Translucent Zirc. Cantilevers?

[PDC]

Got a case (8-10) with #10 as a cantilever that I'm considering using the Argen Anterior Z material. I know Emax is contraindicated for cantilevers, but has anyone used the Argen Anterior stuff for situations like this? I also thought about the Katana material, but the purported strength isn't as strong as Argen's. Shade is a D-2, so I would really prefer the translucent stuff. Any user experiences with cantilevers and the translucent zirc?
Thanks!

 

[JohnWilson]

So the plan is no cutback and that why you're thinking of use this sort of material?

Like most things if you are willing to risk and you have good guidance and plenty of room you can make just about anything work. In my lab I would just use a HT HS zirconia and cut it back facially to give the esthetics.

Good luck on your case

 

[Patrick Coon]

I would have to suggest against it. The higher Translucent or Anterior Zirconias are in the same class of ceramics as e.max with similar strengths and almost identical fracture toughness.

 

[rkm rdt]

make a wing

 

[eyeloveteeth]

^ 100% make a wing.

It may be a 700 MPA zirconia - but look at the fracture MPA to make proper determination.

 

[CoolHandLuke]

that mpa rating is also only at or above a certain thickness. thinner than that is less strong.

 

[DevonR]

Does Argen Anterior even come in D2? Last I saw, the shade selection was pretty basic.

 

[PDC]

Thanks for the responses. Even though I was trying to avoid layering, which adds another weak link in the chain, I think it might be best to use the higher strength zirconia. If designed and layered properly, I think this is the best avenue to take. You just can't beat that strength.

 

[eyeloveteeth]

what?! there is no flexural strength to layering!? it's only as strong as the porcelain at that point and the stress of a cantilever and the torque it would go through AND it's the maxillary aesthetic zone.

I would make a wing, do as much through coloring and HT zirconia as you can and then very minimal glaze + you charge for an anterior unit and the wing and the pontic - 2 connections too at this point

 

[CoolHandLuke]

exactly.

 

[Getoothachopper]

Of the thousands iv'e done in the Aesthetic type material the only one iv'e had back that I can remember which fractured the next day was a cantilever #7 ,,,,,,my 2 cent

 

[ps2thtec]

I would have to suggest against it. The higher Translucent or Anterior Zirconias are in the same class of ceramics as e.max with similar strengths and almost identical fracture toughness.

There's that term "fracture toughness". I hear that's the new "orange". Um I mean the new MPa

 

[Patrick Coon]

There's that term "fracture toughness". I hear that's the new "orange". Um I mean the new MPa

Uh-oh, here comes the science class. . .

Yes, many companies (ours especially) have perpetuated the flexural or biaxial flexural strengths of ceramics as being what is most important. But in reality, it is fracture toughness that we really need to pay attention to. From Wikipedia: "In materials science, fracture toughness is a property which describes the ability of a material containing a crack to resist fracture, and is one of the most important properties of any material for many design applications."

Link: https://en.wikipedia.org/wiki/Fracture_toughness


Here are a couple excerpt from the ISO Standard as well.




When classifying dental ceramics, because LD and ZrO2 are both delivered in a form other than "powder, paste, or aerosols" they are classified as Type II ceramics. We then classify them further by their recommended clinical indications as in Table 1. e.max falls in Class 4 (looks like it could be Class 5, but. . .) and Zenostar MT would be a Class 5.

Table A.1 shows recommended Fracture toughness for these classes. While these are not required to be met for the ISO standard, they are highly recommended and we follow them. This is why though e.max could be rated as a Type II, Class 5 dental ceramic due to it's Biaxial Flexural Strength of 500 MPa, because it only has a fracture toughness of ~2.75 we classify it as a Type II, Class 3. Zenostar MT has a fracture toughness ~3.3 and we classify it as Type II, Class 4.

 

[JMN]

Uh-oh, here comes the science class. . .

Yes, many companies (ours especially) have perpetuated the flexural or biaxial flexural strengths of ceramics as being what is most important. But in reality, it is fracture toughness that we really need to pay attention to. From Wikipedia: "In materials science, fracture toughness is a property which describes the ability of a material containing a crack to resist fracture, and is one of the most important properties of any material for many design applications."

Link: https://en.wikipedia.org/wiki/Fracture_toughness


Here are a couple excerpt from the ISO Standard as well.

View attachment 25678
View attachment 25677 View attachment 25676

When classifying dental ceramics, because LD and ZrO2 are both delivered in a form other than "powder, paste, or aerosols" they are classified as Type II ceramics. We then further classify them further by their recommended clinical indications as in Table 1. e.max and Zenostar falls in the Class 4 (looks like it could be Class 5, but. . .) and Zenostar MT would be a Class 5.

Table A.1 shows recommended Fracture toughness for these classes. While these are not required to be met for the ISO standard, they are highly recommended and we follow them. This is why though e.max could be rated as a Type II, Class 5 dental ceramic due to it's Biaxial Flexural Strength of 500 MPa, because it only has a fracture toughness of ~2.75 we classify it as a Type II, Class 3. Zenostar MT has a fracture toughness ~3.3 and we classify it as Type II, Class 4. View attachment 25676 View attachment 25677 View attachment 25678

That one got printed out. Thanks!

 

[Patrick Coon]

That one got printed out. Thanks!

Glad it's helpful!

 

[eyeloveteeth]

There's that term "fracture toughness". I hear that's the new "orange". Um I mean the new MPa

Fractural Toughness was always a thing and was listed in identceram for a reason. It was the marketing machines that used flexural strength as some weird unicorn.

 

[EJADA]

Do it out of emax just make a big connector. And ya a bit risky I know. In the early 2000s I did several successful emax cantilever laterals. But with today's technology I too would use zirconia. But I still believe a well designed emax especially with a double abut could work.