Avaliação de hipersensibilidade a metais e toxicidade genética associadas ao uso de aparelhos ordotônticos fixos

• Autor(a) principal: Westphalen, Graziela Henriques
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional PUCRS
• Texto Completo: http://hdl.handle.net/10923/408
• topic: ODONTOLOGIA; ORTODONTIA; HIPERSENSIBILIDADE; TOXICOGENÉTICA; MATERIAIS DENTÁRIOS

The aim of this study was to evaluate the hypersensitivity to metals and the genetic toxicity associated with the use of fixed orthodontic appliances. Hypersensitivity reactions were verified through the patch test carried out by a dermatologist before and two months after the placement of orthodontic appliances in a group of patients. The genetic toxicity was evaluated by using the micronucleus test and the comet assay. The sample was constituted of cells of the oral epithelium of the patients. For micronucleus test, cells were sampled before and 30 days after the placement of orthodontic appliance. For comet assay, the sample was obtained before and 10 days after the placement of orthodontic appliance. For either the micronucleus test or the comet assay, slides were mounted and processed according to standard protocols and analyzed under light microscope. Statistical analysis was performed by non-parametric tests (Fisher’s Exact Test, McNemar and Wilcoxon) and descriptive analysis. Regarding hypersensitivity, no differences were observed between the reactions before and after placement of the orthodontic appliances, which indicates that they did not sensitize patients. The comet assay showed low DNA damage level either before or after orthodontic appliance placement. Conversely, micronucleus test revealed a significant increase of permanent chromosomal damages in the period of 30 day after the placement of orthodontic appliance. Thus, more studies are still needed to understand the genetic toxicity potential of orthodontic devices, and long term studies of follow-up of the orthodontic patients are suggested.