下颌第一磨牙颊（牙合）缺损不同修复形式的三维有限元分析

发布时间：2018-06-12 02:52

本文选题：下颌第一磨牙 + 颊（牙合）缺损　；参考：《郑州大学》2016年硕士论文

【摘要】：目的应用三维有限元方法,建立颊（牙合）缺损根管治疗后不同修复形式的下颌第一磨牙有限元模型,分别在垂直和斜向载荷下,观察分析不同形式修复后下颌第一磨牙牙体组织的应力峰值及应力分布情况,寻求一种应力分布相对合理的修复形式,为临床中下颌第一磨牙颊（牙合）缺损根管治疗后修复形式的选择,提供生物力学方面的实验理论数据。材料与方法1.选择一牙列完整、咬合关系正常,无牙周疾病,下颌磨牙无明显磨耗的年轻成年女性志愿者,通过CBCT扫描获取实验图像,Mimics软件读取图像并进行初步处理,Geomagic软件精修,造型软件Solidworks装配各模块和有限元软件Ansys Workbench划分网格,材料赋值,边界设定,建立正常下颌第一磨牙的三维有限元模型。2.在正常下颌第一磨牙三维有限元模型的基础上,对牙冠和根管进行形态修整以模拟根管治疗和牙体组织的缺损,设定材料参数,组装各模块并进行网格划分,获得下颌第一磨牙颊（牙合）缺损行根管治疗后模型及分别以IPS e.max CAD瓷材料进行嵌体修复(嵌体Ⅰ)、树脂内部重建后嵌体修复(嵌体Ⅱ)、覆盖颊尖的高嵌体修复(高嵌体Ⅰ)、覆盖整个牙合面的高嵌体修复(高嵌体Ⅱ)、全冠修复和玻璃纤维树脂桩核冠修复的三维有限元模型。3.在牙合面近远中边缘嵴中央、中央窝、近远中颊尖顶,与牙体长轴成15°加载垂直向载荷,每个加载点力值为40N;在近远中颊尖颊斜面中心点与牙长轴成60°加载斜向载荷,每个加载点力值为100N,模拟牙齿正中和侧方咬合下的受力情况,输出各个模型在两种载荷下的应力分布云图,观察分析剩余牙体组织的等效应力和最大主应力的分布及大小。结果1.建立了正常下颌第一磨牙的三维有限元基础模型及颊（牙合）面大面积缺损根管治疗后以ipse.maxcad嵌体、高嵌体、全冠、桩核冠等形式修复的下颌第一磨牙三维有限元模型,包括牙本质、牙胶尖、复合树脂、嵌体、高嵌体、覆盖体、全冠、玻璃纤维桩、粘接层、牙周膜及牙槽骨等结构。2.在垂直载荷下,完整牙体组织牙釉质的等效应力和最大主应力主要集中在咬合力加载区,峰值位于远中颊尖;牙本质的应力主要集中牙颈部和根尖区,峰值位于远中根根尖区的颊侧。斜向载荷下,牙釉质的等效应力和最大主应力主要集中在咬合力加载区,峰值均位于远中颊尖;牙本质的应力主要集中于牙根的舌侧面,峰值均位于近中根根尖区舌侧面。3.不同形式修复后牙体组织在不同载荷下的应力情况:(1)垂直载荷下,牙釉质的等效应力和最大主应力均集中在咬合力加载区,其等效应力峰值变化为:嵌体Ⅱ嵌体Ⅰ高嵌体Ⅰ高嵌体Ⅱ。嵌体Ⅰ、嵌体Ⅱ、全冠和桩核冠牙本质的等效应力峰值位于远中根根尖区颊侧,而高嵌体Ⅰ和高嵌体Ⅱ牙本质的等效应力峰值位于颊髓线角区,不同形式修复后牙本质的等效应力峰值变化为:高嵌体Ⅱ高嵌体Ⅰ全冠桩核冠嵌体Ⅰ嵌体Ⅱ。六种修复形式牙本质的最大主应力峰值均位于远中根根尖区颊侧,且峰值相差不大。(2)斜向载荷下,不同修复形式下牙釉质的应力峰值位置不同,其等效应力峰值变化为:高嵌体Ⅰ嵌体Ⅰ嵌体Ⅱ高嵌体Ⅱ。而牙本质的等效应力峰值只有高嵌体Ⅱ位于髓室底部,其余五种修复形式的应力峰值均位于近中根根尖区舌侧,且牙本质的等效应力峰值变化为:高嵌体Ⅱ高嵌体Ⅰ桩核冠全冠嵌体Ⅱ嵌体Ⅰ。嵌体Ⅰ、高嵌体Ⅰ和高嵌体Ⅱ修复后牙本质的最大主应力峰值位于颊髓线角区,嵌体Ⅱ、全冠和桩核冠的最大主应力峰值位于近中根根尖区舌侧,其应力峰值变化为:高嵌体Ⅰ高嵌体Ⅱ嵌体Ⅰ嵌体Ⅱ桩核冠全冠。结论1.将cbct扫描技术和逆向工程软件mimics、geomagic、造型软件solidworks和有限元分析软件ansysworkbench相结合,能够快捷有效的建立三维有限元模型。所建立的正常下颌第一磨牙模型及颊（牙合）缺损根管治疗后的不同修复形式的模型均具有良好的几何相似性和力学相似性;2.无论从应力峰值大小还是应力分布情况来看,下颌第一磨牙颊（牙合）缺损根管治疗后,以IPS e.max CAD瓷材料进行全冠及玻璃纤维桩核冠修复后,剩余牙体组织上的应力在生物力学上较为合理;3.玻璃纤维桩没有改变修复后牙齿的应力分布及应力峰值;4.在进行根管治疗及窝洞预备时,要尽量保留髓室底部的牙体组织。
[Abstract]:Objective to establish a finite element model of mandibular first molar with different repair forms after the treatment of buccal (occlusal) defect root canal with three-dimensional finite element method. The stress peak and stress distribution of the mandibular first molar were observed and analyzed under vertical and oblique loads, and a relatively reasonable stress distribution was sought. The form of repair for the clinical medium and mandibular first molar buccal (occlusal) defect after the root canal treatment of the choice of repair form, provide biomechanical experimental theoretical data. Material and method 1. select a complete tooth, normal occlusion relationship, no periodontal disease, mandibular molar without obvious wear of young adult female volunteers, through CBCT scan obtained by scanning Taking the experimental image, the Mimics software reads the image and carries on the preliminary processing, the Geomagic software refinements, the modeling software Solidworks assembly modules and the finite element software Ansys Workbench division grid, the material assignment, the boundary setting, and establishes the three-dimensional finite element model of the normal mandibular first molar with the three-dimensional finite element model of the normal mandible first molar. On the basis of the shape repair of the crown and root canal to simulate the root canal treatment and tooth tissue defect, set material parameters, assemble each module and mesh to obtain the mandibular first molar buccal (occlusion) defect after root canal treatment model and IPS E.Max CAD porcelain material for inlay repair (inlay I) and internal reconstruction of resin. Posterior inlay repair (inlay II), high inlay repair (high inlay I) covering the cheek apex (high inlay I), high inlay repair (high inlay II) covering the entire denture surface. The three-dimensional finite element model.3. of the full crown restoration and the repair of the glass fiber resin post coronal is in the middle of the middle and distal crest of the occlusal surface, the central fossa, the proximal and middle buccal spires, and the 15 degrees of the long axis of the tooth. The force value of each loading point is 40N, and the oblique load of the center point of the buccal tip cheek and the tooth long axis is 60 degrees in the near distance. The force value of each loading point is 100N, and the stress situation under the normal and lateral bite of the teeth is simulated. The stress distribution