3D Printed Implant Model Work Discrepancies

[GhostFake]

We have done implant model work for years now, mostly printing them on our Formlabs 3B and for the most part we have not had many issues, until recently.
We have had a couple accounts that have complained about light/open contacts, specifically on implant cases, which usually end up in contact add-ons. But more recently we've been having a lot more issues and we are at a loss as to why they are happening. We just got one case back that in the mouth the mesial contact is open (they made some adjustments to get it to seat) but on our printed model the mesial contact is closed (see attached pictures) the case itself was scanned with a Primescan, using the Neodent Scanbody and designed in Exocad, using a Neodent Digital Analog and a Neodent Ti-Base.

But to make things even more baffling, we have one office that we've done implants for, digitally, for years. And in the last several weeks have had 3 different implant cases, with 3 different implant platforms, come back for remakes. What makes these cases so interesting is that the scanbodies they used were seated all the way but turned an impossible amount so the crowns wouldn't seat. (see attached pictures of the Straumann WN Variobase) the scanbodies were aligned correctly with the correct library, but the abutments were tweaked just enough that they needed to be redone. And a very similar situation happened with a Neodent case and a Neoss case using an Elos scanbody and Analog. Each of these cases were teaked just enough to be a problem when seated, and needed to be adjusted in the lab if not remade entirely. Anyone have any ideas what exactly could be the problem here? Or what we could possibly be screwing up on our end?
We've currently got a couple tests going on with our 3d printer to see if something funky is going on with our printer, but any ideas for trouble shooting would be much appreciated.

 

[ztech]

We have done implant model work for years now, mostly printing them on our Formlabs 3B and for the most part we have not had many issues, until recently.
We have had a couple accounts that have complained about light/open contacts, specifically on implant cases, which usually end up in contact add-ons. But more recently we've been having a lot more issues and we are at a loss as to why they are happening. We just got one case back that in the mouth the mesial contact is open (they made some adjustments to get it to seat) but on our printed model the mesial contact is closed (see attached pictures) the case itself was scanned with a Primescan, using the Neodent Scanbody and designed in Exocad, using a Neodent Digital Analog and a Neodent Ti-Base.

But to make things even more baffling, we have one office that we've done implants for, digitally, for years. And in the last several weeks have had 3 different implant cases, with 3 different implant platforms, come back for remakes. What makes these cases so interesting is that the scanbodies they used were seated all the way but turned an impossible amount so the crowns wouldn't seat. (see attached pictures of the Straumann WN Variobase) the scanbodies were aligned correctly with the correct library, but the abutments were tweaked just enough that they needed to be redone. And a very similar situation happened with a Neodent case and a Neoss case using an Elos scanbody and Analog. Each of these cases were teaked just enough to be a problem when seated, and needed to be adjusted in the lab if not remade entirely. Anyone have any ideas what exactly could be the problem here? Or what we could possibly be screwing up on our end?
We've currently got a couple tests going on with our 3d printer to see if something funky is going on with our printer, but any ideas for trouble shooting would be much appreciated

I assume you have ran a resin calibration on your printer. I would outsource a model to a place that has a carbon printer and get a model for comparison to one of the models above. Then go from there. I use Argen when I run into any fit problem so I can confirm accuracy of the printer first.

 

[GhostFake]

I assume you have ran a resin calibration on your printer. I would outsource a model to a place that has a carbon printer and get a model for comparison to one of the models above. Then go from there. I use Argen when I run into any fit problem so I can confirm accuracy of the printer first.

Alright, we will give that a shot, thank you!

 

[tuyere]

If you have a reasonably-modern scanner, you can scan the print and then compare the scanned mesh to the original STL using a comparative analysis program like GOM Compare (part of free Zeiss Quality Suite). Medit has a similar functionality, but I remember it being pretty limited in comparison. The comparison will give you a lot of feedback on what's wrong, where, and to what extent- an overall scaling issue will present very differently than, say, underexposure leading to short margins, that sort of thing. This approach is our go-to whenever we're not sure where the fault lies across a couple of different steps/parts.

