口腔种植导板定位误差及其对种植精度的影响研究

发布时间：2018-12-29 07:42

【摘要】：种植牙舒适美观,可以较好地恢复缺牙区的功能,而且不损害相邻牙,已经成为口腔医学界公认的缺失牙的首选修复方法。种植体的植入位置需要避开颌骨中神经管、邻牙牙根等重要解剖结构,且要保证种植体与骨界面结合处有充足的骨量,同时植入的方向和角度需要充分考虑后期的修复。传统的种植方法无法在术前进行科学的种植手术规划、术中主要依靠医生的经验、难以精确地控制种植位置和角度,使得种植手术存在安全隐患和失败的风险。数字化种植技术的兴起在一定程度上弥补了传统种植方法的缺陷。虽然采用数字化种植技术后种植体的植入精度相比于传统种植方法有明显改进,但仍有待进一步提高。口腔种植导板是数字化种植技术实现的关键载体,从前期患者数据的采集开始,方案设计、加工制造等数字化种植中的各环节误差都会累积到导板上。而导板的定位精度直接影响到种植备孔的精确度并最终影响种植体的植入位置。本研究旨在构建一种在术前评价口腔种植导板定位误差的方法。首先,提出了基于三角网格曲面的定位误差分析模型;其次,探究了导板定位曲面的布局及误差对导板定位误差的影响,本文采用种植体的位置偏差来描述导板定位误差;然后进行导板的设计制造,加工出具有特定定位曲面的导板,并评价了导板定位曲面的误差。最后,通过实验和仿真分析的方法评价了导板定位误差。本文的主要工作和研究成果如下:1.分析了三角网格曲面装配接触特性,提出了基于三角网格曲面装配模型的定位误差分析方法,并给出了其中雅可比矩阵的表达式;2.构建了定位曲面误差分析方法,提出了采用定位点误差表达定位曲面误差的方法,讨论了导板定位曲面误差及定位曲面布局对定位误差的影响;3.针对具有特定定位曲面的导板,进行了导板定位曲面的误差分析。实验表明:定位曲面误差与其在导板上所处位置无关。所制备的导板定位曲面的整体平均偏差在0.169 mm;4.采用实验及仿真方法进行导板定位误差的评价,其仿真结果与实验结果具有一致性。结果表明,因导板定位问题而引起种植体颈部和顶端的偏差均接近1mm,且种植体顶端偏差要大于颈部偏差。另外,导板定位误差受定位曲面布局及定位曲面误差的共同影响。在同一定位曲面布局下,定位误差随定位曲面误差递增;定位误差与定位曲面布局之间无明显线性关系。
[Abstract]:The dental implant is comfortable and beautiful, can restore the function of the missing tooth area, and does not damage the adjacent teeth, so it has become the preferred restoration method of missing tooth in the field of stomatology. The implant should avoid the important anatomical structures such as the middle jaw canal and the root of the adjacent tooth, and ensure that there is sufficient bone mass at the interface between the implant and the bone. At the same time, the direction and angle of the implant should be fully considered in the later stage of restoration. The traditional implant method can not carry out the scientific planning of the implant operation before operation, and it is difficult to accurately control the location and angle of the implant by relying mainly on the experience of the doctor during the operation, which makes the implant operation have the risk of safety hidden trouble and failure. The rise of digital planting technology to some extent makes up for the defects of traditional planting methods. Although the precision of the implant with digital planting technology is obviously improved compared with the traditional planting method, it still needs to be further improved. Oral implant guide plate is the key carrier of digital implant technology. From the beginning of data acquisition, scheme design, processing and manufacturing, the errors in digital implant will accumulate to the guide board. The positioning accuracy of the guide plate directly affects the precision of the implant hole and finally the implant location. The purpose of this study was to establish a method to evaluate the positioning error of oral implant guide before operation. Firstly, the positioning error analysis model based on triangular mesh surface is proposed. Secondly, the layout of guide plate positioning surface and the influence of the error on the guide plate positioning error are explored. In this paper, the implant position deviation is used to describe the guide plate positioning error. Then the guide plate is designed and manufactured, and the guide plate with a specific positioning surface is machined, and the error of the guide plate positioning surface is evaluated. Finally, the positioning error of guide plate is evaluated by experiment and simulation. The main work and research results are as follows: 1. The contact characteristics of triangular mesh surface assembly are analyzed, and the location error analysis method based on triangular mesh surface assembly model is proposed, and the expression of Jacobian matrix is given. 2. The error analysis method of positioning surface is constructed, and the method of expressing the error of positioning surface by using the error of positioning point is put forward, and the influence of positioning surface error of guide plate and the layout of positioning surface on positioning error is discussed. 3. The error analysis of guide plate with special positioning surface is carried out. The experimental results show that the error of the positioning surface is independent of the position on the guide plate. The overall average deviation of the orientation surface of the prepared guide plate is 0.169 mm;4.. The experimental and simulation methods are used to evaluate the positioning error of the guide plate, and the simulation results are consistent with the experimental results. The results show that the deviation between the neck and the tip of the implant is close to 1 mm due to the location of the guide plate, and the deviation of the top of the implant is greater than that of the neck. In addition, the positioning error of the guide plate is affected by both the positioning surface layout and the positioning surface error. Under the same positioning surface layout, the positioning error increases with the positioning surface error, and there is no obvious linear relationship between the positioning error and the positioning surface layout.
【学位授予单位】：浙江工业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R783.6

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