Influence of Surface Treatments on the Bond Strength of MDP Containing Resin Cements to Zirconia Ceramics

Objectives: (1) to evaluate the effect of silane and ceramic primers on the bond strength of resin to zirconia. (2) to compare these effects on polished and sandblasted zirconia surfaces.
Methods: Thirteen groups of sintered zirconia plates (n=12) were prepared with different surface treatment methods, either polished (P), or sandblasted (SB). Surface treated specimens were prepared by bonding cylinders of luting cements (φ=2,5mm, h=3mm). Shear bond strengths were measured with a universal testing machine. The following resin based luting materials and proposed primers were used in this study: Panavia F 2.0 cement (Kuraray), Clearfil Ceramic Primer (Kuraray), G-Cem LinkAce cement (GC), Ceramic Primer II. (GC) and Silane (Ultradent Products Inc.). A resin reinforced glassionomer cement, (F) Fuji Plus (GC) on polished zirconia surface served as control (Group C). Both resin cements were tested on polished and sandblasted surface without and with the application of ceramic primers or silane.
Results: The bond strength of G-CEM LinkAce was significantly higher than those of Panavia F 2.0 in each subset. Sandblasting increased significantly the adhesion of both examined luting materials. Both Clearfil Cemamic Primer and Ceramic Primer II. increased bond strength, but these effects were significantly lower compared to the effects of the physical adhesion improvement. Silane slightly decreased bond strength.
Conclusions: Sandblasting is an effective method to increase bond strength. The application of a primer containing both silane and MDP improve bond strength to zirconia. Application of a silane is not an effective method to increase bond strength.