• 3 minute Read

This Guy 3-D-Printed His Own Retainers—And They Fixed His Teeth

No more eye-popping orthodontist bills.

Amos Dudley wanted to straighten his teeth, but he didn’t want to pay the dentist to do it. Then he took a look around and realized that, as an undergrad, two things were true. “A) I’m broke, and b) I have access to expensive digital fabrication tools,” he wrote in a blog post. You can guess what happened next—Dudley 3-D-printed his own teeth aligner.

Of course, being an undergrad also gave Dudley a predisposition to research the process before starting. Well, that and the possibility that he could do himself some real damage. “If you want to lose your lunch,” he says, “search Google to see how amateur wire braces can go horribly wrong.”

It turns out that a dentist isn’t just taking a mold of your teeth and using it to make a retainer. The process requires lots of experience when planning the design of the aligner, as well as in the taking of the mold and the building of the aligner itself. Just one example: “A technician plans out a route for the teeth to travel over the course of the procedure, so that they move but don’t intersect one another,” says Dudley.

But he didn’t let that put him off. “So what does one need to do this themselves?” he writes. “Knowledge of orthodontic movement, a 3-D scanner, a mold of the teeth, CAD software, a hi-res 3-D printer, retainer material, and a vacuum forming machine. I realized, I had—or could acquire—all of these things.”

Dudley went to work, and his method is part MacGyver, part CSI, combined with a lot of patience. “The actual manufacture didn’t take very long,” he tells Co.Exist, “but I had to do it one small step at a time, with lots of waiting for materials and school interruptions.” For instance, he made the ultra-precise alginate mold on which everything else is based (by biting down on the material, just like you would at the dentist), and then dropped it upside down in a yogurt container before pouring in liquid Permastone to make the cast. “When it came out, I simply broke off the top to reveal the casting, and used a razor blade to smooth out the surrounding area.” He then marked it up with colored dots to help with the next step: laser scanning.

Next up was taking this 3-D scan of how his teeth were “now” and comparing it to how they should look when the teeth were all in their correct positions. Dudley used software to send each frame of the resulting 3-D animation to a high-res 3-D printer, and then (finally) used a vacuum forming machine to make the actual aligners.

“I was pleased to find, when I put the first one on, that it only seemed to put any noticeable pressure on the teeth that I planned to move,” says Dudley. “I’ve been wearing them all day and all night for 16 weeks, only taking them out to eat.”

As you can see in his photos, the results are impressive, and if Dudley decides he wants to whiten his teeth in the future, he has these little trays ready to go. This is exactly the kind of thing people are thinking of when they say that 3-D-printing technology has disruptive power. You should almost certainly not try this at home, but that shouldn’t spoil our enjoyment of an amazing hack. Then again, perhaps nobody but a grad student would have the time to spend on the research and work involved here. Right now, it’s probably still cheaper for most of us just to visit our orthodontist.

“I probably saved a few thousand dollars. I only spent about $60 on materials, and the real Invisalign [plastic aligner] costs several thousand. However, I used equipment at my university that would be quite expensive to buy.”

About the author

Previously found writing at Wired.com, Cult of Mac and Straight No filter.