How Invisalign became the biggest user of 3D printers (wired.com)

by mikhael 129 comments 179 points
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129 comments

[−] LurkandComment 56d ago
1) Currently on invisign - mould 24 of 42

2) For 5k (Cdn) - I get 42 moulds, a method used to scan and submit my progress for each mould duration, feedback and advice from a dentist, a scan test to see who they fit

3) Considering the cost of braces and the flexibility these allow (as long as you are disciplined in wearing them) it's well worth it

4) My teeth were really misaligned. At 42 I just decided to do it so I could smile more in pics. Not confidence issue, just sometimes in life you have to do things for yourself

5) You can see the 3d printing lines and its pretty detailed given how lightweight and accurate the shape is for each tooth

6) There are little mounts they install on your teeth for the moulds to latch on to as well, so its not just a fit on the teeth but the mounts as well

7) Each individual mould has a unique number on the package in comes in as well as on the mould. Each package has my name, the dentist and the mould number out of 42.

8) I could see changes starting with mould 6

9) If look even close to mould 42, I will be extactic

10) it also comes with an attachment for your phone that alows you to submit self exams each mould. Its really cool. its very impressive

[−] aewens 56d ago
Just be prepared near the end for refinements. When I did mine, I had to do another 6 months of refinements near the end to help get the locking of my bite grip to be where it needs to be. I was otherwise expecting that day to be when I’d be done, and later learned refinements are a fairly common occurrence when going through Invisalign.

As the sibling comment, it’s definitely worth it. Best of luck!

[−] Oarch 56d ago
Best of luck! I completed mine 2 years ago and have to say it was 100% worth the patience.
[−] nntwozz 56d ago
I've had good smile all my life but now at 41 I've started to feel a tightness between my teeth.

Lo and behold I read that as we age the jaws shrink which makes the teeth crowd together.

I'm going for a free mouth scan in a couple weeks.

[−] torben-friis 55d ago
How long does the process last? Are the moulds monthly or something like that?

I haven't done any similar treatment and I'm considering it at 35. Worried about the length since I heard it takes far longer for adults.

[−] gonzalohm 55d ago
Do you know what type of plastic they use? I have a 3D printer and I wouldn't want to put 3D printed stuff on my mouth. It's way too easy to end up with microplastics
[−] RealityVoid 55d ago
The article says the braces are 2 layers. The inner one is polyester and the outer one is polyurethane. They also don't currently 3d print the braces themselves but instead thermo form them on top of 3d printed molds.
[−] YZF 55d ago
I went through these and am pretty happy with the results. Mostly to counter the crowding of the teeth that happens naturally as you age.

As you probably know you're going to have to wear retainers at night for the rest of your life if you want your teeth to stay where they landed.

[−] silisili 55d ago
I had really bad teeth as a kid, so had braces. Periodically I'd have to go in to get them tightened, and remember the worst whole head pain for a day. Just curious is switching Invisalign molds is a similar process?
[−] tombert 56d ago
Tangential, but I have sleep apnea. Fortunately I have it mild enough to get away with a mouthpiece instead of a CPAP (which is good anyway because I also have bruxism).

The mouthpiece works great and I would recommend everyone get tested for sleep apnea if your insurance covers it, but I have to admit that paying for it bothered me. Even with insurance covering some of it, it cost me about $600.

I know that there's a deceptively high amount of engineering required for these kinds of things, but it was very hard to wrap my head around paying $600 for what amounted to a couple pieces of clear plastic. I actually got them to send me the STL of the scan of my teeth, and some back of napkin math indicated that it would have cost me about fifteen cents of resin to print it out myself. Instead I'm paying about 4000x that price.

Obviously this is not apples to apples, I'm sure they're using different and/or better resin that what I have, and as I said there's probably engineering and fine-tuning for this, but even still it was not fun to pay for.

All the same, I sleep like 10x better, so I suppose that considering that $600 is a cheap price to pay.

[−] tredre3 56d ago
I think your comment would have been more insightful if you had at least pretended to try to account for labor before saying "They charged me 4000x the cost of goods!".

To be clear I'm not even asking for you to account for the cost of your printer, the 3d scanner, and software licenses in your math. Let's assume that all those are free. How many hours of specialized human time was spent on consultations, scans, design, reviews, to produce working guards for you?

The next question is then, of course, how much do they charge for subsequent guards now that the scan has been done and validated? Is it still 4000x the cost of raw resin?

[−] tombert 56d ago
I did qualify multiple times that there are costs associated with engineering, So I feel that it it's implied that the 4000x figure is a naive one.

I'm sure labor is involved, and maybe it's a lot, but it still seems like an awful lot of money for a piece of plastic.

