基于钛合金（TC4）材料的义齿逆向设计及3D打印技术研究

发布时间：2018-03-09 08:38

本文选题：义齿　切入点：逆向建模　出处：《辽宁工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文选用钛合金(TC4)材料进行义齿的金属3D打印,采用理论研究与实验验证相结合的方式进行。具体方法是借助现有完善的先进硬件实验设备,采用逆向成型技术,结合部分三维CAD、有限元分析等支撑软件为工具和平台,最后获得修复体,具体内容如下:(1)进行义齿的逆向建模,对患者有问题的牙齿进行预备。使用印模材料对患者的口腔组织形态进行制备,灌出石膏模型。待石膏模型干燥后,使用COMET L3D精度为0.03mm的扫描仪对上颌、进行预备的下颌和临床标准牙冠进行扫描,扫描的文件导入到Geomagic Studio逆向工程软件中进行处理,包括模型点云数据简化与降噪、模型点云数据补缺和曲面模型重建及实体化,最后生成CAD三维实体模型三个部分。义齿的逆向建模是最基本的部分,也是最关键的,因为最后得到的模型直接影响后续的上下颌咬合和实验部分。(2)得到的CAD三维实体模型导入到三维软件中进行上下颌静态咬合,首先将处理后的义齿与预备体下颌进行装配,测得预备牙长8mm,宽9mm。在进行安装义齿时,需要留有一定空间添加胶进行固定,因为牙冠的厚度为1.5mm,所以需要对标准义齿的外形做成长11mm,宽12mm。测得预备牙外侧高4mm,内侧高2mm,并且对标准义齿进行边缘调整,最后整个义齿高度为6.5mm。(3)在满足咬合关系后,需要对义齿进行三维有限元分析。首先对义齿进行定义材料属性和网格划分,并施加不同载荷力,通过查看总变形量云图和总应力云图,得到义齿的变形量最大为0.0011395mm,主应力最大为22.588MPa,临床口腔加载600N载荷力时最大变形为0.002mm,主应力临界值为38MPa,满足临床要求。(4)进行义齿TC4合金材料的金属3D打印,探究激光扫描功率、扫描速度和倾斜角度对试样件几何尺寸的影响规律,并利用正交试验探索工艺参数的范围。通过观察洛氏硬度、显微硬度和金相组织,确定一组最佳参数,最佳参数为:激光扫描功率为280W、扫描速度1200mm/s、倾斜角度为55°,并进行义齿的最后打印。对打印后的义齿进行扫描,与设计的数字化模型进行3D对比,发现义齿咬合面部分的误差最大为0.0150mm,义齿边缘部分的误差最大为0.2524mm,综合误差非常小,说明打印的一组参数符合标准。通过以上研究,采用软件与实验相结合的方法来制取义齿是可行的,从而也使得临床上制取义齿变得不再单一,尽管这种方法不太成熟,需要进一步提高精度,但是采用这种方法既能缩短研制周期又能降低产品成本,是值得深入研究。
[Abstract]:In this paper, titanium alloy TC4) is used for metal 3D printing of denture, which is carried out by combining theoretical research with experimental verification. Combining part of 3D CAD, finite element analysis and other supporting software as the tool and platform, finally get the prosthesis, as follows: 1) the reverse modeling of denture, Prepare patients with problematic teeth. Use the impression material to prepare the patient's oral tissue morphology and put out the plaster model. After the gypsum model is dried, use a scanner with COMET L3D accuracy of 0.03mm to treat the maxilla. The prepared mandible and clinical standard crown were scanned, the scanned files were imported into the Geomagic Studio reverse engineering software for processing, including model point cloud data simplification and noise reduction, model point cloud data supplement and surface model reconstruction and materialization. Finally, three parts of CAD 3D solid model are generated. The reverse modeling of denture is the most basic part and the most important part. Because the final model directly affects the subsequent maxillary and mandibular occlusal and experimental part. 2) the CAD 3D solid model is imported into the 3D software for the static occlusion of the maxilla and mandible, and the processed denture is first assembled with the prefabricated mandible. The length of the prepared tooth is 8 mm and the width is 9 mm. When the denture is installed, it is necessary to leave some space for fixing the denture by adding glue to the denture. Because the thickness of the crown is 1.5 mm, the shape of the standard denture needs to grow 11mm and 12mm wide. The outer height of the preparatory denture is 4mm, the medial height is 2mm, and the edge of the standard denture is adjusted. Finally, the height of the denture is 6.5mm. Three dimensional finite element analysis of denture is needed. Firstly, the material attributes and mesh are defined, and different load forces are applied to the denture. The maximum deformation of denture is 0.0011395mm, the maximum principal stress is 22.588MPa, the maximum deformation is 0.002mm when the clinical oral cavity is loaded with 600N load force, the critical value of principal stress is 38MPa. The effect of scanning speed and tilt angle on the geometric size of the specimen is studied. The range of process parameters is explored by orthogonal test. By observing Rockwell hardness, microhardness and metallographic structure, a group of optimum parameters are determined. The best parameters are as follows: laser scanning power is 280 W, scanning speed is 1200 mm / s, tilt angle is 55 掳, and the final printing of denture is carried out. It is found that the maximum error of denture occlusal surface is 0.0150 mm, the maximum error of denture edge is 0.2524 mm, and the comprehensive error is very small, which indicates that the set of parameters printed conforms to the standard. It is feasible to use the method of combining software with experiment to make denture, which makes the clinical denture more simple, although this method is not very mature and needs to be improved further. However, this method can shorten the development cycle and reduce the product cost, which is worthy of further study.
【学位授予单位】：辽宁工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R783.1;TG146.23

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