Abstract: Light projecting to the surfaces of natural teeth results in different reflection or refraction index, which is caused by the different sizes of microstructures on the surfaces of teeth and may lead to the visual changes of teeth color. This article chiefly introduces natural microtextures of teeth and basic knowledge of colorimetry, then summaries the theoretical or experimental studies on the relationship between surface roughness of a subject and its color appearance in physical fields. With regard to porcelain denture in dentistry, it has been
proved that surface microtextures of different sizes express different parameters of colorimetry, such as chroma, hue and value. The stability of denture color is also influenced. In addition, the polishing equipments used for dental restorations nowadays are developed day by day, so they can provide technical supports for making the shapes of denture surface microstructures. The purpose of this passage is to sum up the influences of surface microtextures on the color expression of porcelain dentures and to analyse the feasibility and significance of these relative studies.

Key words: natural teeth, color, microtexture