附着体类型对种植支持可摘局部义齿应力分布的影响  

Influence of attachment type on stress distribution of implant-supported removable partial dentures

作　　者：杨雪[1,2] 荣起国[3] 杨亚东[1] 

机构地区：[1]北京大学口腔医学院.口腔医院修复科,北京100081 [2]北京大学口腔医学院.口腔医院第一门诊部,北京100034 [3]北京大学工学院生物医学工程系,北京100871

出　　处：《北京大学学报（医学版）》2015年第1期72-77,共6页Journal of Peking University:Health Sciences

摘　　要：目的:研究种植支持可摘局部义齿修复下颌远中游离端缺失的应力分布,探讨附着体类型对于种植体、各支持组织、义齿以及附着体的应力影响。方法:建立可摘局部义齿修复下颌双侧前磨牙和磨牙缺失的KennedyⅠ类牙列缺损的三维有限元模型,分别为采用传统可摘局部义齿(无种植体)、种植体+Locator附着体+可摘局部义齿、种植体+Magfit磁性附着体+可摘局部义齿进行修复。分析对比各主要成分的应力分布,得到最大von Mises应力值和位移值。结果:建立含有牙体组织、牙周组织以及种植体、附着体、可摘局部义齿的三维有限元模型。有种植体的模型义齿基托下黏骨膜的最大位移量(Locator模型垂直向载荷9.38μm、斜向载荷45.48μm,Magfit模型垂直向载荷9.54μm、斜向载荷39.45μm)小于没有种植体的RPD(removable partial dentures)模型(模型垂直向载荷95.27μm,斜向155.70μm)。Locator和Magfit两种类型的附着体相比较,Locator模型中种植体颈部周围皮质骨的最大应力值大于Magfit模型(Locator模型垂直向载荷10.850 MPa、斜向载荷43.760 MPa,Magfit模型垂直向载荷7.100 MPa、斜向载荷19.260 MPa)。Magfit模型中末端基牙的牙周膜受力更小(Locator模型垂直向载荷0.520MPa,Magfit模型垂直向载荷0.420 MPa)。结论:在修复下颌KennedyⅠ类牙列缺损时,种植支持可摘局部义齿可减少对末端基牙的扭力,提高义齿稳定性;Locator和Magfit磁性附着体两者对比,Locator附着体水平约束作用更大。Objective： To compare influences of different retention attachments on stress among supporting structures. Methods： By 3-dimensional laser scanner and reverse engineering computer aided design（ CAD） software,a basic partially edentulous digital model with mandibular premolar and molar missing was established. Implant attachment and removable partial dentures（ RPD） were added into the basic model to build three kinds of models： RPD only,RPD ＋ implant ＋ Locator attachment,and RPD ＋ implant ＋ Magfit attachment. Vertical and inclined loads were put on artificial teeth unilaterally.By means of 3-dimensional finite element analysis,the stress distribution and displacement of the main supportive structures were compared. Results： A complete 3-dimensional finite element model was established,which contained tooth structure,and periodontal structures. The displacement of the denture was smaller in Locator（ 9. 38 μm vertically,45. 48 μm obliquely） and Magfit models（ 9. 54 μm vertically,39. 45 μm obliquely） compared with non-implant RPD model（ 95. 27 μm vertically,155. 70 μm obliquely）. Compared with the two different attachments,cortical bone stress value was higher in Locator model（ Locator model 10. 850 MPa vertically,43. 760 MPa obliquely; Magfit model 7. 100 MPa vertically,19. 260 MPa obliquely）. The stress value of abutment periodontal ligamentin Magfit model（ 0. 420 MPa vertically）was lower than that in Locator model（ 0. 520 MPa vertically）. Conclusion： The existence of implant could reduce maximum von Mises value of each supportive structure when KennedyⅠ partially edentulous mandible was restored. Comparing the structure of Magfit and Locator attachment,the contact of Magfit attachment was rigid,while Locator was resilient. Locator attachment could improve stability of the denture dramatically. Locator had stronger effect on defending horizontal movement of the denture.

关 键 词：义齿 局部 可摘 义齿 植入物支持 义齿精密附着体 有限元分析 

分 类 号：R783.4[医药卫生—口腔医学]