ABSTRACT
The aim of this study was to compare the adhesive efficacy of different dentin bonding agents on human permanent and primary dentin. For this aim, different dentin bonding agents were administered on permanent and primary dentin, and samples prepared for the investigation of the formed hybrid layer and resin tags at the resin-dentin interface were investigated with scanning electron microscopy. While hybrid layer formation was observed with total-etch bonding systems, an obvious gap formation was seen with the self-etch system. A statistically significant thicker hybrid layer formation was observed in primary dentin when compared to permanent dentin. We conclude that different clinical applications may be helpful due to the structural changes of primary teeth.