【作者】 杨国利；

【导师】 石培凯； 董福生；

【作者基本信息】 河北医科大学 ， 口腔临床医学， 2004， 硕士

【摘要】 目的：通过建立不同数目种植体支持的单个过大种植磨牙三维有限元模型，采用三维有限元法，分析不同数目种植体支持的单个过大种植磨牙种植体骨界面应力分布，为临床种植修复提供设计依据。方法： 1．三维有限元模型建立：CT扫描下颌第一磨牙自然缺失的成人下颌骨标本，将CT扫描结果导入AutoCAD中，建立三维模型，导出为ACIS文件，再导入ANSYS进行计算。种植体的三维模型在ANSYS中建立，并在ANSYS中模拟建立三种种植模型:1、单个4.8mm直径种植体单冠修复，单个直径（4.8mm）种植体支持下颌单个磨牙缺失;2、两个3.5mm直径种植体单冠修复，双种植体（直径均为3.5mm）支持下颌单个磨牙缺失，两种植体长轴平行，长轴垂直于牙合面，均位于颌骨颊舌向中线上; 3、单个7mm直径种植体单冠修复，单个大直径（7mm）种植体支持下颌单个磨牙缺失。采用ALGOR有限元分析程序自动划分节点和单元，种植体骨界面上的单元有六面体和四面体，完成三维有限元模型，节点数和单元数如下：单个直径为4.8mm种植体，划分有限元网格，得到22121个单元，5863个节点；两个直径均为3.5mm种植体，划分有限元网格，得到23800个单元，5720个节点；单个直径为7mm种植体，划分有限元网格，得到26161个单元，7146个节点。 2、加载：给予<WP=4>垂直集中加载160N，斜向加载100N，载荷方向自颊侧向舌向与牙合面成45度角。3、分析方法：采用美国ALGOR大型通用有限元分析系统软件进行分析。结果：1、在垂直加载下，三组种植模型的应力分布规律是大致相同的，均在种植体的颈部周围的骨皮质和根尖部的骨松质出现应力集中。2、在斜向加载下，三组种植模型的应力分布规律是大致相同的，种植体的舌侧颈部骨皮质出现应力集中，种植体的舌侧颈部骨松质出现应力集中。3、在垂直加载下，三组种植模型的皮质骨Von Mises等效应力值范围分别为：单个直径为4.8mm种植体单冠修复（0.3~7.7Mpa）,两个直径为3.5mm种植体单冠修复（0.2~6.0MPa）, 单个直径为7.0mm种植体单冠修复（0.2~4.7MPa）。4、在斜向加载下，三组种植模型的皮质骨Von Mises等效应力值范围分别为：单个直径为4.8mm种植体单冠修复（0.1~20.5Mpa）,两个直径为3.5mm种植体单冠修复（0.1~18.2MPa）, 单个直径为7.0mm种植体单冠修复（0.1~10.0Mpa）。5、在垂直加载下，三组种植模型的松质骨Von Mises等效应力值范围分别为：单个直径为4.8mm种植体单冠修复（0.1~0.94MPa）,两个直径为3.5mm种植体单冠修复（0.08~0.94MPa）, 单个直径为7.0mm种植体单冠修复（0.05 ~0.71 MPa）。6、在斜向加载下，三组种植模型的松质骨Von Mises等效应力值范围分别为：单个直径为4.8mm种植体单冠修复（0.01~1.41MPa）, 两个直径为3.5mm种植体单冠修复（0.01~1.22MPa）,单个直径为7.0mm种植体单冠修复（0.01~ 0.86MPa）。7、在垂直加载下，单个直径为4.8mm种植体单冠修复时种植体骨界面最大应力值为<WP=5>7.7Mpa；两个直径为3.5mm种植体单冠修复时种植体骨界面最大应力值6.0 Mpa，单个直径为7.0mm种植体单冠修复时最大应力值为4.7Mpa；在斜向加载下，单个直径为4.8mm种植体单冠修复时种植体骨界面最大应力值为20.5Mpa；两个直径为3.5mm种植体单冠修复时种植体骨界面最大应力值为18.2Mpa,单个直径为7.0mm种植体单冠修复时最大应力值为10.0Mpa,从实验结果看，单个直径为7.0mm种植体单冠修复时种植体骨界面应力分布最好，两个直径为3.5mm种植体单冠修复时种植体骨界面应力分布较好，单个直径为4.8mm种植体单冠修复的种植体骨界面应力值最大，不利于应力分布。结论：1种植体数目及种植体直径对单冠种植修复骨界面应力分布有影响。2两个种植体直径的和大于单种植体直径时，两个种植体支持单冠修复骨界面应力值及应力分布优于单个种植体支持固位单冠。3两个种植体直径的和等于单种植体直径时，单个种植体支持固位单冠修复骨界面应力值及应力分布优于两个种植体支持固位单冠修复。4 种植体数目及种植体直径对骨界面应力集中的部位没有影响。应力集中均发生在颈部及根尖部。更多还原

