Microtensile bond strength of a resin cement to glass infiltrated zirconia-reinforced ceramic: the effect of surface conditioning.

OBJECTIVES This study evaluated the effect of three surface conditioning methods on the microtensile bond strength of resin cement to a glass-infiltrated zirconia-reinforced alumina-based core ceramic. METHODS Thirty blocks (5 x 5 x 4 mm) of In-Ceram Zirconia ceramics (In-Ceram Zirconia-INC-ZR, VITA) were fabricated according to the manufacturer's instructions and duplicated in resin composite. The specimens were polished and assigned to one of the following three treatment conditions (n=10): (1) Airborne particle abrasion with 110 microm Al(2)O(3) particles + silanization, (2) Silica coating with 110 microm SiO(x) particles (Rocatec Pre and Plus, 3M ESPE) + silanization, (3) Silica coating with 30 microm SiO(x) particles (CoJet, 3M ESPE) + silanization. The ceramic-composite blocks were cemented with the resin cement (Panavia F) and stored at 37 degrees C in distilled water for 7 days prior to bond tests. The blocks were cut under coolant water to produce bar specimens with a bonding area of approximately 0.6mm(2). The bond strength tests were performed in a universal testing machine (cross-head speed: 1mm/min). The mean bond strengths of the specimens of each block were statistically analyzed using ANOVA and Tukey's test (alpha<or=0.05). RESULTS Silica coating with silanization either using 110 microm SiO(x) or 30 microm SiO(x) particles increased the bond strength of the resin cement (24.6+/-2.7 MPa and 26.7+/-2.4 MPa, respectively) to the zirconia-based ceramic significantly compared to that of airborne particle abrasion with 110-microm Al(2)O(3) (20.5+/-3.8 MPa) (ANOVA, P<0.05). SIGNIFICANCE Conditioning the INC-ZR ceramic surfaces with silica coating and silanization using either chairside or laboratory devices provided higher bond strengths of the resin cement than with airborne particle abrasion using 110 microm Al(2)O(3).