Bonding of single-component adhesives to dentin following chemomechanical caries removal

To determine the effect of chemomechanical caries removal on the bonding quality of contemporary single-component adhesives to dentin.

N-monochloro-DL-2-aminobutyrate solution (NMAB) and Carisolv gel were used to chemomechanically remove dentin caries in 60 extracted human molars. Caries removal with rotating instruments served as the control. Two single-component adhesive systems, Syntac Single Component and Excite, were applied to bond the hybrid composite Tetric Ceram to the treated dentin surfaces. The prepared samples were sectioned for microtensile bond strength testing and SEM examination of the bonding interfaces. The debonding patterns of the fractured samples were also assessed.

No statistically significant differences were found between the bond strengths of either adhesive to the conventionally and the NMAB-treated dentin (p > 0.05). However, the Carisolv-treated dentin yielded significantly higher (p > 0.05) bond strength values with both adhesives compared to those on dentin prepared with rotating instruments. No statistical difference could be discerned between the 2 adhesive systems (p > 0.05), nor was the interaction between the 2 variables under investigation (method of caries removal and the type of adhesive) statistically significant (p = 0.7712). SEM images indicated unspecific effects of the tested variables on both the thickness of the hybrid layer and the length of the resin tags.

Under the conditions of this study, using the Carisolv chemomechanical caries removal system to prepare dentin surfaces enhanced the dentin/adhesive bond strength. In addition, the chemical nature of the adhesive systems seems to have no effect on the values of bond strength.