Effect of Hydrofluoric Acid Etching Surface Treatment of Zirconia on the Shear Bond Strength with Resin Cement

You-Jung  Kang1   

1Department of Prosthodontics, Oral Science Research Center, College of Dentistry, Yonsei University, Seoul, 03722, Korea


Objectives: The purpose of this study was to investigate the effect of hydrofluoric (HF) acid surface treatment of zirconia on its shear bond strength (SBS) with resin cement. Methods: Based on the surface treatment method, 52 zirconia specimens were divided into four groups which were airborne-particle abrasion treatment group (APA), 9% HF acid etching group (HFE), the group with 9% HF acid gel with hot etching performed once (HFHE1), and the group with 9% HF acid gel with hot etching performed twice (HFHE2). After the primer was applied to the specimens of each group, the resin cement adhered to the zirconia. Thereafter, the SBS was measured using a universal testing machine. The surface of the representative specimens of each group was observed using a scanning electron microscope (SEM). SBS was performed, followed by statistical analysis of the result using One-way ANOVA (α=0.05). Results: The HFHE1 group showed a significant difference in SBS compared with the other groups. The SEM analysis found a change in the surface morphology for all surface-treated samples. Conclusions: Within the limits of this study, surface treatment with low-concentration of HF acid hot etching formed a uniform microporous structure on the zirconia surface and exhibited high SBS.

Figures & Tables

Figure 1. Scanning electron microscopic images of surface-treated zirconia (magnification ×60,000) (A) initial zirconia; (B) airborne-particle abrasion with 50 μm Al2O3 (group APA); (C) 9% hydrofluoric acid etching (group HFE); (D) 9% Hydrofluoric acid gel with hot etching performed once (group HFHE1); (E) 9% Hydrofluoric acid gel with hot etching performed twice (group HFHE2)