While the one-piece milled zirconia posts and cores are found to be a better esthetic option for ceramic crowns comparing with cast post and core, it's not widely used? Why?
Probably because they are to stiff and cause root fracture; more than metal posts.
if you mean post and cores for implant supported restorations, one piece zirconia abutments are not widly used due to their fragility, moreover for internal connections. In fact, if there is a correct fit, minimal tollerance could produce fractures of the zirconia connection.
For this reason, metal core with zirconia abutment at the moment is the best option for highliy demanding esthetic cases (please see Canullo 2007 J Prost)
Zirconia post and cores aren't popular for a few reasons. You can't bond them in unless you surface treat them and not many people have the materials to accomplish that. That are very rigid which, in the event of a failure, is usually catastrophic. They are also very difficult to adjust due to their high hardness value.
Excellent to see we are all in full agreement and the reasons enumarated.
One could simply conclude: there is an important misfit of elasticity modulus of the previous rct tooth and xirconia.
My opinion is: I would distinguish between the abutment for implant and the Zirconia post for natural teeth.I agree with Dr. Rosati's comments,for natural teeth, and also with Michael Mansell. For implants,i agree with Luigi Canullo's article written in 2007 with J.Prost.
Mainly because it is a really stupid material and outmoded technique to use.
Post and cores preparation for this material destroys sound tooth tissue unecessarily and you cannot get normal adhesives to stick to the zirconia..
Avoid if you have any sense . .
I agree, if you have to make large reconstructions, used the post core gold! oldfashioned
Thanks for answers Doctors, your opinions are highly appreciated
but can I ask if these opinions based on personal experiencing the failure of zirconia post and core in your clinics or you never proceeding with such material avoiding the concept and your opinions are hypothetical reasoning?
thanks in advance for replying
Dear Alaa, how are you?
First at all, the esthetic superiority of zirconia post and core are false. To achieve this post you should cross, at least, 1,4 mm of ceramic crown (ceramic and infrastructure) and a cement layer, so if you respect the materials properties you will never see the interference of the post. When you see book ad papers showing the light transmission you see the difference right? but who has a light point inside the mouth to reproduce the direction of this light to outside to allow us to see this difference.
About the zirconia post it is worst than metal post to produce catastrophic fractures.
cheers
Jefferson
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