Effect of Air-powder Polishing on Dentin Adhesion of a Self-etching Primer Bonding System

The purpose of this study was to evaluate the effect of air-powder polishing with sodium bicarbonate (SB) or crystalline cellulose (CC) on the bond strength of a self-etching primer bonding system to dentin. Ground human dentin surfaces were prepared using 600-grit SiC paper. The teeth were divided into three groups according to dentin treatment: control, air-powder polishing with SB, and air-powder polishing with CC. The dentin surfaces were bonded with a self-etching primer bonding system, followed by a light-cured resin composite. microTBS test and SEM analysis were performed. The results of microTBS test indicated that air-powder polishing with SB affected bond strength to dentin, while that with CC did not influence bond strength. SEM observation of air-polished dentin surfaces showed that dentin surfaces air-polished with SB were roughened and covered with a smear layer, while those with CC were smooth and the smear layer was removed.