Are Universal Adhesives Effective for Bonding to Zirconia in the Long Term?

Background: The bond capacity of universal adhesives should be comparable to a specific primer for zirconia. Thus, this study evaluated the bond strength to zirconia of four universal adhesives and a zirconia primer over long-term storage.

Materials And Methods: The surfaces of 75 samples of zirconia were sandblasted with 50 µm aluminum oxide particles and then divided into groups ( = 15): G1 - Single Bond Universal (SBU); G2 - All Bond Universal; G3 - Peak Universal Bond; G4 - Ambar Universal (AU), and G5 - Z-Prime Plus (ZP).