title: 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.
authors.affiliation: Department of Semiology and Clinics, School of Dentistry, Universidade Federal de Pelotas, Pelotas, RS, Brazil.
authors.forename: Aline Ferreira de
authors.initials: AF
authors.lastname: Almeida
authors.affiliation: School of Dentistry, Department of Restorative Dentistry, School of Dentistry, Universidade Federal de Pelotas, Pelotas, RS, Brazil.
authors.forename: Eliana do Nascimento
authors.initials: Edo N
authors.lastname: Torre
authors.affiliation: School of Dentistry, Department of Restorative Dentistry, School of Dentistry, Universidade Federal de Pelotas, Pelotas, RS, Brazil.
authors.forename: Maicon Dos Santos
authors.initials: Mdos S
authors.lastname: Selayaran
authors.affiliation: Department of Semiology and Clinics, School of Dentistry, Universidade Federal de Pelotas, Pelotas, RS, Brazil.
authors.forename: Fábio Renato Manzolli
authors.initials: FR
authors.lastname: Leite
authors.affiliation: School of Dentistry, Department of Restorative Dentistry, School of Dentistry, Universidade Federal de Pelotas, Pelotas, RS, Brazil.
authors.forename: Flávio Fernando
authors.initials: FF
authors.lastname: Demarco
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR, Brazil.
authors.forename: Alessandro Dourado
authors.initials: AD
authors.lastname: Loguercio
authors.affiliation: Department of Semiology and Clinics, School of Dentistry, Universidade Federal de Pelotas, Pelotas, RS, Brazil.
authors.forename: Adriana
authors.initials: A
authors.lastname: Etges
mesh_terms: D000328:Adult; D000077463:Carbamide Peroxide; D004847:Epithelial Cells / Q000187:drug effects; D005260:Female; D005881:Gingiva / Q000187:drug effects*; D006801:Humans; D008297:Male; D015162:Micronucleus Tests; D009061:Mouth Mucosa / Q000187:drug effects; D010545:Peroxides / Q000008:administration & dosage / Q000009:adverse effects*; D011897:Random Allocation; D018709:Statistics, Nonparametric; D013997:Time Factors; D014073:Tooth Bleaching / Q000009:adverse effects* / Q000379:methods; D016896:Treatment Outcome; D014508:Urea / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D055815:Young Adult
chemical_list: D010545:Peroxides; D000077463:Carbamide Peroxide; D014508:Urea