DNA Damage in Oral Mucosa Cells of Patients with Fixed Orthodontic Appliances

Objective: the release of toxic metal ions from orthodontic alloys has induced concerns regarding the biocompatibility of fixed appliances. this study investi-gated the genotoxic effect of metal appliances in a sample of patients undergoing fixed orthodontic treatment.materials and methods: the study included twenty-five healthy individuals re-quiring orthodontic therapy in both jaws. the patients were treated by stainless steel orthodontic brackets and nickel-titanium or stainless steel arch wires. the oral mucosa cells were gathered just before the appliance placement and 9 months later. the cells were centrifuged, fixed and dropped onto slides. after staining, the micronucleus (mn) assay was used to determine genome alteration. the data were analyzed by paired sample t-test.results: the mean micronuclei frequency in the buccal mucosa was 10.6 ± 5.7 per 1000 cells before the appliance placement and 9.2 ± 6.37 per 1000 cells 9 months later. no significant difference was found in the mn count before and 9 months after therapy (p=0.336).conclusion: under the conditions used in this study, application of fixed ortho-dontic appliances did not expose healthy individuals to increased risk of dna damage in oral mucosa cells.