Análise antimicrobiana do flavonóide epigalocatequina-3-galato como agente de limpeza cavitária em dentina artificialmente cariada

Abstract

The aim of this study was to evaluate the efficacy of the flavonoid epigallocatechin-3-gallate (EGCG) in concentrations of 0.5%, 1% and 2% as an antimicrobial solution in artificially carious dentin, with 2% chlorhexidine and 0.9% saline solution as controls. Twenty-five slabs of human dentin (4 mm x 4 mm) were immersed for five days in Brain Heart Infusion broth (BHI-broth) inoculated at first day with Streptococcus mutans UA159 (Batch Culture Model). On the fifth day of the experiment, the blocks were randomly divided into five groups: group I - negative control - 0.9% saline solution, group II - positive control - 2% chlorhexidine, group III - 0.5% EGCG, group IV - 1% EGCG, group V - 2% EGCG. Each slab was subjected to 15 µl of the tested solution for 60 seconds. After treatments, artificially carious dentin was removed from the dentin slabs and analyzed by counting colony forming units (CFUs). All experiments were performed in triplicate and the data obtained in CFUs mean values converted to log base-10. The statistical tests used were analysis of variance (ANOVA) followed by Tukey test. There was no statistical difference between EGCG concentrations and saline (p > 0.05). Furthermore, there is no statistical difference between EGCG concentrations (p > 0.05). However, there was statistically significant difference between chlorhexidine and the other groups (p < 0.05). From the data obtained in this study, is possible to conclude that the substance tested is not effective on elimination of pathogen S. mutans when used in a concentration of 0.5%, 1% and 2% in artificially carious dentin.