The clinical application of dental zirconia has increased. Adhesion on dental zirconia is important in the usage such as the hybrid type abutment to adhesive to titanium cylinder. For the analysis of surface roughness to influence on various material properties, conventionally the value of depth directions such as the Ra has been widely used. However, the periodicity (wavelength) of roughness in the horizontal direction may also influence adhesive property. The Fourier transform that can perform frequency analysis was effective for the examination of a complicated roughness curve, composed of multiple waves. Shear bond strength test was conducted in the specimen with four kinds of surface roughness (control, low, high, low and high frequency element). Shear bond strength became strong (14MPa) in the specimen with a short wavelength (high frequency element), and weak (4~5MPa) for a long wavelength (low frequency element). The surface sensitive properties depend not only on the Ra but also on the wavelength. In this study the Fourier transform was effective for various characteristic examinations of surface properties such as the adhesive property and shear bond strength could be better understood by wavelength dependence.
Key words: dental zirconia, surface roughness, Fourier transform, shear bond strength, resin cement