Dental Scrap.

[MiltonFu]

I have some thousand of dollars worth of dental scrap available to me in Quebec. Is anyone interested in acquiring it?.
The content is Platinum, Gold and Palladium.
There is also a small quantity of silver/mercury nonsense.
Please PM me for further details.

 

[goldsilverpro]

What color is the metal - yellow or white?

 

[MiltonFu]

Appears white and dark.

 

[goldsilverpro]

I was hoping that you would say yellow. It is possible for white dental alloys to contain precious metals, but it is more likely that they contain NO precious metals. How do you know they contain Au, Pt, and Pd?

 

[Lou]

Any platinum/palladium containing gold dental alloys that I've experienced have been a dark bronze looking appearance.

Are they still sealed in their containers?

 

[MiltonFu]

I know they contain precious metals because the dental stuff came from my mouth and my dentist said it was precious metal when he put them in.
:lol:

Relax guys, I have had a few lots and have recovered platinum , palladium and gold from the lots.I have sampled these and they are no different.
Platinum/palladium recovery is just too time consuming, so I have decided to trade the lots.

 

[Anonymous]

I was hoping that you would say yellow. It is possible for white dental alloys to contain precious metals, but it is more likely that they contain NO precious metals. How do you know they contain Au, Pt, and Pd?

I would have to disagree with this from the standpoint of a C&B dental restoration. I have been a dental technician for over ten years and specifically I am a gold tech. Full contoure gold crown and bridge are yellow in almost all cases unless combined as an abutment in porcelain fused to metal (PFM) bridgework. PFM framework is quite the opposite where the vast majority is white. The reason is PFM framework is designed to be really thin. With coping thickness 0.3 mm is ideal so it needs to be strong. Joint strength is also of critical concern in bridgework and often there is very little room.
In the lab we use loadstar by ivoclar, Sagittarius and Aquarius for porcelain alloys. We pay way over spot for our alloys. We only ever use yellow alloys in PFM framework when requested by the Doctor and then it's 95% metal occlousal PFM where a large amount of metal is showing.
In the lab I now work at in the last 7 years that I have been there I have never once done a restoration in non-precious metal. In fact, the lowest gold content I have used is in the loadstar at 51.5%.
The only time I use a non-precious dental alloy is to make samples to put in our sample case or reduction coping to aid a doctor in an adjustment we have made. It is later tossed in the trashcan.
The previous lab I worked in was massive. We did everything in the most expensive alloys unless requested and I did only about 5% of the restorations in non-precious metal. You will rarely see large span bridewrk coming from a high quality lab in non-precious because it is so hard to get to fit perfect. This is why only large labs make them because you need a $30k laser wielder to get them to fit at all and they are still total garbage. Actually I have only ever done them in sample cases where the fit was not critical.

Loadstar Composition: (PFM crown and bridge)
White
* Au 51.5
* Pd 38.5
* In 8.5
* Ga 1.5
* Ru < 1.0
* Re < 1.0

Sagittarius Composition: (used for implants)
White
* Au 75.0
* Pt 2.0
* Pd 16.8
* Ag 2.0
* Cu < 1.0
* Sn 2.0
* In < 2.0
* Re < 1.0

Aquarius hard Composition (metal occlusion, some implant)
Yellow
* Au 86.1
* Pt 8.5
* Pd 2.6
* In 1.4
* Ru < 1.0
* Ta < 1.0
* Fe < 1.0
* Li < 1.0

 

[Harold_V]

I was hoping that you would say yellow. It is possible for white dental alloys to contain precious metals, but it is more likely that they contain NO precious metals. How do you know they contain Au, Pt, and Pd?

I would have to disagree with this from the standpoint of a C&B dental restoration.

That's a curious comment, and was not supported in practice in my years of refining. While I occasionally experienced white dental alloys of value, the vast majority of them were a very stark blue/white alloy, very hard, not ductile in the least. A simple test for the stuff was to attempt to bend it. End result in all cases was an abrupt fracture and total separation.

To insure that I was not tossing values, these items were routinely partially dissolved and tested on every occasion. In fact, I took advantage of the fact that processing with AR is not a good idea for base metals by processing them in volume, using the base metals to cement the values repeatedly, until I had eliminated the base metals.

I have long wondered what the correct name would be for the metal in question, the hard, non-ductile alloy.

Would you mind addressing my repeated results, and also discuss the alloy in question? I'd be in your debt eternally!

Harold

 

[teabone]

Chromium nickel alloy is used in majority of partial dentures or removable pieces. Permanent structures are more likely to be made from pgms.

 

[Anonymous]

The metal that you were dealing with was cobalt-chromium. It is certainly used more then any chromium nickle alloys for the last 15 years because of its higher bio-compatibility. They are marketed as being nickle and beryllium free because a percentage of the population was having a reaction to these substances.

However the devices that are created by these alloys are a different animal from what I was intending to discuss. They are called removable partial dentures or RPDs, and they are not considered part of crown and bridge (C&B). They are most certainly never gold but they could have gold clasp arms in very rare occasions. After thinking on this I can see that as a refiner these must have been common as they do not last long and are cheap to produce. I am surprised that they were ever sent in for refining and not just tossed straight in garbage as a dental technician can tell a mile away whats it made of.

I would assume that you my not have seen many C&B restorations because often they can last a lifetime. For a doctor to remove such a device it needs to be cut off like one would remove a cast from a broken arm. The result would resemble a mangled mess of metal and other white looking materials (porcelain and cement). It would not look like a finished product but a destroyed one. This is then: A. sent to the lab for a shade match. B. given to the patient by the Doctor to keep or C. put in the Dr. pocket to be added to his collection. I vote C.

 

[Palladium]

I would have to say ribtor has been doing this for quite sometime. What exactly do you do again ?

 

[teabone]

Yes, I forgot about cobalt being in the mix. The interesting thing about these alloys are that they register as a high karat white gold on some electronic testers and are passed off on e-bay as precious bearing material. So buyer beware.

 

[Recyclebiz_com]

They are also pretyy unreactive to most acids, so you'll frequently see eBay sellers claiming, correctly, that they took them to a jeweler or other scrap buyer who tested them and advised them they are high-karat gold.

Of course, there are also those who know perfectly well that they are non-precious, but it's a nice racket, selling non-precious scrap for high-karat prices, especially when they quote "All Sales Final".

 

[61 silverman]

here is the test result from apiece of white dental scrap that i have.
I used a test stone for my testing, the solution used to disolve the streak is AR labeled for testing Platinum..

 

[61 silverman]

Here is a couple more results.. :shock: 8)

 

[61 silverman]

many of these test swabs will turn back to allmost white when they DRY all the way, I think that is because the test solution does not get used up so the available acids disolve the tin in stannous chloride therefor removing the reaction.. IS THIS CORRECT..??? I have added a fresh drop of stannous and the reaction appears immediately, just as intence as the first time..
MARK

 

[lazersteve]

The various swabs look positive for Pd, Au, and possibly Pt.


Steve

 

[61 silverman]

Steve , Thank you for that confirmation, am I right about the color dissapearing and returning with new stannous? Mark

 

[lazersteve]

That's normal with Pd or when you have excess oxidizers in the solution.

Steve

 

[Lou]

Looks noble to me! Good use of swabs!