Effect of Silanization on the Long-term Resin Bond of a Modified Resin Cement to Sandblasted Procera AllCeram Intaglio Surface

A phosphate-modified resin cement (Panavia 21, Kuraray) has demonstrated a long-term durable resin bond to sandblasted aluminum-oxide ceramics. However, the influence of silanization and ceramic surface treatment on the long-term resin bond to commercial ceramic systems is unclear. Procera AllCeram (Nobel Biocare) densely-sintered aluminum-oxide ceramic copings offer a rough intaglio surface which is created during their unique fabrication process. Objectives: The purpose of this study was to evaluate the long-term bond strength of Panavia 21 to sandblasted Procera AllCeram intaglio surface with and without silanization. Bond strength to untreated, ultrasonically cleaned Procera surface was the control. Methods: Square samples of densely-sintered high purity alumina with Procera AllCeram intaglio surface were randomly divided into 4 groups (n=10). The sample surfaces were either sandblasted or ultrasonically cleaned. Half of the samples were pretreated with Clearfil New Bond/Porcelain Bond Activator (containing silane coupling agent). Composite resin cylinders were bonded with Panavia 21 TC to the ceramic samples. After storage in distilled water for 180 d and repeated thermocycling for 12,000 cycles, shear bond strengths were tested in an Instron universal testing machine. Data were analyzed using one-way ANOVA and Tukey’s multiple comparison (a=0.05). Failure modes were examined with a light microscope. Results: Without Silane treatment, mean bond strengths values were 4.33 ± 1.5 MPa after cleaning and 6.91 ± 2.5 MPa after sandblasting. For the groups with silane application, they were 12.07 ± 2.2 MPa after cleaning and 16.1 ± 2.4 MPa after sandblasting. Difference between groups was highly significant. Failure modes were 100 % adhesive at the ceramic surface. Conclusions: Sandblasting and silanization significantly increased long-term bond strengths of Panavia 21 TC to the Procera AllCeram intaglio surface. The significantly highest bond strength was achieved after sandblasting and application of a silane-coupling agent.