Microscopic evaluation of dentin interface obtained with 10 contemporary self-etching systems: correlation with their pH

This study investigated micromorphological differences in the hybridized complex formed using 10 commercially available self-etch bonding systems. In addition, the influence of the pH of the primer of these adhesives was evaluated. The self-etching systems tested were AdheSE, Adper Prompt L-Pop, Clearfil SE Bond, Etch&Prime 3.0 (Degussa, Germany), Prime & Bond NT Non Rinse Conditioner (Dentsply, Konstanz, Germany), One-Up Bond F, OptiBond Solo Plus Self Etch, Prompt L-Pop and Xeno III. One hundred non-carious human third molars were used. The teeth were divided into two groups of 50 and prepared for evaluation by optical microscopy or scanning electron microscopy. The specimens in each group were further divided into 10 subgroups of five specimens each to evaluate the 10 bonding systems. The pH of the primers of the bonding systems was measured. The results demonstrated morphological differences at the interface, depending on adhesive composition. The differences mainly concerned thickness of the hybrid layer, the absence or presence of microscopic voids at the adhesive-composite interface and whether the dentinal tubuli were completely sealed. The pH was not the determining factor conditioning the action of the self-etching adhesives.