[Effect of surface hot-etching treatment on zirconia/resin bonding strength].

OBJECTIVE: To evaluate the effect of hot-etching pretreatment of surface of zirconia on the shear bond strength of interface between zirconia and the two different resin cements. METHODS: Smooth enamel surfaces of fresh extracted human teeth and zirconia discs were prepared, and the surface of zirconia discs were treated with the following different methods: no treatment, airborne particle abrasion with 50 mum Al2O3 particles, hot-etching treatment for 60 min. The surface morphology was observed with scanning electron microscope (SEM). Two commercial resin bond systems (Super Bond C&B and Panavia F2.0) were used to cement the zirconia discs to enamel surfaces according to the instruction. Shear bond test was conducted with universal testing machine at a crosshead speed of 1 mm/min. Single-factor ANOVA (analysis of variance) statistical analysis was performed to compare the differences of shear bond strengths between the groups (alpha=0.01). RESULTS: The shear bond strengths of Super Bond group were (23.37+/-3.94) MPa, (25.95+/-3.05) MPa and (34.52+/-1.8) MPa respectively for no treatment, airborne particle abrasion, and hot-etching treatments. The shear bond strengths of Panavia group were (12.91+/-3.33) MPa, (14.00+/-3.28) MPa, and (18.47+/-4.16) MPa respectively for no treatment, airborne particle abrasion, and hot-etching treatments. The shear bond strengths were increased by hot-etching treatment compared with no treatment and airborne particle abrasion treatment (P<0.01). CONCLUSION: The result indicated that the hot-etching technique could improve the shear bond strength between zirconia and resin cements.