微种植体压低基牙后双端固定桥修复的生物力学分析

目的探讨微种植体压低基牙后,固定桥力学行为的改变,为临床压低基牙后再进行牙体预备提供理论依据。方法建立考虑基牙牙槽骨水平吸收10%上颌后牙分别压低0 mm,0.5 mm,1.0 mm,1.5 mm,2.0 mm后双端固定桥修复的三维有限元分析模型,施加垂直及斜向载荷比较压低基牙前后修复体、牙、牙周膜及硬骨板的应力变化情况。结果随着压低量增加,修复体、牙体上应力在一定程度上有改变,这个改变与修复体结构、牙体结构有很大关系,牙周膜及硬骨板面积增大,整体上应力有所降低,皮质骨和松质骨上应力变化并不明显。结论采用微种植体压低基牙后预备固定桥或全冠能够降低基牙牙备量,减少基牙的损伤,降低失髓风险,增加基牙牙周膜面积,改善冠根比,整体上降低垂直载荷和斜向载荷的不利影响,合理地改变修复体、牙、牙周膜、硬骨板的应力分布。

The biomechanical analysis of the rigid fixed bridge after intrusion in abutment with micro screw implant

[ Objective ] To Study the variety of the fixed bridge＇ mechanical behavior after abutments have been intruded by micro screw implant and to provide theoretical principles for the chnical practice of teeth preparation after the intrusion of abutments. [ Methods ] The three-dimensional finite element mathematical model of rigid fixed bridge repairing on double end of maxillary molar was developed.Under the condition of 10% simulative abutment alveolar absorption, vertical and oblique forces were loaded to the built mathematical model after the abutment has been intruded for 0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm.Stress variety of prosthesis, teeth, periodontal ligaments and supporting tissues was compared before and after the intrusion of abutments. [ Results ] .Stress variety of the prosthesis occurred, which has much relationship with the structure of prosthesis and teeth, the areas of periodontal ligaments increased, stress decreased on the whole along with the increasing of the length of intrusion.Stress variety of cortical and cancellous was not obvious. [ Conclusion ] By preparing the fixed bridge or full crown after the abutments＇ intrusion by micro screw implant, it can decrease the amount of abutment preparations, reduce the damage of abutments, lower the risk of losing the dental pulp, increase the area of abutment periodontal ligament, improve the ratio of the root crown, reduce the adverse effect of vertical and horizontal forces on the whole, and change the stress distribution of prosthesis, teeth, periodontal ligaments and supporting tissues reasonably, so to extend the service life of abutment and fixed bridge prosthesis.