Emulsões amazônicas bioativas para limpeza do preparo cavitário: atividade antibacteriana, citotoxicidade, alteração de cor e compatibilidade biológica

Abstract

The cleaning procedure is a step in cavity preparation of tooth structure to receive the restorative treatment, this step aims to remove debris and microorganisms of the cavity, allowing a direct interface between tooth and restoration. Oil-copal resin is a natural product, used by Amazonian populations and recognized for its medicinal properties such as antimicrobial activity against the microorganisms in the oral cavity. This study evaluated the biological compatibility and antimicrobial activity in mouse molar of the emulsions formulated cleaning the cavity of the base oil-resin of copaiba (Copaifera multijuga), the following concentrations: 10% copal, copal to 10% with amyrin, copal 30% and 30% with copal amyrin. The antibacterial activity of these emulsions were analyzed by the minimum inhibitory concentration, minimum bactericidal concentration and cell viability analysis by fluorescence techniques, compared to ATCC 25175 Streptococcus mutans, Streptococcus oralis ATCC 10557, Streptococcus salivarius ATCC 7073 and Lactobacillus casei ATCC 7469. The cytotoxic activity of emulsions were evaluated by tests of the hemolysis tests and cell culture, compared to murine fibroblasts NHI3T3 by the Alamar Blue test. The color change was evaluated difference between the starting and ending of the specimens of dentin when in contact with the test emulsions at different times, 10 seconds, 30 seconds and 10 minutes. The biological compatibility of the copal emulsions were evaluated by washing the cavity with the test emulsion followed by pulp capping with calcium hydroxide pastes associated with oil-resin of copaiba amyrin 10% + 1% in molars of rats. The test emulsions at all concentrations showed antibacterial activity against microorganisms relevant to dentistry. In cytotoxic activities, all emulsions tested showed cell lysis, with an EC50 ranging from 11 to 32μL/mL. The emulsions of the oil-resin of copaiba with amyrin showed better behavior and hemolytic activity that the emulsions without amyrin. In the test cell culture was observed that the emulsions of the oil-resin of copaiba decrease cell viability showing cytotoxicity. Evaluating the color change, the emulsions of the oil-resin of Copaiba with amyrin were less clinically noticeable color change, ΔE <3.3, within 10 minutes. The pulp capping with emulsions and pastes the oil-resin of Copaiba observed behavior was similar to control, when used in the emulsion of the oil-resin of Copaiba to 10% with amyrin. The authors concluded that testing of emulsions and pastes the base of the oilresin of Copaiba are promising for application in dentistry, requiring more research to improve the pharmacological, physical, mechanical and biological properties.