Three-dimensional finite element modelling of all-ceramic restorations based on micro-CT
Three-dimensional finite element modelling of all-ceramic restorations based on micro-CT
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DOI：
10.1016/j.jdent.2013.02.014
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发表时间：
2013-05-01
影响因子：
4.4
通讯作者：
Griggs, Jason A.
中科院分区：
文献类型：
--
作者：
Della Bona, Alvaro;Borba, Marcia;Griggs, Jason A.
目的：为了描述和应用一种方法的建模牙冠和三个单元的固定部分义齿（FPD）的有限元分析（FEA）从三维图像获得使用micro-CT scanner.Methods：一个冠和三个单元的固定部分义齿（FPD）的陶瓷框架（Y-TZP）和镶瓷（VM 9）制成的使用X射线micro-CT扫描仪与6.97 μ m的像素大小进行扫描。在每0.034 mm处生成两种结构的切片图像，并通过交互式图像控制系统（Mimics）进行处理。根据X线图像的亮度和对比度，采用阈值法和区域生长法提取基牙、框架和贴面的不同掩模。每个模型的3D对象被合并到非流形组件中，并同时进行网格划分。结果：有限元模型与结构的形状相似度很高。非流形装配的使用确保了不同结构部件之间的匹配表面和重合节点。对于冠模型，拉应力集中在内核的内表面，靠近所施加的负载。对于FPD模型，最高的拉伸应力位于框架中，连接器和桥体的颈部区域。结论：将micro-CT扫描与Mimics软件相结合，可以生成有效的牙冠和FPD的三维模型，强调其在牙科研究中作为设计工具的重要性。临床意义：本文所述的三维有限元分析方法是预测应力分布的重要工具，有助于牙科修复体的结构设计。(C)2013爱思唯尔有限公司保留所有权利。
Objectives: To describe and apply a method of modelling dental crowns and three-unit fixed partial dentures (FPD) for finite element analyses (FEA) from 3D images obtained using a micro-CT scanner.Methods: A crown and a three-unit fixed partial denture (FPD) made of a ceramic framework (Y-TZP) and veneered with porcelain (VM9) were scanned using an X-ray micro-CT scanner with a pixel size of 6.97 mu m. Slice images from both structures were generated at each 0.034 mm and processed by an interactive image control system (Mimics). Different masks of abutments, framework and veneer were extracted using thresholding and region growing tools based on X-ray image brightness and contrast. 3D objects of each model were incorporated into non-manifold assembly and meshed simultaneously. Volume meshes were exported to the FEA software (ABAQUS), and the load-generated stress distribution was analyzed.Results: FEA models showed great shape resemblance with the structures. The use of non-manifold assembly ensured matching surfaces and coinciding nodes between different structural parts. For the crown model, tensile stresses were concentrated in the internal surface of the core, near to the applied load. For the FPD model, the highest tensile stresses were located in the framework, on the cervical area of connectors and pontic. Conclusions: Valid 3D models of dental crown and FPD can be generated by combining micro-CT scanning and Mimics software, emphasizing its importance as design tool in dental research.Clinical significance: The 3D FEA method described in this work is an important tool to predict the stress distribution, assisting on structural design of dental restorations. (C) 2013 Elsevier Ltd. All rights reserved.