Evaluation of the genotoxic potential of different delivery methods of at-home bleaching gels: a single-blind, randomized clinical trial

Abstract

Objective: This single-blind, parallel, randomized clinical trial evaluated the genotoxic potential and effectiveness of 10% hydrogen peroxide (HP) in patients submitted to at-home bleaching.

Materials and methods: Sixty young volunteers with maxillary incisors equal to or darker than M1.5 were included in the study. Patients were submitted to bleaching for 14 days (30 min/day) with one of the three 10% HP treatments: the bleaching agent was delivered in a bleaching tray (White Class, FGM), whitening strips (White Strips, Oral-b), or in prefilled disposable trays (Opalescence Go, Ultradent). The color change was evaluated with the Vita Bleachedguide, and the micronucleus test of exfoliative oral mucosa was carried out, starting from a count of 1000 cells, at the baseline, immediately after and 30 days after the end of the treatment. The micronucleus data were evaluated with the Kruskal-Wallis and Wilcoxon tests and color change with the two-way ANOVA test and the Tukey test (α = 0.05).

Results: Significant whitening was observed for all groups after 14 days (p = 0.001) and was maintained after 30 days, with no difference between groups (p = 0.42). The micronucleus count did not indicate genotoxic potential in any of the groups studied (p = 0.32), irrespective of the time intervals (p = 0.62).

Conclusion: No genotoxic effects of 10% HP were observed in patients submitted to at-home bleaching systems (30 min/day for 14 days), even 30 days after the end of treatment.

Clinical significance: It is safe to use different systems to deliver 10% HP during at-home bleaching according to the manufacturers' recommendations, with no risk of genotoxic effects applied.

Keywords: At-home bleaching; Bleaching gels; Genotoxicity; Micronucleus test.