of each model under the two loads is output, and the equivalent stress of the residual tooth tissue is observed and analyzed. Results 1. the three-dimensional finite element model of the normal mandibular first molar and the three dimensional finite element model of the first molar of the mandible, including ipse.maxcad inlay, high inlay, full crown and pile core crown, were established after the treatment of the normal mandibular first molar, and the three dimensional finite element model of the mandibular first molar, including dentin, gutta cusp and composite resin, was repaired. Inlay, high inlay, cover, full crown, glass fiber pile, adhesive layer, periodontal membrane and alveolar bone, the equivalent stress and maximum principal stress of the enamel in complete dentin are mainly concentrated in the loading area of the bite force, the peak is located in the distal cheek tip, and the stress of dentin mainly concentrates on the neck and the apex area, the peak is far away from the.2.. The equivalent stress and maximum principal stress of the enamel are mainly concentrated in the loading area of the bite force under the oblique load. The peak value of the dentin is mainly located in the distal and middle buccal tips. The stress of the dentin is mainly concentrated on the side of the tongue of the root. The peak value of the dentin is located at the different load of the posterior teeth of the posterior part of the root tip of the proximal root zone.3.. Force situation: (1) the equivalent stress and the maximum principal stress of the enamel are concentrated in the loading area of the bite force under the vertical load. The peak value of the equal effect force is: the inlay II inlay I high inlay I high inlay II. The inlay I, the inlay II, the peak value of the equivalent stress of the whole crown and the pile core dentin is located at the buccal side of the root tip of the distal root, while the high inlay I and high inlay The peak value of the equivalent stress of the dentin is located in the buccal cord angle area. The peak value of the equivalent stress of different forms of repairing posterior dentin is: high inlay II high inlay I full crown coronal inlay I inlay II. The peak value of the maximum principal stress of the six dentin is located on the cheek of the root tip of the distal root, and the difference of the peak value is not significant. (2) oblique load The peak stress peak position of dental enamel under different repair forms is different, and the peak value of its equal effect force is: high inlay I inlay I inlay II high inlay II. The peak value of the equivalent stress of dentin is only at the bottom of the medullary chamber, and the stress peaks of the other five kinds of repair forms are located in the lingual side of the proximal root apex region, and the dentin essence is the same. The peak value of effect force change is: high inlay II high inlay I pile coronal full crown inlay I inlay I. The maximum peak stress peak of high inlay I and high inlay II repair posterior dentin is located in the buccal pulp line angle region, inlay II, the maximum principal stress peak of the whole crown and pile core is located at the tongue side of the proximal root tip area, and the peak stress change is high inlay. Conclusion 1. the three-dimensional finite element model can be established quickly and effectively by combining CBCT scanning technology with mimics, Geomagic, Modeling Software Solidworks and finite element analysis software ansysworkbench, and the normal mandibular first molar model and buccal (occlusion) defect are established. The models of different repair forms after root canal therapy had good geometric similarity and mechanical similarity. 2. after the root canal treatment of the mandibular first molar buccal (occlusion) defect, the residual tooth tissue was repaired with IPS E.Max CAD porcelain material after the crown and glass fiber post coronal repair. The stress is more reasonable in biomechanics; 3. glass fiber pile does not change the stress distribution and stress peak of the repaired teeth. 4. in the root canal treatment and pit preparation, we should keep the dental tissue at the bottom of the pulp chamber as far as possible.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R781.05

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