[HN Gopher] How Invisalign became the biggest user of 3D printers
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How Invisalign became the biggest user of 3D printers
https://web.archive.org/web/20260321191823/https://www.wired...
https://archive.ph/zOAn7
Author : mikhael
Score : 115 points
Date : 2026-03-19 04:40 UTC (2 days ago)
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(TXT) w3m dump (www.wired.com)
| hattmall wrote:
| 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.
| Legend2440 wrote:
| 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.
| lovich wrote:
| They have to have at least 2 different materials as well. The
| temporary trays were much softer and I had almost ground
| through them in my sleep by the time I had to switch to the
| next one but the final set is much more robust.
| IshKebab wrote:
| Yeah it's also not unreasonably expensive. At least when I
| had them it was only a few thousand pounds. I think they do
| offers regularly.
| adwi wrote:
| https://amosdudley.com/weblog/Ortho
| hattmall wrote:
| Thank you, and that was 10 years ago!
| afavour wrote:
| 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.
| maccard wrote:
| That's pretty wild. I got a mould taken with some sort of a
| putty .
| doubled112 wrote:
| I wear a night guard and have had them made both ways.
|
| The 3D camera was really neat. A little faster, and I
| didn't once dry heave.
|
| I could watch the software and a 3D model slowly form of my
| mouth. Looked surprisingly user friendly. Missed areas were
| highlighted, for example.
| toast0 wrote:
| > A little faster, and I didn't once dry heave.
|
| Dry heaving would have been great. I would regularly
| vomit from impressions. My orthodontist would just
| prepare two sets if impression trays, cause the first one
| was going to go in the medical waste bin.
|
| Impressions for invisilign (when I did it, about a
| million years ago) weren't so bad though. Unfortunately
| invisilign resulted in an open bite for my molars, which
| I really should go back to an orthodontist to address,
| but I'd rather not.
| joe_mamba wrote:
| _> 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 wrote:
| 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.
| joe_mamba wrote:
| > _" The iTero intraoral scanner was originally developed
| by Cadent, Ltd., a company based in Israel."_
|
| There's something with Israel and 3D scanning tech. But I
| don't think I would like the answer.
| greedo wrote:
| 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).
| themafia wrote:
| Even with just regular crowns. I've had a few root canals
| as I've gotten older. They scanned the old tooth, brought
| into 3d modelling software, modified it for purpose,
| checked it's resulting fit against neighboring teeth, and
| then sent it to a mill right in the office and had it glued
| into my head in less than a hour.
|
| My doctor knows I'm into this so he always does it right
| next to me and turns the PC monitor so I can watch the
| entire process. The software is so simple almost anyone
| could use it. Generating a medically correct result is
| obviously where all the skill lies.
| ivan_gammel wrote:
| 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.
| nullable_bool wrote:
| Per point #3, aren't the liners thermo formed around at 3d
| printed model of your teeth?
| ivan_gammel wrote:
| 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 :)
| natpalmer1776 wrote:
| 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?
| BoorishBears wrote:
| 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 wrote:
| 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 wrote:
| 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.
| ivan_gammel wrote:
| 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 mm). 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?
| Projectiboga wrote:
| 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.
| adrr wrote:
| 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.
| kube-system wrote:
| 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.
| joe_mamba wrote:
| _> The difficult part is not the manufacturing, but knowing
| how to do it properly so you don't harm the patient._
|
| And yet I read plenty of horror stories of bad orthodontic
| results. Ask me how I know.
|
| Went to 3 different orthodontist to fix what a bad
| orthodontist did to me when I was a kid, and each gave me a
| completely different treatment plan. I feel like being an
| orthodontist is just eyeballing and patching your way as you
| go to an acceptable resolution.
| jmalicki wrote:
| Given that, shouldn't you be even _more concerned_ about
| people YOLOing it, if even highly trained orthodontists are
| regularly screwing this up?
| roughly wrote:
| As the joke goes, $10 to tighten the bolt, $90 to know which
| bolt to tighten.
| hattmall wrote:
| Sure, but it's a more or less a formulaic process. There's
| not on the fly decision making or emergency responses like in
| orthopaedic surgery or any other surgical design. You make a
| mold or scan of teeth. Calculate the adjustments, make the
| retainer, repeat. With a more widely available tooling the
| process could be even more monitored. i.e. Bi-weekly instead
| of monthly molds for faster and more precise results.
