e.max Occluding Zirconia

[McTeeth]

Hey guys,
I had a dentist ask me if there are any concerns with e.max occluding zirconia?
My response was," Not that I know of, how is the patients function?"

My initial thinking is...if each are fine to occlude natural teeth, then why not be ok to occlude with each other? Can a chemistry guru shed any light on this for me?
Thanks,
Sean

 

[jy147147]

It is two different materials and I don't think it would work together.

I had several doctors asked me before and I show them Zirconium crown's quality. in my experience Zirconium crown can compete with E-max.

I think they are worry about fracture and at the same time they also worry about shade. So I would show them reduced Zirconium crown and stack up some porc on it

Or Mill full contour and cutback and stack some porc.

A lot of doctor surprised with it.

 

[corona]

depends ....... are we talking the posteriors ? bis ? anteriors ? each area of the arch has different clencning forces ....posteriors having the strongest clenching ...... how much reduction is being planned ? what kind of occlusal scheme and classification are we talking about ? are the canine incisal thirds totally intake and cuspid rise discluding the posteriors completely ? If the doctor wants a quick answer then doing same material against each other would probably be recommended . IMO though .... lots of variables .

 

[Contraluz]

Hey guys,
I had a dentist ask me if there are any concerns with e.max occluding zirconia?
My response was," Not that I know of, how is the patients function?" My initial thinking is...if each are fine to occlude natural teeth, then why not be ok to occlude with each other? Can a chemistry guru shed any light on this for me? Thanks,
Sean

Great question! There are many things that go into this. I hope we get some more people to respond to this thread, since, I am sure, we will find many different answers to it.

As of monolithic e.max opposing monolithic Zr, if the occlusal surfaces are polished, I'd venture to say you are fine. However, more often than not, my client recommend (or straight out give) their pts a night guard after treatment.

As soon as you get into layered porcelain (who does that today on posteriors, anyway... ),there are different answers due to the different composition of the various porcelains.

In my own experience, an old Zr prostheses (full lower arch) can finish up a layered opposing PFM prostheses in less than a year, if the pt is not careful (bruxer) or doesn't wear a guard.

 

[Contraluz]

IMO though .... lots of variables

Very true! You cant just give a 'one size fits all' answer. It seems though, todays dentistry is trying to go that way...

 

[charles007]

Neither material is going to break/chip assuming techniques are ok.
The more educated question would be,
1. Which materials glaze/stain will wear away first, lol
2. Are the 2 restorations out of occlusion.
Highly polished zirconia or LD/Emax will be fine.

My $.02

 

[McTeeth]

Great question! There are many things that go into this. I hope we get some more people to respond to this thread, since, I am sure, we will find many different answers to it.

As of monolithic e.max opposing monolithic Zr, if the occlusal surfaces are polished, I'd venture to say you are fine. However, more often than not, my client recommend (or straight out give) their pts a night guard after treatment.

As soon as you get into layered porcelain (who does that today on posteriors, anyway... ),there are different answers due to the different composition of the various porcelains.

In my own experience, an old Zr prostheses (full lower arch) can finish up a layered opposing PFM prostheses in less than a year, if the pt is not careful (bruxer) or doesn't wear a guard.

Thank you. Yeah, i see it the same way...high polished shouldn't abrade. What's thjis layered posterior crown you speak of?

 

[McTeeth]

depends ....... are we talking the posteriors ? bis ? anteriors ? each area of the arch has different clencning forces ....posteriors having the strongest clenching ...... how much reduction is being planned ? what kind of occlusal scheme and classification are we talking about ? are the canine incisal thirds totally intake and cuspid rise discluding the posteriors completely ? If the doctor wants a quick answer then doing same material against each other would probably be recommended . IMO though .... lots of variables .

Fair enough. Posterior, and I think we all know that it will be a quad triple tray impression w/ minimal reduction. No canine in the impression either.

 

[Contraluz]

What's thjis layered posterior crown you speak of?

Something like the Dodo bird. Nobody has seen it in a loooong time...