Effects of surface treatments on shear bond strengths between a resin cement and an alumina core

Statement of problem. Although bonding to all-ceramic restorations is desir able, there is little information on the use of resin cements containing a phosphate monomer, and the importance of different surface treatments on th eir adhesion to high-strength core materials. Purpose. This study attempted to determine the shear bond strength values b etween Panavia 21 resin cement (Kuraray) and an alumina core material (In-C eram) after 3 surface treatments and the application of a silane coupling a gent. Material and methods. Forty-five In-Ceram cylindrical rods were fabricated and assigned to 3 groups. Group I specimens were treated with a 9.5% hydrof luoric (HF) acid, group II with a 5% HF acid, and group III were sandblaste d. All specimens were coated with a silane coupling agent (Cavex Clearfil P hotobond and Activator) before cementation with Panavia 21 to sandblasted n ickel-chromium rods. As a control, group TV consisted of 8 porcelain (Vitad ur Alpha) rods treated with a 5% HF acid and silane. All specimens were sub jected to a load of 1.2 kg during cementation, then stored under water for 36 hours. A jig mounted on a Hounsfield Universal Testing machine was used at a crosshead speed of 0.5 mm/min to test the shear bond strengths. Results. The results were 14.65 +/- 4.64 MPa for group I, 18.03 +/- 6.13 MP a for group II, and 22.35 +/- 5.98 MPa for group III In-Ceram specimens; an d 18.05 +/- 8.46 MPa for control (group IV). Conclusion. The use of Panavia 21 resin cement and a silane coupling agent can achieve a successful bond between either sandblasted or 5% HF acid-etch ed In-Ceram core material.