Avaliação da atividade antimicrobiana das formulações cinza e branca do agregado trióxido mineral: participação das espécies reativas do oxigênio

• Autor(a) principal: Ribeiro, Caroline Sousa
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal Fluminense (RIUFF)
• Texto Completo: https://app.uff.br/riuff/handle/1/20128
• topic: Materiais biomédicos e odontológicos; Endodontia; Produtos com ação antimicrobiana; Biomedical and dental materials; Endodontics; Products with antimicrobial action; CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA::CLINICA ODONTOLOGICA

The Mineral Trioxide Aggregate (MTA) in its gray and white presentations is a biomaterial that has been used in Endodontics. The objective of this study was to evaluate the antimicrobial activity of gray and white MTA, by induction reactive oxygen species (ROS). In vitro the antimicrobial activity of MTA was determined on E. coli mutant (AB2463-RecA13), triple mutant (BW535), wild (AB1157 - provided by repair mechanism), E. coli (ATCC33780), P. aeruginosa, B. fragilis and E. faecalis. The diffusion method on Müller Hinton agar (MHA) was employed. A base layer was made using MHA agar and four wells were made by removing agar at equidistant points. MTA was placed into the wells immediately after manipulation. The plates were incubated at 37 °C for 48 h under aerobic and anaerobic conditions. Afterward the zones of inhibition were measured. The damage caused to the plasmid DNA was evaluated through the 0.8% agarose gel electrophoresis. The zone of inhibition under aerobic conditions was significantly greater than anaerobic (p < 0.01). Under aerobic conditions, both formulations were effective against the strains of AB2463-RecA13 and triple mutant E. coli, P. aeruginosa and E. faecalis. However they not showed zone of inhibition against the AB1157 e ATCC33780 strains of E. coli. About both MTA there was no significant difference in the antimicrobial activity (p > 0.05).They synthesized ROS that promoted damage in the plasmid DNA when compared sterile distilled water (control). We concluded that MTA under aerobic condition provoked antimicrobial activity by induction ROS and under anaerobic condition ROS were reduced quickly. Besides, the antimicrobial activity occurred by a damage caused directly to the bacterial DNA.