| plomme wrote:
| 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 wrote:
| 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.
| meroes wrote:
| Also no one has mentioned many mouths needed some teeth
| shaving to re-align. You are NOT doing that at home.
|
| Also who's attaching the attachments (I had 13 at first) to
| the teeth to help the aligners grab hold?
| infinitewars wrote:
| Most teeth align themselves as kids age. This is almost never
| necessary.
| imperialdrive wrote:
| There are folks working on solutions for when teeth do not
| align themselves.
| porridgeraisin wrote:
| Depends on diet.
|
| If you keep them on soft food young, the jaw muscles don't get
| stimulated enough to grow so that the teeth that are coming out
| sit properly. Misalignment and opportunity for decay ensues.
|
| If you give them decently hard food early on in life you solve
| most problems.
|
| After that it can still happen but there's less chance.
| CaliforniaKarl wrote:
| How early on in life?
| orthoxerox wrote:
| When they grow molars to chew with. Give them whole carrots
| to snack on.
| jonah wrote:
| Also, breastfeeding and not weaning them off on to "baby
| foods" too soon is better in the same ways you describe.
| leopld wrote:
| Yes, the 12 billion dollar company must be doing something that
| no one needs.
| y-curious wrote:
| Have you heard of the Big 4 consultancies?
| infinitewars wrote:
| If you look at places in the world where there are no
| dentists... their teeth are excellent.
|
| Anecdotally, our three boys all were told they MUST have
| braces (each for different reasons). We did this for exactly
| none of them. And their teeth came out perfect by adulthood.
| missedthecue wrote:
| My childhood teeth were perfect until I became a young
| adult and my wisdom teeth came in. My Ortho assured me that
| I had space and I didn't need them removed. I never had my
| wisdom teeth taken out, but they did shift all my naturally
| straight teeth and some became crooked. I'm looking into
| Invisalign to correct this because it does cause self
| confidence issues and I want to have my toothy smile back.
| Legend2440 wrote:
| Ok, sure, it's usually cosmetic. So what?
| b3ing wrote:
| Until wisdom teeth come in later on and cause crowding or
| visual issues
| troupo wrote:
| "almost never" for 8 billion people is "hundreds of millions of
| people need this".
|
| E.g. I do
| tombert wrote:
| 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.
| chrony3705 wrote:
| > All the same, I sleep like 10x better, so I suppose that
| considering that $600 is a cheap price to pay.
|
| First time?
|
| Price is not determined by cost to produce.
|
| It's determined by the price a customer is willing to pay.
| tombert wrote:
| I suspect the introduction of the infinite-money pits of
| insurance doesn't help either.
|
| Since I _do_ have the 3D scan of my teeth, I 've debated
| designing my own, but I'm not sure which resins to buy that I
| could safely put in my mouth every night.
| jopsen wrote:
| Even if you find a safe resin.
|
| Might there be microscopic layer lines? Or other unknowns
| you're not familiar with? Making 3d prints that can be
| cleaned is non-trivial, maybe there is a surface finish
| involved, etc.
|
| Also how do you know your design is correct? Won't cause
| your teeth to move? A 3d scan doesn't mean you know what a
| mouth guard should look like.
|
| All of a sudden, having a product that's made with a vetted
| process is pretty attractive -- and 600 USD seems like a
| bargain.
|
| What's the cost of having your teeth fixed, if they
| accidentally move? (Not to mention the discomfort, which
| can be considerable)
| tombert wrote:
| I'm not entirely sure what you're trying to convince me
| of. I _did_ pay the $600, I even said that it 's probably
| a cheap price to pay to treat the apnea.
|
| That doesn't really change the fact that it feels kind of
| viscerally wrong to pay $600 to pay for two glorified
| pieces of plastic, and a part of me still does feel I
| could clone it competently. I haven't bothered for the
| aforementioned safe resin, and also because I already
| have it and I have enough money to just eat the cost and
| complain about it.
| shiandow wrote:
| An important corollary to this rule is that that customer
| _need not be you_.
| hobofan wrote:
| Every company operating on that basis is a busniess waiting
| to be disrupted by a cost-plus competitor.
| bad_haircut72 wrote:
| The company competing on cost plus is wasting resources by
| solving problems that arent very profitable to solve
| regularfry wrote:
| Every business _still_ operating on that basis has a moat
| somewhere else.
