taha
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i have question why the metal frame work in the try in is fit but after building up the porcelain become short from the margen
i have question why the metal frame work in the try in is fit but after building up the porcelain become short from the margen
I've never had this happen but what do you mean by "margin creep" what causes that?Margin creep. Happened to us with high Pd/Ag alloy and we lost an account over it. Never used it again.
I've never had this happen but what do you mean by "margin creep" what causes that?
Thanks for explaining, but when you polish or and do the final check under the microscope before it leaves the lab, would you not noticed that the metal is curled or not seating properly on your die and solid models? I would, and would not let that pass me.As the metal is continually fired the margin will bow out or "creep" from it cast postion. Some metals can react like a ribbon when grinded on one side. It will sort of "curl" up like a ribbon when you run a scissor over on side to make it curly. You can test alloys by taking a .3mm thick strip and grinding it on only one side. Lay it on a flat surface after firing it to see it has lifted or curled. Putting porcelain on it will make it curl even more making the margin open or loose the sharp edge.
As the metal is continually fired the margin will bow out or "creep" from it cast postion. Some metals can react like a ribbon when grinded on one side. It will sort of "curl" up like a ribbon when you run a scissor over on side to make it curly. You can test alloys by taking a .3mm thick strip and grinding it on only one side. Lay it on a flat surface after firing it to see it has lifted or curled. Putting porcelain on it will make it curl even more making the margin open or loose the sharp edge.
ARGELITE 71
ARGEDENT BIO 88
ARGEDENT EURO
I use
Argelite PF+
Argedent 80
Argenco-W+ (white full cast)
Argenco-40 HN (gold full cast)
Argenco-20 N (gold full cast)
and Captek
That's all my metals, have no problems at all, very pleased, other than the price of gold........thanks Obama, you dueche bag!!!!!!!
I hate working with NP metal, good thing we only use it for our maryland bridges when DR's request it. One time in the summer we had another lab send their cases to us while they shut down for vacation for a week, and all their PFM crowns were in NP metal YIKES. They wanted them finished up to the opaque stage.Hey Al, see, no mention of Non-Precious at all..........lol I don't even have it on my fee schedule. It doesn't exist!!!!!! except on the front and rear of your car as a bumper........lol
It not happened with me but with my friend
He said when the doctor try in the crown and the bridge fit but when try to cementation he found short from the finish line
That mean something happened after porcelain cycle
He use bego wiron 99
It is may some dimension change happened in the metal while the the porcelain cycle ?
Welcome to all, my first post .........
Taha,
You probably can't answer this, the better question is, "Why did your friend send the case out with open margins!!!!!!!
Generally speaking, you don't see margin creeping with NP alloys......
Having not seen this bridge, I would bet that the margins were thinned out way to much, then the margins were sandblasted off....... Or maybe it is marginal creep....Point being, the lab had to see it, why even finish the case.
Soo much wasted time and money............
Marginal creep is more of a bad fitting crown at the margin, margins change after firing porcelain. More of a tight fit, open margins, (bad fitting crown at the margins)
I no longer use np, but when I used Rex 3 and Tallidums, you don't get marginal creep unlike other precious metals...
John Wilson,
Check with Norbert at Argen on your use of Agelite71, Norbert told me last year that the Zinc in 70+ is a no no. Some labs have problems with Vita and Zinc........ I use vm13 now with argelite 61 with paste opaques with Avante build-up liquid. Wouldn't recommend this to anyone else but I haven't had any problems at all....May change to 75+6 to lower the silver content and for press to metal.......
Charles007