种植体支持的上颌无牙颌固定义齿三维有限元建模

目的:建立种植体支持的上颌无牙颌固定义齿三维有限元模型,以便分析种植固定桥及上颌骨的应力分布,为临床应用提供参考。方法:选择1例上颌牙列缺失,牙槽骨中度吸收的志愿者,对其头颅部进行锥形束CT(cone-beam-computed tomography,CBCT)扫描,并利用计算机软件进行数据转换,完成上颌骨三维实体模型的重建;利用光学测量与平面影像测量相结合的方法 ,完成Bego种植体(L=13 mm、D=4.5 mm)的精确建模;并用激光扫描的方法完成种植固定桥的建模,为后面的有限元分析提供准确的数据。结果:成功地建立了种植体支持的上颌无牙颌固定义齿三维有限元模型,并在保持原模型力学相似性的基础上对其进行了简化,提高了分析效率和精确性。结论:基于CBCT扫描、三维激光扫描、逆向工程技术和快速成型技术建立种植体支持的上颌无牙颌固定义齿几何模型,利用有限元软件进行网格划分生成有限元模型的方法是可行的,并保证了很好的几何相似性。

Establishment of three-dimensional finite element models of a dental implant fixed dentulous maxillary

Objective:Through the establishment of a 3D finite element model of a dental implant fixed edentulous maxillary and analysis of the stress distribution of implant in different position,we propose to provide a reference for clinical applications. Methods:In this research,we selected a volunteer of edentulous maxillary and moderate alveolar bone absorption, and then scanned his head with cone-beam computed tomography(CBCT). This research used a series of computer software for data conversion to reconstruct three-dimensional solid model of the maxillary. The three-dimensional solid model of Bego implant was accurately obtained by an integrated method,which combined the optical measurement of implant profile data by 3D optical grating projection with the plane-image measurement of characteristic details. A 3D finite element model of a dental implant fixed bridge was built successfully by laser scanning. Results:We successfully established the three-dimensional finite element model,and simplified it with maintaining the similar mechanics of the original model to improve the efliciency and accuracy of the analysis. Conclusion:Three-dimensional finite element models of a dental implant fixed edentulous maxillary established by the method of combining CBCT,3D laser scanning, rapid prototyping,and to generate finite element model by grid partition of finite element sofoware are feasible and with a good geometric similarity.