Color change in zirconia

[PDC]

I have a large zirconia frame from Argen which is an A-1 shade. It appeared to have a lot of yellow shading and had more of an A-2 appearance. The pontics were pretty large and seemed to have more yellow than other areas of the frame. After firing it with zirliner, the yellow seemed more intense on the pontics so I ground back the facial of one of them in an effort to brighten it. Rezirlined and noticed everything seemed to lose the yellow appearance. Now seems to have a more uniform A-1 shade.
Anybody have any thoughts as to what caused this? Poor sintering?

 

[CoolHandLuke]

well it starts with c.

contamination

calibration

cears, ceets, cattlestar galactica...


its either a contamination of the liquid or the muffle or the beads.

or a furnace temperture has changed due simply to age.

 

[JohnWilson]

Bears eat Beets FACT!

 

[JohnWilson]

False.... Black Bear

 

[PDC]

well it starts with c.

contamination

calibration

cears, ceets, cattlestar galactica...


its either a contamination of the liquid or the muffle or the beads.

or a furnace temperture has changed due simply to age.

So could this affect the structural integrity? It still seems to have all the rigidity.

 

[CoolHandLuke]

not sure, but i doubt it.

 

[LuthorCorp]

Bears eat Beets FACT!

Bears... Beats.... .... BattleStar Galactica

 

[rkm rdt]

I have a large zirconia frame from Argen which is an A-1 shade. It appeared to have a lot of yellow shading and had more of an A-2 appearance. The pontics were pretty large and seemed to have more yellow than other areas of the frame. After firing it with zirliner, the yellow seemed more intense on the pontics so I ground back the facial of one of them in an effort to brighten it. Rezirlined and noticed everything seemed to lose the yellow appearance. Now seems to have a more uniform A-1 shade.
Anybody have any thoughts as to what caused this? Poor sintering?

Replace your zirliner with GC Lustre Paste and sleep well my friend.

 

[BobCDT]

Argen is now selling one of THE least expensive discs found in the US. I would only guess this is the same material they use in the milling center. I would question the material...

 

[Marcusthegladiator CDT]

I don't know how Agren processes their material. But perhaps this was not fully pre shaded prior to sinter. And an Argen tech stained the green zirc. Then after your fired it some of the color disappeared. Now I doubt that you fired the Zirliner at 1200 w/10 min hold, which is one way to brighten stained zirc. But just wanted to suggest a possibility.

 

[PDC]

I don't know how Agren processes their material. But perhaps this was not fully pre shaded prior to sinter. And an Argen tech stained the green zirc. Then after your fired it some of the color disappeared. Now I doubt that you fired the Zirliner at 1200 w/10 min hold, which is one way to brighten stained zirc. But just wanted to suggest a possibility.

This sounds about right. I believe the zirliner fires around 970C and after doing that a couple of times and then firing VM9 (which also fires high) , the frame lightened up considerably. Obviously, Argen dropped the ball somewhere in the coloring process. Thank goodness it's an A1 shade!

 

[PDC]

Argen is now selling one of THE least expensive discs found in the US. I would only guess this is the same material they use in the milling center. I would question the material...

I've used them for quite some time now and have been pleased for the most part. Only have an occasional shade or fit problem. Durability has been excellent. From what I read, their Argen Z is internationally certified.
Just my experience with them.

 

[rkm rdt]

Argen is now selling one of THE least expensive discs found in the US. I would only guess this is the same material they use in the milling center. I would question the material...

Are you speaking as a lab owner or a rep of the competition Bob?

 

[Contraluz]

Are you speaking as a lab owner or a rep of the competition Bob?

I had the same thoughts...

 

[BobCDT]

RMK,
I'm speaking form what I know based on the manufacturing process of zirconia powder and discs and related costs to do so. After all the time I have vested in DT I'm certainly not going to compromise my integrity over the sale of a few zirconia discs. It's no problem to me as I get it. My lab is currently using Katana UTML and is waiting for the complete shade lineup of the Zolid FX multi. I think it's on the way to the US now. For large span bridges we are using Bio ZX for dental direkt. It's pretty simple, you get what you pay for.

 

[Polarmolar]

Big bridges I only use vita yz it's expensive and most milling centres won't carry it. It is also pretty damn good for shades as it goes by value which to me is more important anyway and super hard to achieve. I use argen Z also but don't trust it for single anterior or complicated shades or any zirconia I need to paint on to be honest. Is it doable sure but do I wanna hope my guy will nail it every time on a big bridge ...nope. Ain't no one got time for dat haha.


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