Genotoxic potential of 10% and 16% Carbamide Peroxide in dental bleaching

Abstract

Dental bleaching has become one of the most frequently requested esthetic treatments in dental offices. Despite the high clinical success observed with this procedure, some adverse effects have been reported, including a potential for developing premalignant lesions, root resorption and tooth sensitivity, especially when misused. The aim of this study was to evaluate the genotoxic response using a micronucleus (MN) assay, after the application of two concentrations of carbamide peroxide. Thirty-seven patients were divided into two groups and randomly received either a 10% carbamide peroxide (CP) (19) or a 16% carbamide peroxide (18) concentration for 21 days in individual dental trays. Gingival margin cells were collected immediately before the first use (baseline), and then 15 and 45 days after baseline. The cells were placed on a histological slide, stained by the Feulgen technique, and evaluated by an experienced blinded examiner. One thousand cells per slide were counted, and the MN rate was determined. The two groups were analyzed by the Wilcoxon rank-sum test and the Kruskal-Wallis equality-of-populations rank test. A slight increase in MN was observed for both groups, in comparison with the baseline, at 15 days. However, no difference was observed between the two groups (10% and 16%), at either 15 or 45 days (p = 0.90). When bleaching is not prolonged or not performed very frequently, bleaching agents containing carbamide peroxide alone will not cause mutagenic stress on gingival epithelial cells.

Can tooth bleaching agents cause genotoxicity in the oral epithelium? A systematic review with meta-analysis

“…The search strategy identified 154 potentially relevant studies. After screening titles and abstracts, four full-text manuscripts were assessed for eligibility, and four observational studies (Almeida, et al, 2015;de Geus, et al, 2015;Rezende, et al, 2016;Del Real García, et al, 2019) were included in the meta-analysis. Table 1 and Figure 1 show the study selection flowchart and the specific reasons for exclusions.…”

“…Genetic disorders such as dentinogenesis imperfecta, amelogenesis imperfecta, or pathologies acquired during dental formation are examples of intrinsic factors, as well as the inadvertent ingestion of fluorine in childhood. The deposition of food and beverages on the dental surface and the use of tobacco result in extrinsic staining (Goldberg, et al, 2010;Almeida, et al, 2015). In these cases, esthetic procedures such as tooth bleaching are extensively required due to psychological factors and the need for inclusion and wellbeing of the patient in society (Dahl & Pallasen, 2003).…”

“…Tooth bleaching is a conservative and little invasive esthetic procedure. Although the literature describes different bleaching techniques, at-home tooth bleaching is the most used due to excellent long-term results (Almeida, et al, 2015;Monteiro, et al, 2019). This technique generally implies the use of a bleaching agent applied to an individualized impression tray, which the patient uses in periods varying from 30 minutes to one whole night, for at least two weeks (Almeida, et al, 2015;Alonso De La Peña, et al, 2013).…”

“…Studies indicate dentinal hypersensitivity and gingival injury as an unintended consequence of tooth bleaching (Almeida, et al, 2015;Monteiro, et al, 2019;Alonso De La Peña, et al, 2013;Klaric, et al, 2013). As for the safety of using hydrogen peroxide as a bleaching agent, some discussions are raised considering the possible carcinogenic potential.…”

“…Among the methods used for assessing these potential changes, the micronucleus test represents a minimally invasive, simple, and fast tool used as an exposure biomarker of several genotoxic agents, allowing a correlation to the risk of cancer (Almeida, et al, 2015;Monteiro, et al, 2019). This test is performed in mammals in vivo and detects mutagenic substances that break chromosomes (clastogenic substances) or interfere with the formation of the mitotic spindle, changing the equitable Research, Society andDevelopment, v. 11, n. 1, e11411124928, 2022 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v11i1.24928 3 distribution of chromosomes during cell division (Flores & Yamaguchi, 2008).…”