Broken emax

subrisi

subrisi

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Doctor sent this to me, Was done 2 years ago. He said this is thick enough and proof that emax is not strong enough. I think he is wrong. In the central fossa area it is way too thin and he clearly adjusted the occlusion in that area making it even thinner. Any suggestion how to proof that emax is not too weak and he just has to prep enough? FGrp_07272016_150640 (1).jpg
 
Car 54

Car 54

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CRA newsletter and research...Glidewells own tracking history of emax and it's success rate.

He put microcracks in it when he adjusted it, and didn't properly smooth and re-polish the surface.

It looks like it was conventionally cemented? Maybe if he bonded it it, would also help for strength, especially on smaller preps?
 
subrisi

subrisi

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Car54, where do I find the CRA newsletter? IS it on Glidewell's website?
 
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sirmorty

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I'm really stating to think about including a proper tool for adjustments to some accounts.
It would save me time and the hassle of remakes. But the pessimist in me says there is no guarantee they will actually use it.

It looks really thin to me in the picture. If he is cementing you need at least 1.5 mm occlusal reduction according to the emax prep guide. But I know not everyone gets that, I think we all break the material rules from time to time and sometimes you pay the cost.
 
Car 54

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Car54, where do I find the CRA newsletter? IS it on Glidewell's website?

Do a Google search for Clinicians report emax, and look at the PDFs for "Clinicians Report BruxZir and eMaxCAD" (press is stronger @~400 mpa, and I think CAD is ~370mpa) and "IPS emax 5 year Clinical performance report"

https://www.google.com/search?q=clinicians+report+emax&ie=utf-8&oe=utf-8&safe=active

Here are some of my notes from a seminar I went to in April/May of 2016 by Dr DiTolla of Glidewell. The failure rate they track (remember these are all caliber of Dentists and labs sending to them). I can't remember how many 1000s of units they tabulated, but:

Gold failure rate 0%
Bruxzir failure rate .04 or .09%, not sure of my note there. (1 mm thickness is ideal, you can get by with .6 The Glidewell hammer test was done on a BruxZir at 1.5 mm thick)
emax failure rate 1.8% 1.5 mm is "ideal" for emax occlusion on posteriors.
pfm's failure rate 1.8%

He said most restorations break/fracture when seating, or within the 1st year. Also mentioned was the fact if the emax is 1mm thick occlusally, to adjust the opposing, and that a note should be sent with the case stating so, as if it is adjusted at that "thinness", you will not be able to smooth and polish out the micro-cracks.
 
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sidesh0wb0b

sidesh0wb0b

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I'm really stating to think about including a proper tool for adjustments to some accounts.
It would save me time and the hassle of remakes. But the pessimist in me says there is no guarantee they will actually use it.

It looks really thin to me in the picture. If he is cementing you need at least 1.5 mm occlusal reduction according to the emax prep guide. But I know not everyone gets that, I think we all break the material rules from time to time and sometimes you pay the cost.
theres more to that.
you need 1.5mm FROM THE DEEPEST PART of the preparation for proper thickness. just because theres a 1.5mm ball that can float between opposing and prep during MIP doesnt mean that excursives dont close that gap down to .5mm

ideal preparations are 1.5mm from the deepest feature they want to capture(most often; the central dissectional groove region)
 
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