Effect of ceramic surface treatment on the shear bond strengths of two resin luting agents to all-ceramic materials.

The purpose of this study was to evaluate the bond strengths of some resin luting cements of two different all ceramic materials (In-Ceram, IPS-Empress). Composite cylinders 3.2 x 2 mm were prepared on the ceramic surfaces for a shear test. Four ceramic surface treatments were performed. (i). As received, (ii). grinding with diamond bur, (iii). sandblasting with 50 microm alumina grit and (iv). HF acid treatment and sandblasting with 50 microm alumina grit. Ceramic specimens were treated with one of the four methods and then cemented together with each of the two luting agents. The tested luting cements were Panavia F and Clearfil Se Bond (CSeB). The CSeB demonstrated the highest bond strength (59.95 MPa) regardless of the ceramic blocks. The average of load to fracture the In-Ceram blocks luted with Panavia F cement was 25.89 MPa. The mean shear bond strength of IPS Empress blocks luted with Panavia F cement was 10.31 MPa. Grinding the surface with a diamond bur for In-Ceram blocks luted with Panavia-F was 30.93 MPa and with CSeB was 77.04 MPa. For IPS-Empress blocks these values decreased to 12.39 MPa for Panavia-F and 30.84 MPa for CSeB. Acid etching of the surfaces with HF acid demonstrated a weak tendency to improve bond strength (In-Ceram-->Panavia-F= 14.59 MPa and CSeB=59.32 Mpa; IPS-Empress--> Panavia-F=5.85 MPa and CSeB= 23.33 MPa).