Avaliação in vitro da atividade antimicrobiana, da citotoxicidade e da união aos dentes artificiais de resinas acrílicas autopolimerizáveis modificadas pela incorporação de clorexidina.

• Autor(a) principal: Silva, Adriana Menucci Bachur da
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/14217
• topic: Polymethyl Methacrylate; Chlorhexidine; Bacteria; Streptococcus mutans; Staphylococcus aureus; Polimetil metacrilato; Clorexidina; Bactérias; Streptococcus mutans; Staphylococcus aureus; CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA

The incorporation of chlorhexidine (CHX) to acrylic resin would be capable to create a prolonged device for antimicrobial release, and would be very important for the healing after surgeries in patients using dentures. The aim of this investigation was to analyze the antimicrobial activity of resin brands (Duralay and VIPI) specimens containing different concentrations of CHX (0.5%, 1% and 2%) and control after exhaustion periods of 3, 15, 30 and 60 days, the cytotoxic properties to L929 cells, and the interference of CHX in the bonding of the resin to artificial teeth. For the antimicrobial exhaustion test against Streptococcus mutans and Staphylococcus aureus. A hundred and ninety two acrylic specimens measuring 5mm (diameter) X 2mm (thickness) were used, and separated in 4 groups: Control, and with 0.5%, 1% and 2% CHX. The specimens were exhausted for 3, 15, 30 and 60 days with 100µl distilled water changed daily. The test was performed in triplicate using 96 flat bottomed well plates. The cytotoxic activity against L929 cells was performed by elution of each specimen in 1mL of complete DMEM (medium), as recommended by ISO 10993-5-2009, after 10, 7, 3 and 1 days. The eluates (50µL) were added to previous growth monolayers of L929 fibroblasts cultivated in a flat bottomed 96 wells culture plate. The bond test was performed as recommended by ISO 21112-2005. Six artificial teeth were fixed in wax blocks measuring 70x25x7 mm with a groove 5 mm wide and 1.5 mm deep, made from silicone cast and denture flasks were used with VIPI auto polymerizing resin. The specimens (100) were divided into 4 groups: control, 0.5% chlorhexidine, 1% and 2%, and the tensile test was performed on EMIC apparatus. All of the specimens containing CHX were capable to inhibit the growth of S. mutans, whereas S. aureus were capable to grow after 15, 30 and 60 days after exhaustion in the group of 0.5% CHX, though all groups, including 0.5% CHX were statistically different from the control group (p<0,001). Only the group with 0.5% CHX demonstrated a suitable pattern of cytotoxicity (lower than 30% of cytotoxic effect). The bond test did not reveal significant difference when CHX was incorporated to the acrylic resin. There was a difference in cytotoxicity between the brands of acrylic resins. The VIPI resin was more cytotoxic than Duralay, and was probably due to the concentration of benzoyl peroxide and oxygen reactive specimens of each resin brands. The results alowed to conclude that, for at least 60 days, there was no significant bacterial growth in the groups with CHX in both bacterial species evaluated, only 0.5% CHX had a tolerable cytotoxicity (less than 30% accepted by ISO) and CHX did not interfere with the bond between tooth structure and resin.