Influence of in-office whitening on the color matching and surface characteristics of single-shade resin composites.

Objective: The color matching of single-shade resin composites after in-office whitening was investigated.

Materials and methods: Four single-shade resin composites were used. A total of 35% hydrogen peroxide was used as the whitening agent. The resin composite was placed in a cavity of an artificially discolored bovine tooth. The color differences between the restoration and surrounding enamel before and after whitening were determined based on ΔE*_ab, ΔE₀₀, and ΔWI_D. The color stability, surface roughness (Sa), and surface gloss (GU) of the resin composite alone were also evaluated. Statistical analyses were performed using repeated-measures analysis of variance with the Tukey-Kramer test.

Results: Based on the 50:50% of perceptibility and acceptability thresholds of ΔE*_ab and ΔE₀₀, none of the resin composite restorations were clinically acceptable before or after whitening. Regarding ΔWI_D, although all resin composites showed "acceptable match" in the baseline, they showed "mismatch" after the third session of whitening. Most of the resin composites alone were stable in color against whitening.

Conclusions: Although the single-shade resin composites failed to achieve the expected color matching on discolored teeth either before or after the whitening, the impact of the whitening on the color of the resin composite alone may be negligible.