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Micro-shear bond strength of resin-bonding systems to cervical enamel.

PURPOSE
To evaluate the micro-shear bond strength of current adhesive systems to cervical and mid-coronal enamel.


MATERIALS AND METHODS
Two commercially available resin adhesives were investigated; a self-etching primer system (Clearfil SE Bond) and a one-bottle adhesive system (Single Bond) intended for use with the total-etch wet-bonding technique were employed. Two regions of enamel, cervical and mid-coronal regions, were chosen from the buccal surface of extracted molars and were then bonded with each adhesive system and submitted to the micro-shear bond test. In addition, the conditioned enamel surfaces without any bond and the enamel-resin adhesive interfaces were studied morphologically using scanning electron microscopy (SEM).


RESULTS
No significant differences were found between the adhesive systems used (P > 0.05). However, for both bonding systems, cervical enamel showed significantly lower bonding than mid-coronal enamel (P < 0.05). The relatively lower bond strengths obtained from cervical enamel probably resulted from its aprismatic structure, which appears to be more resistant to dissolving in acids than prismatic mid-coronal enamel.