The Effect of Surface Modification on the Microtensile Bond Strength of Zirconia Ceramics

Objective. To determine the long-term microtensile bond strength of zirconia, which has been silica-coated using a novel technique, to dual-cured resin cement. Background. Earlier research has shown that one of the major clinical problems with the use of indirectly placed zirconia restorations is the difficulty in achieving adequate bonding with the underlying substrate (i.e., tooth structure, implant abutment). To date, different protocols for cementation of zirconia have been developed, but the long-term effectiveness of these methods is unknown. Materials. A novel molecular vapor deposition technique has been developed to deposit a silica layer on zirconia. Two porcelain and ten zirconia (ZrO2) blocks were manufactured. The blocks were air abraded and separated into six groups: 1) porcelain – HF etched and silanized, 2) ZrO2 – tribochemical coated and silanized, 3) ZrO2 – treated with primer, 4) ZrO2 – treated with novel silica layer of 3.2-nm and silanized, 5) ZrO2 – treated with novel silica layer of 5.8-nm and silanized, and 6) ZrO2 – treated with novel silica layer of 30.4-nm and silanized. All blocks were bonded to composite blocks using dual-cure resin cement and cut into microtensile bars. Microtensile bond strength was measured using a universal testing machine for zero, one, and three months. Results and Conclusion. Will be presented at the HPD Research Day. Grants. This study was funded by a grant from the Health Professional Division.