Lewinstein I
Department of Restorative Dentistry, Hebrew University- Hadassah School Dental Medicine, Jerusalem, Israel.
J Oral Rehabil. 1993 Jan;20(1):107-14. doi: 10.1111/j.1365-2842.1993.tb01520.x.
The purpose of this study was to analyze theoretically and experimentally the relations between the horizontal and the vertical changes of impressions taken with a mandibular stock tray. According to the theoretical analysis the ratio between the horizontal (delta X) and the vertical changes (delta Z) can be expressed as: [formula: see text] where mu is the Poisson's ratio and Lx and Lz are the horizontal and vertical dimensions of the die, respectively. With regard to the experimental findings the Poisson's ratio calculated by this expression was mu = 0.44 which fits the range of Poisson's ratio for rubber materials. In addition it was shown that the ratio between the vertical and horizontal strains is constant for a particular impression technique.
本研究的目的是从理论和实验两方面分析用下颌全口托盘制取的印模水平变化与垂直变化之间的关系。根据理论分析，水平变化（δX）与垂直变化（δZ）的比值可表示为：[公式：见原文]，其中μ为泊松比，Lx和Lz分别为模型的水平尺寸和垂直尺寸。关于实验结果，用该表达式计算出的泊松比为μ = 0.44，这与橡胶材料的泊松比范围相符。此外，研究表明，对于特定的印模技术，垂直应变与水平应变的比值是恒定的。
