下颌磨牙及其桩核修复体力学特性光测分析

Optical analysis of mechanical characteristics of mandibular molar and its post-core prosthesis

目的研究磨牙大面积牙体缺损多根桩金属烤瓷全冠修复体对磨牙应力的影响。方法将离体下颌磨牙包埋于透明复合树脂模拟的牙周组织中,形成18mm×16mm×22mm的包埋块,利用数字化光学测试手段得到修复前、后在垂直载荷作用下的位移和应变,并进行力学分析。结果桩核修复体虽然充分利用残根的生理几何特征,但分散牙体传递的力却是一个渐进过程;在同级载荷作用下,桩核修复体的应变大于自然牙。结论桩核修复后的磨牙应避免使用过大咀嚼力;光测技术为口腔医学领域提供了一种有效的分析途径。

Objective To investigate the effects of stress of the multi-post-core poreelain-fused-metal prosthesis on a molar with large dental defects. Methods An extracted mandibular molar was embedded in transparent composite resin which simulated periodontal ligament. And the size of the embeded block is 18 mm × 16 mm × 22 mm. With the method of digital optical test, the data of displacement and strain were obtained under the vertical stress before and after the post-core restoration. The mechanical characteristics were also analyzed simultaneously and some conclusions were drawn in this paper. Results Though the post-core prosthesis can make full use of inherent geometry features of left root, it is a gradual process of dispersing the occlusion loads. Under the same level load, the strain of post-core prosthesis is higher than the strain of original molar. Conclusions The high occlusion loads should be avoided on the restored molar. In addition, it is proved that the digital optical method is another effective means in stomatology.