Abstract: Objective To evaluate the effect of HF etching at room temperature on instant bond strength of YTZP to resin. Methods 48 YTZP plates were prepared and assigned into 6 groups according to different surface treatments, including alumina sandblasting, 90 min 40%HF etching, 15 min ultrasonic 40% HF etching, followed by application of any one of two universal adhesives. Bonded specimens were prepared and received shear bond strength testing after 24 h water storage. The surface roughness and microcosmic morphology of the YTZP surfaces receiving any one of the three different roughened methods were evaluated by an atomic force microscope (AFM) and a scanning electron microscope (SEM) respectively. Results HF etching created larger surface roughness and higher shear bond strength than alumina sandblasting. Conclusion Etching with 40% HF at room temperature can be an alternative to alumina sandblasting for resin bonding improvement of YTZP.

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