Desoldering dental amalgams?

Thread Starter

Consistency

Joined Dec 5, 2016
2
I was having a conversation with a friend about desoldering fumes and that we should probably be wearing reusable respirators because of the heavy metals from the fumes. We stumbled on a dental amalgam page regarding sources of heavy metals, how amalgams are a source of mercury, then he said... imagine if it's possible desoldering amalgams... I said probably not but I am curious. Neither of us have amalgams to test it out but hypothetically... Would it be possible to melt an amalgam with a soldering iron while taking into consideration the high melting point of the metals in the amalgam?
 

SLK001

Joined Nov 29, 2011
1,543
Sure, it is possible to melt an amalgam, but probably not with an iron. As for the solder fumes, no heavy metals are in it in any significant concentrations. The fumes, however, can be a respiratory irritant.
 

GopherT

Joined Nov 23, 2012
8,012
I was having a conversation with a friend about desoldering fumes and that we should probably be wearing reusable respirators because of the heavy metals from the fumes. We stumbled on a dental amalgam page regarding sources of heavy metals, how amalgams are a source of mercury, then he said... imagine if it's possible desoldering amalgams... I said probably not but I am curious. Neither of us have amalgams to test it out but hypothetically... Would it be possible to melt an amalgam with a soldering iron while taking into consideration the high melting point of the metals in the amalgam?
The "fumes" are the organic paste holding the flux salts in place in the hollow core solder. Lead ions and tin ions to not turn into vapor at soldering iron temperatures. The fumes can be an irritant in prolonged exposure but rarely for the levels a Hobbiest sees.

The amalgam will melt between 600 and 700C. What is your goal? Do you plan on getting rich by stealing people's fillings?
 
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Thread Starter

Consistency

Joined Dec 5, 2016
2
The "fumes" are the organic paste holding the flux salts in place in the hollow core solder. Lead ions and tin ions to not turn into vapor at soldering iron temperatures. The fumes can be an irritant in prolonged exposure but rarely for the levels a Hobbiest sees.

The amalgam will melt between 600 and 700C. What is your goal? Do you plan on getting rich by stealing people's fillings?
Where did you get the 600 and 700C figure?

Amalgam seems very close to "Tin-Silver-Copper (Sn-Ag-Cu, or "SAC") solders" which exhibit the "ternary eutectic behavior (217 ˚C)". Plus there is low temperature desoldering wire on the market which might lower the temperature required to desolder them.

https://en.wikipedia.org/wiki/Amalgam_(dentistry)
https://en.wikipedia.org/wiki/Tin-silver-copper
https://en.wikipedia.org/wiki/Solder#Lead-free_solder

I've recently heard from a friend of the family having their amalgams removed and their teeth were butchered since the amalgam was drilled out with a high speed drill. Seems more logical to desolder them than to drill them out.
 

crutschow

Joined Mar 14, 2008
24,397
I've recently heard from a friend of the family having their amalgams removed and their teeth were butchered since the amalgam was drilled out with a high speed drill. Seems more logical to desolder them than to drill them out.
Desolder? :eek:
Hate to think of what the temperature needed to desolder the amalgam would do the the teeth and soft tissue. o_O
 

SLK001

Joined Nov 29, 2011
1,543
I've recently heard from a friend of the family having their amalgams removed and their teeth were butchered since the amalgam was drilled out with a high speed drill. Seems more logical to desolder them than to drill them out.
So, you're going to stick a 700°+ object into your mouth? Don't you know that even teeth conduct heat? And where do you think that heat will go? Have you ever cooked a steak?
 

WBahn

Joined Mar 31, 2012
25,277
I've recently heard from a friend of the family having their amalgams removed and their teeth were butchered since the amalgam was drilled out with a high speed drill. Seems more logical to desolder them than to drill them out.
Huh???!!!!

Are you under the impression that amalgam fillings are done by pouring molten material into some cavity in your tooth?

The mercury is mixed with the powered alloy of the other three components to form a fast setting putty at room temperature that is then packed into the prepared cavity. It then hardens and that is that.
 

shortbus

Joined Sep 30, 2009
7,461
Amalgam seems very close to "Tin-Silver-Copper (Sn-Ag-Cu, or "SAC") solders" which exhibit the "ternary eutectic behavior (217 ˚C)". Plus there is low temperature desoldering wire on the market which might lower the temperature required to desolder them.
What flux is used to solder the fillings to tooth enamel?
 

Kermit2

Joined Feb 5, 2010
4,163
Does Saliva cause stomach cancer?

Yes. But, only if swallowed in tiny amounts over a very long period of time. Not likely in your case, so don't worry about it.
 

kubeek

Joined Sep 20, 2005
5,683
Does Saliva cause stomach cancer? Yes. But, only if swallowed in tiny amounts over a very long period of time. Not likely in your case, so don't worry about it.
Wait, I should not swallow my own saliva because it causes cancer? Sounds rather odd...
 

Hypatia's Protege

Joined Mar 1, 2015
3,208
What flux is used to solder the fillings to tooth enamel?
I should think Mn-Mo oxide (following vacuum metalization) should do the trick:eek: -- Of course, inasmuch as we're talking dentistry, some wholesome NaF based flux is well-neigh obligatory!;););)

Does Saliva cause stomach cancer?

Yes. But, only if swallowed in tiny amounts over a very long period of time.
Too true for those enamored of 'chew':eek:

TTFN
HP:p
 
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