Possible to replace master model in exocad after designing done?

[ddsTech]

Desperate Exocad question here....

I'm working on a Mx 12-unit implant case (4, 3-unit bridges). Modelwork was done in a way that caused me to have to individually scan, import and align abutment scans. I went ahead and designed the entire huge case and milled in pmma to verify fit. Turns out alignment of abutment scans was not perfectly accurate.

I then used meshlab to get perfect alignment of abutment scans into a new master model and would like to replace the old misaligned master model with the new properly aligned mesh. Then I:

1. Tried renaming new model to original models' name to trick Exocad into using the new model. That didn't work.

2. Tried importing new model as a visualization mesh and aligning imported abutments scan to the new model. That didn't work because imported die scans only align to the master (unaligned original) model.

3. Tried aligning imported abutment scans to new mesh (imported as visualization mesh) using 3 point alignment. That works, but then the imported abutment scan isn't recognized as being part of the master model. This means you can't mark a margin on it.

I could possibly rescan the case and use the milled pmma as a waxup, but that's a ton of work and the milling is not as nice as my original design, not to mention it doesn't fit perfectly.

How can I move forward with my new, properly-aligned model and all of my previously-designed CAD work?

Thanks!

 

[cadfan]

Exocad is saving the cases in scene s so rename a model is not in the scene was only the first scan bad something missed on the abutments or is the position wrong import the abutments as new scan done with multidie if only parts are wrong.
You can try your 3 rd version with regisrated generic visualization and save only this as stl and than rename the old in for example 2 and new one in the old one than go into the modellation software and cancel your modelation than adapt new margin line and save.


Or rescan with bad pmma and replace the old modelation which you save as stl as situ and adapt.

 

[ddsTech]

Exocad is saving the cases in scene s so rename a model is not in the scene was only the first scan bad something missed on the abutments or is the position wrong import the abutments as new scan done with multidie if only parts are wrong.
You can try your 3 rd version with regisrated generic visualization and save only this as stl and than rename the old in for example 2 and new one in the old one than go into the modellation software and cancel your modelation than adapt new margin line and save.


Or rescan with bad pmma and replace the old modelation which you save as stl as situ and adapt.

Thanks for the help.

Exocad's multidie registration (1 point) with the master model was not accurate, so the perfectly good individual abutment scans aren't positioned precisely. I tried using the "mesh registration" option in the "view" menu for a more accurate multi-point registration, but that doesn't appear to work for imported die scan registration.

Sorry, but I don't understand the second half of your comment. Could you please restate it a different way?

 

[ddsTech]

Cadfan,
This is the part of your post I don't understand...

"You can try your 3 rd version with regisrated generic visualization and save only this as stl and than rename the old in for example 2 and new one in the old one than go into the modellation software and cancel your modelation than adapt new margin line and save."

 

[cadfan]

Exocad is saving in scenes so your third way was not bat but you have to make some additional steps if you have a way to registrate the new model do it than go into the submenu free field with mouse and save the model you need as stl . after that you can try to rename the models but this model is not in the scene thats why you must try to change things for example the präpline in the submenu but i am not sure if it works. additional a second step save your modelation as stl too than start the case new präp and so on very fast and use the adaption funktion ( situ model ) so its done in 15 minutes.

The multidie registration is not for jaws its for single stumps for example abutments on a master
model where the margin is not 100% acurate than you scan the abutments only a secod time on a multi die plate or each one single and import them into the master model and melt the stumps together .or you have two different stump models one stump is on the first good the other on the second so you melt together what you need,

3 things are important a scene is not a model , you need to registrate the new model however in the old one to have the same position this position versus model must be saved as stl only than you can rename it to work with your modelation is not real its only in the scene if you need it real you must blip every other thing of than you can save it as stl or off to work with.

 

[cadfan]

Cadfan,
This is the part of your post I don't understand...

"You can try your 3 rd version with regisrated generic visualization and save only this as stl and than rename the old in for example 2 and new one in the old one than go into the modellation software and cancel your modelation than adapt new margin line and save."