 

[GhostFake]

If you have a reasonably-modern scanner, you can scan the print and then compare the scanned mesh to the original STL using a comparative analysis program like GOM Compare (part of free Zeiss Quality Suite). Medit has a similar functionality, but I remember it being pretty limited in comparison. The comparison will give you a lot of feedback on what's wrong, where, and to what extent- an overall scaling issue will present very differently than, say, underexposure leading to short margins, that sort of thing. This approach is our go-to whenever we're not sure where the fault lies across a couple of different steps/parts.

Awesome, thank you! I will look into that!
We also scanned the printed model to compare in exocad and for the most part it was within acceptable range. The only problem is that the scanbody was about .2mm tilted to one side, leading us to believe that maybe the analog was not fully seated.

 

[mmbh]

Had that issue in the past. It wasn't our form 3b+ printer. The Dr office was autoclaving the scan bodies and it warps them enough to screw everything up. Got them new set and everything was back to normal.

 

[GhostFake]

Had that issue in the past. It wasn't our form 3b+ printer. The Dr office was autoclaving the scan bodies and it warps them enough to screw everything up. Got them new set and everything was back to normal.

I am currently awaiting a call back about that. The scanbodies that they are using are the plastic ones so I think this could possibly be part of the problem, at least with the office that had 3 different platforms with issues. Thank you for this lead

 

[mmbh]

Sure. It completely eliminated the issue for us. They disinfect them a different way now.

 

[GhostFake]

Sure. It completely eliminated the issue for us. The disinfect them a different way now.

Yeah, the office is using the Autoclave to disinfect them, we are going to get them a new batch and see if that helps. Thank you for mentioning that. And in the meantime we will continue making sure our modelwork and analogs are on point.

 

[rkm rdt]

Are the contacts with single crowns open too or just the implants?
You’re dme files could be corrupted which happened to me once.

 

[GhostFake]

Are the contacts with single crowns open too or just the implants?
You’re dme files could be corrupted which happened to me once.

Its only been the implant cases. Do you think deleting and re-downloading the implant library would do the trick?

 

[rkm rdt]

Its only been the implant cases. Do you think deleting and re-downloading the implant library would do the trick?

I’m not an expert on that but contacting tech support would be my approach.
If it’s only implants and the crowns are accurate then it doesn’t appear to be an issue with your printer to me.

 

[zero_zero]

We stopped using plastic scan bodies for a long time, because they can deform and some of them are not radio-opaque, to see if they are seated correctly.
As for checking the printer's accuracy, for each new batch of resin I print a test model, which is basically a small solid model which has a crown fitted to. Check to see how it fits and how are the contacts...if it's off they you know what to do. Quick and easy

 

[GhostFake]

I’m not an expert on that but contacting tech support would be my approach.
If it’s only implants and the crowns are accurate then it doesn’t appear to be an issue with your printer to me.

Okay, I will reach out to our distributor and see if there is anyway we can check our libraries for any corrupted files. Thank you for that!

 

[GhostFake]

We stopped using plastic scan bodies for a long time, because they can deform and some of them are not radio-opaque, to see if they are seated correctly.
As for checking the printer's accuracy, for each new batch of resin I print a test model, which is basically a small solid model which has a crown fitted to. Check to see how it fits and how are the contacts...if it's off they you know what to do. Quick and easy

We've got a few different calibration prints we can run, but we just printed a new model today and everything is lining up perfectly. Our problem now is figuring out what is going on with those scanbodies. We've mentioned it to the office since they do run those PEEK scanbodies in the Autoclave, but they don't sound super convinced by our discussion.

 

[mmbh]

Even if technically some may claim to be autoclavable, there is usually a temp limit and sterilization time parameters that needs to be strictly followed.

 

[GhostFake]

Even if technically some may claim to be autoclavable, there is usually a temp limit and sterilization time parameters that needs to be strictly followed.

That's something I need to find out as well. All of the scanbodies they are using are PEEK material, but they don't think that is what is causing the issue. But we've tried so many different avenues and it keeps coming back to this.