Resin bond strength to a zirconia-reinforced ceramic after different surface treatments

This study evaluated the microtensile bond strength between a composite resin and a zirconia-reinforced alumina-based glass-infiltrated ceramic after different ceramic surface treatments. Blocks (12 mm x 10 mm x 5 mm3) of a ceramic containing zirconia were fabricated, polished, and divided at random into seven groups, with each group receiving a different surface treatment. The adhesive system and composite resin were applied to the treated ceramic; these composite-ceramic blocks were stored in distilled water (37 degrees C) for seven days. At that point, they were cut along two axes to produce specimens with a cross-sectional area of 1.0 (+/- 0.1) mm2. The specimens (n = 20) were loaded in tension in a universal testing machine with a cross-head speed of 0.5 mm/minute. The microtensile bond strength values were calculated and statistically analyzed using ANOVA and Tukey's test (alpha = 0.05). Among the seven groups, specimens with both a silica coating and a silane coupling agent showed the highest mean microtensile bond strength values. All specimens treated with 9.5% hydrofluoric acid failed during the cutting procedure; among all specimens, the majority of the failures were cohesive. A positive correlation was observed between the fracture type and the microtensile bond strength (r = 0.63).