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. METHODS: 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 microm 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 x 1.0 x 20 mm) were obtained and subjected to a tensile force at a crosshead speed of 0.5 mm/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 degrees C for 24 h. Statistical analyses were performed with ANOVA and Tukey's test (P<0.05). RESULTS: 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). SIGNIFICANCE: 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. Copyright 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
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. METHODS: 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 microm 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 x 1.0 x 20 mm) were obtained and subjected to a tensile force at a crosshead speed of 0.5 mm/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 degrees C for 24 h. Statistical analyses were performed with ANOVA and Tukey's test (P<0.05). RESULTS: 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). SIGNIFICANCE: 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. Copyright 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
Authors: Zahra A AlZaher; Danah F Almaskin; Masoumah S Qaw; Tahani H Abu Showmi; Reem Abualsaud; Sultan Akhtar; Mohammed M Gad Journal: Int J Dent Date: 2020-11-04