Microtensile Bond Strength of Self-etching Adhesives to ‎Ground Enamel

Objective: This study compared the microtensile bond strengths to ground enamel of three one-step self-etching adhesive systems, a self-etching primer system and an etch-and-rinse adhesive system. Methods: Human enamel was ground flat with 320-grit silicone carbide paper. The self-etching adhesives Clearfil S Tri Bond^TM (Kuraray), Futurabond NR^TM (Voco) and Hybrid bond^TM (Sun-Medical), the adhesive with a self-etching primer Clearfil SE Bond ^TM(Kuraray) and the etch-and-rinse adhesive Admira Bond^TM (Voco) were applied as directed, followed by a core of the same manufacturers' hybrid resin composite. A microtensile bond strength evaluation was performed after 48 hours of water storage, using untrimmed beams approximately 1.0 ± 0.1 mmNR² in cross-sectional area at a crosshead speed of 0.5 mm/minute. Results: There were no pretest failures in any group and failures were predominately adhesive or mixed. Adhesion to enamel of Futurabond NR (29± 5.7) and Clearfil SE bond (27± 4.3) was not significantly different from Admira Bond (32 ± 3.8). Clearfil S tri bond and Hybrid bond demonstrated significantly lower bond strengths (17 ± 3.1 and 20± 3.5) than other adhesives. (One way ANOVA, Tukey-Kramer Multiple-Comparison Test;p< 0.05). Conclusion:Bond strength to ground enamel of self-etching adhesive systems was dependant on the type of adhesive and some materials showed bond strength that was not different than that of etch-and-rinse systems.