种植体支抗辅助竖直压低下颌第二磨牙的三维有限元研究

发布时间：2018-04-19 10:20

  本文选题：三维有限元 + 下颌第二磨牙　； 参考：《大连医科大学》2017年硕士论文

【摘要】：目的:1建立种植体支抗竖直压低下颌第二磨牙的三维有限元模型并优化牙周膜参数与网格密度;2研究种植体支抗竖直压低下颌第二磨牙过程中不同时间阶段牙根、牙周膜及牙槽骨的应力应变情况;3研究竖直压低不同舌倾角度下颌第二磨牙过程中,牙根、牙周膜及牙槽骨的应力应变情况;4研究竖直压低下颌第二磨牙时,不同骨质密度对牙根、牙周膜及牙槽骨应力应变的影响;5研究竖直压低下颌第二磨牙时,不同牙周支持组织高度对牙根、牙周膜及牙槽骨应力应变的影响。方法:1应用逆向工程软件Geomagic Studio 10.0对下颌第二磨牙三维数据进行优化,应用有限元分析软件ANSYS 15.0建立种植体支抗竖直压低下颌第二磨牙的三维有限元模型;根据牙周膜参数设置(线性参数与非线性参数)与网格划分密度(高、中、低网格密度),将实验分为六个工况,分别对下颌第二磨牙的牙根、牙周膜及牙槽骨的应力应变进行分析。2建立下颌第二磨牙舌倾40°的三维有限元模型,根据3M链状皮圈在口腔内的衰减规律,得到第0、1、7、14、21与28天施加于下颌第二磨牙的力值分别为100g(1N)、75g(0.75N)、59g(0.59N)、43.75g(0.4375N)、32.5g(0.325N)、22.5g(0.225N)。将上述力值代入模型模拟不同时间阶段,对下颌第二磨牙牙根、牙周膜及牙槽骨的应力应变进行分析;3建立下颌第二磨牙舌倾40°、30°、20°、10°与0°的三维有限元模型,对其牙根、牙周膜及牙槽骨的应力应变进行分析;4建立下颌第二磨牙舌倾40°的三维有限元模型,按照四种骨质密度的材料参数对牙槽骨进行设置,对牙根、牙周膜及牙槽骨的应力应变进行分析;5建立下颌第二磨牙舌倾40°的三维有限元模型,依次降低牙周支持组织高度1mm,得到牙周支持组织高度分别为-1mm、-2mm、-3mm、-4mm、-5mm、-6mm与-7mm的有限元模型,对牙根、牙周膜及牙槽骨的应力应变进行分析。结果:1成功建立了包含下颌第二磨牙、牙周膜、硬骨板、松质骨、皮质骨及种植体支抗的三维有限元模型,几何相似度高,结构完整,网格质量优良;实验设定的三种网格密度对牙根、牙周膜及牙槽骨的应力应变分布与大小没有明显影响;不同牙周膜参数的设置对牙根与牙周膜应力应变的分布与大小均有影响,对牙槽骨应力应变分布没有影响,但对其应力应变大小有影响。2竖直压低下颌第二磨牙的不同时间阶段,牙根、牙周膜及牙槽骨的应力应变集中分布区域基本相同,牙根的应力应变集中主要分布于牙根颊侧根中1/3处、颊侧牙颈部及牙根舌侧根中1/3处;牙周膜的应力应变集中分布于舌侧根尖区与颊侧牙颈部;牙槽骨的应力应变集中分布于牙槽窝四个线角的颈部区域与颊侧根分叉区域;随作用力加载时间增加,牙根、牙周膜及牙槽骨最大等效应力与应变递减,第一天递减最快;牙周膜的最大等效应变远远大于牙根与牙槽骨。3竖直压低下颌第二磨牙过程中,随着磨牙舌倾度的减小,牙根舌侧与牙周膜颊侧颈部的应力应变集中分布区域逐渐扩大;牙槽骨颊侧应力应变集中范围减小,舌倾20°时最小,舌侧应力应变集中范围增加,舌倾20°时最大,舌侧应力应变集中比颊侧显著;牙根与牙周膜的最大等效应力与应变逐渐增大;牙槽骨的最大等效应力与应变增大,舌倾20°时最大;牙齿压低的趋势大于颊侧移动的趋势。4竖直压低下颌第二磨牙过程中,不同骨质密度对牙根与牙周膜的应力应变分布与大小没有影响;随骨质密度的降低,牙槽骨颊侧根分叉区的应力集中逐渐显著,应变集中由硬骨板转移到松质骨区域;随骨质密度的降低,牙槽骨最大等效应力递增,主要是硬骨板的最大等效应力递增,牙槽骨的最大等效应变也递增,A/B类骨密度时主要是硬骨板的最大等效应变递增,C/D类骨密度时主要是松质骨的最大等效应变递增。5竖直压低下颌第二磨牙过程中,随着牙周支持组织高度的降低,牙根、牙周膜及牙槽骨的应力应变分布向根尖区集中,最大等效应力与应变递增;当根分叉暴露后,牙根、牙周膜及牙槽骨的应力应变高度集中于根尖,最大等效应力与应变显著增大。结论:1牙周膜非线性参数设定模型的牙周膜对应力的缓冲作用更明显,应力分布更符合实际情况。在后续实验中,牙周膜可以进行非线性的超弹性设定,网格划分可以选择中等网格密度,在保证精确的同时,有利于提高运算效率。2由于牙根的应力集中分布区域不位于根分叉与根尖区,所以根尖与根分叉在竖直压低下颌磨牙时不会产生明显的吸收;牙槽骨的颊舌侧边缘处均有应力集中,提示我们在竖直压低下颌磨牙时,不仅颊侧牙槽骨可能存在吸收,舌侧牙槽骨也会有吸收的风险;由于牙周膜应变较大,应控制初始力值,以保护牙周膜,100g的初始加载力值比较合适。3由于牙槽骨舌侧应力应变分布与大小随磨牙的直立而增加,并且牙齿压低的趋势大于颊侧移动的趋势,因此,舌侧牙槽骨的吸收风险更值得关注;随着磨牙舌倾度减小,施加的作用力应该减小,磨牙舌倾20°时应该用最小力值。4竖直压低下颌磨牙时,牙槽骨密度低的患者容易产生潜行性吸收,对于牙槽骨密度低的患者,要适当降低初始加载力值,既有利于保护种植体支抗的稳定性,又可以防止牙槽骨的病理性吸收。5有牙周问题的下颌第二磨牙进行竖直压低时,要减小作用力(小于100g);根分叉暴露是竖直压低下颌第二磨牙的禁忌症。
[Abstract]:Objective: 1 to establish implant anchorage down vertical mandibular second molar three-dimensional finite element model and optimization of periodontal membrane parameters and the mesh density of planting; 2 different periods of anchorage of vertical lower mandibular second molars during root, stress and strain condition of periodontal ligament and alveolar bone; the root of the vertical down 3 different angles of lingual inclination of the mandibular second molar in the process of periodontal ligament and alveolar bone, the stress and strain; 4 of the vertical lower mandibular second molars, different bone density on the root, periodontal ligament and alveolar bone stress; 5 of vertical down second mandibular molars, different periodontal support the height of root tissue, periodontal ligament and alveolar bone stress. Methods: 1 three dimensional data using the reverse engineering software Geomagic Studio 10 of the mandibular second molars were optimized using finite element analysis software ANSYS 15 to establish a Implant a three-dimensional finite element model of vertical anti depression of the mandibular second molar; periodontal membrane is arranged according to the parameters (linear parameters and nonlinear parameters) and mesh density (high, low density grid), the experiment was divided into six conditions, respectively, of the mandibular second molar root, the stress and strain of periodontal ligament and the alveolar bone of.2 to establish three-dimensional finite element model of the mandibular second molar lingual inclination of 40 degrees, according to the attenuation of 3M elastomeric chain in the oral cavity, get the 0,1,7,14,21 28 days and imposed on the mandibular second molar force values were 100g (1N), 75g (0.75N), 59G (0.59N). 