Síntese e caracterização de adesivos com polifenóis. Efeito sobre o grau de conversão e a resistência adesiva

Abstract

The aim of this study was to evaluate the effect of resveratrol and quercetin on conversion degree and bond-strength of an experimental methacrylate- based dental adhesive. The two-step experimental adhesive was made by mixing hydroxyethylmethacrylate (HEMA) and 2,2-bis [4- (2-hydroxy-3-methacryloxypropoxy) phenyl] -propane (BisGMA) monomers, ethanol and a photoinitiator system. Resveratrol and quercetin were added to the adhesive base at following concentrations of 10 μg / mL, 20 μg / mL, 100 μg / mL, 250 μg / mL, 500 μg / mL and 1000 μg / mL. The conversion degree (CD) of the adhesives was measured using infrared spectroscopy. Tests of microshear bond strength were performed 24 hours after photoactivation. The data were analyzed using ANOVA and Tukey test (α = 0.05). The CD of adhesives with resveratrol recorded was from 61.74% to 75.86% (p> 0.05) and in adhesives with quercetin the remained between 62.58% and 67.82% (p> 0,05). Compared to the control group (77.26%), only the adhesive with 1000 μg / mL of resveratrol (61.74%) showed significant decreasing on CD (p = 0.001). There was no statistical difference on microshear bond strength at resin/enamel interface (Mpa) between the control group and the adhesives with resveratrol (p> 0.05). In adhesives with quercetin at 10, 20 and 250 μg / mL concentrations there was a significant decreasing on microshear bond strength (p <0.05). The addition of resveratrol and quercetin into the experimental adhesive kept the degree of conversion within the expected limits for a dental adhesive. The microshear bond strength of experimental adhesives with resveratrol at all tested concentrations and with quercetin at 100 μg / mL, 500 μg / mL and 1000 μg / mL concentrations didn’t change.