Rupp Frank, Axmann Detlef, Jacobi Anne, Groten Martin, Geis-Gerstorfer Jürgen
Section of Medical Materials and Technology, Department of Prosthodontics and Medical Materials, University of Tuebingen, Osianderstr. 2-8, D-72076 Tuebingen, Germany.
Dent Mater. 2005 Feb;21(2):94-102. doi: 10.1016/j.dental.2004.02.006.
Clinically relevant accuracy of dental impressions depends on flowing and wetting properties of the applied impression materials. The major objective of this study was to develop an experimental set-up and an analysis strategy for wettability measurements of impression materials during their working time.
High-resolution drop shape analysis was used to study contact angles on thin unset films of two polyether and two vinyl polysiloxane (VPS) impression materials. Qualitative and quantitative analysis of the contact angle evolution in terms of initial values and the equilibrium state of hydrophilicity, as well as in terms of kinetics of hydrophilization were extended using a mathematical model approach.
Compared to VPS impression materials, polyethers show pronounced and constant initial hydrophilicity throughout prescribed working time. The kinetics of the VPS impression materials towards more hydrophilic equilibrium surface states is very fast compared to polyethers. This possibly balances the disadvantage of the initial VPS impression materials hydrophobicity. Generally, the experimental and analytical methods have proven to yield detailed insights into the wetting characteristics during setting.
Both, high initial and a fast kinetics towards increased hydrophilicity may improve flowing and wetting processes during impression taking. Therefore, time-resolved wettability studies should be regarded when developing advanced impression materials and defining working times. They may supplement rheological studies.
牙科印模在临床上的相关准确性取决于所应用印模材料的流动性和润湿性。本研究的主要目的是开发一种实验装置和一种分析策略，用于在印模材料的工作时间内测量其润湿性。
采用高分辨率液滴形状分析法研究两种聚醚和两种乙烯基聚硅氧烷（VPS）印模材料未固化薄膜上的接触角。使用数学模型方法，从初始值、亲水性平衡状态以及亲水化动力学方面，对接触角演变进行定性和定量分析。
与VPS印模材料相比，聚醚在规定的整个工作时间内表现出显著且恒定的初始亲水性。与聚醚相比，VPS印模材料向更亲水平衡表面状态转变的动力学非常快。这可能弥补了VPS印模材料初始疏水性的缺点。总体而言，实验和分析方法已证明能够深入了解凝固过程中的润湿特性。
高初始亲水性和向增加亲水性的快速动力学都可能改善取模过程中的流动和润湿过程。因此，在开发先进的印模材料和确定工作时间时，应考虑时间分辨润湿性研究。它们可以补充流变学研究。
