Johnston William M
Division of General Dentistry and Materials Science, College of Dentistry, The Ohio State University, Columbus, OH, USA.
J Esthet Restor Dent. 2014 Jul-Aug;26(4):217-23. doi: 10.1111/jerd.12112. Epub 2014 Jun 29.
There are several ways to measure the translucency of materials, as various basic colorimetric concepts have been used to describe the translucency of natural and esthetic dental materials. There are currently no guidelines regarding which method to use to describe the translucency of these materials.
Two initial purposes of this study are to review the initial developments of the major translucency measurement methods first in the color science literature and then in the dentistry literature, and to review in the dentistry literature the recent uses of the various translucency measurement methods in light of the objectives of the presented research.
A major color science textbook was reviewed to obtain the background information and selected references regarding the original methods of opacity measurement and the original references regarding the development and use of a translucency parameter were also reviewed. Then the recent dentistry literature was reviewed to describe the uses of the various methods of opacity or translucency determinations for various dental materials.
The three major methods of translucency measurement were found to be contrast ratio, transmittance, and translucency parameter, with the contrast ratio and transmittance methods each having the possibility of being either luminous or spectral. Translucency measurements were mainly used to describe dental resin composites and dental ceramic materials, but prosthetic elastomers, fiber posts, orthodontic brackets, natural tooth dentine and enamel, and combinations of materials were also studied using at least one of these methods.
The more-developed use of models that relate the thickness of the translucent materials to the translucency measurement of interest is encouraged. Also, care must be taken when comparing previously generated translucency measurements with any newly generated data because technical details of the thickness and the backings used in previous research must be matched or adjustments must be made to make any newly generated data comparable with published values.
The method of specifying the translucency of esthetic dental materials may be based on clinical appearance requirements of the patient, on technical demands of optimizing the setting of underlying material, or on both. The method or methods used to describe translucency may provide clinically relevant information in order for the clinician to select the optimum material to satisfy these requirements.
有多种方法可用于测量材料的半透明度，因为各种基本的比色概念已被用于描述天然和美学牙科材料的半透明度。目前尚无关于使用哪种方法来描述这些材料半透明度的指南。
本研究的两个初始目的是首先回顾颜色科学文献中主要半透明度测量方法的初步发展，然后回顾牙科文献中的相关内容，并根据所呈现研究的目标，回顾牙科文献中各种半透明度测量方法的近期应用。
查阅了一本主要的颜色科学教科书，以获取关于不透明度测量原始方法的背景信息和选定参考文献，还查阅了关于半透明度参数发展与应用的原始参考文献。然后回顾近期的牙科文献，以描述各种用于不同牙科材料的不透明度或半透明度测定方法的应用情况。
发现半透明度测量的三种主要方法为对比度、透光率和半透明度参数，对比度和透光率方法都有可能是发光的或光谱的。半透明度测量主要用于描述牙科树脂复合材料和牙科陶瓷材料，但也使用这些方法中的至少一种研究了修复性弹性体、纤维桩、正畸托槽、天然牙本质和牙釉质以及材料组合。
鼓励更多地使用将半透明材料的厚度与感兴趣的半透明度测量相关联的模型。此外，在将先前生成的半透明度测量值与任何新生成的数据进行比较时必须谨慎，因为先前研究中使用的厚度和背衬的技术细节必须匹配，或者必须进行调整以使任何新生成的数据与已发表的值具有可比性。
指定美学牙科材料半透明度的方法可能基于患者的临床外观要求、优化底层材料设置的技术需求或两者兼顾。用于描述半透明度的一种或多种方法可能提供临床相关信息，以便临床医生选择最佳材料来满足这些要求。
