PFM metal containing silver.

[stt672]

For the obvious reasons I have stayed away from PFM metal containing any silver. I am now thinking about trying some. What can you tell me about it. What brands of porcelain. Do I need to designate a porcelain oven only for this metal. How often do I need to do oven purging. Special build liquid? What is the limit on frameworks, 6 unit, 10 unit, longer? Is there a limit on the % of silver you feel comfortable. Or who will tell me just stay away from it. I guess it is just the fear of the unknown but I would like to get some pros and cons of using PFM metal containing silver. I just received a CAD-CAST from BEGO I was actually impressed. It takes a lot to impress this anal retentive tech when it comes to margins. The down side is their CAD-CAST metals contain silver.

Scott

 

[cheadlemick]

Scott i always find it best to read the destructions, but in general Pd alloys with Ag are fine to use with most modern porcelains though not all! Remember elements are added to alloys for a reason! Get yourself O'Briens materials book for more info!

 

[rkm rdt]

I've been using Noritake EX-3 for years so the transition to Bego's cad/cast was easy.

I am guilty of firing my pfms in my pressing furnace so I do have to purge once in a while....especially after staying overnight in upstate NY.

 

[charles007]

Silver alloys are fine, no problems if you follow the guidelines..I used silver Noble alloys with different brands of porcelain for to many years, 25-28% silver with out any greening or checking. Just make sure the CTE of the alloy is a match for your porcelain . I rather be in the middle of the CTE than the upper top limits. If your told by the alloy company to slow cool for over 1 minute, such as 2-3 minute slow cool, run from that alloy, or porcelain., unless you like deep checking in your porcelain. What brand of porcelain are you using on your zir frames ? I would try to use the same brand of porcelain on your pfms.. Noritake, GC, Creation, Ivoclar, Shofu, all work well with silver. If your looking to use the higer silver alloys 37%, your limited on the porcelains that will match..

 

[PaulMelott]

Don't do it!

 

[AL1]

I use Argen s eruo metal cte 14.1 14.4 40%au 39.4% pd 10% ag I use creation porc. and a little gc. used it for years no problems no special treatment.

 

[AL1]

Miss spell its euro

 

[doug]

What is the "Obvious Reason" you have stayed away from Ag in you metal? We've used two different Jensen alloys for the past 22 years and had no, zero, zip, zilch, nada problems with it. Yes, we purge. We use Omega 900 and d. SIGN porcelain.
Current alloy is Superior Plus. We do not fire all ceramic crowns in the same furnace.

 

[PCDL]

Ditto, we have been using both Jensen and Bego's alloys with silver for years with no detrimental effects on our restorations. I would recommend the Superior from Jensen, and the BegoPal300 from Bego. Good alloys.