[−] cryzinger 56d ago
Even if the actual specialist labor had been minimal, there's also the amount of time and effort it takes to accumulate enough knowledge to become a specialist. It's like the joke about spending $200 for a repair guy to come kick your printer in just the right spot to fix a print jam--you pay him $50 for kicking it, and $150 for knowing where to kick it :)
[−] ricardobeat 56d ago
Yes, they will charge a similar amount for producing another guard from an existing scan - I’ve had that done. It was also completely unnecessary in my case, it’s clearly an easy money grab for some offices.
[−] y-curious 56d ago
With sleep apnea, I highly recommend you look into myofunctional therapy, which is like airway physical therapy. (full disclosure, my mom is a myofunctional therapist). It worked for several friends; They still use their cpap but they get much better sleep after committing to a routine. Not advertising but spreading the word, find someone local!
[−] wisemang 55d ago
[−] tombert 56d ago
I hadn't heard of this. I'll give it a look and see if I my insurance covers it...thanks!
[−] y-curious 55d ago
If it doesn’t, you can try and find some free resources online. If you’re in NYC, my mom’s business is HappyMyo and you can tell her her son sent you from HN. Good luck and I hope it helps you, it sounded really hippie and lame when I heard the name but I’m a believer now.
[−] tombert 55d ago
I do live in NYC and I actually did see that practice when I was searching. I might check it out though apparently my insurance will not cover it. I'll dig a bit further.
[−] hattmall 56d ago
So shouldn't this really be something that could be opened sourced. I think I've seen a few write ups of people that did their own, but seems like a highly functional implementation could be democratized.
[−] ivan_gammel 56d ago
It is definitely not that simple for a number of reasons. Yes, aligners and retainers in theory may be printed on some commercially available hardware. At your own risk, because you will be printing a medical device and you will need:

1. A treatment plan: simulated movement of teeth at every step, taking into account all forces. That’s specialized software or external lab service.

2. Precision. You put too much pressure at the wrong angle and you will need a surgery to fix the damage, because the tooth root moved in wrong direction.

3. Plastic. You cannot use ordinary 3D printer ink. You need a plastic that can survive the chemical environment in your mouth, maintain the pressure, and you probably want it to look good (no discoloration etc).

4. Finish: Align Tech, Straumann etc do not stop after 3D printing, there are few other steps involved to make sure there’s no sharp edges etc.

5. Maybe you will need attachments (to focus pressure in the right direction on certain teeth) or wires.

Align Tech is Apple of clear aligners, but now competition exists, producing aligners at scale is commercially more efficient, considering all the risks and required qualifications, and of course the best materials for aligners are patented and not sold OTC to everyone.

Disclosure: I worked at Align 10 years ago and later was CTO of European DTC competitor.

[−] natpalmer1776 56d ago
How many of these risks and problems are exaggerated in scope and potential due to both a desire for a regulatory moat and a general fear of litigation in the medical space?

That is to say, how good is “good enough” when done at small-scale in developing nations or medically underserved communities?

[−] ivan_gammel 56d ago
1. There‘s always a reason or two for the treatment. The problems with bite may affect your health in various ways. There’s aesthetic component in it, sometimes even cultural preferences for how your teeth should look like. But let’s say patient cannot afford to care about final position when signing up for the treatment. They just trust the doctor saying they need it. Failure mode: patient is unhappy with outcome and will ruin your business from marketing perspective.

2. Let‘s say the practice does it in old way, with impressions - no intraoral scanner. The scanner of impressions still needed, but it can be cheaper. Someone needs to build it and achieve required accuracy (let’s say, 50 μm). Who? Why? Failure mode: bad scan leads to aligners not fitting your teeth from day 1. Oops.

3. Let‘s say someone builds a good OSS alternative to OrthoCAD (Who? Why?), so that orthodontist on site could build a treatment plan and export it into series of 3D models for printers. Failure mode: good treatment plans are rarely possible or output is garbage (aligners do not fit, cause pain etc)

4. Maybe some company develops good plastic or patent expires, so that it is possible to produce it in India, China or other inexpensive location with strong industrial base. That would be cool, otherwise: non-compliant plastic breaks in patient’s mouth, decomposes with patient ingesting some toxic chemicals or is simply not strong enough to move teeth in desired position, so you have problem with 2nd aligner.

5. Maybe you get to this point, but you still need a printer that can maintain the same precision in printing. And you need a good cutting and finishing process. Someone needs to build such device. Failure modes are similar to the mentioned above.

6. The ortho supervision sounds easy, but how many patients in developing countries do even have a possibility to see orthodontist? They are definitely not in position to treat themselves.

So, in this process, what is good enough exactly? Who and why would drive the costs down while building an on-site solution?

[−] BoorishBears 56d ago
Smile Direct Club and co have shown its founded 100% in real risk of harm.

They were a company theoretically doing the same thing with still more resources than an average individual has, and ruined people's bites and teeth.

