popularity of cobalt chrome milling versus zirconia milling

[Paddy]

I'm a dentist with an interest dental technology. Can anyone give me an opinion on relative popularity of milled zirconia versus cobalt chrome. Personally, I've always preferred ceramic bonded to cobalt chrome - really nice aesthetics and good ceramic to metal bond strength. Also is you ever need to replace the prosthesis, it's much easier to remove. However, recently I'm seeing some really nice aesthetics with zirconia. Is there an increasing shift to zirconia which will make milled CoCr obsolete? Feedback from technicians much appreciated!

 

[doug]

Welcome to the bored!

 

[CoolHandLuke]

milled zirconia versus cobalt chrome

for what, crowns? partials?

one is used almost exclusively over the other, in both applications.

 

[Affinity]

Ive seen the pendulum swing back to Drs wanting PFMs after Zr bridges have failed. I do 95% zirconia, the rest is gold crowns or emax, maybe 1-2 pfm cases per year, only because I dont accept them other than when nothing else will work. The bond of porcelain to chrome is undeniable though, if done right. Both break though. And ultimately the excessive time-consuming nature of bonding porcelain to metal/multiple bakes/ shrinkage/ masking gray.. its just not profitable anymore, unless you are willing to pay $400, which I doubt you are.

 

[tehnik]

I think alternative right now is metal frame with cemented zirconia overstructure. It is both strong and esthetic. But it needs room to be strong.

 

[grantoz]

i ve been on holiday for a month so i will be nice if your zi crowns dont look better than your cocr porc then change your techo

 

[TheLabGuy]

Car bumper pfms vs. zirconia? This a joke? I'm not even dignify this with a response.

 

[rkm rdt]

I bet he sends work to Disturbed.

 

[Paddy]

Welcome to the bored!

THANKS

 

[Paddy]

for what, crowns? partials?

one is used almost exclusively over the other, in both applications.

Not partials, single or multiple units, conventional and implant retained.

 

[Paddy]

I think alternative right now is metal frame with cemented zirconia overstructure. It is both strong and esthetic. But it needs room to be strong.

Interesting. Thanks. I presume this is for implant bridges?

 

[Paddy]

Ive seen the pendulum swing back to Drs wanting PFMs after Zr bridges have failed. I do 95% zirconia, the rest is gold crowns or emax, maybe 1-2 pfm cases per year, only because I dont accept them other than when nothing else will work. The bond of porcelain to chrome is undeniable though, if done right. Both break though. And ultimately the excessive time-consuming nature of bonding porcelain to metal/multiple bakes/ shrinkage/ masking gray.. its just not profitable anymore, unless you are willing to pay $400, which I doubt you are.

Thank you for your detailed reply. This tells me a lot.

 

[Paddy]

i ve been on holiday for a month so i will be nice if your zi crowns dont look better than your cocr porc then change your techo

Thanks

 

[CoolHandLuke]

Not partials, single or multiple units, conventional and implant retained.

literally none of our customers mill their own implant interfaces. in either zirconia or titanium or cocr.

 

[mmbh]

We stopped doing pfm's completely.

 

[Paddy]

Thanks for the reply. I'm just interested in the dental technicians' perspective (not the dentists'),particularly those who do milling for fixed prostheses. I work in England (in the U.K.). There has recently been a seismic shift to milled zirconia with dental technicians suggesting we use more of it. Even my ceramist who has worked some aesthetic wonders with ceramic bonded to CoCr seems to be singing the praises of zirconia. Historically, I've not been impressed with zirconia - issues with debonding of layered ceramic, while the monolithic restorations look artificial. Recently, staining of the monolithic structure has really improved aesthetics and (I presume) I don't have to worry about fracture of layered ceramic. At the same time, there seems to be quite large market for milled CoCr - hard and fully dense as well as soft milled CoCr which needs to be sintered in an argon furnace - is milling CoCr (or even titanium) a thing in the USA, it seems everyone just uses zirconia?

 

[tuyere]

We do a small but constant stream of CoCr crowns and copings, zirconia isn't really an appropriate fit for everything. The majority of work is now zirconia, though. I've been told that in the US you tend to see titanium used in preference of CoCr.

 

[CoolHandLuke]

when was the last time you did zirconia 2008?

2009 they invented a thing called Zirliner and since then precious few delaminations ever occur. its an agent applied to the zir before layering that helps bond the porc.

multilayer zirc became a thing in like 2013 and in the 10 years since its been out its oversold and replaced all use of the White zirconia by a million miles.

adding Microlayering kits to the mix and now most average competence techs can get good results and most exceptional techs get exceptional results with less effort.

 

[doug]

I rarely got enough reduction for PFG crowns. I got a little more for zirconia from the ones who had been doing Emax. I can't imagine enough room for both materials to be esthetic, much less last for any length of time under normal occlusal forces.

edit for spelling

 

[desertfox384]

From the techs perspective: zirconia is much less time consuming than metal, less mess than metal, we don’t burn the hell out of our fingers finishing it, and failure rates (in my experience) are less than or equal to metal. What’s not to like?