QUIZ: What is wrong with those crowns???

[JKraver]

... Oh, this is not a joke. Your ceramist ran these up clocked out and never came back from lunch.

 

[Car 54]

I think you nailed it wit rapid dry-out, and using modeling liquids that can be diluted to lesson tearing.
I'm so use to using programmed ovens I push start and walk away without having headaches like these crowns.

In my case, with using so many different porcelains and programs, and having a brain dead day, hit the wrong program and having the porc be all around he bottom of the firing tray
from being dried out to fast and run up to fast.

 

[charles007]

Lucky me has only melted 1 single unit emax in 8+ years pushing the wrong program...

 

[rkm rdt]

Lucky me has only melted 1 single unit emax in 8+ years pushing the wrong program...

you're not busy enough! The best time is when the pt is in the chair.

 

[robcat]

I'd wager my lunch money that your ceramist grabbed the wrong porcelain. Sadly, I've seen it before, and it's easier than ever to do now that we have so many different types of substructures in the lab. The CTE difference between zirconia and standard pfm (9ish to 13ish) is just enough to blow off chunks like we see lying on your sagger tray. Again...I have berated my stupidity more than once after pulling a similar looking crown out of the oven.

Of course, most of my oven errors involve firing on the wrong program and transforming my lovely restorations into funky marbles.

 

[Accutech]

Hmm

 

[howitsmade]

The answer is: moisture problem. After changing liquid from dedicated to CC to universal liquid ML-H, I have to increase preheating time about 2 minutes. Problem occurred just after changing liquid to ML-H (on a first crown). Alloy, powders and even a hanky was the same.

 

[CatamountRob]

The answer is: moisture problem. After changing liquid from dedicated to CC to universal liquid ML-H, I have to increase preheating time about 2 minutes. Problem occurred just after changing liquid to ML-H (on a first crown). Alloy, powders and even a hanky was the same.

Nice. I just use water.

 

[ts4341]

This thread is BRUTAL!!!

 

[CatamountRob]

This thread is BRUTAL!!!

Yeah, some of these guys are just plain cruel, I try and try to rein them in and keep them on track but one guy can only do so much. Mostly it's the Canadians, they're mean bastards.

 

[wojtek121]

The answer is: moisture problem. After changing liquid from dedicated to CC to universal liquid ML-H, I have to increase preheating time about 2 minutes. Problem occurred just after changing liquid to ML-H (on a first crown). Alloy, powders and even a hanky was the same.

This is obvious at the beginning every ceramist had a problem with the drying time and moisture control

 

[NickB]

Buccal margin is slightly shy. Only slightly....doc may not even notice.