Not sure if it works your new jaw must be registrated to have the same position than your old model but the software wouldnt axept it as stumpjaw but the position is ok so if you blip everything out and save it as stl its a real model a generic visualisation exists only in the scene.this real model can be renamed in the software. if you give this model the name of the old on after a restart this model is loaded not the old on but if you start the scene because you want your modelation its the old one the scene is only something like foto so it doesent work . if you save your modelation although as stl or off you have a real situ model to adapt fast . the margin line adaption ill think doesenst work beacause its scenebased

 

[Toast]

What about opening DentalCADApp and import the new model only, no antagonist or separate gingiva. Set up the case within the app, right click--advanced--add/remove layer. Select pre-op and import the stl of the pmma as the pre-op. It will ask if you want to remove the bottoms of the crowns to make adaptation easier, choose yes. You can now adjust the position of the pre-op until the bridges are where you want them. Then adapt to pre-op. It should come out better then scanning the pmma as a wax-up especially if the abutments weren't too far off originally. Im not in front of my computer right now to double check all the steps but I know I done this in a similar situation before.

 

[ddsTech]

Thanks, Cadfan and Toast for your help! I ended up resolving the problem in a couple of hours following your instructions, starting a new file and importing all of the previously saved stl models from the original project (not including the misaligned master model). Toast's post made Cadfan's posts clearer for me. I never was able to succeed by just renaming files for replacement, but may give that another shot just for fun later.

Here's what I learned from this project:
1. Saving stl models from within an Exocad scene stores their current transformation (location, rotation). Very handy if they're already aligned with other models!
2. Completed, fused restoration stl's can be imported into other scenes and used as pre-op models.
3. Sometimes, Exocad has a hard time precisely aligning meshes that don't have distinctive anatomy. From now on I'll put a few "locator" dimples on the surface of implant abutments.
4. Meshlab is great for aligning difficult meshes. Just remember to store their "transformation matrix" before exporting to a new stl filename.
5. Mill your case in wax or pmma first to check accuracy of fit if you have any questions about scan accuracy.

 

[Toast]

Glad it all worked out in the end. Thanks for sharing what you learned too, threads like this will help many down the road. When I get in a situation like yours I start to feel like any profitability the case had is lost (not to mention being late for dinner again). But I have to remind my self that the next time I'll know what to do and hopefully breeze right through it.
I thought about this some over the weekend and I'm wondering if if this would have worked:
• import orig. mesh into meshlab
• cut abutments from mesh
• import new mesh
• align new mesh to orig. mesh - highlight original mesh (0) chose "glue here mesh" , highlight new mesh (1) and choose "point based gluing" then process.
• "flatten visible layers" to merge into one mesh
• "export as" pick project folder and use file name of original mesh and choose yes when asked if you want to replace file since it already exist
A while back I had an implant case that was supposed to be screw retained but was mistakenly scanned with an Atlantis scan body. Instead of rescanning the whole case I scanned the model with the correct scan body using the Identica software. Then did as described above and everything opened just fine in exocad.

 

[dmonwaxa]

Toast what function within MeshLab did you use to (trim) cut abutments from mesh?

 

[Toast]

There are several selection choices towards the upper right.
1) "select vertex clusters" works well with the mesh pictured because the scan body isn't attached to anything so it's quick.
2) "select vertexes" gives you a rectangular selection box. This works well but sometimes you have to select several times to get everything you want.
3) "Delete selected set of selected vertices, faces that share on of the deleted vertexes are deleted too" This delete option is the one I use.
To unselect, shift + select area
This tutorial pdf has helped me a lot, I'm fairly new to MeshLab but getting the hang of it.
http://www.cse.iitd.ac.in/~mcs112609/Meshlab Tutorial.pdf

 

[dmonwaxa]

Thanks, thought there was a better way to accomplish this,,,,been doing pretty much the same as you and with same results.

 

[Toast]

Thanks, thought there was a better way to accomplish this,,,,been doing pretty much the same as you and with same results.

I would like to have a "free form" selection option in MeshLab.