Are Invisalign Aligners Made with 3-D Printers?

Hello,

I am a fifth grade student at [name redacted] school in Elgin, Illinois. My class is working on a project about how technology is used in everyday life and I am going to talk about 3D printing. My teacher said clear braces like Invisalign are one example but I cannot find information about this online. I know. I looked EVERYWHERE. Can you please tell me if she was right and how the process works?

Sincerely,

Joshua

Dear Joshua,

This is a great question! Yes, your teacher is correct. Invisalign aligners are made with 3-D printers. The technical term for the process is Stereolithography or SLA for short. A company called Formlabs gives a really good overview about how SLA works. It’s a bit high-tech, but there are videos you can watch on it too. To view the page, go here: https://formlabs.com/blog/ultimate-guide-to-stereolithography-sla-3d-printing/

When patients are in the office, digital images of a patient’s mouth are taken, and those are stored in the computer system. Specialized software creates a virtual map of the person’s mouth and is used to create digital models of what their mouth looks like at that moment, what it will look like in the end, and the individual steps or movements the teeth will need to make to get there. Each movement represents a different aligner. Patients will start with the first one, which closely represents where their teeth are now, then move to one that’s slightly different to encourage the teeth to shift to a new position. This continues on through several aligners. Each one is worn for a couple weeks and the average patient usually has 20-30 different aligners, meaning their treatment will last about a year.

The initial data is transferred from the dental office to a manufacturing plant where one of the first steps is to form the individual aligners using SLA or 3-D printing. If you check out the page linked earlier, you’ll get a better idea of how it works, but the gist is that the aligner is slowly built up in layers using a specialized thermoplastic material. It’s an automated process. The printer references the “map” of the mouth made earlier, so the finished aligner takes on the exact shape of one of the stages of movement and matches the person’s teeth and oral structures perfectly.

From there, each aligner is given a tag with an ID number, so that it’s easy to tell which patient any given aligner belongs to—that’s important in a factory that processes thousands each day and in busy dental offices with lots of Invisalign patients! It also identifies where the aligner sits in the sequence, whether it’s the 1^st, 30^th, or will be worn somewhere in between.

From there, the aligners are trimmed to feel comfortable against the gums and then polished, so they’re nice and smooth. The factory ships the finished aligners back to the local dentist, who then will usually give just a few to a patient at a time and perform checks to see progress as the person moves through their aligners.

There are lots of factories that make Invisalign aligners. The infrastructure and technology cost millions (if not billions by now) of dollars to put in place. The video below was designed to teach dentists how the aligners are made, so it might be a little hard to follow, but check it out if you want to see the process in action and the real machines being used!

This blog is sponsored by Dr. Steve Sirin, an Elgin Invisalign provider and family dentist.