Genotoxicity of 22% Carbamide Peroxide Bleaching Agent on Oral Cells using the Micronucleus Technique

Abstract

Introduction: Several bleaching products and methods were introduced over the last years. However, the consequences of 22% carbamide peroxide on the genetic material of oral mucosal cells is uncertain. Aim: This study investigated the genotoxic effect of 22% carbamide peroxide on oral mucosal cells using the Micronucleus (MN) technique. Materials and Methods: Sixteen volunteers participated in the study. At-home bleaching was performed for 2 hours per day for 21 days. Cells were collected by scraping the oral mucosa at four different evaluation times: Baseline (before treatment), 14 days, 21 days, and 52 days after the beginning of bleaching procedure. One thousand cells from each volunteer were examined and the frequencies of MN, binucleated cells, and metanuclear alterations were recorded. After preparing the slides, the microscopic fields were analysed from right to left, until a total of 1,000 cells were analysed. Data were analysed statistically using Kruskal Wallis test at 5% significance level. Results: There was a significant increase in the number of metanuclear alterations and binucleated cells between the baseline and day 21 (p<0.0001). The frequency of MN between the evaluation times was not significantly different (p=0.08). One month after bleaching, the alterations were similar to the baseline values. Conclusion: Although at-home bleaching using 22% carbamide peroxide can cause temporary effects on mucosal cells, the alterations disappear one month after finishing the bleaching treatment.

Keywords

• dna damage
• human genetics
• micronucleus
• tooth bleaching