Effect of Different Etching Modes on Dentin Bond Strength of Two Universal Adhesives

The present study aimed to evaluate the micro-shear bonding strength and failure patterns of two types of Universal Bonding agents to superficial dentin using self-etch and etch-and-rinse. In this study, 35 intact extracted premolar teeth were selected and superficial dentin were exposed by disk. In the next step, two blocks were obtained from each tooth and they were subsequently divided into 5 equal groups (n=14). Scotchbond Universal (3M/USA) was used in group 1 with a self-etch method. The same bond was utilized in group 2 with total-etch technique. In group 3, All-bond universal (BISCO/USA) was used with self-etch method and it was used in group 4 by etch-and-rinse technique. Finally, Single bond 2 was used in group 5 as a control group. The Z250 XT (3M/USA) resin composite was bonded on the surfaces of samples and were cured. Micro shear bonding strength was calculated by microtensile testing machine and failure modes were determined by stereomicroscope. The data were analyzed using one-way ANOVA and Tukey test. The mean±SD values of scotch bond self, scotch bond total, All-bond self, All-bond total, and Single bond total were 35.74±6.21, 29.50±3.89, 24.60±3.53, 31.47±4.73, 18.09±3.87, respectively. The self-etch technique for Scotchbond Universal and the etch-and-rinse technique for All-bond Universal has higher microshear bonding strength. Adper single bond 2 showed significantly the lowest bond strength (P<0.05). According to the obtained results, the microshear bonding strength of universal adhesives was material-dependent although universal adhesives showed higher bond strength.