Experimental etch-and-rinse adhesive systems containing MMP-inhibitors: Physicochemical characterization and resin-dentin bonding stability

ObjectivesTo evaluate the degree of conversion (DC%), water sorption (WS), solubility (SO) and the resin-dentin bonding stability (μTBS) of experimental (EXP) etch-and-rinse adhesive systems containing MMP-inhibitors: Galardin-GAL, Batimastat-BAT, GM1489-GM1 and chlorhexidine diacetate-CHX.MethodsDC% was measured using FT-IR spectroscopy, while WS and SO were calculated based on ISO4049. Thirty-six human molars were wet ground until the occlusal dentin was exposed. The adhesive systems were applied and resin composite buildups were incrementally constructed. After 24 h immersion in distilled water at 37 °C, the specimens were cut into resin-dentin beams with a cross-sectional area of 1 mm2. The μTBS was evaluated after 24 h, 6 months and 12 months of water storage at 37 °C. Adper Single Bond 2 (SB2) was used as a commercial control. The data were analyzed using ANOVA and Tukey's HSD test.ResultsSB2 presented the highest DC% (p < 0.05). CHX presented the lowest WS (p < 0.05). GM1, GAL and BAT presented similar WS when compared with SB2 (p > 0.05). SO was found to be not significant (p > 0.05). All adhesive systems maintained μTBS stability after 6 months of water storage. Only BAT, GM1 and CHX maintained μTBs stability after 12 months of water storage.ConclusionsThe experimental adhesive systems with GM1489 and chlorhexidine diacetate presented the best physicochemical properties and preserved resin-dentin bonding stability after 12 months of water storage.Clinical significanceGM1489 could be suitable for inclusion as an MMP-inhibitor in etch-and-rinse adhesive systems to maintain resin-dentin bonding stability over time.