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

应力分析是分析义齿变形和观察义齿断裂的方法之一，松尾介绍了在动态载荷条件下观察义齿试件的模态分析方法。通过模态分析，可以很好地定位应力集中点。我们引进了Ometron公司的非接触式红外应力分析仪SPATE 9000来测量金属试件、主要连接器和人体干燥下颌骨中的应力。Ometron设备的引入使得获得这些材料中的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，都观察到了从固定部分扩展的半圆形应力模式，这是一种在一端紧固样品中常见的模式。我们通过对人体干燥的头骨进行动态冲击并监测传播的冲击波的衰减来发现冲击波的传播路径。这些实验使我们有可能进一步了解这些头骨的反应机制。在上颌方向施加到下颌骨的力以一种在头骨结构中传播的方式在头骨上传播。另一方面，在下颌角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.