Yamamura M
Kanagawa Shigaku. 1989 Dec;24(3):450-62.
This study was conducted to perform mechanical evaluations of crown restorations by Laser Holographic Interferometry (LHI). However, in an application of LHI, the Fujinon Holox FHLX-II system (He-Ne Gas Laser GLG-5700, NEC Co.) to this experiment, it was mandatory to do some modifications for loading and measuring evaluations, thereby a whole sequence of this system could be successfully carried out. The experiments were conducted in the following manner: Ten pieces of full cast crowns were constructed by a conventional procedure with 12% Au-Ag-Pd alloy and each test-piece was cemented alternately by zinc phosphate cement on a master die (stainless steel) with a chamfer margin. Successive vertical loadings (0kg-30kg) were applied for each test-piece and holograms were taken for crown restorations under loadings of both 15Kg & 30Kg with an accuracy of 0.3 micron. Three-dimensional measurements of nine points on surface of a testpiece were obtained through interference fringes, which were converted into mathematical values and statistical comparisons were performed for mean values under loadings of both 15 Kg & 30 Kg. The following results were obtained from this experiment. 1. It was successfully performed that an application of Laser Holographic Interferometry (a real time) became an efficient method with some modifications for mechanical evaluations of crown restorations. 2. Besides modification for rigid fixation of a test-piece, it made possible to conduct the loading experiment under Kg unit, which was impossible in previous studies. 3. Three-dimensional measurements were also made possible by an application of mathematical calculations, thereby a total system of experimental procedures was established. 4. Reference points were marked on surface of a test-piece, and this made possible to compare with the displacement values of other test-pieces. 5. Displacements of experimental crowns with both 15 Kg & 30 Kg under areas of loadings showed remarkably and they were gradually spread out toward the outer directions of restorations with slight displacements. From this experiment, it was proved that a cemented crown showed a certain deformational behavior under loadings. Therefore, this system contributes to become an efficient method evaluating mechanical features of crown restorations for further studies.
本研究旨在通过激光全息干涉测量法（LHI）对全冠修复体进行力学评估。然而，在将富士能Holox FHLX-II系统（氦氖气体激光器GLG-5700，日本电气公司）应用于本实验时，必须对加载和测量评估进行一些修改，从而能够成功执行该系统的整个流程。实验按以下方式进行：用12%的金-银-钯合金通过传统工艺制作10个全冠铸件，每个试件用磷酸锌粘固剂交替粘固在带倒角边缘的主模型（不锈钢）上。对每个试件施加连续的垂直载荷（0kg - 30kg），并在15Kg和30Kg载荷下对全冠修复体拍摄全息图，精度为0.3微米。通过干涉条纹获得试件表面九个点的三维测量结果，将其转换为数学值，并对15 Kg和30 Kg载荷下的平均值进行统计比较。从该实验中获得了以下结果。1. 通过对激光全息干涉测量法（实时）进行一些修改，成功地使其成为一种评估全冠修复体力学性能的有效方法。2. 除了对试件进行刚性固定的修改外，还能够在千克单位下进行加载实验，这在以前的研究中是不可能的。3. 通过应用数学计算也能够进行三维测量，从而建立了一个完整的实验程序系统。4. 在试件表面标记了参考点，这使得能够与其他试件的位移值进行比较。5. 在15 Kg和30 Kg载荷下，实验全冠在加载区域的位移显著，并且它们逐渐向外修复体方向扩展，位移较小。从这个实验证明，粘固全冠在加载下表现出一定的变形行为。因此，该系统有助于成为一种评估全冠修复体力学特征的有效方法，以供进一步研究。
