Effect of Intraoral Humidity on Dentin Bond Strength of Two Universal Adhesives: An In Vitro Preliminary Study

This study investigated the effect of intraoral humidity on microtensile bond strength (μTBS) to dentin two universal adhesives applied in self-etch (SE) mode. Forty extracted human molars were selected for this study. Dentin specimens allocated into four groups, standardized and then bonded with commercial multimode adhesives, according conditions (50% relative (RH) 90% RH). Following composite resin build-up 24 h water storage, μTBS interface was analyzed. The 50% RH higher Scotchbond Universal (SBU) than Prime&Bond (PBU), while RH, SBU had significantly lower values PBU. With PBU, mean not different between both settings tested (p > 0.05), SBU, < 0.05); other group. Within limitation vitro study, it can be concluded that: 1) bonding performance systems depends settings; 2) increased exerts a detrimental 2-hydroxyethyl methacrylate (HEMA)-containing adhesive tested. However, phenomenon observed HEMA-free tested; 3) further research area is needed investigate systems, temperatures settings.