43.75g (0.4375N), 32.5g (0.325N), 22.5g (0.225N). The stress value in different time stages into the simulation model of the mandibular second molar, the stress and strain, periodontal ligament and alveolar bone were analyzed; 3 of the mandibular second molar lingual inclination of 40 degrees, 30 degrees, 20 degrees, three-dimensional finite element 10 DEG and 0 DEG The root type, stress and strain of periodontal ligament and alveolar bone were analyzed; 4 to establish a three-dimensional finite element model of the mandibular second molar lingual inclination of 40 degrees, according to the material parameters of four kinds of bone mineral density of alveolar bone is set on the root, the stress and strain of periodontal ligament and alveolar bone were analyzed; 5 to establish a three-dimensional finite element model of the mandibular second molar lingual inclination of 40 degrees, in order to reduce the height of periodontal supporting tissue 1mm, get the height of periodontal supporting tissue were -1mm, -2mm, -3mm, -4mm, -5mm, -6mm and -7mm finite element model of stress and strain on the root, periodontal ligament and alveolar bone were results: 1 developed a mandibular second molar, periodontal ligament, bone plate, cancellous bone, cortical bone and implant the three-dimensional finite element model of geometric similarity is high, the grid structure is complete, excellent quality; three grid experiment set density on the root, periodontal ligament and alveolar bone The stress and strain distribution and size has no obvious effect; different periodontal parameters should have influence on stress and strain distribution and size of teeth and periodontal membrane, alveolar bone should have no effect on stress and strain distribution, but the size of stress and strain during different period of time, effect of depression of the mandibular second molar vertical.2 the root, periodontal ligament and alveolar bone on the stress and strain distribution area is basically the same, the root stress and strain concentration is mainly distributed in the root buccal root 1/3, buccal tooth neck and root lingual root 1/3; periodontal membrane stress and strain distribution in the apical area and buccal lingual tooth neck; stress and strain distribution in the alveolar fossa four line angle of the neck region and buccal root bifurcation alveolarbone with force; loading time increases, the root, periodontal ligament and alveolar bone should decrease the maximum equivalent stress and strain, the first day of decreasing the fastest; The maximum effect of periodontal membrane and alveolar bone becomes far greater than the root.3 vertical down mandibular second molar in the process, with the decrease of molar inclination of tongue, lingual root and periodontal ligament of buccal cervical stress concentration regions gradually expanded; stress concentration range should be reduced alveolar bone buccal, lingual inclination of 20 minimum degree, stress concentration should be increased the scope of the lingual lingual inclination of 20 degrees, the maximum stress, strain concentration than the buccal side of the tongue