两种种植体支持式下颌半口固定义齿种植体应力有限元分析

发布时间：2018-07-21 17:05

【摘要】：目的设计两种种植体支持式下颌半口全牙列固定义齿,研究在不同下颌骨垂直高度降低情况下种植体应力分布情况。方法利用锥束计算机断层扫描成像(CBCT)扫描下颌骨及上部义齿,形成下颌骨基准模型,将基准模型中下颌骨垂直高度分别下降0、5、10和15mm,组装种植体后,建立颏孔前6枚平行种植体支持和"All-on-four"支持的不同下颌骨垂直高度的种植体有限元模型,分别为6-种植体模型和4-种植体模型,共两组(8个)。在右下颌第一磨牙中央窝静态加载250N垂直力,用Ansys 15.0软件进行模型各部分的应力分析。结果在相同的加载条件下,种植体最大应力值位于颈部;两组8个模型最大应力值分布显示,不同下颌骨垂直高度下4-种植体组的最大应力值在40.12~49.06 MPa之间,6-种植体组的最大应力值在80.62~109.64MPa之间;6-种植体组的最大应力值是4-种植体组的2倍。两组模型中种植体最大应力在下颌骨垂直高度降低5mm时均表现为最低,随着下颌骨垂直高度降低,应力逐渐增大,而垂直高度下降0mm的模型最大应力要略大于下降5mm模型。结论 4-种植体和6-种植体支持的无牙颌固定义齿在相对极端的载荷下种植体都没有出现破坏性应力,4-种植体有着更加合理的应力分布;下颌骨垂直高度下降5mm组应力最小,说明适当降低垂直高度有利于种植体应力更加合理的分布。
[Abstract]:Objective to design two kinds of implant-supported mandibular full dentures and to study the stress distribution of the implants under different mandibular vertical height reduction. Methods the mandibular reference model was established by using cone-beam computed tomography (CBCT) to scan the mandible and the upper denture. The vertical height of the mandible in the reference model was reduced by 0 ~ 5 ~ 10 mm and 15 mm, respectively, and the implant was assembled. The finite element models of different mandibular vertical height supported by six parallel implants and "All-on-four" were established, which were 6-implant model and 4-implant model respectively, two groups (8). The vertical force of 250N was statically loaded in the central fossa of the right first molar, and the stress of each part of the model was analyzed by Ansys 15.0 software. Results under the same loading conditions, the maximum stress value of the implant was located in the neck, and the distribution of the maximum stress value of the two groups of 8 models showed that, The maximum stress values of the 4- implant group at different mandibular vertical heights were between 40.12 and 49.06 MPA and the maximum stress values of the 6-implant group were between 80.62 and 109.64 MPA, and the maximum stress values in the 4-implant group were twice as high as those in the 4-implant group. In the two groups of models, the maximum implant stress was the lowest when the vertical height of mandible decreased 5mm. With the decrease of vertical height of mandible, the stress gradually increased, and the maximum stress of the model with vertical height decreasing 0mm was slightly larger than that of 5mm model. Conclusion neither 4-implant nor 6-implant supported edentulous fixed denture has more reasonable stress distribution under relatively extreme loads, and the lower mandibular vertical height is the smallest in 5mm group. It shows that proper reduction of vertical height is beneficial to more reasonable distribution of implant stress.
【作者单位】：第二军医大学长海医院口腔科;上海交通大学医学院附属新华医院口腔科;同济大学生命科学与技术学院;
【基金】：上海市科学技术委员会科研计划项目(12ZR1438400)~~
【分类号】：R783.6

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