ObjectiveThis work aimed to evaluate the influence of smear layer on the bonding effectiveness and durability of the self-adhesive resin cements to dentin.MethodsA total of 48 fresh caries-free third molars with exposed dentin surface were divided into two groups. The dentin surfaces were treated using a standard grit diamond bur (group A) or further polished using a fine grit diamond bur (group B) and then bonded with either of the two self-adhesive resin cements, namely, Clearfil SA Cement (CSA, Kuraray) and Multilink Speed (MS, Ivoclar Vivadent). After 24 h or 2-year water storage, a microtensile bond strength test was performed.ResultsIn group A, the dentin surface was rough, the smear layer was thick, and the dentin tubule orifice detritus showed low embolism value. In group B, the dentin surface roughness decreased, the embolism pro-portion increased, and the smear layer became thin. The initial bonding strengths of CSA and MS in group A were significantly lower than those in group B (PPPP>0.05).ConclusionThe properties of the smear layer and the types of self-adhesive resin cement used affected the bond strength and durability.
