All-on-4种植参数对骨组织应力影响的三维有限元分析

发布时间：2018-05-15 03:15

本文选题：无牙颌 + All-on-4　；参考：《第四军医大学》2014年硕士论文

【摘要】：无牙颌是口腔修复临床中的常见病，对患者的外貌、发音、咀嚼功能和社交等产生很大影响。全口义齿修复是传统的无牙颌修复治疗方法，但由于缺少固位基牙，以及牙槽骨的吸收和软组织的萎缩变薄，使得全口义齿的固位和稳定性较差，咀嚼效率不高，常出现黏膜压痛溃疡，修复效果令人不尽满意。随着口腔种植技术的发展，种植体的应用大大提高了全口义齿的固位和稳定，提升了无牙颌患者咀嚼效率以及使用舒适度。但是，对于部分牙槽嵴严重萎缩的无牙颌患者，种植修复经常面临骨量不足的问题。对此，为减少手术并发症，有学者提出了All-on-4种植修复方案。此方案是指在无牙颌中采用4颗种植体，包括2颗直式前牙种植体和2颗倾斜后牙种植体，支撑一个固定的全口无牙颌修复体。该方案可通过应用倾斜后牙种植体，来避开上颌窦或下牙槽神经等相关解剖结构，并减少远中游离距和增大种植体与骨的接触面积。在All-on-4中，如何选择合适的后牙种植体倾斜角度、上部修复体悬臂梁长度以及后牙种植体长度等参数，以减小种植体周围骨组织的应力，增加种植体和义齿的长期存留率，是一个需要研究和探讨的问题。研究目的：采用三维有限元法，分析All-on-4远中种植体不同倾斜角度及悬臂梁长度、远中种植体不同长度、上部结构不同加载方式对种植体周围骨组织应力的影响，为临床提供生物力学参考。研究方法：CT扫描获得无牙颌下颌骨的三维数据，采用Mimcs、Geomagic和Unigraphics软件对图像进行相应处理后得到无牙颌下颌骨的三维实体模型。在HyperMesh软件中对模型进行四面体网格划分，建立无牙颌下颌骨的三维有限元模型。分别建立远中种植体倾斜0°、15°、30°和45°时，所对应悬臂梁长度分别为19.5mm、17.2mm、13.3mm和9.8mm的All-on-4种植修复有限元模型，赋予模型中各部分的材料属性，设定模型的边界约束，150N垂直静载荷施于上部结构右侧悬臂梁末端，观察种植体周围骨组织的等效应力峰值和应力分布。建立远中种植体倾斜均为45°悬臂梁长9.8mm，而远中种植体长度分别为13mm、15mm、17mm和19mm的All-on-4种植修复有限元模型。设定材料属性和边界约束，150N垂直静载荷施于上部结构右侧悬臂梁末端，观察种植体周围骨组织的等效应力峰值和应力分布。分别在远中种植体倾斜0°、悬臂梁长19.5mm和倾斜45°、悬臂梁长9.8mm的两组All-on-4种植修复有限元模型中，对上部结构施以单侧游离端、单侧非游离端、前牙区、双侧游离端、双侧非游离端、双侧游离端及前牙区、双侧非游离端及前牙区加载，每个加载点大小均为150N垂直静载荷，观察种植体周围骨组织的等效应力峰值和应力分布。研究结果： 1.建立了下颌骨体高25mm、宽8mm、颏孔间距离53mm、颏孔区管嵴距约8mm、皮质骨在各个方向的厚度均为2mm的无牙颌下颌骨三维有限元模型。 2.在对All-on-4远中种植体倾斜角度和悬臂梁长度对周围骨组织应力影响的研究中，增大远中种植体倾斜角度的同时，不断减小悬臂梁长度，种植体周围骨组织的应力均减小。 3.在对All-on-4远中种植体长度对周围骨组织应力影响的研究中，增加远中倾斜种植体的长度，种植体周围皮质骨和松质骨的应力均减小，但没有倾斜角度及悬臂梁长度共同应用时，对种植体周围骨组织应力的影响大。 4.在不同加载方式对All-on-4种植体周围骨组织应力影响的研究中，单侧游离端、单侧非游离端、前牙区、双侧游离端、双侧游离端及前牙区加载时，远中种植体倾斜45°、悬臂梁长9.8mm的模型中，其种植体周围骨组织的应力低于倾斜0°、悬臂梁长19.5mm的模型；而双侧非游离端、双侧非游离端及前牙区加载时，倾斜45°模型中种植体周围骨组织的应力略高于倾斜0°模型；表明在上部结构游离端加载时，远中种植体倾斜角度大悬臂梁短的All-on-4种植设计能降低周围骨组织的应力。 5.由应力分布图可以看出，无论在上部结构的何种部位进行加载，种植体周围皮质骨和松质骨的等效应力都主要集中在种植体颈部。结论：以上实验结果表明，在All-on-4中，悬臂梁长度对种植体周围骨组织应力的影响大于倾斜角度对种植体周围骨组织应力的影响；远中倾斜种植体长度的增加可以减少种植体周围骨组织的应力，但没有倾斜角度及悬臂梁长度共同应用时，，对种植体周围骨组织应力的影响大；在上部修复体游离端加载时，远中倾斜种植体较远中垂直种植体能显著减小骨界面应力。
[Abstract]:Odonless jaw is a common disease in the clinic of oral repair. It has a great influence on the appearance, pronunciation, masticatory function and sociality of the patients. Complete denture repair is a traditional method for the treatment of edentulous jaws. However, the lack of retainable base teeth, the absorption of alveolar bone and the thinning of the soft tissue, make the retention and stability of the complete denture poor. With the development of dental implant technology, the application of implant greatly improves the retention and stability of complete denture, improves the masticatory efficiency and the use of the maxillary crest patients. In order to reduce the complications of surgery, a All-on-4 implant repair scheme is proposed to reduce surgical complications. This scheme refers to the use of 4 implants in the edentulous jaws, including 2 straight anterior teeth implants and 2 tilted posterior dental implants to support a fixed full oral edentulous prosthesis. The scheme can be used for application. Incline implant to avoid the anatomic structures such as the maxillary sinus or the inferior alveolar nerve, and reduce the distance between the distal and the implant and the contact area of the bone. In All-on-4, how to choose the appropriate angle of the posterior implant, the length of the cantilever beam of the upper prosthesis and the length of the posterior dental implants, in order to reduce the surrounding of the implant. The stress of bone tissue increases the long-term retention rate of implant and denture, which is a problem that needs to be studied and discussed.
Objective: to provide a biomechanical reference for clinical application of three-dimensional finite element method (3D finite element method) for the analysis of the stress of bone tissue around the implant by the different angles and length of the cantilever beam of the All-on-4 and the different length of the implant and the different loading ways of the superstructure.
Research methods: the 3D data of mandible of edentulous jaw were obtained by CT scanning. The 3D solid model of edentulous mandible was obtained by using Mimcs, Geomagic and Unigraphics software to obtain the three-dimensional solid model of the mandible of the edentulous jaw. In the HyperMesh software, the tetrahedral mesh was divided and the three-dimensional finite element model of the mandible of the edentulous jaw was established.
