倾斜基牙固定修复前后牙周组织受力的实验研究

Experimental Study on Stress Distribution in Periodontal Tissue of Titled Abutment before and after Fixed Restoration

目的:研究倾斜基牙固定修复前后牙周组织受力情况,为临床固定义齿设计提供理论依据。方法:以下颌第2双尖牙和第2磨牙为基牙制作环氧树脂模型,其中第2双尖牙近中倾斜5°,第2磨牙近中倾斜30°,修复前第2磨牙骀面中央窝垂直加载225N,修复后第2磨牙体桥体(牙合)面中央窝各垂直加载225N。应用贴片云纹干涉法分别测试其牙周组织修复前后受力情况。结果:第2磨牙近中牙槽嵴顶受力较大,远中牙槽嵴顶受力较小,修复后其应力分布趋于均匀。结论:倾斜牙齿受垂直向载荷时近中牙槽嵴顶出现应力集中现象,作为基牙进行固定修复后其牙周组织受力比较均匀,有利于牙周组织健康。

Objective: To study the stress distribution in periodontal tissue of titled abutment before and after fixed restoration. Methods: The second bicuspid and the second molar in mandible were selected as abutments, and the epoxy-resin molds were then created, in which the masial-tilt degrees of second bicuspid and the second molar were about 5 and 30 respectively. Before fixed restoration, a vertical force of 225N was applied to the central fossa of the second molar; after fixed restoration, the same force was applied to the central fossae of the second molar and pontic. The stress distribution in periodontal tissue was measured with a sticking film moire interference method before and after fixed restoration. Results: Before restoration, the stress on the mesial crest of second molar was bigger than that on the distal one; after restoration, the stress distribution tended to evenly. Conclusion: When a vertical load acts on the tilted abutments, the stress concentrated on the mesial crest. After fixed restoration, the stress on the periodontal tissue of titled abutment was distributed evenly, which is beneficial to the health of periodontal tissue.