【作者】 谭荣；

【导师】 施斌；

【作者基本信息】 武汉大学 ， 口腔修复学， 2004， 硕士

【摘要】 目的：本研究的目的是分析封闭介质的类型、封闭介质的厚度、载荷的大小、载荷的方向对单个种植义齿的应力分布的影响。 方法：利用三维有限元分析方法(Three-dimensional Finite Element Method，3D-FEM)，在右侧下颌第一磨牙的区域，分别建立四个单个粘结固定型种植义齿的计算机模型。采用磷酸锌水门汀(zinc phosphate，ZP)和玻璃离子水门汀(glass ionomer，GI)这两种临床上常用的封闭介质，分别建立25μm和100μm两种厚度的模型。在义齿的(牙合)面施加10N和150N的轴向载荷，在义齿的颊侧(牙合)轴嵴处施加10N和150N的颊舌向的载荷，测定基台、种植体表面及封闭介质内的应力值和应力集中区域。 结果：轴向载荷下，种植体表面的应力主要集中在种植体的颈部皮质骨内和根尖区域，且种植体颈部的应力值比根尖部大。颊舌向载荷下，种植体表面的应力主要集中在种植体的颈部皮质骨内。而且，颊舌向载荷下，种植体表面的应力明显大于轴向载荷下的应力。随着载荷的增大，种植体表面的应力呈比例增大。在两种不同类型的封闭介质的模型中，种植体表面的应力相差不大，但在同样载荷下，同样厚度的ZP内的应力明显高于GI。在两种不同厚度的封闭介质的模型中，种植体表面的应力差别很小，但在同样载荷下，同种类型的封闭介质内，25μm的应力较100μm时大，且差别相当显著。 结论： 1．封闭介质的类型对种植体表面的应力分布影响很小，但GI较ZP的抗疲劳能力更强，更适合用于粘固种植义齿的冠修复体。 2．封闭介质的厚度对种植体表面的应力分布影响非常小，但在保证封闭介质的粘结强度和较低的溶解性的同时，厚的封闭介质的抗微折性能较薄的封闭介质更强。 3．载荷的方向对种植体表面的应力分布影响很大，水平载荷下的应力值显著高于轴向载荷下，故要尽量避免种植义齿受到斜向载荷。 4．载荷的大小对种植体表面的应力分布影响非常显著，随着载荷的增大，种植体表面的应力水平相应增大，故要防止应力集中，减少种植义齿所受到的(牙合)力。更多还原

【Abstract】 Purpose: The objective of this study was to test the effects of (1) cement type, (2) cement thickness, (3) loading magnitude, (4) loading direction on stress distribution of the single implant denture.Material and Methods: Four three-dimensional computer models of single cement-retention implant denture were generated in the right lower first molar area, respectively. Zinc phosphate and glass ionomer were used in the thickness of 25 and 100 # m . Models were loaded axially (10N and 150N) on the occlusion, and loaded buccollingually (10N and 150N) on the buccal edge of the occlusion. The area and level of stress concentrationon the abutment, implant and within luting agents were tested.Results: The stress on the implant denture chiefly concentrated in the neck and the apical of the implant under the axial load, and the stress in the neck of the implant was bigger thanthat in the apical of it. But under the buccollingual load, the stress on the implant denturechiefly concentrated in the cervical cortical bone of the implant. And the stress under the buccollingual load was much higher than that under the axial load. The stress on the implant denture increased in proportion to the magnitude of the load. The difference of the stress on the implant denture was not significant in the models of the two luting agents. But under the same load, the stress in the same thickness ZP was much higher than that in the GI. The difference of the stress on the implant denture was not significant in the models of the twokinds of thickness luting agents. But under the same load, the stress in the 25 nm luting agentwas much higher than in the 100#m in the same luting agent.IIConclusions:1. The type of the luting agents had very little effect on the stress level and stress distribution of the implant. But GI had the more favorable mechanical properties for resisting to microfracture than ZP did, so GI was more adapted to cement-retained implant denture.2. The thickness of the luting agents had very small effect on the stress level and stress distribution of the implant. But the thick luting agent had the more favorable mechanical properties for resisting to microfracture than the thin luting agent.3. The directpn of the load had very significant effect on the stress level and stress distribution of the implant. And the stress under the buccollingual load was significantly higher than that under the axial load, so the oblique load on the implant denture should be avoided as far as possible.4. The magnitude of the load had very significant effect on the stress level and the stress distribution of the implant. And corresponding with the load increasing, the stress level on the implant increased. So the occlusion on the implant denture should be decreased.更多还原