牙釉质与牙本质的透光率分析

目的：分析牙釉质及牙本质透光率与厚度和年龄的关系，为全瓷修复体更好模拟天然牙透光率提供实验基础。方法：利用爱色丽COlOri7分光光度仪分别对360例不同厚度（厚度为0．9mm、0．6mm、0．3ram）不同年龄（年龄范围13～71岁）的牙釉质、牙本质磨片进行透光率（T）的测量，采用SPSSl7．0软件对结果进行分析。结果：不同厚度的牙釉质及牙本质的透光率均存在显著差异，随厚度的减小而增大（P〈O．05）。牙釉质的透光率与年龄没有相关性，牙本质的透光率与年龄呈负相关（r=-0．401～-0．437）。相同厚度的牙釉质透光率均大于牙本质的透光率（P〈0．05）。结论：天然牙釉质与牙本质的透光率存在显著差异，并随厚度的变化而发生改变。牙本质的透光率随年龄增长而降低。因此，在全瓷修复时需选择不同透光率的底层瓷和饰瓷，并考虑其厚度比例以及不同年龄牙本质的透光率特性。

Transmittance Analyze of Enamel and Dentin.

Objective： To analyze the relationships between age, thickness and the transmittance of enamel and dentin, so as to lay a foundation for all ceramic restoration simulating the transmittance of natural teeth. Methods： X--rite color i7 Spectrophotometer was used to examine the transmittance of enamel and dentin specimens in differ- ent thickness （0.9mm, 0.6mm and 0.3mm ） and different ages（from 13 to 71 years） , A total of 360 specimens were measured. The results were analyzed with SPSS17.0 software. Results： There were significant differences on the transmittance of enamel and dentin slices with different thickness. The transmittance increased with the decrease of the thickness （P~0.05）. The transmittance of enamel had no correlation with age, while negative correlation was found between the transmittance of dentin and age（r= --0. 401~--0. 437）. The absolute transmittances of en- amel were greater than those of dentin at the same thickness （P%O. 05）. Conclusion： There was significant differ- ence on transmittance between enamel and dentin,and the difference changed with the variation of their thickness. The transmittance of dentin decreased as the age increased. So dental professionals need to choose a specific trans- mittance of core porcelain and veneer porcelain, and more attention should be paid to the thickness ratio in all ceram- ic restorations and the transmittance of dentin in different ages.