Capacidade antimicrobiana e de biomodificação do resveratrol em dentina afetada por cárie

Abstract

To preserve tooth structure, selective removal of carious tissue has been indicated. However, as it is a substrate that presents greater variability along the interface, damages in the union are reported. Strategies are developed in order to minimize the limitations of this substrate. Resveratrol (RVT) is a natural phenolic compound with antioxidant action that presents biocompatibility in dentin. The objective of this study was to evaluate in vitro the antimicrobial potential and the influence on adhesion to caries-affected dentin of dentin pretreatment with a resveratrol/ethanol solution at concentrations of 0.001%, 0.002% and 0.003% w/v compared to control groups (distilled water or 100% ethanol) and 2% chlorhexidine solution. Sixty sound third molars submitted to induction of dentin affected by pH cycling were used. For microtensile (n=6), teeth were treated with the treatment solutions for 1 minute, restored and analyzed in a universal testing machine immediately and after 6 months of storage in distilled water. Micropermeability (n=2) was used to analyze the morphology of the hybrid layer using confocal laser microscopy. For the microbiological test (n=3) 4x4x2 mm3 dentin specimens were made and divided into six groups. The specimens were submitted to an in vitro cariogenic challenge for 5 days, immersed in TSB containing yeast extract with 10% sucrose and inoculated with S. mutans ATCC 25175. After the experimental period, the biofilm formed was collected and the ratio of colony forming units has been established. For the microtensile test, the two-way ANOVA test was performed, followed by the Tukey test. For microbiology, data were logtransformed and analyzed by ANOVA, followed by Tukey's test. The significance level was set at 5%. The ethanol-treated group achieved higher bond strength (p=0.028) when compared to the adhesive-only group, but it did not show a significant difference among the RVT groups and CHX (p>0.05). All groups showed lower bond strengths after 6 months compared with immediate test (p<0.001).There was a statistical difference in relation to the antimicrobial potential between chlorhexidine and the other groups (p<0.001). Pretreatment with resveratrol did not impair bond strength to dentin artificially demineralized and did not demonstrate significant antimicrobial potential against S. mutans.