Clear Aligner Manufacturing and ABB Robot Cells

Every clear aligner is a one-off. Each tray fits one patient's teeth at one stage of treatment, and a course of treatment uses a whole series of them, so clear aligner manufacturing means making huge numbers of parts that are all different and all have to fit closely. This post looks at how orthodontic appliances were made by hand, how Align Technology turned 3D printed moulds into a mass product, and how robots now trim, mark and pack aligners, including a production line that uses an ABB six-axis robot. It ends with direct 3D printing and the problems still open.

An Invisalign clear aligner, one tray from a patient's series. Photo: Smikey Io / Wikimedia Commons (CC BY-SA 3.0)

How orthodontic appliances were made by hand

For most of its history orthodontics was hand work. Edward Angle created the first basic system for classifying malocclusions in the late 1800s, and the appliances of his era were built from bands, wires and ligatures. Until the mid-1970s braces were made by wrapping metal around each tooth. Removable appliances such as the Hawley retainer, named for its inventor Dr Charles A. Hawley, combine a wire running along the outside of the teeth with an acrylic base. A dental technician made each one on a plaster model of the patient's mouth, bending the wire with pliers and shaping the acrylic by hand.

A dental laboratory technician at his bench, where appliances were long made by hand. Photo: U.S. Department of Labor via Wikimedia Commons (public domain)

The idea behind today's aligners is older than the product. In 1945 Kesling made a rubber tooth positioner and proposed using a series of them to move teeth in small steps. In the 1960s Nahoum introduced a clear thermoformed plastic appliance that could move teeth, Ponitz developed an invisible retainer in the 1970s, and in 1993 Sheridan developed the Essix retainer. Every one of these still depended on a technician who poured plaster models, cut and reset teeth on them by hand and pressed heated plastic sheets over the result. Making a long series of steps for one patient was slow.

A clear thermoformed plastic retainer in its case. Photo: Teemeah / Wikimedia Commons (CC BY-SA 3.0)

Align Technology changed the scale. Zia Chishti and Kelsey Wirth, classmates at Stanford's business school, founded the company in 1997; the FDA cleared Invisalign in 1998 and US sales began in 1999. Software replaced the hand-reset model. Each stage of treatment is designed on a computer and its mould is built up in layers of photo-sensitive resin by stereolithography, then plastic is thermoformed over the printed mould and cut free. Align makes its aligners in Juárez, Mexico, and draws up treatment plans in Costa Rica. In July 2025 the company said it was producing more than one million custom aligner parts a day.

A US Army dental technician uses a CAD/CAM system to build a 3D model for printing at Hohenfels, Germany, July 2023. Photo: Spc. Brandon Best, U.S. Army via Wikimedia Commons (public domain)

Clear aligner manufacturing lines in 2026

Demand is still growing. Align reported a record 692,000 clear aligner cases shipped in the second quarter of 2026, up 7.4 percent on a year earlier, and its managers count manufacturing throughput as part of the plan. A case is a set of trays, so a factory runs a long chain of steps for every patient: print the moulds, thermoform the plastic, trim each tray along the gum line, mark it with an ID, then clean, check and pack it. Trimming with a hand tool is slow, and the edge depends on the technician, so it is the step most automation suppliers go after.

A patient's teeth being scanned for Invisalign treatment at a dental clinic, 2021. Photo: Drozlemorto / Wikimedia Commons (CC BY-SA 4.0)

Several companies now sell trimming cells. Shenzhen RayForm Technology advertises an aligner production line in which an ABB six-axis robot with 0.02 mm repeatability trims each aligner along the gum line in 25 seconds or less, with under 0.3 mm deviation. Machine vision reads each unit's ID before a laser marks it and the robot cuts it. Niryo offers a smaller cell in which its Ned3 Pro cobot feeds a laser aligner cutter and can cut up to 96 aligners without anyone stepping in. Niryo pitches it at orthodontic practices and labs that want to bring aligner production back in house.

The new generation ABB IRB 1200, launched in 2025, a compact arm for machine tending and small parts. Photo: ABB

ABB's part in this is the arm. Trimming and handling aligners suits small robots: the new generation IRB 1200, launched in 2025, is built for machine tending and small parts, and the IRB 1300 comes in a Clean Room version for tidy production areas. An IRB 360 FlexPicker could drop finished trays into bags at high speed, and a GoFa cobot could load printers and thermoformers next to staff. Apart from the RayForm line, I found no reported ABB installations in aligner plants, so these are possibilities. The cut line changes for every aligner, so the robot has to take a new path from the CAD file each time, the kind of job engineers plan offline in RobotStudio.

ABB IRB 360 FlexPicker robots packing small items into boxes at high speed. Photo: ABB

Where clear aligner manufacturing is heading

The biggest change coming is direct 3D printing, where the aligner itself is printed and no mould is needed. Align bought the Austrian 3D printing company Cubicure in early 2024 to scale this up, and it planned a limited market release of directly printed retainers and attachments in 2026. Its first direct printed appliance on the market was the Invisalign Palatal Expander. Direct printing removes the mould, the thermoforming and much of the trimming. It adds other jobs, such as taking parts off the printer, washing and curing the resin and handling soft parts without bending them, and robots can be set up for those.

An airman removes the supports from a 3D printed hard night guard in the dental lab at RAF Lakenheath, April 2024. Photo: Airman 1st Class Alexander Vasquez, U.S. Air Force via Wikimedia Commons (public domain)

For patients, the change shows up as price and waiting time. Clinics already scan teeth with intraoral scanners instead of taking impressions, and some practices and dental schools now make aligners on site. On 1 October 2026, for example, dentalnews.pk reported that Fatima Memorial College of Dentistry in Pakistan had launched in-house clear aligner fabrication. A compact cell with a printer, a thermoformer and a small robot is the sort of setup a practice like that might grow into. Our post on dental robots covers the robots working in the dental chair itself.

An iTero intraoral scanner, used to take digital impressions for Invisalign, in a dental clinic. Photo: Drozlemorto / Wikimedia Commons (CC BY-SA 4.0)

The open problems are cost, materials and skills. A robot cell is a big purchase for a small lab and only pays off with enough volume to keep it busy. Directly printed parts need resins that hold their shape in the mouth, and Align has told investors that direct fabrication will weigh on margins while it scales, partly because of resin costs. Every tray has a different shape, so vision, fixtures and cut paths have to work without hand tuning, and technicians who once trimmed by hand need training to run printers and robots. Aligners are medical devices, so each change to the process also has to be checked and documented.

An engineer programs a robot cell in RobotStudio next to an ABB industrial robot. Photo: ABB

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