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