EFFECTS OF THERMOCYCLING AND WATER STORAGE ON THE MICROTENSILE BOND STRENGTH OF THE SELF-ETCH ADHESIVES TO DENTIN

Purpose: the purpose of this study was to evaluate the effect of aging process, including thermocycling and water storage, on the microtensile bond strength of the one-step and two-step self-etch adhesive systems. material and methods: seventy two human third molars were selected for this study. one-step (clearfil s3 bond, adhese one and adper easy one) and two-step (clearfil se bond, adhese and adper se plus) self-etch adhesive systems were applied to the prepared cavities on dentin surfaces and restored with a resin composite. after water storage in distilled water at 37 0c for 24 h, the specimens were subdivided into 3 groups according to aging conditions; control, thermocycling (10.000 cycles), and water storage (6 months). following to aging procedures, randomly selected five specimens obtained from each tooth (n=20) were used and the microtensile bond strength (μtbs) of specimens was determined in a universal testing machine (lf plus, lloyd instruments, ametek inc.,england) with a crosshead speed of 0,5 mm/min. one-way anova and post hoc tukey comparisons tests (α=0.05) were used for the statistical analyses (p=0.05). results: the highest bond strength was observed in clearfil se bond adhesive system, whereas, the lowest bond strength was determined for adper easy one. the differences in bond strength between clearfil s3 bond and clearfil se bond, and adhese one and adhese in thermocycling groups, and adhese one and adhese, and adper easy one and adper se plus in water storage groups were found to be significant (p<0.05). conclusion: thermocycling and water storage aging procedures do not affect on the bond strength of the selfetch adhesive systems. moreover, two-step self-etch adhesives had significantly higher μtbs values than one-step self-etch adhesives.