Direct 3D printing of aligners – how Graphy technology works and what it changes in orthodontics

For many years, aligners were made the same way: printing a model, thermoforming a foil, trimming, polishing. Each stage costs time and material and is a potential source of error. Direct 3D printed aligners shorten this path: the CAD file goes straight to the printer, and a finished aligner comes out of the UV chamber. We explain how it works, what it requires and who it makes sense for.

What is direct aligner printing?

Instead of printing a model and forming a foil over it, the aligner is printed directly from a special resin. Graphy Tera Harz TC-85DAC is a material developed specifically for this purpose: the clinician or technician designs the aligner in CAD software and controls its thickness, stiffness and elasticity in selected zones – something a thermoformed foil does not allow.

Shape Memory Aligner – an aligner with shape memory

Tera Harz aligners have a shape-memory property: when deformed and then warmed (e.g. in warm water), they return to their designed geometry. In practice, this means a constant, predictable orthodontic force throughout the entire treatment stage and the ability to seat the aligner without excessive tension. The manufacturer states that directly printed aligners are suitable for a wider range of indications than conventional thermoformed aligners. For retainers after active treatment, the stiffer Graphy TR-07 resin with a limited shape-memory function is available.

The workflow step by step

1. Intraoral scanning – e.g. with the RAYiOS 2 or any other intraoral scanner with open files.
2. Orthodontic setup and aligner design in CAD software – with control over thickness and elasticity zones.
3. Printing on a Graphy-validated 3D printer (LCD / DLP) using TC-85DAC resin. Consult us about the compatibility of your specific printer before you start.
4. Removing excess resin in the Tera Harz Spinner centrifuge – without washing in alcohol, which would alter the material's properties.
5. Curing in a nitrogen atmosphere in the Tera Harz Cure chamber – the stage that ensures full polymer conversion, no tacky layer and biocompatibility.
6. Finishing – removing supports, finishing the margins and polishing according to Graphy's instructions. While the patient is wearing the aligners, Tera Harz Care – a compact ultrasonic cleaner and warmer – is designed for cleaning them and warming them before insertion.

What do the clinic and lab gain?

• Time – no models, foils or thermoforming; the manufacturer points to the potential for "same-day" treatment.
• Clinical control – designed stiffness and elasticity zones instead of a uniform foil.
• Less waste – you do not print models whose sole purpose is thermoforming.
• Patient comfort – a thinner aligner with a smooth surface cured in a nitrogen atmosphere.

What do you need to implement it?

Direct aligner printing is a system, not a single product. You need: a validated printer, TC-85DAC resin, a centrifuge, a UV chamber with nitrogen and a trained team. Curing in a standard chamber or washing in IPA does not deliver the properties declared by the manufacturer – this is the most common cause of disappointment when trying to take a "shortcut".

Who is direct printing right for?

Orthodontic labs and clinics that produce aligners regularly and want to keep the whole process in-house rather than outsourcing it to external manufacturers. If you make only a few aligners a month, thermoforming may remain sufficient; in series production, the difference in time and unit cost becomes obvious.

Where to start?

IMMT is the official representative of Graphy. We help you put together the complete system – from resin and centrifuge to curing chamber – and implement it in your lab. See Graphy 3D resins and washing and post-processing equipment, or arrange a presentation of the Shape Memory Aligner technology.