Accuracy of 3D printing Versus Milling in Fabrication of Clear Aligners Dental Models

Document Type : Original Article

Authors

1 Orthodontic Department, Faculty of Dentistry, Tanta University

2 Orthodontic Department, Faculty of Dentistry, Al Mansoura University

Abstract

Aim: This study compared two techniques for fabricating dental models with attachments (additive 3D printing versus subtractive milling).
Materials and Methods: a random model was selected and scanned with an intraoral scanner, and the STL file of the model was used to create another STL file of a new model with rectangular attachments on the labial and buccal surfaces of the anterior and posterior teeth respectively were created by Maestro software. The new STL file was 3D printed three times by the same 3D printer to produce 3D printed models that constituted group 1. Three 3D-printed discs were created by the same 3D printer with dimensions matching the discs of the milling machine. Group 2 consisted of three milled models fabricated by a milling machine. The models of both groups were scanned with the same intraoral scanner, and the STL files generated were superimposed over the original STL file by the same software (cloud compare). The linear deviations of attachment position were measured in millimeters. One-way ANOVA and t-tests were used to compare the deviation within each group and between the two groups; the significance level was set at a p-value < 0.05.
Results: statistically significant differences between the molars, incisors, canines, and premolars were observed in both groups in all ways of space. Comparing the two groups revealed a non-statistically significant difference between both groups.
Conclusion: 3d printing provided a more economical and less time and material-wasting way for fabricating clear aligners models with attachments than milling.

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