本文選題：三維有限元 + 下頜第二磨牙�。� 參考：《大連醫(yī)科大學》2017年碩士論文

【摘要】：目的:1建立種植體支抗豎直壓低下頜第二磨牙的三維有限元模型并優(yōu)化牙周膜參數與網格密度;2研究種植體支抗豎直壓低下頜第二磨牙過程中不同時間階段牙根、牙周膜及牙槽骨的應力應變情況;3研究豎直壓低不同舌傾角度下頜第二磨牙過程中,牙根、牙周膜及牙槽骨的應力應變情況;4研究豎直壓低下頜第二磨牙時,不同骨質密度對牙根、牙周膜及牙槽骨應力應變的影響;5研究豎直壓低下頜第二磨牙時,不同牙周支持組織高度對牙根、牙周膜及牙槽骨應力應變的影響。方法:1應用逆向工程軟件Geomagic Studio 10.0對下頜第二磨牙三維數據進行優(yōu)化,應用有限元分析軟件ANSYS 15.0建立種植體支抗豎直壓低下頜第二磨牙的三維有限元模型;根據牙周膜參數設置(線性參數與非線性參數)與網格劃分密度(高、中、低網格密度),將實驗分為六個工況,分別對下頜第二磨牙的牙根、牙周膜及牙槽骨的應力應變進行分析。2建立下頜第二磨牙舌傾40°的三維有限元模型,根據3M鏈狀皮圈在口腔內的衰減規(guī)律,得到第0、1、7、14、21與28天施加于下頜第二磨牙的力值分別為100g(1N)、75g(0.75N)、59g(0.59N)、43.75g(0.4375N)、32.5g(0.325N)、22.5g(0.225N)。將上述力值代入模型模擬不同時間階段,對下頜第二磨牙牙根、牙周膜及牙槽骨的應力應變進行分析;3建立下頜第二磨牙舌傾40°、30°、20°、10°與0°的三維有限元模型,對其牙根、牙周膜及牙槽骨的應力應變進行分析;4建立下頜第二磨牙舌傾40°的三維有限元模型,按照四種骨質密度的材料參數對牙槽骨進行設置,對牙根、牙周膜及牙槽骨的應力應變進行分析;5建立下頜第二磨牙舌傾40°的三維有限元模型,依次降低牙周支持組織高度1mm,得到牙周支持組織高度分別為-1mm、-2mm、-3mm、-4mm、-5mm、-6mm與-7mm的有限元模型,對牙根、牙周膜及牙槽骨的應力應變進行分析。結果:1成功建立了包含下頜第二磨牙、牙周膜、硬骨板、松質骨、皮質骨及種植體支抗的三維有限元模型,幾何相似度高,結構完整,網格質量優(yōu)良;實驗設定的三種網格密度對牙根、牙周膜及牙槽骨的應力應變分布與大小沒有明顯影響;不同牙周膜參數的設置對牙根與牙周膜應力應變的分布與大小均有影響,對牙槽骨應力應變分布沒有影響,但對其應力應變大小有影響。2豎直壓低下頜第二磨牙的不同時間階段,牙根、牙周膜及牙槽骨的應力應變集中分布區(qū)域基本相同,牙根的應力應變集中主要分布于牙根頰側根中1/3處、頰側牙頸部及牙根舌側根中1/3處;牙周膜的應力應變集中分布于舌側根尖區(qū)與頰側牙頸部;牙槽骨的應力應變集中分布于牙槽窩四個線角的頸部區(qū)域與頰側根分叉區(qū)域;隨作用力加載時間增加,牙根、牙周膜及牙槽骨最大等效應力與應變遞減,第一天遞減最快;牙周膜的最大等效應變遠遠大于牙根與牙槽骨。3豎直壓低下頜第二磨牙過程中,隨著磨牙舌傾度的減小,牙根舌側與牙周膜頰側頸部的應力應變集中分布區(qū)域逐漸擴大;牙槽骨頰側應力應變集中范圍減小,舌傾20°時最小,舌側應力應變集中范圍增加,舌傾20°時最大,舌側應力應變集中比頰側顯著;牙根與牙周膜的最大等效應力與應變逐漸增大;牙槽骨的最大等效應力與應變增大,舌傾20°時最大;牙齒壓低的趨勢大于頰側移動的趨勢。4豎直壓低下頜第二磨牙過程中,不同骨質密度對牙根與牙周膜的應力應變分布與大小沒有影響;隨骨質密度的降低,牙槽骨頰側根分叉區(qū)的應力集中逐漸顯著,應變集中由硬骨板轉移到松質骨區(qū)域;隨骨質密度的降低,牙槽骨最大等效應力遞增,主要是硬骨板的最大等效應力遞增,牙槽骨的最大等效應變也遞增,A/B類骨密度時主要是硬骨板的最大等效應變遞增,C/D類骨密度時主要是松質骨的最大等效應變遞增。5豎直壓低下頜第二磨牙過程中,隨著牙周支持組織高度的降低,牙根、牙周膜及牙槽骨的應力應變分布向根尖區(qū)集中,最大等效應力與應變遞增;當根分叉暴露后,牙根、牙周膜及牙槽骨的應力應變高度集中于根尖,最大等效應力與應變顯著增大。結論:1牙周膜非線性參數設定模型的牙周膜對應力的緩沖作用更明顯,應力分布更符合實際情況。在后續(xù)實驗中,牙周膜可以進行非線性的超彈性設定,網格劃分可以選擇中等網格密度,在保證精確的同時,有利于提高運算效率。2由于牙根的應力集中分布區(qū)域不位于根分叉與根尖區(qū),所以根尖與根分叉在豎直壓低下頜磨牙時不會產生明顯的吸收;牙槽骨的頰舌側邊緣處均有應力集中,提示我們在豎直壓低下頜磨牙時,不僅頰側牙槽骨可能存在吸收,舌側牙槽骨也會有吸收的風險;由于牙周膜應變較大,應控制初始力值,以保護牙周膜,100g的初始加載力值比較合適。3由于牙槽骨舌側應力應變分布與大小隨磨牙的直立而增加,并且牙齒壓低的趨勢大于頰側移動的趨勢,因此,舌側牙槽骨的吸收風險更值得關注;隨著磨牙舌傾度減小,施加的作用力應該減小,磨牙舌傾20°時應該用最小力值。4豎直壓低下頜磨牙時,牙槽骨密度低的患者容易產生潛行性吸收,對于牙槽骨密度低的患者,要適當降低初始加載力值,既有利于保護種植體支抗的穩(wěn)定性,又可以防止牙槽骨的病理性吸收。5有牙周問題的下頜第二磨牙進行豎直壓低時,要減小作用力(小于100g);根分叉暴露是豎直壓低下頜第二磨牙的禁忌癥。
[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.

【學位授予單位】：大連醫(yī)科大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：R783.5
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本文編號：1772688