Effect of ceramic surface treatment on the microtensile bond strength between a resin cement and an alumina-based ceramic

PURPOSE: The objective of this study was to test the following hypothesis: the silica coating on ceramic surface increases the bond strength of resin cement to a ceramic. MATERIALS AND METHODS: In-Ceram Alumina blocks were made and the ceramic surface was treated: G1--sand-blasting with 110-microm aluminum oxide particles; G2--Rocatec System: tribochemical silica coating (Rocatec-Pre powder + Rocatec-Plus powder + Rocatec-Sil); G3--CoJet System: silica coating (CoJet-Sand) + ESPE-Sil. The ceramic blocks were cemented to composite blocks with Panavia F resin cement (under a load of 750 g/1 min). The cemented blocks were stored in distilled water at 37 degrees C for 7 days and sectioned along the x and y axes with a diamond disk. Samples with an adhesive area of ca 0.8 mm2 (n = 45) were obtained. The samples were attached to an adapted device for the microtensile test, which was performed in a universal testing machine (EMIC) at a crosshead speed of 1 mm/min. RESULTS: The obtained results were submitted to ANOVA and Tukey's test. Mean values of tensile strength (MPa) and standard deviation values were: (G1) 16.8+/-3.2; (G2) 30.6+/-4.5; (G3) 33.0+/-5.0. G2 and G3 presented greater tensile strength than G1. There was no significant difference between G2 and G3. All the failures took place at the ceramic/resin cement interface. CONCLUSION: The silica coating (Rocatec or CoJet systems) of the ceramic surface increased the bond strength between the Panavia F resin cement and alumina-based ceramic.