I’ve been getting tagged in some FB comments on how to do a Hybrid with CEREC and I think its a good time to clarify some stuff. There are really 3 things you need to nail when doing a hybrid, be it digital or not. First, and most important, you need to get a passive fit of the prosthesis. I know everyone things that IOS scanners are super accurate, and for quads, they are. But for implants the stitching of hundred of images can lead to inaccuracy cross arch, or if you want to get “fancy” cross arch trueness. Can you do a hybrid without the dominos (Photogrammetry)? The short answer is yes, but you are still throwing the dice (pun intended). The second thing you need to get is the bite. With a converted denture, this is easy. With a denture, not so much. In this case we copied the patient’s denture by taking a CBCT, converted the DICOMs to STL, then, in Meshmixer, cut a window. The last thing, and this doesn’t sound hard, but it is, is to get the midline.
Here is the uncut and cut dentures in Meshmixer. The window will allow you to scan the healing abutments in CEREC while getting the buccal bite.
I won’t bore you with the details, you can see my other Photogrammetry cases on digitalenamel.com. But you need 3 scans in CEREC and one in Imetric: Upper healing abutments/scan bodies, the bite with the denture that has the window, and the opposing. In Imetric you scan the dominos and merge the healing abutment scans and export to ExoCAD.
Here you can see the healing abutment/scan bodies and the bite. Note, you do not call this case an implant case, just call it a crown, you will export to STL or PLY anyway before you get to the margin step.
So I get asked, can we do this in two appointments. Once appointment scan, one deliver final, be it Zirconia or Pekkton or whatever. The short answer is yes, but experience (read F-ups) that you really need a try in, wither in 3D Printed resin or in PMMA. You want to check the fit, the bite, the midline and tooth/gingiva display. In this case, the PMMA looked OK. There was too much of an abrupt shelf on the buccal. The fit and bite were great. If we had gone straight to Zirconia, we would either have to grind off the shelf (read just kill me now) or send it back. But I am always impressed by the bite. This is without adjustment.
You can see that shelf as well as the midline is slightly off. So these are things you can simply email your lab, in this case Prosmiles, and they can correct in the final.
But I think you can see that the bite is right on.
If you want to try this out live, we will be lining up multiple arches to scan using any IOS scanner and the Imetric system! Doc will learn the analog as well as the digital workflow from everything from singles, over dentures and hybrids! Come to Implant Pathway Nov 5-7!1. Register at https://www.implantpathway.com/restorative-solutions/
Also I have put my 3D Printing Party online! 12 CE credits and hours of hands on from surgical guides, to aligners, to digital dentures and hybrids and more!