中度牙周炎套筒冠式牙周夹板修复基于CBCT取像的三维有限元分析

发布时间：2018-05-26 23:21

本文选题：牙周炎 + CBCT　；参考：《锦州医科大学》2017年硕士论文

【摘要】：目的本实验拟建立中度牙周炎完整牙列套筒冠牙周夹板的三维有限元分析模型,通过修复前后牙周膜内应力的分布变化,为套筒冠牙周夹板的修复效果提供实验室依据。方法本实验研究方法如下:一、从50名志愿者中筛选出1名实验对象,进行下颌骨CBCT扫描,建立含健康完整牙列下颌骨三维几何模型(包括完整牙列、牙周膜、牙槽骨),验证模型有效性,分析健康状态下牙周膜应力分布,提供参考。二、修改健康完整下颌骨模型,建立中度牙周炎完整牙列下颌骨三维几何模型,分析牙周膜应力变化,与健康模型进行对比,分析差异。三、修改中度牙周炎下颌骨模型,建立中度牙周炎完整牙列套筒冠夹板修复后下颌骨三维模型法,分析牙周膜应力改变,与未修复完整牙列下颌骨模型对比,分析差异。结果实验结果如下:一、成功基于CBCT建立含完整牙列及牙周膜的下颌骨模型,解剖形态逼真。有限元分析显示牙周膜应力规律符合以往研究。正常完整牙齿咀嚼时,牙周膜的Von Mises应力值大致在2.39 MPa~3.96 MPa;二、中度牙周炎和套筒冠修复后的牙周膜Von Mises应力值相对正常情况来说,都有不同程度的增加,应力增幅也不一样。套筒冠修复后的各牙周膜Von Mises应力值均比牙周炎模型的小,对比各牙应力增量变化幅度,套筒冠修复后的牙周膜应力增幅相比牙周炎模型降低很多,相对降幅约12.55%~102.66%,可以说明套筒冠修复在一定程度上有助于改善牙周膜受力情况。三、套筒冠修复降低了牙周膜应力,将大多数应力转移到牙槽骨上。牙周炎模型牙齿的Von Mises应力最大值约31.3 MPa,下颌骨的Von Mises应力最大值约4.99 MPa;套筒冠修复后模型,牙齿的Von Mises应力最大值约25.6 MPa,而下颌骨的Von Mises应力最大值有所增加,约6.51 MPa。套筒冠修复后的牙齿的Von Mises应力相对中度牙周炎模型的应力降幅约8.04%,套筒冠修复后的下颌骨的Von Mises应力相对中度牙周炎的应力增幅约14.21%。结论一、基于CBCT建立完整牙列下颌骨模型是可行的,模型可信度好,满足对此模型进行调整及分析的需要。二、套筒冠牙周夹板可有效减小中度牙周炎各牙不利应力,有利于减小咬合创伤对牙周炎的影响,利于牙周炎的长期治疗维护。三、从生物力学角度判断,利用有限元方法对中度牙周炎、套筒冠修复进行力学仿真模拟分析是有很大帮助的,可以为中度或重度牙周炎修复治疗提供较好的临床理论研究指导作用,为今后牙齿修复临床手术提供了宝贵的科学依据。
[Abstract]:Objective to establish a three-dimensional finite element analysis model of periodontal plywood with complete abutment crown for moderate periodontitis, and to provide a laboratory basis for the effect of periodontal plywood restoration through the distribution of stress in periodontal ligament before and after restoration. Methods the methods of this experiment were as follows: 1. One sample was selected from 50 volunteers, and the mandibular CBCT scan was performed to establish a three-dimensional geometric model of mandible with healthy and complete dentition (including complete dentition and periodontal ligament). Alveolar bone to verify the validity of the model, to analyze the periodontal ligament stress distribution under healthy conditions, to provide a reference. Second, the healthy intact mandible model was modified, and the three-dimensional geometric model of the complete dentition mandible was established, and the stress changes of periodontal ligament were analyzed, compared with the healthy model, and the difference was analyzed. Third, the mandibular model of moderate periodontitis was modified, and the mandibular model was established after the restoration of the complete denture with crown splint. The stress changes of periodontal ligament were analyzed, and the difference was analyzed compared with the model of the unrepaired complete dentition mandible. Results the results were as follows: first, the mandibular model with complete dentition and periodontal ligament was successfully established based on CBCT, and the anatomical morphology was lifelike. Finite element analysis shows that the stress law of periodontal ligament accords with previous studies. The Von Mises stress value of periodontal ligament was about 2.39 MPa~3.96 MPA when normal teeth were chewed, and the Von Mises stress value of periodontal ligament after moderate periodontitis and abutment crown repair was increased in different degree and the increase of stress was also different compared with the normal condition. The Von Mises stress value of each periodontal membrane was smaller than that of periodontitis model. Compared with each tooth stress increment, the periodontal ligament stress increase after abutment crown restoration was much lower than that of periodontitis model. The relative decrease was about 12.55 and 102.66, which indicated that the restoration of sleeve crown was helpful to improve the stress of periodontal membrane to some extent. Thirdly, the socket crown reduced the stress of periodontal membrane and transferred most of the stress to the alveolar bone. The maximum value of Von Mises stress in periodontitis model teeth was about 31.3 MPA, the maximum value of Von Mises stress in mandible was about 4.99 MPA, the maximum value of Von Mises stress in teeth was about 25.6 MPA, and the maximum value of Von Mises stress in mandible was increased (about 6.51 MPA). Compared with moderate periodontitis model, the Von Mises stress of the teeth repaired by the sleeve crown decreased by 8.04, and the Von Mises stress of the mandible repaired by the sleeve crown increased about 14.21% compared with that of the moderate periodontitis. Conclusion 1. It is feasible to establish a complete dentition mandibular model based on CBCT, and the model is reliable and meets the needs of adjustment and analysis of the model. Second, the periodontal splint of the abutment crown can effectively reduce the adverse stress of each tooth in moderate periodontitis, which is beneficial to the reduction of the effect of occlusal trauma on periodontitis and to the long-term treatment and maintenance of periodontitis. Third, judging from the biomechanical point of view, it is very helpful to use finite element method to simulate and analyze the mechanics of moderate periodontitis and sleeve crown repair. It can provide good theoretical guidance for the treatment of moderate or severe periodontitis, and provide a valuable scientific basis for the clinical operation of dental repair in the future.
【学位授予单位】：锦州医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R781.42

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