瓷层厚度比和瓷粉混合比对饰面瓷半透性的影响

Influence of porcelain layer thickness ratio and powder mixing ratio on the translucency

目的:研究瓷层厚度比和瓷粉混合比对饰面瓷半透性的影响,分析利用改变厚度比和混合比的方法调整饰面瓷半透性的可行性。方法:制作不同瓷层厚度比试件(釉瓷与体瓷试件11组,遮色瓷与体瓷试件4组)以及不同瓷粉混合比试件(釉瓷与透明瓷试件11组,釉瓷与体瓷试件11组,体瓷与遮色瓷试件5组),测量各组试件的透射率、颜色参数(黑背景),计算平均透射率差(ΔT)、色差(ΔE)。结果:透射率与釉瓷/体瓷厚度比(E/D)呈正比,与遮色瓷/体瓷厚度比(O/D)呈反比,E/D比例变化时T与L*、a*、b*之间为对数曲线关系。釉瓷中加入不超过50%的透明瓷可以增加半透性并且无明显色差;体瓷中加入不超过30%的釉瓷时透射率有限度的增加。结论:分层试件的透射率与2种组份的透射系数及各自的厚度有关,并与厚度呈指数关系;通过控制瓷层的厚度可以调整饰面瓷局部的半透性;瓷粉混合可以有效的增加半透性且颜色基本不变,但在降低半透性的同时会产生较大的色差。

Objective：To study the influence of porcelain layer thickness ratio and mixing ratio on the translucency of veneering porcelain. Methods： 42 groups of specimens with different porcelain thickness ratio and mixing ratio were made by Vita VMK 95 dentin porcelain, enamel porcelain and transparent porcelain. The transmittance （T） and color parameters on black backing were measured by the spectrocolorimeter. The average transmittance difference （AT） and color difference （AE） were investigated. Results： The transmittance increased with the increase of the enamel/dentin porcelain thickness ratio （ E/D ） and decreased with the increase of the opaque/dentin porcelain thickness ratio （O/D）. The logarithmic relationship was found between T and L^＊ , a^＊ , b^＊ of E/D group. Adding less than 50% transparence porcelain into enamel porcelain could increase translucency without prominent color difference. Adding less than 30% enamel porcelain into dentin porcelain had the same effects. Conclusion： The transmittance of layered specimen is connected with the transmittance coefficient and thickness of each layer and have exponential relationship with the transmittance coefficient. The translucency of veneering porcelain could be changed by adjusting the layer thickness. Porcelain mixing ratio can increase the translucency without prominent color change. Meanwhile it can decrease the translucency with a great color difference.