静动态载荷下基牙压低后的生物力学分析

摘要

目的:探讨静态与动态加载微种植体压低基牙后的基牙生物力学行为的改变,为压低基牙的牙体预备提供理论依据.方法:考虑基牙牙槽骨水平吸收10％,建立上颌前牙分别压低0、0.5、1.0、1.5、2.0mm后双端固定桥修复的三维有限元分析模型,比较压低基牙前后修复体、牙体、牙周膜及皮质骨的应力变化情况.结果:随压低量的增加,基牙、牙体、牙周膜及皮质骨上应力分布在一定程度上有所改变,这种改变与基牙结构、牙周膜面积的变化有很大关系,牙周膜面积增大,整体应力则降低.在动态压低周期中,卸载终期仍有少量的应力残余.结论:微种植体压低基牙后有助于基牙及支持组织的应力分布；在动态压低中,基牙及支持组织的应力具有时间依赖性.%Objective:To explore the alteration of the abutment biomechanical behavior after abutments being intruded by microscrew implanting,and to provide theoretical basis for the clinical practice of tooth preparation after intrusion of abutments under static and dynamic loads.Methods:Three-dimensional finite element mathematical model of rigid fixed bridge repairing on double ends of maxillary molar was developed.Under the condition of 10 ％ simulative abutment alveolar bone absorption,verti cal and horizontal forces were loaded to build mathematical model after abutments have been intruded for 0.5,1.0,1.5,and 2.0 mm.Stress variety of prosthesis,teeth,periodontal ligaments and cortex bone were compared before and after the intrusion of abutments.Results:Stress alteration of the prosthesis occurred,which was related with the structure of abutments and the increase of areas of periodontal ligaments.The overall stress decreased along with the increasing of the length of intrusion.In one mastication period,some residual stress was left after unloading.Conclusions:By preparing the fixed bridge after the intrusion of abutments by microscrew implanting,the stress of abutments and supporting tissues can be reduced.The abutments and their related tissues have time-dependent mechanical behaviors during one mastication.