两种义齿修复下颌单侧游离端缺失基牙及缺牙区牙槽嵴应力分布的比较

目的：分析两种不同结构义齿修复单侧游离端缺失时基牙及缺牙区牙槽嵴应力分布特点，为临床义齿选择提供依据。 方法：应用三维有限元方法分别测定并比较应用键槽缓冲式附着体义齿和单端固定桥义齿修复单侧游离端缺失时基牙及缺牙区牙槽嵴应力分布情况。结果: 键槽缓冲式附着体义齿基牙牙根应力峰值(1.42E+5)MPa，基牙牙周膜应力峰值(1.33E+4)MPa,缺牙区牙槽嵴应力峰值(3.49E+5)MPa。单端固定桥义齿基牙牙根应力峰值(1.45E+7)MPa，基牙牙周膜应力峰值(2.25E+6)MPa，缺牙区牙槽嵴应力峰值(1.45E+3)MPa。两种义齿基牙应力峰值均在根中、上1/3及颈部。结论:在游离端缺失修复时， 键槽缓冲式附着体义齿可减少基牙负荷，但牙槽嵴条件要好，两种义齿修复均要注意牙槽嵴健康。

Comparison of stress distribution in abutment and alveolar ridge between two kinds of distal-extention absence dentures

Objective To analyze the stress distribution of abutment and alveolar ridge between two kinds of distal-extention absence dentures,and provide evidence for the application of different dentures in clinic.Methods Attachment denture and cantilever fixed bridge were used to restore the distal-extention absence respectively,the stress distribution of abutment and alveolar ridge was compared by three-dimensioal finit element method.Results The stress peak values of abutmen root,periodontal membrance,alveolar ridge were(1.42E+5)MPa,(1.33E+4)MPa and(3.49E+5)MPa,respectively,in attachment denture;while in cantilever fixed bridge,the stress peak values of them were(1.45E+7)MPa and(2.25E+6) MPa,(1.45E+3)MPa,respectively.And the stress peak values of these two kinds of dentures were all located in the mid-upper 1/3 and the cervical of abutment.Conclusion Compared with cantilever fixed bridge,the attachment denture could decrease the stress of abutment and be helpful to its protection,the hight of residual alveolar ridge should be taken into account when the two kinds of dentures are used for distal-extention absence.