【Abstract】 Objective: Different implant quantity was applied to restore wide-distanced molar. Three-dimensional finite element models were built up. The aim of this experiment is to study the effects of different implants in single wide-distanced molar implant restoration on the stress distribution of implant-bone interface and to provide theory for clinical application. Method: Three implant designs restored single wide-distanced molar: odel1, ingle small implant (diameter:4.8mm) restoration; model 2, two implants (diameter:3.5mm*2) restoration; model 3, single big implant(diameter:7.0mm).Computed Tomography was used to build up a three-dimensional finite element model. Three-dimensional finite element models were built up on computer with the ALGOR finite-element-analyzing software. After the nodes of the implant-to-bone interface were selected, he stress average values were analyzed.When an axial load of 160N and an oblique load of 100N were applied, the stress distribution of three implant designs was compared. Result: 1.When an axial force was loaded, he maximal stress areas were formed at the neck and root tip region of implants. 2. When an oblique force was loaded, the maximal <WP=7>stress areas were formed at lingual neck region of implants. 3. When an axial force was loaded, the Von Mises stress quantities scope of three model in cortical bone were as follow: single small implant(diameter:4.8mm) restoration:0.3~7.7Mpa; two implants(diameter:3.5mm*2) restoration: 0.2~6.0Mpa; single big implant(diameter:7.0mm) restoration: 0.2~4.7Mpa.4. When an oblique force was loaded, the Von Mises stress quantities scope of three model in cortical bone were as follow: single small implant(diameter:4.8mm) restoration: 0.1~20.5Mpa; two implants(diameter:3.5mm*2) restoration: 0.1~18.2MPa; single big implant(diameter:7.0mm) restoration: 0.1~10.0Mpa. 5. When an axial force was loaded, the Von Mises stress quantities scope of three model in cancellous bone were as follow: single small implant(diameter:4.8mm) restoration: 0.1~0.94MPa; two implants(diameter:3.5mm*2) restoration: 0.08~0.94MPa; single big implant(diameter:7.0mm) restoration: 0.05 ~0.71 MPa. 6. When an oblique force was loaded, the Von Mises stress quantities scope of three model in cancellous bone were as follow: single small implant(diameter:4.8mm) restoration: 0.01~1.41MPa ; two implants(diameter:3.5mm*2) restoration: 0.01~1.22MP; single big implant(diameter:7.0mm) restoration: 0.01~ 0.86MPa. 7. When an axial force was loaded,the maximal stress quantity of single small implant(diameter:4.8mm) restoration was 7.7Mpa；the maximal stress quantity of two implants(diameter:3.5mm*2) restoration was 6.0 Mpa; the maximal stress quantity of single big implant(diameter:7.0mm) <WP=8>restoration was 4.7Mpa. When an oblique force was loaded, the maximal stress quantity of single small implant(diameter:4.8mm) restoration was 20.5Mpa; the maximal stress quantity of two implants(diameter:3.5mm*2) restoration was 18.2Mpa ; the maximal stress quantity of single big implant(diameter:7.0mm) restoration was 10.0Mpa.The stress distribution of single big implant(diameter:7.0mm) restoration was best, The stress distribution of two implants(diameter:3.5mm*2) restoration was better, and the stress distribution of single small implant(diameter:4.8mm) restoration was not good. Conclusion: 1.Implant quantity and diameter had influenced stress distribution between bone and implant.2.When area of two implant was bigger than that of one implant, stress distribution of two implants was better than that of one implant. 3. When area of two implant equaled to that of one implant, stress distribution of one implan was better than that of two implants.4. Implant quantity and diameter hadn’t influenced stress distribution place, the maximal stress areas were formed at the neck and root tip region of implants.更多还原