What’s the “pin” in gold teeth?

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Tevlon

Member
Joined
Apr 12, 2012
Messages
16
I have these old teeth lying around. If you look at the back side, there is a silver coloured metal dot. Is it a pin or something for setting the tooth in the gold? If so what metal is commonly used for this? I have never played with dental scrap before so if anyone of you have seen this please let me know.

Thanks
 

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Mercury is possible if any of the crowns were built up over old amalgams. I think with modern stuff they'll usually remove any old amalgam fillings and replace them with modern materials in the build up, but with old stuff, anything's possible.

Do be VERY careful with dental gold! The PGMs usually used in those alloys, particularly platinum, are very toxic. This forum has lost members to PGM exposure. :cry:

Dave
 
Golden crowns are cast and you don't do it in the mouth over old fillings. It's done in a cast and adjusted by filing and grinding to match the teeth below. I can't imagine how it could be any amalgam mixed in with the gold unless as a minor contaminant.

The pin is embedded in the porcelain cap and were often made from PGM alloys with gold plate on top to easily embed in the casting. I did a number of them when I started this hobby and I were happily surprised by several grams of PGM:s after I got the gold out. I really like the color of the aqua regia when I dissolved it. I got unused caps out of a dentistry school that was demolished around 1990.

DSC_1020.jpg
You can see where the pins have been embedded.

Yeah, this was back in the days when I didn't have as many beakers as I have today. :D

Göran
 
Mercury is still possible. One should assume mercury is present in dental. Not all dentists have the same standard of care....especially when you are handling crowns and bridges that may have been installed 40-50 years ago.




Sent from my iPhone using Tapatalk
 
I thought I had something nice. That pic is easily 100 times better.

I thought it was mostly gold. I was going to separate it from the teeth and just melt it and sell it for it’s value, as long as I knew it was safe. I have a store close by with an xrf. Now I’m not sure. Should I save it and hope to find more similar stuff and recover everything? What would you do?

Thanks for all the help so far. This forum is great.
 
There were no gold on my caps, only the pins.

I think that the gold on your piece is worth many times more than the PGM in the pins. Just use a hammer to smash the porcelain caps so you only have metal left, then if you want to do it you could melt it down. Do it in a fume hood or outside with the wind blowing from the side so you get no smoke in your face. Dental stuff can be contaminated with mercury and it's always best to be on the safe side.

If you're only after the value, just melt and sell it. You might not get the value of any PGM:s included but the XRF should reveal to you if there is any significant amount in the alloy. Just check with the buyer if he pays for PGM:s and if he have any lower limit for payout.

Göran
 
I’ll try to bend the gold and separate the pins. Then I can test separately. And I only melt outside so no worries there. I also have some different dental scrap. Can you guys provide any info on how these are made and their composition? If they are more or less likely to have dangerous ingredients?
 

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The stuff in solution appear to be old denture teeth.They used to make those out of porcelain with gold and PGM pins that they where built around.

Almost all denture teeth now are made out of PMMA or some other type of acrylic or plastic.

If you ever find any of those still on their manufacturers tooth card. They are worth more like that than what the amount of PM's in them are.

The cut restorations on the towel are just old crowns. Most likely gold but many PFM (porcelain fused to metal) crowns have a lot of PMG's in them. Back in the day when it was cheaper to use palladium than gold. You are talking close to 70% in some cases.

The 4 unit bridge is most likely close to 90% gold. I say this because of the window crown style unit on it. Probably something like a degussa golden gate ally from back in the day or another 90% gold alloy.
 
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