Effect of airborne-particle abrasion on dentin with experimental niobophosphate bioactive glass on the microtensile bond strength of resin cements

Abstract

PurposeThe objective of this study was to evaluate the microtensile bond strength (μTBS) of two resin cements bonded to dentin pre-treated with experimental niobophosphate bioactive glass (NBG). MethodsThe experimental bioactive glass was prepared by mixing different amounts of NbO5; (NH4)2HP4; CaO; Na2CO3. The particle size distribution and composition of the bioactive glass powder were determined. Twenty flat dentin surfaces from sound extracted human molars were polished with 600-grit SiC paper and air-abraded using experimental bioactive glass niobium powder. The bonding procedures were accomplished by the application of two resin cements: self-etching Panavia F or self-adhesive RelyX U-100. The resin-bonded specimens were cut and the μTBS test was performed after 24h. The failure mode was determined with a stereomicroscope at 40× magnification. The results were statistically analyzed by two-way ANOVA and Tukey tests (α=0.05). ResultsThe two-way ANOVA did not detect interactions between factors, but only a difference between the self-etching and self-adhesive cement (p=0.001). The self-etching resin cement Panavia F obtained a higher μTBS than the self-adhesive cement Relyx U-100. The predominant failure mode of the cements was adhesive/mixed between the resin cement and dentin. ConclusionA new bioactive glass containing niobium did not interfere with the immediate bonding performance of self-etching and self-adhesive cements.