In doing the all-on-x treatment, I’m doing a PMMA prosthesis first that lets the patient test out the design for a week or so and all the occlusal adjustments can be done prior to making the final out of zirconia.
Now I am needing to make it out of zirconia. What is the best way to go from a milled PMMA to zirconia with a slight cutback on the gums for pink porcelain? Do I start a new case? Do I just use the old case and try and modify it with a visualization mesh? Do I scan in the adjusted PMMA and use that as a wax-up (the scan can’t see the underside of the pmma)? I like the design of the PMMA and generally want to keep it but need to take into account the adjustments made for occlusion and gingiva. What is the best way to do this?
I think the best way is use the adjusted PMMA scan as a waxup. I think using a new case would be best, as long as your impression/scan of the implants is good. Did the PMMA seat passively?
You can always add your PMMA scan of the adjusted occlusion as a “preop scan” and have your existing job adapt to preop scan. That way, you wouldn’t lose the location of the implants, still have your gingiva and teeth as separate designs, and you can cutback just the gingiva if you want.
Those are both good suggestions – I think the wax-up will be easiest since it is all passive. Any way to do a cutback on a design generated from a wax-up? Seems simple enough to be able to draw your area you want reduced, but it may only be feasible with the anatomy/gingiva file itself.
Hmmmm, once your waxup is copied over, can you go into expert mode, then “reduce”, but paint the teeth as areas you don’t want reduced? Might be a pain to have to paint all the teeth, but I can’t think of another way to isolate them at the moment if there isn’t a separate gingiva mesh.