PURPOSE: The aim of this study was to evaluate the effect of water storage (24 hours and 1 year) on the tensile bond strength between the IPS Empress 2 ceramic and Variolink II resin cement under different superficial treatments. MATERIALS AND METHODS: One hundred and eighty disks with diameters of 5.3 mm at the top and 7.0 mm at the bottom, and a thickness of 2.5 mm were made, embedded in resin, and randomly divided into six groups: Groups 1 and 4 = 10% hydrofluoric acid for 20 seconds; Groups 2 and 5 = sandblasting for 5 seconds with 50 microm aluminum oxide; and Groups 3 and 6 = sandblasting for 5 seconds with 100 microm aluminum oxide. Silane was applied on the treated ceramic surfaces, and the disks were bonded into pairs with adhesive resin cement. The samples of Groups 1 to 3 were stored in distilled water at 37 degrees C for 24 hours, and Groups 4 to 6 were stored for 1 year. The samples were subjected to a tensile strength test in an Instron universal testing machine at a crosshead speed of 1.0 mm/min, until failure. The data were submitted to analysis of variance and Tukey's test (5%). RESULTS: The means of the tensile bond strength of Groups 1, 2, and 3 (15.54 +/- 4.53, 10.60 +/- 3.32, and 7.87 +/- 2.26 MPa) for 24-hour storage time were significantly higher than those observed for the 1-year storage (Groups 4, 5, and 6: 10.10 +/- 3.17, 6.34 +/- 1.06, and 2.60 +/- 0.41 MPa). The surface treatments with 10% hydrofluoric acid (15.54 +/- 4.53 and 10.10 +/- 3.17 MPa) showed statistically higher tensile bond strengths compared with sandblasting with 50 microm(10.60 +/- 3.32 and 6.34 +/- 1.06 MPa) and 100 microm (7.87 +/- 2.26 and 2.60 +/- 0.41 MPa) aluminum oxide for the storage time 24 hours and 1 year. CONCLUSIONS: Storage time significantly decreased the tensile bond strength for both ceramic surface treatments. The application of 10% hydrofluoric acid resulted in stronger tensile bond strength values than those achieved with aluminum oxide.
PURPOSE: The aim of this study was to evaluate the effect of water storage (24 hours and 1 year) on the tensile bond strength between the IPS Empress 2 ceramic and Variolink II resin cement under different superficial treatments. MATERIALS AND METHODS: One hundred and eighty disks with diameters of 5.3 mm at the top and 7.0 mm at the bottom, and a thickness of 2.5 mm were made, embedded in resin, and randomly divided into six groups: Groups 1 and 4 = 10% hydrofluoric acid for 20 seconds; Groups 2 and 5 = sandblasting for 5 seconds with 50 microm aluminum oxide; and Groups 3 and 6 = sandblasting for 5 seconds with 100 microm aluminum oxide. Silane was applied on the treated ceramic surfaces, and the disks were bonded into pairs with adhesive resin cement. The samples of Groups 1 to 3 were stored in distilled water at 37 degrees C for 24 hours, and Groups 4 to 6 were stored for 1 year. The samples were subjected to a tensile strength test in an Instron universal testing machine at a crosshead speed of 1.0 mm/min, until failure. The data were submitted to analysis of variance and Tukey's test (5%). RESULTS: The means of the tensile bond strength of Groups 1, 2, and 3 (15.54 +/- 4.53, 10.60 +/- 3.32, and 7.87 +/- 2.26 MPa) for 24-hour storage time were significantly higher than those observed for the 1-year storage (Groups 4, 5, and 6: 10.10 +/- 3.17, 6.34 +/- 1.06, and 2.60 +/- 0.41 MPa). The surface treatments with 10% hydrofluoric acid (15.54 +/- 4.53 and 10.10 +/- 3.17 MPa) showed statistically higher tensile bond strengths compared with sandblasting with 50 microm(10.60 +/- 3.32 and 6.34 +/- 1.06 MPa) and 100 microm (7.87 +/- 2.26 and 2.60 +/- 0.41 MPa) aluminum oxide for the storage time 24 hours and 1 year. CONCLUSIONS: Storage time significantly decreased the tensile bond strength for both ceramic surface treatments. The application of 10% hydrofluoric acid resulted in stronger tensile bond strength values than those achieved with aluminum oxide.
Authors: Lourenço Correr-Sobrinho; Ana Rosa Costa; Ana Paula P Fugolin; Daniel Sundfeld Neto; Jack L Ferracane; Carmem S Pfeifer Journal: Biomater Investig Dent Date: 2019-11-27