Microtensile bond strength of a resin cement to a novel fluorcanasite glass-ceramic following different surface treatments

摘要

Objectives. This study evaluated the effect of surface treatments on the bond strength of fluorcanasite and lithium disilicate glass-ceramics, with the possibility of eliminating HF etching of these ceramics.rnMethods. Fifteen blocks of an experimental fluorcanasite and a lithium disilicate glass-ceramic (IPS e.max CAD~?) were assigned to one of the following three surface treatments: (1) machined with 60 μm finish, (2) machined and grit blasted, (3) machined and HF etched. The ceramic blocks were duplicated in composite resin (Spectrum~?) and cemented together with a resin luting agent (Variolink II~?). Thirty microbars per group (1.0 × 1.0 × 20 mm) were obtained and subjected to a tensile force at a crosshead speed of 0.5mm/min using a universal testing machine until failure. The mode of failure was determined using scanning electron microscopy. The appropriate bonding procedure was assessed for durability by storing in water at 100℃ for 24 h. Statistical analyses were performed with ANOVA and Tukey's test (P<0.05).rnResults. Machining alone significantly increased the bond strength (MPa) of the fluorcanasite (27.79 ±6.94) compared to the lithium disilicate (13.57 ±4.52) (P<0.05). HF etching resulted in the lowest bond strength (8.79 ±2.06) for the fluorcanasite but the highest for the lithium disilicate (24.76±9.38). Regarding durability, the machined fluorcanasite (15.24 ±5.46) demonstrated significantly higher bond strength than the machined and HF etched lithium disilicate (12.28 ± 3.30).rnSignificance. The fitting surface of the fluorcanasite glass-ceramic should retain the machined finish and be directly treated with silane. The use of HF acid is contraindicated.