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

Abstract

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

Can a Novel Device with Pure Dry Air Increase the Shear Bond Strength of Dental Composites to Dentin? An Experimental Study

“…Composite resins and their adhesives have been the center of interest of researchers in recent decades. This can be explained by a growing interest and more demand from patients to undergo aesthetic direct and indirect restorations, which require a good adhesion to enamel and dentin because composites, unlike amalgam, do not require mechanical retention [15][16][17]. No previous study has focused on the air and water mechanism used by practitioners to bond composite restorations.…”

Impact of adhesive application errors on dentin bond strength of resin composite

“…This moisture has been found to not affect the thickness of the adhesive nor of the hybrid layer, but to shorten the resin tags [ 21 ]. A number of studies have shown that shortened resin tags can negatively affect the performance of Scotchbond Universal [ 21 , 22 ]. In contrast, other studies have found no negative impact of increased residual moisture [ 23 , 24 ].…”

A Comparative Study on the Effect of Peri-Implant Infection Management Lasers (1064-nm Q-Switch Nd:YAG, 1064-nm Nd:YAG and 980-nm Diode) on Titanium Grade 4 Surface

“…The thermostatic tank with a recirculation pump was activated to induce a temperature of 37.5 • C, which was measured with the double probe K thermocouple thermometer, HI 935002 digital thermometer, K probe, 2 inputs (HANNA INSTRUMENTS Italia srl-Viale Delle Industrie, 11-35010 Ronchi di Villafranca Padovana, Italy). Additionally, the humidity was maintained at around 93 Kg/m 3 and measured with the HI9564 digital thermo-hygrometer (HANNA INSTRUMENTS Italia srl) [24,25].…”