Hybridization efficiency of the adhesive/dentin interface with wet bonding

Although it is generally proposed that dentin bonding results from adhesive infiltration of superficially demineralized dentin, it is not clear how well the resin monomers seal the dentin collagen fibrils under wet bonding conditions. The aim of this study was to determine the quality and molecular structure of adhesive/dentin (a/d) interfaces formed with wet bonding as compared with adhesive-infiltrated demineralized dentin (AIDD) produced under controlled conditions (optimum hybrid). From each extracted, unerupted human 3rd molar, one fraction was demineralized, dehydrated, and infiltrated with Single Bond (SB) adhesive under optimum conditions; the remaining, adjacent fraction was treated with SB by wet bonding. AIDD and a/d interface sections were stained with Goldner's trichrome; corresponding sections were analyzed with micro-Raman spectroscopy. The histomorphologic and spectroscopic results suggest that, under wet bonding, the a/d interface is a porous collagen web infiltrated primarily by the hydrolytically unstable HEMA.