Rudolph Heike, Graf Michael R S, Kuhn Katharina, Rupf-Köhler Stephanie, Eirich Alfred, Edelmann Cornelia, Quaas Sebastian, Luthardt Ralph G
Department of Prosthetic Dentistry, Center of Dentistry, Ulm University.
Dent Mater J. 2015;34(5):572-84. doi: 10.4012/dmj.2014-197. Epub 2015 May 1.
Among other factors, the precision of dental impressions is an important and determining factor for the fit of dental restorations. The aim of this study was to examine the three-dimensional (3D) precision of gypsum dies made using a range of impression techniques and materials. Ten impressions of a steel canine were fabricated for each of the 24 material-method-combinations and poured with type 4 die stone. The dies were optically digitized, aligned to the CAD model of the steel canine, and 3D differences were calculated. The results were statistically analyzed using one-way analysis of variance. Depending on material and impression technique, the mean values had a range between +10.9/-10.0 µm (SD 2.8/2.3) and +16.5/-23.5 µm (SD 11.8/18.8). Qualitative analysis using colorcoded graphs showed a characteristic location of deviations for different impression techniques. Three-dimensional analysis provided a comprehensive picture of the achievable precision. Processing aspects and impression technique were of significant influence.
在诸多因素中，牙印模的精度是影响牙修复体适配性的一个重要决定性因素。本研究的目的是检验使用一系列印模技术和材料制作的石膏模型的三维（3D）精度。针对24种材料 - 方法组合中的每一种，制作了10个钢制犬齿的印模，并用4型模型石膏灌注。将模型进行光学数字化处理，与钢制犬齿的CAD模型对齐，并计算三维差异。使用单向方差分析对结果进行统计分析。根据材料和印模技术的不同，平均值在 +10.9/-10.0 µm（标准差2.8/2.3）至 +16.5/-23.5 µm（标准差11.8/18.8）之间。使用彩色编码图进行的定性分析显示了不同印模技术偏差的特征位置。三维分析提供了可实现精度的全面情况。加工方面和印模技术有重大影响。