should be obvious; the maximum equivalent tooth root and periodontal ligament of the stress and strain increase gradually; the maximum equivalent stress and strain of the alveolar bone increased, the maximum lingual inclination of 20 degrees; the teeth down trend than trend of.4 buccal moving down vertical mandibular second molars in different bone density on the root and periodontal membrane should have no effect on stress and strain distribution and size; with the decrease of bone density, bone buccal root furcation area of stress concentration by Fade, strain concentration by bone plate transferred to cancellous bone region; with lower bone density, bone maximum equivalent stress increasing, mainly is the maximum equivalent bone plate stress increasing, the maximum effect of the alveolar bone is increasing, A/B bone density is mainly the maximum effect of bony plate change increase C/D bone mineral density is mainly the maximum effect of cancellous bone increased progressively with the.5 vertical down the mandibular second molar process, decrease with the height of periodontal supporting tissue of root, periodontal ligament and alveolar bone on the stress and strain distribution to the apical area, the maximum equivalent stress and strain increase when the root; the bifurcation after exposure, the root, periodontal ligament and alveolar bone stress and strain is highly concentrated in the root tip, the maximum equivalent stress and strain increase significantly. Conclusion: the stress buffering effect of periodontal membrane 1 nonlinear parameters of periodontal membrane set model is more obvious, the stress distribution is more In line with the actual situation. In subsequent experiment, periodontal membrane can be elastic nonlinear super set, can choose medium mesh grid density, to ensure accurate at the same time, to improve the operation efficiency of.2 because of the root stress concentration regions are not located in the root furcation and root tip region, so the root tip and root bifurcation obviously the absorption in the vertical lower mandibular molars without; buccal lingual alveolar bone were at the edge of the stress concentration that we in the lower mandibular molar vertical, not only buccal alveolar bone absorption may exist, the lingual alveolar bone will be absorbed by the risk; due to periodontal ligament strain, should control the initial stress value and to protect the periodontal ligament, the initial loading force value of 100g is suitable for.3 due to stress and strain distribution and size increases with the increase of molar lingual alveolar bone should be upright, and the teeth down trend is greater than the buccal movement, Therefore, the risk of lingual alveolar bone absorption of more concern with the tongue; molar inclination decreases, the applied force should be decreased and the molar lingual inclination of 20 degrees with the minimum value of the vertical force.4 lower mandibular molar, alveolar bone density in patients with low prone gummatous absorption for alveolar bone density in patients with low, to appropriate to reduce the initial loading force value, is conducive to protecting the stability of planting anchorage, and can prevent the absorption of alveolar bone pathological.5 periodontal problems of mandibular second molar vertical down, to reduce the force (less than 100g); furcation exposure is the vertical down of the mandibular second molar contraindications.

【学位授予单位】：大连医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R783.5
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本文编号：1772688