I don't think there's a good enough here

[−] jmalicki 56d ago
These kinds of things can slowly move your bone structure over time. After all, that is their entire point. You don't want to accidentally mess up your teeth and jaw even more.
[−] regularfry 56d ago
This would be what I'd worry about. How many of us do any metrology on our printed artefacts? It's really easy to get a subtly warped print and without having some sort of calibration of the process I wouldn't want to make any accuracy claims whatsoever.
[−] nullable_bool 56d ago
Per point #3, aren't the liners thermo formed around at 3d printed model of your teeth?
[−] ivan_gammel 56d ago
IIRC, yes. It’s been some time ago, I don’t know how manufacturing looks now. It’s different process compared to 3D printing at home. It doesn’t mean it should be different, it just has to maintain certain properties. I’m not chemical or bioengineer to go into detail of it :)
[−] Projectiboga 55d ago
Yes just the safe to be in the mouth and for it to handle significant pressure from teeth biting changes this from simple 3D filliment to something much more involved during the design and regulatory processes.
[−] afavour 56d ago
I did Invisalign a few years ago. Manufacturing the retainers is surely only a small part of the puzzle.

They used a specialized sort of 3D camera on a stick to get an incredibly accurate model of my mouth, any open source solution would need an equivalent. And you’d also need open source code from somewhere to work out which teeth need to move where and at what stage in the treatment.

[−] joe_mamba 56d ago
>They used a specialized sort of 3D camera on a stick to get an incredibly accurate model of my mouth

AFAIK Align's 3D scanning system is more or less branched from the same Israeli tech that went into the Xbox 360 kinect camera and the iPhone face-ID.

[−] avensec 56d ago
While both were originally companies based in Israel, the technology behind the Kinect is different.

iTero scanners (owned by Align Technology) use parallel confocal imaging via red light lasers. Their newer models also use Multi-Direct Capture techniques.

Kinect used a Light Coding technique, an infrared projector and camera. It was developed by a company called PrimeSense, which was later purchased by Apple.

[−] greedo 56d ago
They also use this camera system when creating implants. After the implant post was installed, they scan your mouth to determine the optimum shape for your crown (that goes on the post).
[−] maccard 56d ago
That’s pretty wild. I got a mould taken with some sort of a putty .
[−] kube-system 56d ago
Orthodontics is simply “making a retainer” the same way orthopedics is simply “putting screws in a leg”.

The difficult part is not the manufacturing, but knowing how to do it properly so you don’t harm the patient.

[−] Legend2440 56d ago
Certainly it's not impossible to DIY, but it's more difficult than just popping some aligners on your 3d printer.

Manufacturing them requires a resin printer and a vacuforming setup, but that's still the easy part. It's a whole system with a dental 3D scanner, software for rearranging your mouth, and attachment points that have to be epoxied onto (and later removed from) your teeth by a dentist.

[−] plomme 56d ago
A point I didn’t see sibling comments make is that the dentist often has to file between teeth for them to sit and align correctly. They did so several times in my case. I would not want to do that to myself!
[−] sithadmin 56d ago
It’s been tried, with some success. Pretty sure I’ve seen a post here on HN from someone that DIy’d it end to end.

But it’s also something that’s not responsible to shortcut. Shifting teeth around too fast can result in permanent root damage and even loss of teeth. There was a whole cottage industry in the US for a while focused on under cutting Invisalign with a reverse-engineered product, but they often moved on accelerated treatment timelines that caused a not-insignificant amount of harm to patients, and cut corners on intake (DIY at home mold kits) that also contributed to problems. Pretty sure all of the companies doing this are basically dead now.

[−] adrr 56d ago
Need expensive printers and you need CAD software that can correctly move the teeth. Also not all it can be done by software, sometimes you need to blank out certain teeth that dentist will make the call.
[−] desireco42 55d ago
My 2 kids had those and it is amazing compared to traditional way, pulling healthy teeth, wearing braces which are brutal to your teeth.

It should be illegal to pull kids teeth when this tech exists. Dentists were angry about this but it is superior in every way. I think costs will come down, but they are already cheaper then alternatives.

I am happy my wife researched and discovered Invisalign.

One required much more alignment, I don't remember but it was 20+ weeks, other was done in 16 weeks. Now they have retainers and that is it.

[−] itsdesmond 56d ago
I don’t like this interviewer’s tone, at all. It was like… confrontational but in a teenage way.
[−] smithcoin 55d ago
Nobody tells you how much it hurts, but it’s worth it (just in the increase in dental hygiene alone in my case).

For some reason now it’s assumed these were some kind of injection molding, but it makes perfect sense that it’s 3-D printed.

[−] smallnix 55d ago
He does have a German wikipedia page
[−] b3ing 56d ago
There’s a dental procedure in Latin America that is cheaper but only a few places in the US do it.
[−] infinitewars 56d ago
Most teeth align themselves as kids age. This is almost never necessary.