The Technology Behind Clear Aligners: From Design to Tray

How are clear aligners made? 3D printing, medical thermoplastics, planning software: the Infinity Aligner technology explained.

A clear aligner may look simple at first glance — a thin transparent tray moulded to your teeth. In reality, each tray is the result of a high-precision manufacturing process combining artificial intelligence, 3D printing and cutting-edge biomedical materials. Here is a behind-the-scenes look at this technology.

Step 1: digital capture with the intraoral scanner

Everything begins in the dental practice, with an intraoral scanner that captures the exact geometry of your teeth and gums in just a few minutes. The result is an STL file — a 3D model with precision in the range of 20 to 50 microns. This file is instantly transmitted to Infinity Aligner laboratories via a secure platform.

Step 2: software-assisted planning

Orthodontic technicians use specialised software to individually segment each tooth on the 3D model and plan every movement to a tenth of a millimetre. The software automatically generates a sequence of intermediate positions — one per aligner — respecting the biological limits of tooth movement. The practitioner validates or adjusts the plan before launching production.

Step 3: 3D printing of models

Each planned intermediate position is 3D printed as a physical jaw model. Infinity Aligner uses high-resolution photopolymer resin printers (XY resolution < 50 microns) to ensure maximum fidelity between the virtual and physical model. These printers can produce dozens of models simultaneously.

Step 4: thermoforming of medical-grade plastic

Over each printed model, a sheet of medical-grade thermoplastic is heated then vacuum-pressed to perfectly conform to the model's shape. The material used — typically medical-grade polyurethane or glycolised polyethylene terephthalate (PETG) — is BPA-free, FDA and CE certified, and offers the perfect balance between rigidity (to exert effective forces) and elasticity (to facilitate placement and removal).

Step 5: cutting, polishing and quality control

Each thermoformed tray is precisely cut at the gum line by a CNC machine, then its edges are polished to eliminate any roughness and maximise gingival comfort. Each piece is then visually and dimensionally inspected before being cleaned, sterilised and individually packaged.

Conclusion

The orthodontic tray you wear is the result of a complete technological chain, combining digital precision, materials chemistry and clinical expertise. It is this manufacturing rigour that guarantees the effectiveness and safety of your Infinity Aligner treatment.