Importing Files From CAD/CAM Scanner Into FEA Software

Objectives: To investigate whether large STL files can be imported into FEA analysis software. FEA analysis of dental structures has been limited by the complexion of the geometry when a mesh is to be generated manually. With the availability of 3D scanners, images can be obtained in digital form for importing to FEA
Methods: An STL file of a three-unit bridge (#18-#20) was obtained with a laser scanner (E4D Technologies). The properties of the file were as follows: #Faces: 878903, #Vertices 441034. The original file size exceeded the import limit of 10K facets for SolidWorks (SW) 2014 Student Edition. However, SW can accept larger files in DXF format. Therefore the file was reduced to 12413 faces and 7354 vertices using Meshlab (http://meslab.sourceforge.net) and exporting it as a DFX file. The DFX file was imported into SW for analysis, and a 3D model was reconstructed and saved as a SW part (.prt) file. Material properties were successfully assigned to the model.
Results: A complex geometry was imported in to SW modeling and reconstructed in 3D, by reducing faces, vertices and changing the file format. Computational times using this method exceeded two hours. Material properties were assigned, however creating a new mesh for the simulation module of SW has not yet been achieved.
Conclusions: The conversion of STL files into DFX files allowed a three-unit bridge model to be directly imported into SW. Reduction in file size made the highly detailed model manageable for SW. The simulation module for stress and strain analysis could not be activated, most likely due to the absence of the abutment teeth in the bridge model.