Effect of Whitening Dentifrices on Short-Term Color Stability and Tooth Sensitivity After In-Office Bleaching: A...

This randomized, single-blind clinical trial evaluated the effect of whitening dentifrices on short-term color stability and tooth sensitivity after in-office bleaching.

A total of 120 participants treated with 40% hydrogen peroxide were randomly assigned to six dentifrice groups (n = 20): one conventional dentifrice (control) and five whitening dentifrices with different mechanisms (abrasive, optical, and chemical). One whitening formulation also contained potassium nitrate as a desensitizing agent. Tooth color was measured spectrophotometrically at baseline, immediately after bleaching, and at 1 week, 1 month, and 3 months using the CIELAB system (ΔE*ab). Tooth sensitivity was recorded using a numeric rating scale at 24 h, 48 h, and 7 days. Color change data were analyzed using repeated-measures ANOVA with Greenhouse-Geisser correction, whereas tooth sensitivity data were analyzed using Friedman, Wilcoxon signed-rank, and Kruskal-Wallis tests with Bonferroni adjustment (α = 0.05).

No significant differences in color change were observed among groups at any evaluation time point (p > 0.05). A significant time × group interaction was detected (p < 0.05), mainly due to a reduction in ΔE*ab values in the control group at 3 months, whereas whitening dentifrices did not show significant intragroup changes over time. No significant differences were found among whitening dentifrices. Tooth sensitivity peaked within the first 48 h and decreased over time, approaching zero by Day 7. The dentifrice containing desensitizing agents exhibited significantly lower sensitivity scores during the early postbleaching period (p < 0.05).

No statistically significant differences in color change were observed among dentifrice groups at individual time points; however, differences in color change patterns over time were identified. These findings reflect differences in intragroup trends rather than direct intergroup superiority. Tooth sensitivity was transient and resolved within 1 week in all groups, with lower early sensitivity scores observed in the formulation containing desensitizing agents.