Evaluation of the microtensile bond strength of composite resin restoration in dentin prepared with different sizes of aluminum oxide particles, using the air abrasion system.
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AIM: The purpose of this in vitro study was to evaluate the influence of the abrasive technique on the microtensile bond strength of composite resin restorations. In addition, any differences in the microtensile bond strength were observed when different aluminum oxide particle sizes were used. METHODS: Flat coronal dentin surfaces were randomly distributed into 3 groups, according to surface treatment: Group A27 Air-abraded dentin with 27 microm aluminum oxide particles; Group A50-Air-abraded dentin with 50 microm aluminum oxide particles; Group HS cut dentin with a #1013 diamond bur in high-speed rotary instrument. After the bonding procedure (Single Bond/Z100), the teeth were stored in distilled water at 37 masculineC for 48 h prior to sectioning. Then, each bonded tooth was longitudinally sectioned producing sticks with a cross-sectional area of 0.81 mm2. The tensile load was applied at a crosshead speed of 0.5 mm/min, until the stick fractured. The data were analyzed by one-way ANOVA and post hoc multiple comparisons using Tukey's test. RESULTS: No difference was observed in composite bond strength when 27 and 50 microm aluminum oxide particles were used for dentin surface preparation using an air abrasion system. However, air-abraded dentin, using 27 microm aluminum oxide particles, demonstrated a higher bond strength when compared to dentin prepared by the conventional method (bur in high-speed). CONCLUSIONS: The air-abraded dentin, using 27 microm alumina powder, demonstrated higher composite bond strength when compared to bur-cut dentin, raising the possibility that this method may increase restoration longevity.