Effect of the Surface Treatment Method Using Airborne-Particle Abrasion and Hydrofluoric Acid on the Shear Bond Strength of Resin Cement to Zirconia

The purpose of this study was to evaluate the shear bond strength (SBS) of two different resin cements (Panavia F 2.0 (Kuraray Medical Inc, Okayama, Japan) and Variolink N (Ivoclar Vivadent AG, Schaan, Liechtenstein)) to 112 zirconia specimens with airborne-particle abrasion and 20%, 30%, or 40% hydrofluoric acid (HF) for 1 or 2 h. A total of eight specimens were used to observe the phase transformation after surface treatments. Six specimens were treated only with HF etching and the average surface roughness (Ra) was analyzed. A one-way ANOVA test was applied for SBS and the effect of HF concentration on Ra. An independent t-test was performed for the comparison of Panavia F 2.0 and Variolink N, and the influence of the HF application time on Ra. A higher HF solution increased SBS and Ra. HF etching produced a lower rate of monoclinic phase transformation. Panavia F 2.0 showed a higher SBS than Variolink N.