Effect of Brazilian red propolis on microtensile bond strength and sealing ability of the methacrylate-based bonding agents

The aim of the study was to analyze the sealing ability and microtensile bond strength of a dental adhesive with propolis.Red propolis extract was added to an experimental methacrylate-based adhesive (EA) at following concentrations: 100 (EA PV100), 250 (EA PV250) e 500 μg/mL (EA PV500). Single Bond Universal adhesive (SB) and EA without propolis were used as controls. The effectiveness of the dentin sealing was evaluated at nanoscale (silver uptake) and microscale (dye microleakage). Microtensile bond strength (µTBS) was measured 24 hours after the bonding process. Data were analyzed by one-way ANOVA and Tukey’s test (α=0.05).EA PV500 showed the best coronal sealing, with better performance than the control and the commercial adhesive. Immediate µTBS values ranged from 28.94 + 9.25 MPa (EA PV100) to 39.09 + 9.60 MPa (SB). Comparing SB and EA with propolis, a significant decrease in µTBS was noted (p<0.05). The EA without propolis had similar performance to SB (p=1.000).Nanoleakage and microleakage were not eliminated in any of the groups, but EA PV500 µg/mL exhibited the best sealing ability, with superior performance compared to the control and commercial adhesive. A decrease in μTBS of AE with propolis was observed.