A Basic Study on Dental Prosthetic Field with Noncontact Dynamic Stress Analysis System

应力分析是义齿变形分析和义齿断裂观察的常用方法之一。Matsuo介绍了用模态分析方法来观察动态载荷条件下的义齿样品。模态分析可以很好地确定应力集中点的位置。但发现它不适合很好地测量应力浓度。我们引入了Ometron的非接触式红外应力分析仪，用于测量金属测试和平，主要连接器和人类干燥下颌的应力。Ometron设备的引入使得在这些材料中获得动态应力分布模式成为可能。结果表明，在所有主要连接器样品中，观察到从固定部分扩展的半圆形应力模式，这是在一端紧固样品中常见的模式。我们通过对干燥的人类头骨进行动态冲击，并监测传播冲击波的衰减，找到了冲击波的传播路径。这些实验使我们有可能进一步了解这些头骨的反应机制。在上颌骨方向作用于下颚的力以某种方式通过颅骨结构扩散到整个颅骨。另一方面，在下颚的角落或颈部观察到应力模式。

Stress analysis is one of methods which has been used to analyze denture deformation and to observe denture fracture.Matsuo introduced the modal analysis method to observe a denture sample under dynamic load conditions. Modal analysis has made it possible to locate the points of stress concentraction fairly well. But it was found to be unfit to measure stress concentractoin well.We introduced Ometron's non-contact infrared stress analyzer Spate 9000 to measure stress in metal test peaces, major conectors, and a human dry lower jaw.The introduction of the Ometron's equipment has made it possible to obtain dynamic stress distribution patterns in these materials.The results showed that in all of major connector samples, a semi circular stress pattern expanding from the fixed portion, a pattern commonly observed in one-end fastened samples, was observed.We found the propagation routes of shock waves by giving dynamic impact to the dried skulls of humans and monitoring the attenuation of the propagating impact waves. These experiments has made it possible for us to further understand the mechanisms of these skulls' response. A force applied to the lower jaws in maxilla direction propagates through the skull structure in a way to scater across the skull. On the other hand, stress patterns was observed in the corner or the neck of the lower jaw.