Shear Bond Strength of New Self-etching Adhesives

Objectives: To determine the shear bond strength to dentin of new self-etching adhesives. Methods: Proximal enamel of human third molars was removed to obtain dentin samples, which were randomly assigned to the adhesives (n=12): XP Bond (XP, Dentsply Detrey) and Scotchbond  (SB, 3M ESPE), total-etch adhesives bonded to 35% phosphoric acid etched dentin, and Xeno V (XV, Dentsply), Easy Bond (EB, 3M ESPE), Adper Scotchbond SE (ASSE, 3M ESPE), Adper Prompt L-pop (PLP, 3M ESPE), and Clearfil S3(CS, Kuraray), 1-step self-etching adhesives. The adhesives were applied to the dentin, as per manufacturer's instructions. Samples were shear tested to failure at a crosshead speed of 5 mm/min, with a single plane lap shear testing apparatus. Data were analyzed with one-way ANOVA and Tukey-Kramer tests. Failure mode was determined from SEM micrographs of the failed surface at 2 kX. Results: SBS data are shown in table below. Mean values with same superscript were not significantly different (P<0.001). ASSE was the only self-etching system to yield bond strength similar to both total-etch systems. Samples bonded with XV yielded significantly lower SBS values than all other groups. Conclusions: Most 1 step self-etching adhesive systems tested in this in-vitro study, yielded lower bond strength values to dentin than the total etch system and should need further development, to be predictable. Study performed at UICOB, R&D unit nº4062 of FCT. sofiaaol@fmd.ul.pt.