不同边缘设计的髓腔固位冠修复下颌前磨牙的应力分析

发布时间：2018-09-18 11:32

【摘要】：目的采用三维有限元方法,研究髓腔固位冠修复下颌第一前磨牙牙体缺损时,不同边缘设计对牙体组织和修复体所受应力的影响。方法建立4种边缘设计形式(平面对接式边缘、直角肩台、135°肩台、凹面形边缘)的下颌第一前磨牙髓腔固位冠修复模型。加载点为牙齿长轴与牙合面交点,方向为与牙齿长轴平行、与牙齿长轴成45°,力量大小为100N。计算分析4种边缘设计形式的髓腔固位冠修复后牙体组织和修复体颈部的应力分布情况及最大Von Mises应力值。结果(1)沿牙齿长轴方向加载,应力集中出现在修复体和牙齿颈部的舌侧边缘,平面对接式边缘和直角肩台的颈部应力分布要比135°肩台和凹面形边缘的应力分布均匀;(2)施加与牙齿长轴成45°的载荷,应力主要集中在颊侧边缘,平面对接式边缘较其他3种边缘形式的应力分布要更为均匀,牙齿和修复体的最大应力值均明显高于与牙齿长轴平行加载情况下的应力值;(3)无论施加与牙齿长轴平行还是与牙齿长轴成45°的载荷,平面对接式边缘的牙齿和修复体颈部的应力值均最小,修复体颈部的应力值要大于牙齿颈部的应力值;(4)平面对接式边缘牙釉质的应力水平高于牙本质。结论从基牙和修复体受力情况来讲,髓腔固位冠修复采用平面对接式边缘和直角肩台优于其他边缘设计。
[Abstract]:Objective to study the effect of different edge designs on the stress of mandibular first premolars by using three dimensional finite element method (FEM). Methods four kinds of edge design models were established for the restoration of mandibular first premolar pulp cavity retention crown with four types of edge design (plane docking edge, right angle shoulder abutment 135 掳shoulder abutment, concave edge). The loading point is the point at which the tooth axis intersects with the occlusal surface, the direction is parallel to the tooth axis, 45 掳with the tooth axis, and the force is 100 N. The stress distribution and maximum Von Mises stress of the dental tissue and the neck of the restoration were calculated and analyzed after the restoration of four kinds of marginal design forms of the pulp cavity retainer crown. Results (1) when loaded along the long axis of the tooth, the stress concentrated on the lingual edge of the prosthesis and the neck of the tooth. The stress distribution in the neck of the plane-butt edge and the right-angle shoulder abutment is more uniform than that of the 135 掳shoulder plate and concave edge. (2) the stress is mainly concentrated on the buccal edge under a load of 45 掳on the long axis of the tooth. The stress distribution of the plane docking edge is more uniform than that of the other three edge forms. The maximum stress values of teeth and prostheses are significantly higher than those of teeth under loading parallel to the long axis of the tooth; (3) whether the load is applied at 45 掳parallel to the long axis of the tooth or to the long axis of the tooth, The stress value of the tooth and the neck of the prosthesis is the smallest, and the stress of the restoration neck is larger than that of the tooth neck. (4) the stress level of the enamel of the plane-butt edge is higher than that of the dentin. Conclusion in terms of the stress of abutment teeth and prostheses, the prosthesis of pulp cavity retainer crown is superior to other edge designs by plane docking edge and right shoulder abutment.
【作者单位】：解放军总医院口腔修复科;太原理工大学;
【基金】：国家自然科学基金(3081307) 北京市科技计划项目(2010B078,Z141100002114031)~~
【分类号】：R783

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