Can I use surgical guide on the Form 3 (not B)


I want to use the Surgical Guide resin (not for medical purposes) but only have a Form 3+.
I know the documentation says that the Surgical Guide resin isn’t compatible with the Form 3+ but if I put the cartridge in will the printer work?
What are the actual differences between the 3B and 3?


Hi @tsmoney ,

Unfortunately, Surgical Guide and other biocompatible resins are not compatible with the Form 3+. The Form 3B and 3B+ have additional functionality to print with these other biocompatible materials, as well as having a white shell in order to easily differentiate the models. There is a short guide on our site that details the differences between the models, and also a handy material selector that will let you know which printers each resin is compatible with.

If there are specific properties of Surgical Guide that you are interested in, we might be able to recommend a similar material that could print on your Form 3+. Please let us know if we can assist with that!


It’s a software lockout, otherwise you could. I’ve printed with Biomed Clear on a $200 Elegoo printer and the parts came out just as good. You still need to follow the wash and cure steps though.

The IFU with the Bio resin says use this resin with an SLA printer like the Form 3B. Even the instructions don’t say you need to use their printer. Even more interesting is that… somewhere… Form even states that the Form 3B printer is NOT considered a medical device, so any regulatory excuses are just to cover for being locked out in software.

It would be great if Formlabs stated exactly what mechanical differences exist (if any) between the Form 3 and the Form 3b to make it suited to the “bio medical” resin printing.

OR are the differences simply software and thats what the extra money is for?

How do the “plus” range of printers sit in all this?

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@Dxxxx I believe the + upgrades are legitimate. Mid product life upgrades are common, and I’m sure it was easy to swap in better motors from a new supplier, etc. As far as hardware differences between 3 and 3+, there are none. When buying my machine, I was told there were certifications the 3B had to go through in order to be certified by the FDA. Which makes sense. Then I noticed a design defect that affected all machines, a defect that would cause aluminum flakes to fall into the medical resin during regular use, and I was told the printer is not considered a medical device by the FDA, just the resin. When they first launched the machine, they had a… I don’t know if mandatory per se, but strongly encouraged… $3000 service contract for each machine. I think that’s the reason for the SKU difference. It wouldn’t make sense for $500 because they would make that up on being able to sell the material.

Not quite sure if what you were told was correct !!

Interesting article here:

@Dxxxx I’m totally open to being corrected - the med device clearance/definition is a weird process to navigate. The way I understand it, is the resin is considered bio-compatible, but not the printer.
Formlabs even says it here: customer_v2

  • Formlabs, Inc. hereby declares that it deems its 3D Printer, Form Cure, Form Wash and the resins listed on pages 2 and 3 of the are not classified as Medical Devices as defined in Article 2 of Regulation (EU) 2017/745 (MDR) or in Section 201(h) of the Federal Food Drug & Cosmetic (FD&C) Act at the present time.*

The resin is considered biocompatible >30 days after passing ISO 10993 cytotoxicity tests, but that is the only claim they make. Per your article, it sounds like the the resins and printer are FDA Exempt, and the manufacturer is making no claim about the material being suitable for medical devices, only that it passed cytotoxicity tests. Which makes sense honestly, if I print a spiked ball and swallow it, even though it won’t be cytotoxic, it can still harm me. I think the ISO 10993 claim on material biocompatibility is the best Form can do and it’s up to the end user to be responsible for the application. (This is in contract to the Roland DWX-52D which actually claims it is a Class I device)

That said, I think they have a great lawyer that works with their marketing team to stretch every claim what the material can do that is technically correct, and then in other parts of the website, completely waive all liability when possible. Which, ok, that can be said for a lot of businesses. The kind of sketchy part is, on that same certification page, is their release of liability to HIPAA compliance. Their device phones home and uploads STL/file names to Formlabs servers. For med/dental, this is a pretty big deal. You would think a device built for bio use with an up-charge from the base model would be HIPAA compliant. I think the only way for a user to remain HIPAA compliant is to use both the printer and software completely offline. They say they don’t recommend using patient names on files, but I think it could be argued the dental file itself could be patient identifying, considering dental records are often used to identify bodies.

“Bio Medical” approval is certainly a complex area. Especially when looked at in the context of photo- polymerised resin materials.

In reality for an end user to be able to claim a finished part is “safe” and “FDA Approved (or Certified” will require a lot more than simply printing something on a 3D printer like the Form 3 and hoping for the best.

The printer power (exposure source power) the post printing clean up technique and the post print further exposure to more curing energy are all examples of variables that need careful control and measurement, these in turn need to be supported by (expensive) complex testing to ensure consistency and repeatability.

Its a very complex regulatory minefield and anyone who is misled by a manufacturers vague claim that a material is bio compatible is perhaps worth some sympathy.

With regards ISO 10993 cytotoxicity tests - its hard to see which of the tests is being applied to the marketing claim, and to what part of the standards it has passed. If for example if Formlabs claim refers to a test under ISO 10993 -5, then what was the specific “medical device” being tested

Looking at the Formlabs guide (customer_v2)- claims “Surgical Guide Resin is non cytotoxic, not a sensitizer, non irritating and complies with ISO 10993-1:2018.”

While its interesting that the section of the ISO standard referred to by formlabs is simply a section that ISO lists with its full title as " Biological evaluation of medical devices — Part 1: Evaluation and testing within a risk management process"

In itself its not a specific test…

If we consider the Safety Data sheet for the Surgical guide resin we find this

And this:

The other points regarding FDA compliance are very good points that you raise.

Ya, it’s all pretty vague, even FDA’s own requirements. Getting back to the main point though, the biocompatibility of ISO 10993 just comes down to tissue contact for >30 days. I remember reading about Form’s specific test somewhere, but I think they just printed a few parts and left them on mucosal membranes in mice for > 30 days - or something like that. That part’s fine, I can only assume they followed proper ISO protocol for that. In the IFU that comes with the biomedical resin, the instructions only state that a UV based SLA printer be used - not the Form 3B or the Form 2 specifically. They also only recommend a particular wash/cure cycle. I think the way the claims with cytotoxicity work in general are “We tested this under these conditions and got these results, use this information at your own discretion.”

In my opinion, the UV output of the cure station for an hour blows any variances of power output of the printer laser right out the water. While I can’t confirm that, the parts that come straight off the printer of both my elegoo and my form 3B look identical and have a blueish tint to them (when using biomedical resin). When coming out of the cure station, they both have an equal yellowish tint.

Everything you are saying about the variances in hardware requirements in the 3 and 3B printers makes complete sense. I dug deep down this rabbit hole and cannot find a single lick of difference. Even the short guide posted by Corey M above just says “the differences are that they are different.” I would think, somewhere in all of this, if there was a single claim Form could point to regarding differences, they would point it out. Even if it was just “The 3B has added software to comply with HIPAA regulations for Dental use.” That is a valid reason. Also, just checked, yup: Form 3B | Formlabs
When the Form 3B was released, you were required to purchase a $1500 service plan. I think Form realized they overplayed their hand and were crippling purchases by doing this, so they made up other reasons that their product is different. Even when the Form 3 was announced (before the 3B) it could print in biocompatible. Then they released the 3B and any Form 3 that shipped after that would not be compatible with Biomedical resins. Even on the announcement, Form said initial Form 3 purchasers would be grandfathered into having biomedical compatibility though EOL of their printer. Form 3B Announcement! - #8 by sunshine I don’t think it has anything to do with hardware limitations.

Again, I would love to hear from Form if they can back up their claims.