Oxidative stress and genotoxicity in oral epithelial cells of subjects undergoing Fixed Orthodontic Appliances

Abstract Objectives The aim of this study was to analyze changes in oxidative stress (OS) and the genotoxic damage in oral epithelial cells caused by fixed orthodontic appliances. Materials and methods Samples of oral epithelial cells were obtained from fifty-one healthy voluntary subjects who had an indication for orthodontic treatment. The samples were obtained before and after 6- and 9-months starting treatment. OS was evaluated by quantitation of 8-hydroxy-2’deoxyguanosine (8-OHdG) and by relative gene expression of antioxidant enzymes Superoxide Dismutase (SOD) and Catalase (CAT). DNA degradation and instability were evaluated by multiplex PCR and fragment analysis for human identification. Results Quantitation of 8-OHdG evidenced increase during treatment, although not statistically significant. SOD showed increase of 2.5 and 2.6-fold after 6 and 9 moths of treatment. CAT shows an increase of 3-fold, after six months of treatment, while after 9 months of treatment the level expression decreased to level similar to that before treatment. DNA degradation was found in 8% and 12% of DNA samples after 6 and 9 months of treatment,respectively, while DNA instability was detected in only 2% and 8 % of DNA samples after 6 and 9 months of treatment, respectively. Conclusions Results show light changes in OS and genotoxicity after fixed orthodontic appliances, but also suggesting a biological adaptation response to treatment after 6 months. Clinical relevance OS in buccal cavity represents risk to oral and systemic diseases. Implementation of antioxidant supplementation, use of thermoplastic materials, and time reduction during orthodontic therapy may reduce the risk.