Abstract: Objective To investigate the surface roughness and surface morphology of Y-TZP etched by HF acid at room temperature. Methods Y-TZP plates were prepared and subjected to different treatments, including no treatment as control, alumina sandblasting, 40% HF acid etching for 5, 10, 30, 60, 90 min, and 24 hours. The surface roughness and microcosmic morphology were evaluated by an atomic force microscope (AFM) and a scanning electron microscope (SEM) respectively. Results HF acid etching for 5 and 10 min created similar surface roughness as alumina sandblasting did, all higher than the control. HF acid etching for 30, 60, 90 min, and 24 hours created much higher surface roughness, and presented sponge-like roughened texture. Conclusion 40% HF can etch Y-TZP and create a roughened texture at room temperature.

Key words: zirconia, acid etching, bonding, surface roughness, HF acid