Effect of cleaning methods on the adhesive bonding at air-abraded zirconia/ resin cement interface

The aim of this study was to evaluate cleaning methods applied after different air-abrasion on the bond strength at the zirconia/resin cement interface. Zirconia discs (N=120) were air-abraded with 110 µm Al2O3 particles or 110 µm silica-modified Al2O3 particles and divided into five groups: 1) no cleaning; 2) dry air-stream; 3) wet air-stream followed by dry air-stream; 4) ultrasonic cleaning in distilled water and dry air-stream; 5) ultrasonic cleaning in isopropanol and dry air stream. For the shear bond strength test, the discs were treated with Clearfil SE Bond Primer/Clearfil Porcelain Bond Activator and bonded to the composite resin discs using Panavia F resin cement. The specimens were stored in distilled water and then tested in a mechanical testing machine. Data were analyzed by two-way ANOVA and Tukey`s HSD post hoc test (α=.05). Failure mode was determined under a stereomicroscope. Regardless of the particle used, there was no significant difference in the shear bond strength among the cleaning methods. The groups abraded with 110 µm Al2O3 particles exhibited significantly higher bond strength. The predominant failure mode was adhesive. The particle applied by air-abrasion influences the zirconia bond strength more than the cleaning methods.