不同材质球帽附着体对下颌种植覆盖义齿固位力的影响

Effect of ball attachments with different materials on retention of mandibular implant supported overdenture

目的 :研究不同材质球帽附着体对下颌种植覆盖义齿固位力的影响。方法 :实验分为A组(钛球/钛帽组)、B组(钛球/贵金帽组),每组3个试件。制作标准下颌无牙颌模型,在双侧尖牙区植入4.8×10 RN SP种植体各1颗,常规制作下颌全口义齿,连接附着体。进行5000次摘戴循环,每200次摘戴测试固位力。采用SPSS 13.0软件包对所得数据进行组间比较,并在实验初始、终末期采用扫描电镜观察阳性结构的表面形态变化。结果:A组固位力从(27.00±0.16)N衰减到(4.18±0.03)N,B组固位力从(21.58±0.06)N衰减到(19.15±0.06)N,A组固位力衰减显著大于B组。实验终末,A组球状立体结构严重破坏,而B组球状立体结构光滑清晰。结论:球帽附着体下颌种植覆盖义齿的固位力随着摘戴次数的增加而逐渐降低,其固位力衰减与阳性结构表面破坏有关,贵金属材质抗疲劳性较好。

PURPOSE： To investigate the effect of ball attachments with different materials on retention of mandibular implant supported overdenture. METHODS： The experimental groups were divided into group A （titanium ball / titanium cap group） and group B （titanium ball / golden cap group）, each group had 3 samples. A standard mandibular edentulous model was made, and the implants （4.8＊10 RN SP） were embedded in the bilateral canine region. Mandibular complete dentures were made routinely and the attachments were attached. Five thousand times of insertion-separation cycles were carried out. After 200 times of cycles, the retention force was tested. The difference between 2 groups was compared by using SPSS 13.0 software package. The change of positive structure surface morphology was observed under scanning electron microscope at the beginning and the end of the experiment. RESULTS： The retention force of group A decreased from （27.00±0.16） N to （4.18±0.03） N, and the retention force of group B decreased from （21.58±0.06） N to （19.15±0.06）N. Decay of retention of group A was significantly greater than that of group B. At the end of the experiment, the globular structure of group A was severely broken, while a smooth and clear spherical structure was displayed in group B. CONCLUSIONS： The retention of mandibular implant supported overdenture decreases with the increase of insertion-separation times. The decay of retention force is related to destruction of positive structure surface. The fatigue resistance of the precious metal material is better.