Topical application of sodium ascorbate after in-office dental bleaching: a randomized controlled trial

Abstract

Objective: To evaluate the intensity and risk of tooth sensitivity (TS), and the bleaching efficacy, after the application of 10% sodium ascorbate (SA) following in-office bleaching, in a randomized, parallel, triple-blind, controlled trial. Material and Methods: Forty participants underwent two in-office bleaching sessions with 35% hydrogen peroxide (3x15-min applications) and they were randomized into two groups (n = 20): 1) placebo (application of placebo gel during 10 min) and 2) 10% SA group (application of 10% SA for 10 min). The intensity and risk of TS were assessed using the scales: Visual Analog Scale (VAS, 0-10) and Numerical Scale (NRS, 0-4). Bleaching efficacy was evaluated using the shade guide units Vita Classical and Vita Bleachedguide scales. The VAS scale, and bleaching efficacy were compared between groups using independent t-tests. The NRS scale was analyzed using Mann–Whitney. The risk of TS was analyzed using Fisher’s exact test. Results: No difference in the intensity of TS was detected for both pain scales (p > 0.07). The risk of TS was 95% (95% CI 76 to 99%) for the SA group and 100% (95% CI 83 to 100%) for the placebo group (RR = 0.95; 95% CI 0.86 to 1.05; p = 1.0). Color change was observed in both groups without significant differences (p > 0.20). Conclusion: Topical application of 10% SA for 10 min after in-office bleaching did not reduce the intensity or risk of TS and did not jeopardize the bleaching efficacy.

KEYWORDS

Antioxidants; Controlled Clinical Trial; Dentin Sensitivity; Hydrogen Peroxide; Tooth Bleaching.