Bond Strength of Resin Cement to Surface Treated Zirconia

Session: Bond Strength to Ceramics; Adhesion Between Materials and RepairOral PresentationObjective: To evaluate porcelain surface treatments on the bond strength of a resin cement to zirconia Method: sintered zirconia (Cercon, DeguDent) surfaces were subjected to one of 7 surface treatments. Paste liner (Cercon Ceram Kiss, DeguDent) fired twice and then 110 µm aluminum oxide air particle abraded (APA) with and without 5% hydrofluoric acid etching -120s- (PL-APA-HF & PL-APA respectively) and one paste liner group with only hydrofluoric acid etching (PL-HF). For one group, porcelain powder (Cercon Ceram Glaze, DeguDent) was fired twice onto Zirconia and hydrofluoric acid etched in an ultrasonic bath -15 min- (PP-HF). All the previous groups received silanation (Clearfil Ceramic Primer, Kuraray) before bonding. Two groups were APA treated with and without silanation (APA-S, APA respectively). One group was an as-sintered control. Composite resin (Esthet X HD, Dentsply) buttons were bonded with Panavia F-2.0 (Kuraray Medical) resin cement to the Zirconia surfaces. The 7 groups were subjected to: water storage 24h (n=10) or 21d (n=10) with 6000 thermocycles (5-55OC). An universal testing machine measured the shear bond strength (SBS) and statistical analyses performed (p < .05). Result: All APA alone and control specimens debonded spontaneously after thermocycling. The remaining groups showed a decrease in mean SBS value of 11.7% to 58.5% except the PL-HF group, which showed a 12.7% increase. The SBS value of PL-HF group was the highest at both 24h and 21d; after thermocycling it had a significantly higher SBS than APA-S and PL-APA-HF groups which in turn, were higher than the PL-APA which was higher than PP-HF (p < .05). At 24 hours, no significant difference was noted amongst groups PL-HF, PP-HA and APA-S. Conclusion: paste liner ceramic provides a strong and durable bond and the use of silane coupling agent and the correct choice of ceramic surface treatment appears important for improving bond strength