Influence of dentinal moisture on the properties of universal adhesives

Abstract

PurposeThe aim of this study was to evaluate the microtensile bond strength (μTBS), degree of conversion (DC), and silver nitrate deposition (NL) of three universal adhesive systems, used in etch-and-rinse and self-etch modes, on wet and oversaturated dentin surfaces. Materials and methodsHuman molars were assigned to 12 groups by: Universal adhesive systems: (Ambar Universal APS [AMB]; Prime & Bond Active [PBA]; Scotchbond Universal Adhesive [SBU]; Adhesive strategies: (etch-and-rinse [ER] or self-etch [SE]); and Degree of surface moisture: (wet or oversaturated dentin surface). After restoration, the specimens were sectioned into resin-dentin beams and tested for μTBS, DC, and NL. A three-way ANOVA and Tukey's test were used for statistical analysis (5%). ResultsNo significant difference was observed in μTBS (p > 0.14) and DC (p > 0.67) among the tested adhesives regardless of the adhesive strategy employed when dentin was kept wet. AMB (ER and SE) resulted in a higher mean μTBS and DC values when the dentin was kept oversaturated (p < 0.001). A significant decrease of μTBS (p < 0.0001) and DC values (p < 0.001) were observed for PBA (ER) and SBU (ER and SE) when dentin was oversaturated. For ER and SE, SBU showed a significant increase in NL values in oversaturated dentin compared to those of wet dentin (p < 0.001). ConclusionUniversal adhesives systems showed good adhesive performance to dentin when dentin was kept wet. However, in oversaturated dentin, the response is material dependent.