Aim: To analyze the genotoxic effect of two hydrogen peroxide-containing bleaching products on oral mucosal cells.
Materials and methods: The research was conducted on 22 individuals divided into two groups. Group 1 used ZOOM2 and group 2 the Opalescence BOOST bleaching agent. Specimens of the gingival and the upper lip mucosa were obtained before, immediately after, and 72 h after the bleaching procedure and were analyzed using a micronucleus test.
Results: Seventy-two hours after bleaching treatment with BOOST, samples collected from the oral mucosa exhibited a statistically significant increase of all genotoxicity markers, with large effect sizes (Cohen's d>0.8) observed in the total number of micronuclei (MN), number of cells with 3+ MN, karyolysis and bi-nuclear cells. ZOOM2 treatment showed a significant increase, with medium-to-large effect sizes, in the number of cells with 1 MN, karyolysis, nuclear buds and bi-nuclear cells.
Conclusion: Both preparations demonstrated potential genotoxic effects.
Keywords: Genotoxicity test; hydrogen peroxide; micronucleus test; oral mucosa; tooth bleaching.