Influence of Surface Conditions and Silane Agent on the Bond of Resin to IPS Empress 2 Ceramic

Purpose: The aim of this study was to evaluate the effect of different ceramic surface treatments on the tensile bond strength between IPS Empress 2 ceramic framework and Rely X adhesive resin cement, with or without the application of a silane coupling agent. Materials and Methods: One hundred twenty disks were made, embedded in resin, and randomly divided into six groups: group 1 = sandblasting (100 µm), no silanation; group 2 = sandblasting (100 µm), silane treatment; group 3 = sandblasting (50 µm), no silanation; group 4 = sandblasting (50 µm), silane treatment; group 5 = hydrofluoric acid etching, no silanation; and group 6 = hydrofluoric acid etching, silane treatment. The disks were bonded into pairs with adhesive resin cement. All samples were stored in distilled water at 37°C for 24 hours and then thermocycled. The samples were submitted to tensile testing. Results: The use of silane improved the bond strength in relation to the groups in which silane was not applied (P .05). The most effective surface treatment was etching with 10% hydrofluoric acid, both with (25.6 MPa) and without silane application (16.4 MPa); these values showed a statistically significant difference compared to sandblasting with 50- and 100-µm Al2O3. Sandblasting with 50-µm Al2O3, with (11.8 MPa) and without silane (5.4 MPa), demonstrated significantly higher tensile bond strength than sandblasting with 100-µm Al2O3, with (8.3 MPa) and without silane (3.8 MPa). Conclusion: Combined application of 10% hydrofluoric acid and silane enhanced the bond strength between the IPS Empress 2 ceramic framework and resin agent.