Surface conditioning influences zirconia ceramic bonding

Air-abrasion seems to be mandatory for durable resin bonding to zirconia ceramic. Air-abrasion might compromise the ceramic strength by creating surface defects. Therefore, omitting air-abrasion or using reduced air-pressure seems desirable. We tested the null hypotheses that omitting air-abrasion or using reduced air-pressure does not affect zirconia ceramic bonding independent of using primers. Three mechanical surface conditions (polished, air-abraded at 0.05 or at 0.25 MPa) and 4 priming conditions were tested. After different surface conditioning, zirconia ceramic specimens were bonded, and tensile bond strengths were evaluated after water storage for 3 days or for 150 days with additional 37,500 thermal cyclings for artificial aging. Omitting air-abrasion resulted in debonding during artificial aging independent of using primers. The combination of air-abrasion and priming improved long-term resin bonding to zirconia ceramic significantly. With low-pressure air-abrasion, surface roughness was reduced without affecting long-term bond strength, provided that adequate adhesive primers were applied.