Advanced White. In all composites and mouthrinse groups, the highest and lowest values of ΔWID were at T0-T2 and T1-T2, respectively, with the highest value for Omnichroma with Crest 3D White at T0-T2 and the lowest for G-Aenial Anterior with control groups at T1-T2. The highest roughness values were found with the Omnichroma at T2. Whitening mouthrinses significantly increased roughness and decreased hardness compared to baseline.

Clinical significance: Short-term regular use of whitening mouthrinse can recover color and increase the perception of whiteness without any significant increase in the roughness or hardness of resin composites, while long-term use affects both the roughness and hardness of resin composites.