CAD/CAM positioner produced by fused filament fabrication printing

Objective: To illustrate the production and clinical application of a positioner made entirely from thermoplastic polyurethane using CAD/CAM technology and fused filament fabrication 3D printing for finishing after multibracket treatment.
Materials and methods: Directly after removal of the multibracket appliance, both arches were scanned (T0), including a construction bite to record the desired relationship. After mesh repair, optimisation and segmentation, a visual treatment objective was generated for finishing (maximum range of movement 0.25 to 0.40 mm) using OnyxCeph³ 3D Lab (Image Instruments, Chemnitz, Germany) (T1). Virtual aligners with a thickness of 2.0 mm were constructed over the visual treatment objective, followed by edge smoothing and structural control. Support construction and slicing were done using Simplify3D (Simplify3D, Cincinnati, OH, USA). The positioner was made from medical thermoplastic polyurethane (layer height 0.2 mm) through fused filament fabrication 3D printing and was inserted 1 day after debonding. The patient was instructed to wear the appliance for 24 hours a day except when eating and exercising. A second scan was taken after 14 days (T2). The tooth movements were measured, visualised and compared with the visual treatment objective by superimposing the scans.
Results: Tooth movements in the maxilla ranged between 0.10 and 0.26 mm in translation and 0.1 to 1.2 degrees in rotation; the respective values for the mandible were 0.10 to 0.34 mm and 0.9 degrees. The extent of the tooth movement differed depending on the type of tooth and the direction of movement.
Conclusion: For the first time, a custom-made, clinically applicable CAD/CAM generated positioner made from thermoplastic polyurethane was produced through fused filament fabrication 3D printing.