Abstract
This study evaluated the effect of mechanical loading with a new device on the microtensile bond strength (microTBS) of adhesive systems to dentin. Forty molars were divided according to adhesive systems: self-etch (ClearfilTM SE Bond -CSE) and etch-and-rinse (Adper ScotchbondTM 1XT -ASB); and to aging (n=5): control; MC1-250,000; MC2-500,000; and MC3-750,000 mechanical cycles. Microtensile bond strength was measured and fracture modes were analyzed. Data for microTBS were subjected to Kruskal-Wallis and post hoc tests (p<0.05). Mechanical loading (p<0.001) and adhesive systems (p=0.024) affected microTBS values. The adhesive systems showed a similar behavior, except in the MC3 group, which the self-etch CSE showed the highest microTBS. The new device promotes a decreasing of microTBS as the number of cycles increased. Difference between materials was observed only after 750,000 mechanical cycles.
