A Dimensional Accuracy Test of Major 3D Printers

I had seen a bunch of requests for dimensional accuracy testing and some people having run some minimum feature test prints, but no comparative analysis of 3D printers done. I figured I could get someone to use software from 3D systems to solve this dilemma with an actual dimensional accuracy analysis.

I had STL files of printed dental models submitted with a Stratasys Objet Eden 260vs, Envisiontec Vida, Formlabs Form2, and Park Dental Research Juell Flash OC on different print settings when available. The printed accuracy was compared to the reference STL.

Two important findings:

  1. High resolution does not mean high accuracy. The resolution only comes into play with accuracy when it is more in line with the feature size of the print. 100 microns was a sufficient Z res for high accuracy prints of dental models
  2. All the printers offered the same high level of accuracy from a clinical standpoint.

Here is the link to the post: http://theorthocosmos.com/dimensional-accuracy-3d-printers/


Very interesting info - thanks for posting!

Formlabs does have a whitepaper on dimensional accuracy, though it certainly doesn’t compare printers from other manufacturers. The results are very similar to what you have already found.

The white paper I saw only had Form1+ and not Form2; can you link me to the one you are talking about? It would be interesting to compare.

Here’s a link to our latest White Paper which tests the dimensional accuracy of the new Dental Model Resin on the Form 2.

Thanks! I overlooked it because of the form.

Took a quick glance at the white paper.

It is nice to see this data, but it is hard to compare general dental procedures with orthodontics. They are night and day. The sharp corners and average feature size for crown and bridge work is much smaller than what you would find in a normal dentition, and thus the dimensional accuracy of these prints would be more resolution dependent. This is why the white paper shows an increase in accuracy with small Z Res on the printer.

Orthodontics is dealing with an intact dentition and the average feature size of the items printed is much larger, so the 100 micron Z resolution provides better accuracy than what is seen here. You might consider having some orthodontists do a white paper specific to our needs and use cases.

@freysmiles I know this is not really your department, but what is your opinion on fabricating surgical guides at 100 micron layer height? Right now it is currently not possible to do so, but I’m not sure if that was an attempt to improve clinical success on FL’s part, or if the resin just doesn’t cure properly at 100 micron resolution.

For me, I wouldn’t be creating surgical guides anyways, but I am fabricating occlusal splints in Open Mode with the Dental SG profile. It takes quite awhile for a 6-7 mL print, so for that reason, I would love to use the Dental SG settings at 100 micron. @Frew - do you have any technical info on why Dental SG only has the 50 micron resolution?

I don’t have any technical information as to why the Dental SG is only printable at 50microns, but if they performed the bio-compatibility testing or other testing for FDA compliance at that resolution sometimes there isn’t much wiggle room from the FDA.

The Dental SG doesn’t really have a nice color when it is fully cured so you might wait until the LT is released.

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As @freysmiles mentioned, bio-compatibility testing was done at a 50 micron resolution. Both material properties and process are taken into account for bio-compatibility certification and 50 microns is the resolution that’s going to be best suited for most dental applications.

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