The Study Of Translucency Of Natural Human Tooth And Dental Ceramics

In addition to value, hue and chroma, there are many subtle secondary optical properties of natural human tooth, such as translucency, opacity, iridescence, surface gloss and fluorescence. Translucency has been viewed as the most importance of these secondary properties. In order to imitate natural tooth, dental ceramics should have similar translucency besides the color space. Translucency of prosthesis plays a very important role in the esthetics of prosthesis. Some researchers believed that translucency should be added into the three-dimension color system to form a new four-dimension system. So it is necessary for us to measure and analysis the translucency of natural tooth and relationship between translucency of tooth and dental ceramics. But comparing with the study of color, the research on the translucency seems really scarce. What's more, because the measuring methods and parameters are not unitive between different researchers, the results of different studies could not be compared. In this study, the translucencies of maxillary central incisors newly extracted and the optical properties of both enamel and dentin were measured by means of PR-650 spectra scan spectrocolorimeter. Meanwhile, the optical properties of dental ceramics were measured and compared with dental tissue. Blending of different ceramics and controlling the ceramics thickness were also studied to find out there possibilities to change the translucency, as well as the effect of manufacture technique on the translucency of dental ceramics. Last but not the least, the discrimination of translucency difference was studied while the clinical translucency tolerance established.The results showed that:1. The transmittance of maxillary central incisors which were newly extracted ranged from 0.1568% to 0.6058%. The translucency of incisors in nine regions was different in longitudinal (cervical, middle,...