牙槽骨吸收对冠外附着体义齿基牙及牙周组织应力分布的影响

目的：探讨牙槽骨吸收对冠外附着体义齿基牙及牙周组织应力分布的影响，为附着体义齿临床应用提供理论依据。方法：应用三维有限元方法测定基牙牙槽骨吸收不同时附着体义齿基牙及牙周组织应力分布情况，并与单端固定桥比较。结果：单端固定桥基牙及牙周组织最大应力为(3.63E+5)Mpa;基牙牙槽骨正常时附着体义齿基牙及牙周组织最大应力为（1.27E+5）Mpa，小于单端固定桥；基牙牙槽骨吸收1/3时为(3.87E+5)Mpa,稍大于单端固定桥；基牙牙槽骨吸收1/2时为(1.38E+6）Mpa,明显大于单端固定桥。结论：附着体义齿可减轻基牙及牙周组织应力，随着基牙牙槽骨吸收，基牙所受应力增加；基牙牙槽骨正常时，以C45 为基牙单侧设计冠外附着体义齿修复下颌游离端缺失是适宜的;基牙牙槽骨吸收达1/3，此种修复要慎重，应减少侧向力，当基牙牙槽骨吸收达1/2 不可单侧设计此种修复，应增加基牙或双侧设计。

Effect of aveolar ridge resorption on stress distribution of abutment and peridontal tissue of attachment denture

Objective To explore the effect of aveolar ridge resorption on the stress distribution of abutment and peridontal tissue in attachment denture,and provide evidence for the application of attachment denture in clinic. Methods The stress ditribution of abutment and peridontal tissue of attachment dentures with aveolar ridge resorption of abutment at different levels were measured respectively,and were compared with cantilever fixed bridge by three-dimensional finit element method.Results The stress peach of abutment and peridontal tissue of cantilever fixed bridge was (3.63E+5)Mpa.The stress peach of abutment and peridontal tissue of attachment dentures was (1.27E+5)Mpa with normal aveolar ridge and it was lower than that of cantilever fixed bridge;the peach of abutment and peridontal tissue was(3.87E+5)Mpa when aveolar ridge was absorbed by 1/3,and it was lihgtly higher than that of cantilever fixed bridge,;the peach was (1.38E+6)Mpa when aveolar ridge was absorbed by 1/2,and it was significantly higher than that of cantilever fixed bridge.Conclusion The extralcolonal attachment dentures could decrease the stress of abutment and peridontal tissue,the more the aveolar ridge of abutment is absorbed,the greater the stress of abutment is;when the aveolar ridge of abutment was normal,it is suitable to retore mandibular single distal -extention absence with extralcolonal denture of C4C5 abutment designed singly,when the aveolar ridge of abutment is absorbed by 1/3,the method should be used carefully,it is necessary to decrease lateral forces;when the aveolar ridge of abutment is absorbed by 1/2,the method is not suitable and it is necessary to increase the number of abutmenta and use bilateral design.