改良杆卡式附着体与不同可摘局部义齿对支持组织应力分布的研究

目的探讨改良杆卡式附着体义齿与RPI卡环组、联合卡环组可摘局部义齿修复单侧游离缺失对支持组织的应力分布。方法在下颌47、46单侧游离缺失的环氧树脂模型上分别以改良杆卡式附着体、RPI卡环组、联合卡环组3种固位形式的可摘义齿修复，用三维光弹应力冻结切片技术测试义齿加载后对基牙和缺牙区牙槽骨应力分布。结果对基牙牙槽骨的应力：改良杆卡式附着体义齿〉RPI卡环组〉联合卡环组（P〈0．05）；附着体义齿对基牙的近、远中应力无显著性：差异（P〉0．05）；RPI卡环组义齿有猞支托处的应力大于无拾支托处的应力（P〈0．05）；联合卡环组对远中的应力大于近中（P〈0．05）。对缺牙区牙槽骨应力：改良杆卡式附着体与RPI卡环组均小于联合卡环组（P〈0．05）；附着体义齿、RPI对缺牙区牙从近中到远中的4个切片应力无显著性差异（P〉0．05），联合卡环组远中大于近中（P〈0．05）。结论改良杆卡式附着体义齿有应力中断作用，各点应力分布较均匀。RPI固位的活动义齿应力主要分布在基牙上，缺牙区应力稍小。联合卡环组义齿对失牙区的应力最大，基牙上应力较小。

The stress distribution of the improved rod cassette attachment and removable partial denture to the supportingtissues

Objective To investigate the stress distribution of improved rod cassette attachment and removable partial denture to the supporting tissues for repairing unilateral free deficiency. Methods On mandibular 47,46 unilateral free missing model made of epoxy resin, the improved rod cassette attachment, RPI clasp and joint clasp were respectively used for the repair. Three dimensional pbotoelastic stress frozen section technology was used to test the stress distribution to the alveolar bone of the abutment teeth and edentulous area on load. Results Stress to alveolar bone of the abutment tooth ： the stress of improved rod cassette attachment was greater than that of RPI clasp and the joint clasp （ P 〈 0. 05 ）, and RPI clasp greater than that of the joint clasp （P 〈 0. 05） ; The stress on occlusal bracket was greater than that of the place without occlusal bracket in RPI clasp （P 〈 0. 05 ）, and the distal stress was greater than mesial in joint clasp （P 〈 0. 05 ）. The stress to alveolar bone of the edentulous area： the improved rod cassette attachment and RPI clasp was not different （P 〉 0. 05） but were less than joint clasp （P 〈 0. 05） ; in the four sections of the edentulous area from the mesial to the distal, the difference of the stress of attachment denture and RPI was not significant （ P 〉 0. 05 ）. Conclusion The improved rod cassette attachment denture had stress interruption effect and the stress was more uniform. The stress of RPI clasp denture distributed mainly on the abutment teeth. The stress of the joint clasp denture was more in edentulous area and less in abutment teeth.