IADR Abstract Archives
Error Analysis in Digital Workflow:From Scanning to 3D Printing
Objectives: To analyse the error in the printed implant model fabrication process from scanning, CAD to 3D printing.
Methods: A stone model with four implant analogues with scanbodies and three reference spheres was fabricated as a master model. Six printed models were fabricated in three steps: 1). Model scanning using an intraoral scanner 2). Model design using computer-aided design (CAD) software 3). Model fabrication using a 3D printer. The master model and printed models were digitised by a coordinated measuring machine (CMM). All obtained files were imported into reverse engineering software for error analysis. The relative implant positions to the reference spheres, in terms of the angular deviations of the implant axis and orientation, as well as the linear deviations in both horizontal and vertical implant positions, were analysed and compared between step as demonstrated in Figure1.
Results: In terms of the linear deviation of horizontal implant positions, the propagation error from scanning, CAD, and 3D printing was shown in the printed model, with 3D printing being the major error source. At least two implant positions, the errors in the CAD step were significantly lower than in the other steps. In two implant positions, scanning error was significantly less than 3D printing error, while there was no significant difference when comparing 3D printing error and overall error in all implant positions. In two of four implant positions, the vertical distances between the reference sphere's centre and scanbody position in the printed model were significantly greater than in the master model.
Conclusions: 1. Printed implant model should not be used for complete-arch implant prosthesis fabrication as an accumulated error was shown in the printed implant model.
2. The definitive prosthesis adjusted based on the printed implant model could present underocclusion.
Methods: A stone model with four implant analogues with scanbodies and three reference spheres was fabricated as a master model. Six printed models were fabricated in three steps: 1). Model scanning using an intraoral scanner 2). Model design using computer-aided design (CAD) software 3). Model fabrication using a 3D printer. The master model and printed models were digitised by a coordinated measuring machine (CMM). All obtained files were imported into reverse engineering software for error analysis. The relative implant positions to the reference spheres, in terms of the angular deviations of the implant axis and orientation, as well as the linear deviations in both horizontal and vertical implant positions, were analysed and compared between step as demonstrated in Figure1.
Results: In terms of the linear deviation of horizontal implant positions, the propagation error from scanning, CAD, and 3D printing was shown in the printed model, with 3D printing being the major error source. At least two implant positions, the errors in the CAD step were significantly lower than in the other steps. In two implant positions, scanning error was significantly less than 3D printing error, while there was no significant difference when comparing 3D printing error and overall error in all implant positions. In two of four implant positions, the vertical distances between the reference sphere's centre and scanbody position in the printed model were significantly greater than in the master model.
Conclusions: 1. Printed implant model should not be used for complete-arch implant prosthesis fabrication as an accumulated error was shown in the printed implant model.
2. The definitive prosthesis adjusted based on the printed implant model could present underocclusion.