3种游离端附着体义齿基牙位移的实验研究

目的:探讨3种附着体类型作为下颌单侧游离端义齿固位体对基牙的影响。方法:选用Snap附着体、Ceka附着体和Mini-SG附着体,制作单侧附着体义齿,在义齿侧上下牙列间放置食物片,咬合时用LB-72型高精度半导体激光位移测量仪,测量并计算出基牙在不同方向的位移量,并用随机方差分析法进行统计学分析。结果:3种附着体义齿基牙的近远中向、颊舌向、垂直向的位移、倾斜、扭转均有统计学差异(P<0.05)。Mini-SG附着体导致基牙近远中向的倾斜角度最大,Ceka附着体对基牙近远中向和根尖位移的影响最大,Snap附着体基牙的牙合方移动和逆时针旋转角度最小。结论:Snap附着体的弹性固位装置使应力在基牙和剩余牙槽嵴之间得到了最为均匀的分布,Ceka附着体的应力主要由基牙承担,Mini-SG附着体不能有效减少施于基牙上的有害的扭力。

Study on abutment movement of distal removable dentures retained by attachments

PURPOSE: To study the influence on the abutment movement with three kinds of precision attachments designed for distal-extension removable partial dentures (RPDs). METHODS: Snap attachment, Ceka attachment, Mini-SG attachment were used to retain RPDs. Then food chip was masticated between the upper and lower dentitions on the attachments side.Placement of abutment was measured by LB-72 high-sensitive- 1aser-traneferring-detector and the data were statistically analyzed for random block analysis of variance. RESULTS: The displacement, inclination, and torsion of the abutment movements in the mesial-distal, bucco-lingual and occluso- gingival directions all had statistical significance(P<0.05).The largest mesial-distal inclination occured with the Mini-SG attachment.The Ceka attachment produced more abutment displacement in mesial distal and apical directions. Occlusal displacement and anti-clockwise rotation were the least with the Snap attachment. CONCLUSION: The most equitable distribution of stresses on the supporting structures was achieved by Snap attachment with its resilent assemble, Ceka attachment transfers most of the loading forces to the abutments, Mini-SG attachment can not reduce the excessive torque applied to the abutments effectively.