Statement of Problems: Enamel preconditioning using phosphoric acid has been recommended prior to applying self-etch adhesives. Meanwhile, there is the possibility for etching of the dentin.
Purpose: The aim of this study was to evaluate the shear bond strength (SBS) of two self-etch adhesives to the dentin of the primary and permanent teeth in case of phosphoric acid preconditioning.
Methods and Materials: In this experimental study, the buccal surfaces of 48 permanent molars and 48 primary molar teeth were prepared for bonding of two self-etch adhesives including Clearfil SE Bond (CSEB) and ACE All Bond SE (ABSE), to the dentin. Each of the permanent and primary teeth was randomly divided into 4 groups (n=12). According to the manufacturers’ instructions, CSEB and ABSE were applied on the dentin or etched dentin of both permanent and primary teeth, then, they were bonded with composite resin. The specimens were stored in water at 37^oc for 24 hours and then were thermocycled for 500 cycles. SBS was performed at a crosshead speed of 1.0 mm/min using DARTEC universal machine. The results were statistically analyzed in SPSS 11.5 using Kruskal-Wallis and T-Test.
Results: The bond strength of CSEB was significantly higher than ABSE adhesive in both primary and permanent teeth ( p =0.001). Acid preconditioning significantly increased the dentin bond strengths of ABSE adhesive in the primary and permanent dentin ( p =0.001), and CSEB adhesive in primary dentin.
Conclusion: Bond strength of the studied adhesives was significantly different. While acid phosphoric preconditioning improved the bond strength of the both adhesives in primary teeth, it did not influence the bond strength of the studied two-step self-etch adhesive in the permanent dentin.