Dental golds vary in % of gold from somewhere about 30% to as
high as 90%+. Old fabricated work, shell crowns, called this
because they were a ‘shell’, formed with an array of pliers, of
18-20ga. sheet gold with either a cast or swaged chewing
surface, are 22k. Beware if it is bridgework(2 or more
abutments with spacers(pontics) for missing teeth) because the
spacers were usually a gold/platinum alloyed flat unit with a
vertical or horizontal rod as part of each spacer. These
spacers had the remainder of the tooth that wasn’t a porcelain
facing built up with 4 different melts of solder so about 90% of
the metal on the spacer is solder. This was a very difficult
process to accomplish and took me a long time to get it right.
Most golds from the 1970’s and earlier were of 16kt and higher.
Usually the ‘bright gold’ colored golds were 18k. Most of them
appear yellower than 14k but not quite as yellow as 18k jewelry
gold. They are 18k. The 80’s saw the introduction of some of
the lower kt. golds but there was still plenty of the ‘good
stuff’ out there. Still is for that matter.
Take your pieces of dental work and heat it. The solder will
show up if there is any on it. Take all the pieces including
the button and melt them together on a charcoal block liberally
fluxing with casting flux. DON’T burn it. Take your time and
use a reducing flame. You can pour it in a bucket or jar filled
with water or you can use the whole button if it isn’t too big.
Dental gold is much harder than jewelry gold, and makes great
all-cast, and filigree pieces. There is a jewelry product
called Dura-Gold out now. It is a 14kt. alloy that can take
more abuse and wear. Dentistry has had that kind of gold for
over 50 years! Because dental golds are usually harder they do
take a great shine. When casting it or any gold for that
matter, use a reducing flame, and do it slowly! Let the flame
kiss and caress the gold 'til you get to casting temp and let
her fly. Remember how long it took to wax the piece, so don’t
rush the melt.
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