Effect of acid erosion on enamel bond strength of self-etch adhesives and sonic velocity measurement of enamel.

The purpose of this study was to investigate the effect of acid erosion on the bonding performance of universal adhesives. Freshly extracted bovine teeth were cut into enamel slabs and assigned to either the Er or the control group. Specimens in the Er group were immersed in citric acid solution (pH 2.1) twice a day and stored in artificial saliva, while control specimens were simply stored in artificial saliva. Differences in the mean values between the control and Er groups were greater than expected, despite accounting for the effect of differences in the adhesive systems (p=0.016). The Er group mainly exhibited cohesive failure in the enamel, while adhesive failure was more frequent in the control group. The sonic velocity was found to decrease over time in the acid attacked specimens. The results indicated that bond strengths of universal adhesive tested increased in eroded enamel.