Different zirconia Y classes?

[Bryce Hiller]

So we have a doctor that attended a symposium and is asking us about our zirconia (we use Origin Beyond Plus). He's now insisting that only use zirconia with a Y3 classification, as opposed to Y5 or Y7. I don't know what these classifications are (I do know they're different than ISO classes). I read through the literature that he was provided (I'll link below),but the only information it really offered is that doctors should only used Y3 zirconia, and they repeatedly name BruxZir (I will go ahead and assume Glidewell is a sponsor). Does anyone know what this Y-rating is, whether or not it's important, and how to handle this situation? TIA.

https://www.pccdental.com/uploads/files/1146/V1987-Complete-Packet.pdf

 

[Car 54]

Maybe the amount of Yttria, the higher the percent to gain translucency, the greater chance for cracking, chipping, breaking? Maybe they and the opposing wear differently then?

edit:sp

 

[Bryce Hiller]

Maybe the amount of Yttra, the higher the percent to gain translucency, the greater chance for cracking, chipping, breaking? Maybe they and the opposing wear differently then?

Maybe. Still doesn't make sense to me. If newer generation zirconias look far superior, yet have similar flexural strength ratings in a 4-point test, what's the big deal? Why does it matter that it's a newer iteration?

Oh, and I just found that the doctor that is providing the information to our account writes for Glidewell's magazine. That explains a lot.

 

[CoolHandLuke]

Yttria is a stabilizing agent, not a lot is needed and it doesnt affect the translucency of zirconia. that is controlled by the lattice structure of the crystal and the grain size. and space.

glidewell is not a sponsor

 

[Patrick Coon]

Hi Bryce,

What the doctor is talking about is the molecular percentage of Yttria in the mix. 3YTZP is the higher strength materials (typically 1100-1200MPa flexural strength, and 5+ in fracture toughness). this mix has ~3mol% of yttria. 5YPSZ (typically your High Tranlucent material with 550-700MPa flexural strength and 2.2 fracture toughness) have 5mol% yttria.

Now these are not directly in the ISO standard, but indirectly relate due to the strength values of the materials. So 5y materials due to their strength are listed as Type 2 (a ceramic that is not delivered in a powder, paste, or aerosol form) Class 4 ceramic (Monolithic ceramic for three-unit prostheses involving molar restoration or Partially or fully covered substructure for three-unit prostheses involving molar restorations) , although, most are advertised as a Type 2, Class 3 due to their reduced fracture toughness. 3y materials listed as Type 2, Class 5 materials (Monolithic ceramic for prostheses involving four or more units or partially or fully covered substructures for prostheses involving four or more units).

-edit spelling-

 

[Car 54]

Maybe. Still doesn't make sense to me. If newer generation zirconias look far superior, yet have similar flexural strength ratings in a 4-point test, what's the big deal? Why does it matter that it's a newer iteration?

Oh, and I just found that the doctor that is providing the information to our account writes for Glidewell's magazine. That explains a lot.

Agree, shameless Glidewell promotion. My greater concern is for fracture toughness over flexural strength.

edit: Patrick summed up what I was thinking in his first paragraph while I was typing at the same time.

 

[Bryce Hiller]

Thanks for the info. I'll be contacting B&D to find out about Origin Beyond+. I DO know that this zirconia has an ISO Standard fracture toughness rating of >5. So hopefully that will ease Doc's mind a bit.

 

[Patrick Coon]

 

[Car 54]

Thanks for the info. I'll be contacting B&D to find out about Origin Beyond+. I DO know that this zirconia has an ISO Standard fracture toughness rating of >5. So hopefully that will ease Doc's mind a bit.

I went through the same thing and called Origin and Patrick about 1 month ago with the same concerns.
My Origin fracture toughness numbers are somewhere in my pile of paper work, but 5 sounds right.

 

[Patrick Coon]

I am also uploading the Scientific Report on our new IPS e.max ZirCAD materials. while this is a report specific to ZirCAD, the first 20 pages or so are a good primer on zirconia in general. Talks about the science behind translucency, strength (fracture toughness and flexural strength),different generations of zirconia, etc.

 

[PRO ARTS DL]

The article also doesn't completely say the newer zirconias are not recommended but it seems to go to the conclusion that they haven't been around enough. They have them as "promising" in several parts and even conclude that they will gradually dominate the market.

Here they point out fracture toughness of >5.0 for Beyond Plus:

http://bnddental.com/assets/originbeyondplus_advantagesflyer090117.pdf

 

[Bryce Hiller]

Thank you all for the information!!!

 

[CoolHandLuke]

https://www.azom.com/article.aspx?ArticleID=940

https://www.azom.com/article.aspx?ArticleID=11082

https://www.azom.com/article.aspx?ArticleID=5898

 

[Car 54]

Thank you all for the information!!!

I turned out to be a good thread, including CHL's above links.

 

[CatamountRob]

I turned out to be a good thread, including CHL's above links.

Especially that second one that says that there are dental applications for zirconia. Who would have guessed?

 

[Car 54]

Shiver me timbers, cap'n Jack CRob gave me a jolly roger for me above post, aarrgh.

 

[Car 54]

Especially that second one that says that there are dental applications for zirconia. Who would have guessed?

Well if you're actually going to read them cp to my just opening up the links

 

[CoolHandLuke]

yarr, have i told ye about the time we sailed round the isle of white on a ship crewed entirely by women named Roger ?

 

[CatamountRob]

Well if you're actually going to read them cp to my just opening up the links

Haha, I was going to say that you are a pretty quick reader since you posted that like 5 minutes after Red Beard posted the links.

 

[Car 54]

Haha, I was going to say that you are a pretty quick reader since you posted that like 5 minutes after Red Beard posted the links.

Red Beard...good one From past pictures isn't CHL a bit of a red head, thus your Red Beard? Can't remember, maybe it's the mushrooms.

edit: Winner for that Red Beard "link" with CHL.