| mayukh wrote:
| Yes this. Either have a moat or be a commodity.
| Commodities are cost plus
| chaboud wrote:
| In a market with perfect price discovery, sure. However,
| over the years I have learned that even the best products
| for the job can (and will) lose without the right
| marketing, sales, distribution, etc.
|
| Sometimes the entrenched default that collects an
| inertial premium doesn't get disrupted...
|
| But, yes, anyone without a moat who operates with a
| presumption of retention runs the risk of being knocked
| off of their perch; their fate left to others.
| lotsofpulp wrote:
| As is every individual earning more than median income.
| moffkalast wrote:
| And the material cost also isn't the main thing you're paying
| for, it's time and expertise involved in scanning and
| designing it.
| lxe wrote:
| > I know that there's a deceptively high amount of engineering
| required for these kinds of things
|
| I think there's a deceptively low amount of engineering
| required for most medical and medical-adjacent tech. The high
| costs are rooted in pervasive industry-wide centuries-long FUD
| campaigns.
| gunapologist99 wrote:
| > centuries-long FUD campaigns
|
| That dastardly Ben Franklin with his bifocals..
| SilverElfin wrote:
| I've tried custom molded mouthpieces for grinding but couldn't
| adjust to sleep with them. I notice them and feel the
| discomfort of it not feeling natural despite it being a pricey
| professionally manufactured piece. It just feels too
| artificial. I also wonder about the long term effects of
| polymers in the mouth for long periods of time daily.
| tombert wrote:
| It took me a couple weeks to get used to it, but get used to
| it I did. I would still prefer a universe where I didn't have
| to wear it, but at this point it doesn't bother me too much.
|
| I agree the plastics might be bad for me, but I justify it
| because I suspect that just continuing with the apnea is
| almost certainly worse for me, considering how many diseases
| appear to be caused by it.
| operatingthetan wrote:
| >Even with insurance covering some of it, it cost me about
| $600.
|
| Well that's pretty close to how much the entire CPAP system
| would cost depending on the sale.
| tombert wrote:
| The CPAP actually would have cost me less with insurance! At
| the time it would have cost me about $400.
| tredre3 wrote:
| 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 wrote:
| 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.
| ricardobeat wrote:
| 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.
| cryzinger wrote:
| 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 :)
| y-curious wrote:
| 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!
| tombert wrote:
| I hadn't heard of this. I'll give it a look and see if I my
| insurance covers it...thanks!
| itsdesmond wrote:
| I don't like this interviewer's tone, at all. It was like...
| confrontational but in a teenage way.
| b3ing wrote:
| There's a dental procedure in Latin America that is cheaper but
| only a few places in the US do it.
| LurkandComment wrote:
| 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
| Oarch wrote:
| Best of luck! I completed mine 2 years ago and have to say it
| was 100% worth the patience.
| Insanity wrote:
| My SO is now using it. I'm waiting for her impressions to
| decide if I want to do so.
|
| The dentist told me I'd only need it for like 3-4 months,
| minor corrections. But it seems like such a hassle. Always
| having to remove it before eating anywhere, no coffee, and
| gotta make sure I'd always travel with the next set of
| aligners etc.
|
| Glad it worked well for you though!
| com2kid wrote:
| I lost a few pounds doing it because snacking became so
| annoying. :)
| markphip wrote:
| I am nearing the end, depending on the refinements. The
| first two weeks I was regretting it, but adjusted quickly.
| Honestly for me the issue was more that I did not like the
| way my teeth feel with the trays out (and the rough field
| of the aligners on the teeth). The eating was not that big
| of a deal. I have a travel toothbrush and case I keep with
| me. It has been pretty easy.
|
| Still looking forward to getting the stuff off my teeth.
|
| I needed 15 trays so just 30 weeks. Not that bad.
| aewens wrote:
| 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!
| nntwozz wrote:
| 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.
| malfist wrote:
| Wouldn't be such a big deal if we didn't keep all our teeth,
| but we do now. The migration forward as we age, plus wisdom
| teeth are evolutionary holdovers.
|
| Fun fact, I have one fully grown in wisdom tooth. The rest
| are still there, but never moved. My dentist is always after
| me to get all of them removed, telling me that they won't
| fill a cavity on the grown in one
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