Shoulder strength of a porcelain margin Zirconia crown

[DevonR]

Do you guys think there is a possibility for fracture if you add a porcelain margin to a zirconia crown?

Are there any university studies on this? I can only seem to find ones on the entire crown.

If you have a chipped zirconia margin, anyone using shoulder porcelain to fix it? Do you think that's okay?

 

[rkm rdt]

It should be ok .
I used to use the czr shoulder porcelain with all of my Procera copings.

Beef up your margins to more of a full contour to avoid chipping.

 

[grantoz]

it would be similar to shoulder on a vmk probably the zirconia porcelain shoulder would be stronger as you need less porcelain . But do you need to do it really with high trans copings?

 

[DevonR]

Is a shoulder margin on a zirconia coping the same strength as a pfm shoulder ?

 

[rich green]

Do you guys think there is a possibility for fracture if you add a porcelain margin to a zirconia crown?

Are there any university studies on this? I can only seem to find ones on the entire crown.

If you have a chipped zirconia margin, anyone using shoulder porcelain to fix it? Do you think that's okay?

If the chip is a small one then probably there will be no problems. CZR or similar margin porcelain should do the trick. That is if the margin is designed as a shoulder. If your talking about a chip on a feather edge then, yeah, it could chip, but, with zirc, and with some skill you can make a small fix and have it be invisible. Not so much with pfms. Lots of "dependsies" here.
With most zirc copings, if there are no large chips in margin, I am not sure why one would do a porcelain margin. The zirc is milled to form the margin for you. Maybe I am misunderstanding the question.

 

[Mohammad Khair]

The strength of the porcelain shoulder does not depend on the framework, whether it is metal or zircon, it derives its strength by bonding to the whole porcelain blanket and from the binder/filler ratio of material itself, and the design and thickness of the shoulder.

First when the zirconia material were only white color we use to use porcelain shoulder on it utilizing the exact same technique as with metal with no problem at all.

However, on metal or zircon the porcelain shoulder still the most weak point of any restoration in most situations.

 

[DevonR]

For maximum esthetics, a porcelain margin in the anterior is the best esthetic result. This is where we would use them. I just had a course with Claude Seiber and I believe he is doing this.

 

[rkm rdt]

Good for Claude.

I hope you didn't pay him for that advice.

 

[DevonR]

rkm... we just had Spectrum Day in Toronto on Friday... I'm surprised you weren't there! It was a fantastic line up of speakers!

Good for Claude.

I hope you didn't pay him for that advice.

 

[rkm rdt]

I was scanning with a new client.

 

[lcmlabforum]

Just in time for Halloween . . .
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