不同大连接体义齿对基牙位移的影响

目的研究腭部3种不同大连接体可摘局部义齿对基牙各方向位移的影响。方法应用下颌牙列完整、上颌两侧第一和第二磨牙缺失的塑料实验模型,并在模型上模拟制作牙周膜及牙槽骨黏膜,制作3种腭部大连接体分别为中央开"天窗"的腭板(以下简称W连接体)、前后侧腭杆(以下简称F连接体)和腭杆(以下简称P连接体)的可摘局部义齿。分别在单侧后牙区放置长、短食物片的咬合状态下,负载3、5、7kg咬合力时,采用高精度半导体激光位移测量仪测量并计算同侧基牙在近远中向、颊舌向的水平位移及倾斜、垂直向的位移和水平旋转,并统计分析不同大连接体义齿对基牙位移影响的意义。结果当3种不同连接体义齿分别在单侧咬合长、短食物片时,基牙在近远中、颊舌向和垂直向3个轴向发生的位移、倾斜、旋转的差异均有统计学意义(P值均<0.05)。结论3种不同连接体的可摘局部义齿在单侧咬合长、短食物片时,基牙在实验中显示出不同的位移、倾斜和旋转的运动特点。

Influence of dentures with various major connectors on abutment displacement

Objective To study the influence of 3 kinds of major connecters of removable partial denture (RPDs)in the palate on the abutment movement.Methods A plastic model with intact mandible and a maxilla without bilateral molars was established and the periodontal membrane and oral mucosa were simulated on the model.Then we fabricated the three RPDs with the palatal bar(P connecter),anterior-posterior-lateral palatal bar (F connecter),and palatal plate(W connecter).Short and long food chips were placed in the left posterior occlusion;when the masticated load was 3 kg,5 kg and 7 kg,the displacement of abutments was measured by a LB-72 high sensitive laser transferring detector.The displacement,inclination and torsion of the abutment in mesial-dista,labial-lingual and vertical and horizontal directions were calculated.The influence of different major connectors on the abutment displacement was calculated.Results When the short and long food chips were masticated in the left sides of RPDs with 3 kinds of different major connecters,the displacement,inclination and torsion of abutment in 3 axes were significantly different(all P<0.05).Conclusion The abutment of RPDs with 3 different kinds of major connecters has different displacement,inclination and torsion.