Hi , I was wondering if there is any good literature comparing various materials for construction of all on X in fully edentulous and against opposing natural dentition ? Like metal /acrylic wraparound, peek framework with individual milled crowns and milled zirconia. Would be good to know what protocol works best in the long term with least complications. Many Thanks
Daniel Camm comments:I am interested to hear comments about this. I have done a lot of these cases and have anecdotal opinions about materials, but no real literature reports. I have had some significant problems with about 15 of these fixed hybrid restorations. Let’s hear what others say.
Leffy comments:I like Zr.
Daniel Camm comments:Leffy: I do too. But I have had a problem in several cases where the metal sleeves that are bonded into the prosthesis come loose. That is a real difficult situation to repair. So I try, now, to make a metal frame and bond the teeth to that. It is better, but I still have had problems with the teeth breaking off the frame.
Aquiles Mas comments:Well. Extrapolating from the literature from single units made from zirc against natural teeth the wear is pretty good as long as the surface is polished smooth. The high density and toughness of zirc keeps the surface smooth and more friendly to opposing natural teeth than older feldspathic porcelain. But weighing the complexity of a multiple material prosthesis over a single milled piece of zirc I pick the solid zirc for longer service life and less complications to you and the patient. Stick to the KISS principle and try not to overthink it. I believe that the simpler solution may be best in this case.
Leal . comments:This one is a no brainer. The best material should have the fracture toughness of titanium or milled Co-Cr, the esthetics of feldspatic porcelain and tooth wearing properties of mechanically polished zirconia. Saying this, the best possible solution regarding esthetics and fracture toughness would be a milled Co-Cr framework with pink ceramics to mimic the gingiva and individual zirconia crowns with all zirconia on the palatal side with mechanical polishing only, no glaze at all, and buccal cutback to layer ceramics; all these individual crowns cemented to the framework's opaque. This is the top of the line. Now if you want to have a "close" to the top of the line prosthesis you can have a full mouth PFM (Co-Cr milled) on top of multi unit abutments. Never ever directly to the implant head. If you have a medium to small vertical availability (in terms of prosthesis space) and want to have troubles in the future then go ahead with the trend and ask your lab to do a full mouth milled zirconia. It's cheaper but will definitely fracture down the road. No matter if it's tooth supported of implant supported. Either you have a LOT of vertical prosthesis space or you are burnt. Forget about the 27 rule for Zirconia (3X3X3 mm rule). I am almost exclusively (+90% probably) doing single unit Zirconia crowns and just love the material. You got to love it but you have to know its limits.
ARUN SHAH comments:go for biohpp framerwork and visilign teeth set bonded witrh composite
Greg Kammeyer, DDS, MS comments:Leal, In all due respect the last material I would use is Co-Cr. With the saliva as an electrolyte and dissimilar metals, you are getting corrosion. Do a lit search on it. Modern titanium implants have 8-12 metals that include iron and Nickle. Adding another ad hoc metal mix is contraindicated. Look closely at the parts whenever you follow-up on your cases. They will have a brown rust color. As I note that my self I am coming to understand why all the big implant companies are offering Zirconia implants.
My referring Dr’s seem to favor either monolithic Zirc or Titanium bar with individual Zirc crowns and plastic pink.
I will encourage you in general when you have this kind of question to go to Pub Med, Google Scolar and Chochran data bases for a lit search. The results section of the abstract will help you to know if you should order the article. This is what specialists do in their training and as an ongoing educational resource. Just asking a few opinions, for major questions, may mislead you.
To quote Carl Misch, the price of failure in implant dentistry is VERY high: Loss of patient confidence, loss of Dr confidence, loss of practice momentum and lots of wasted chair hours and lab costs.
Leal . comments:I am sorry that you did not read my post carefully. Co-Cr cast metal corrosion is well documented and connecting this cast metal directly to a dental implant connection is without a doubt a terrible decision. MILLED Co-Cr (and there are some very good products on the market today) on the other hand connected to a multi-unit abutment is what I was referring to. This milled alloy, also quite well documented, has an acceptable corrosion rate. With my respect to your experience, I encourage you to study why milled zirconia is not a good choice for a full mouth rehab, specifically the direction of expansion and sintering shrinkage that culminates with 3 specific stress areas that will end up in a fracture. I would favour a titanium framework with pink ceramics but TiPFM is still not a well documented solution for a number of reasons. Titanium framework with pink acrylics (not the titanium part, but the acrylic part) is most definitely not a top of the line solution; again based on the available literature.
Totally agree with the Carl Misch quote. The last thing you want is a patient coming “to you” after spending a lot of money on a maxillary rehab and realizing that probably the zirconia option was not that good of an option.