The cantilever beam length of the distal implants is 0, 15, 30 and 45 degrees respectively. The length of the cantilever beam is 19.5mm, 17.2mm, 13.3mm and 9.8mm, respectively. The finite element model is used to fix the material properties of each part of the model. The boundary constraints of the model are set, and the vertical static load of 150N is applied to the end of the right cantilever beam of the superstructure, and the implant is observed. The equivalent stress peak and stress distribution of the surrounding bone tissue.
The long and middle implants were all inclined to 45 degree cantilever beam long 9.8mm, and the length of the distal implants was 13mm, 15mm, 17mm and 19mm for the finite element model. The material properties and boundary constraints were set. The vertical static load of 150N was applied to the end of the right cantilever beam of the superstructure. The equivalent stress peak of the bone tissue around the implant was observed and the corresponding stress was observed. Force distribution.
In the finite element model of two groups of All-on-4 implant repair of the distal implants with 0 degrees, cantilever beam long 19.5mm and 45 degrees, and long 9.8mm cantilever beam, the superstructure was loaded with unilateral free end, unilateral non free end, anterior tooth area, bilateral free end, bilateral free end, bilateral free end and anterior tooth area, bilateral non free end and anterior tooth area. The size of each loading point was 150N vertical static load, and the equivalent stress peak value and stress distribution of bone tissue around the implant were observed.
The results of the study:
1. the three-dimensional finite element model of mandibular mandible was established with high 25mm of mandible body, wide 8mm, 53mm between the mental foramen and the distance of the crest of the mental hole area about 8mm, and the thickness of the cortical bone in all directions was 2mm.
2. in the study of the influence of the incline angle of the All-on-4 and the length of the cantilever beam on the stress of the surrounding bone tissue, the stress of the bone tissue around the implant is reduced while the angle of the distal implants is increased and the length of the cantilever beam is continuously reduced.
3. in the study of the effect of the length of All-on-4 on the stress of the surrounding bone tissue, the stress of the cortical bone and the cancellous bone around the implant was reduced, but the stress of the bone tissue around the implant was greatly influenced without the joint application of the inclination angle and the length of the cantilever beam.
4. in the study of the effect of different loading methods on the stress of bone tissue around All-on-4 implant, the stress of the bone tissue around the implant was lower than 0 degrees in the model of the long 9.8mm in the cantilever beam when the unilateral free end, the anterior tooth area, the bilateral free end, the bilateral free end and the anterior tooth area were loaded. The stress of the bone tissue around the implant in the 45 degree tilt 45 degree model is slightly higher than that of the tilted 0 degree model when the bilateral non free end, bilateral non free end and front tooth area are loaded. It shows that the short All-on-4 planting design of the long middle implant inclined angle large cantilever beam can reduce the surrounding bone tissue when the free end of the superstructure is loaded. Power.
5. from the stress distribution map, it can be seen that the equivalent stress of cortical bone and cancellous bone around the implant is mainly concentrated in the neck of the implant no matter what part of the superstructure is loaded.
Conclusion: the experimental results show that in All-on-4, the effect of the length of the cantilever beam on the stress of the bone tissue around the implant is greater than that of the inclined angle on the stress of the bone tissue around the implant. The increase of the length of the long and middle inclined implants can reduce the stress of the bone tissue around the implant, but there is no inclination angle and the length of the cantilever beam. When used, the stress of the bone tissue around the implant is greatly influenced. When the free end of the upper prosthesis is loaded, the far middle vertical implant can significantly reduce the stress of the bone interface.

【学位授予单位】：第四军医大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R783.6

【参考文献】