象牙質に関する色彩学的研究

― 含有金属元素による影響について ―

抄録

The color of natural teeth is semi-translucent enamel with a high transparency and chromatic dentin. The purpose of this study is to analyze the optical properties of human dentin and the relationship between the color spectrum and metal elements in the dentin. 120 specimens of human dentin sample with a thickness of 0.5 mm (±0.05 mm) were made. Reflectance values were measured by a spectrophotometer CAS-ID 1 with a white backing and a black backing. Scattering coefficients, absorption coefficients, R-infinity, CIELAB color coordinates L*, a*, b* and Color depth SQ were calculated based on each reflectance value. Metal elements in dentin were analyzed by electron probe X-ray microanalyzer (EPMA) and Fe, Zn, Mg, Cu and Ni in 10 areas of each dentin specimen were quantified and averaged. Mean L* value of dentin was 11.6±4.7, 29.6±27.3 for SQ, 70.1±11.3 for a*, 11.6±4.3 for C* and -0.1±2.1 for b*. Ni indicated a positive correlation with a* and b* value, Zn showed a positive correlation with L* value. On the other hand, Mg indicated a negative correlation with a* value. It was concluded that those three metal elements could create the dentin color defined in this study.