We’ve known for a while now that medical applications are one of the killer apps for 3D printing. In the past, Make: has covered such amazing innovations as 3D printed prosthetic limbs and life-saving medical hacks that everyday citizens have done to improve their health and even save lives. You can now add doing your own orthodontics to that list. At least, Amos Dudley 3D created his own “orthoprint” to correct a snaggle tooth, or How I Open-Sourced My Face, as he so charmingly puts it.
Amos got the idea to try 3D printing a retainer mold to fix his wayward tooth after seeing this picture of a commercial orthodontic appliance. He noticed that it had striations reminiscent of 3D printing deposition layers.
Doing research, he found quite a bit of information on the whole process by which such appliances are now scanned so that 3D molds can be printed for creating very accurate and comfortable vacuum formed retainers. He decided to try his hand at making his own. He writes:
So what does one need to do this themselves? Knowledge of orthodontic movement, a 3D scanner, a mold of the teeth, CAD software, a hi-res 3D printer, retainer material, and a vacuum forming machine. I realized, I had – or could acquire – all of these things. I have my own 3D printer, but the dimensional accuracy isn’t good enough. NJIT has a digital fabrication lab with a Stratasys Dimension 1200es. That would do the trick. I tested the machine, and found it could give me X,Y accuracy under .1mm, which was close enough. I think a stereolithography printer like a Formlabs Form 2 would have been even better, since they have vast X,Y resolution and accuracy. Vertical print resolution didn’t matter much- the direction of motion was in X and Y, not Z. The same lab also has a vacuum forming machine, and some NextEngine laser scanners.
The first thing he did was to take a mold of his teeth with some cheap alginate powder, Permastone, and a 3D printed impression tray, to get a better picture of what was really going on in his mouth. Notice LI-r (right lateral incisor) projected outward, and CI-r (right central incisor) depressed inward and overlapping.
On his blog post, he runs through all of the steps for making an alginate mold and casting a set of teeth in Permastone. With the casting in-hand, he was able to do a laser scan (with the NextEngine) of his teeth and then use scanner software to generate STL files for the series of aligning retainers he’d need to use to slowly align his tooth. With the aligner molds 3D printed, he moved on to the last step of having them vacuum formed. After forming, he used a Dremel tool to smooth out any rough spots that might irritate his gums.
Here you can see the results, after 16 weeks, in these before and after pictures.
He concludes with these thoughts on the process:
As far as I know, I’m the first person to have tried DIY-ing plastic aligners. They’re much more comfortable than braces, and fit my teeth quite well. 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- a success! I’ve been wearing them all day and all night for 16 weeks, only taking them out to eat. I’m planning on fabricating a bunch of retainers for the current position, which I can use – till I die – at night. They also happen to work very well as perfectly fitting whitening trays, when trimmed down a tiny bit. They’re also fantastic night guards- they’ve been protecting my teeth from nighttime grinding, without being bulky.
As you might imagine, and as in all instances of DIY doctoring, there are great risks here. This was an experiment, done by someone who was extremely thoughtful and thorough, and who was willing to assume the risks. This is not something that should be looked at lightly. As one commenter, perhaps a dentist, responded on the blog post on Amos’ site: “…Your work is pretty good but there is a lot more to this than just a bit of acrylic in the form of a tray. The part where you understand why your teeth have moved takes around 5-6 years of general dentistry plus 4 years of orthodontic specialization. The amount of money it costs to make these trays is not what should be important. That’s without talking about the risks of using removable repositioning trays as a substitute to conventional fixed appliances. Very dangerous.”
So, how much did making his trays cost? Amos says he spent around $60 total in materials (he had free access to the machines). Going through conventional dentistry, the cost of Invisalign braces would have run him somewhere between $3,000 and $8,000.
[via Slate]
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