【作者】 马俊青；

【导师】 王林；

【作者基本信息】 南京医科大学 ， 口腔临床医学， 2004， 硕士

【摘要】 第一部分 微型支抗种植体即刻负载的稳定性及界面研究 一、微型支抗种植体即刻负载的稳定性研究 目的 探讨微型支抗种植体即刻负载的稳定性。 材料和方法 200g力值作用下，以微型种植体为支抗，牵拉犬上下颌第二前磨牙以及种植体间交互牵引，观察2月后牵引侧和对照侧牙齿及微型支抗种植体位移情况。 结果 被牵引牙齿均较对照侧发生明显位移，实验结束时微型种植体无松动，大多微型种植体位移不显著。 结论 微型种植体植入后可即刻施加200g水平力，用作正畸支抗。 二、微型种植体即刻负载的界面研究 目的 研究微型支抗种植体即刻负载的骨界面愈合情况。 材料和方法 微型支抗种植体植入犬下颌骨，施以200g水平力，定期注射荧光标记物，73天后处死动物，制作种植体-骨标本切片，进行光镜、荧光镜、偏光镜、软x线片、扫描电镜等观察及x线能谱分析。 结果 种植体-骨界面形成良好的骨性结合，动态荧光标记显示植入6周时有板层骨形成，9周时板层骨显著。 结论 微型种植体植入后可即刻承载200g正畸力而不影响其骨性愈合过程。 第二部分 微型支抗种植体不同承载方向的三维有限元研究 一、微型种植体-骨有限元模型的建立 目的 生成微型种植体-骨的三维有限元模型，为精确分析微型支抗种植体系统的生物力学特性奠定基础。 材料和方法 在ANSYS软件内，运用参数化设计语言(APDL)，生成三维实体模型，并定义单元属性和划分网格。 结果 建立起有效的种植体三维有限元分析模型，节点总数为5164，南京医科大学硕士学位论文单元总数为29352。结论生成的模型准确的反映了种植体与骨的接触面情况，同时模型后期的运算量适中。二、微型支杭种植体不同承载方向的三维有限元研究目的探讨在不同临床应用中，微型支抗种植体承载不同方向2009正崎力时的应力分布情况。方法牙!」用微型支抗种植体一骨三维有限元分析模型，在与种植体长轴成0度角、30度角、45度角、60度角或90度角等加载条件下进行应力分析计算。结果承载不同方向力时，种植体一骨界面的最大应力均较小，应力大小随着角度的增大而增大，五种承载方向时种植体颈部均为应力集中区。结论种植体可比较安全承载不同方向的2009正崎力，特别是与长轴夹角较小的力，但结合动物实验和有限元分析的结果，在产品国产化时应尽可能改良种植体结构，特别是颈部结构。更多还原

【Abstract】 Part I Stability and interface study on immediately loadedmicro-implant1. Study on Stability of Micro-implant Anchorage Objective To study the stability of micro-implant anchorage which were loaded immediately.Methods After loaded with orthodontic force of 200g for 2 months, the movement of micro-implants and the dogs’ second premolars anchored by micro-implant were studied.Results All the loaded premolars showed apparent displacement, while the micro-implants kept stabile and most of them moved little. Conclusion The micro-implant can withstand 200g of immediate horizontal loading as an orthodontic anchorage.2. Evaluation of the interface between immediately loaded micro-implant and boneObjective To study the peri-implant bone reaction to the immediatelyloaded micro-implant.Methods Micro-implants were implanted into dogs’ mandibular bones, immediately loaded, with polyfluorochrome sequential labeling. Seventy-three days after implantation, the dogs were euthanized and dissected mandibles were prepared. The specimens were evaluated by light microscope, fluorescent microscope, polarized light microscope, microradiography, scanning electron microscope and energy dispersive x-ray spectroscope.Results All results suggested that osseointegrated interfaces were formed between micro-implants and bones. Fluorochrome labels hinted that lamellae bones appeared 6 weeks after implantation, and were formed more extensively another 3 weeks later.Conclusions Micro-implants can be loaded immediately and the interfaces have normal turnovers of osseointegration.Part II Three dimensional FEM analysis of stress distribution around micro-implant loaded with different-directed force1. Establishment of three-dimentional finite element model for micro-implant and boneObjective To establish a three-dimentional finite element model formicro-implant and bone in mandibleMethods In the software ANSYS, APDL was used to establish athree-dimentional model of micro-implant and bone, then elementproperty was defined and the model was meshedResults An appropriate FEM model was established, with totally 5164nodes and 29352 elements.Conclusions The model precisely reflects the contact of micro-implantand bone, while it will not be too complicated for the solution afterloading.2. Three dimensional FEM analysis of stress distribution around micro-implant loaded with different-directedforceObjective To analyze the stress around micro-implant loaded with forces in different directions which may be used in clinical practice. Method Three dimensional finite element analysis software was used to setup micro-implant and bone FEM model. Forces in five directions were applied to the head of micro-implant, that is, referring to the axis of micro-implant and starting from the head of micro-implant, 0 degree, 30degree, 45 degree, 60 degree and 90 degree.Results On all the conditions, the maximum stress of Von Mises werevery small with the neck of implant always being stress focused , and thestress increased with the angle of force.Conclusion The micro-implant can safely loaded with 200g force indifferent directions, especially the one in smaller angle, but combinedwith former animal test, when we intend to localize the product, weshould consider to reform the neck of micro-implant.更多还原