Dental amalgam is a material used by most dentists throughout much 
of the world to fill cavities caused by decay.  This is about all 
that we are told about it by our dentists, and there is probably a 
very good reason why they make no attempt to tell us what it is, 
what is in it, and what it is capable of doing.

It is the material of choice because
it is cheaper than other filling materials,
partly because it is quicker and easier to
work with.  This means that other materials
need a lot more skill to work with, and take
longer to do.  This may be part of the reason
why amalgam is so staunchly defended – fewer
restorations done in one day = less profit.

Dental amalgam is 50% mercury, so it is
probably going to be useful to take a brief
look at mercury itself to help understand why
there is so much controversy about the safety
of amalgam fillings.

Mercury is unique amongst metals in as much
as the melting point(the point at which it
becomes liquid) is very low indeed and that
it will begin to give off vapours well within that comfortable heat range
referred to as "room temperature"

It is these vapours which are dangerous.  Elemental mercury in this 
form can be drawn into the body as we breath and gain access to the 
bloodstream through the lungs. Elemental mercury is deemed to be 
very dangerous indeed, and there are very stringent laws in place 
governing the handling and disposal of it.

Dental amalgam, then, relies heavily on mercury.  This is because if 
you add very fine shavings of other metals to the liquid, they 
dissolve in it, forming a malleable paste that sets hard within a 
short period of time.  This makes it very useful for filling teeth 
because it is easy to work while the job is being done, then sets to 
a hard yet flexible material able to withstand the mechanical 
processes of chewing as well as expanding and contracting in the 
changing temperatures within the mouth without cracking.

50% Mercury, 35% silver, 13% tin, 2%copper and a trace of zinc.  
This is what most of us have in our fillings when they are placed in 
our mouths.  If the mercury stayed where it was put, then there 
would be no problem, but unfortunately, it doesn't.  After about ten 
years, those same fillings will have released anything up to HALF of 
their mercury.  Guess where it goes?

Dentists often refer to them as silver fillings, as this is the 
colour they are when he puts them in.  Exposure to the action of the 
saliva in your mouth soon corrodes them to that black colour that 
most of us know all too well.

Amalgam is a word that was coined to describe the substance formed 
when a metal is dissolved in mercury.  This property of mercury is 
exploited in a number of ways – it's used to extract gold from rocks 
too. But despite all the A.D.A's assurances to the contrary, a 
mixture is all it is, there is no reaction that changes all the 
different metals into one metal, nor even any two of them into one.  
Amalgam still remains a ball of mercury, silver, tin, copper and 
zinc. 


Sources:

http://www.imva.info/vaporsfromhell.shtml

http://www.mercuryexposure.org/index.php?article_id=39

http://www.bcd.com.au

http://www.fplc.edu/risk/vol2/spring/royal.htm

The Scientific Case Against Amalgam, an E-book produced by the 
I.A.O.M.T.


An additional source of Mercury in the environment...

Mercury in the environment is a huge problem.  The fish stocks in 
many rivers and lakes as well as huge numbers of sea fish are 
contaminated with it.  Releases of Mercury in effluent from industry 
and mining, from industrial and Crematorium chimneys and from the in-
appropriate disposal of broken medical equipment are estimated to 
add up to about 158 tons per year in the U.S.A. alone. 

For some strange reason, the deadly metal that is handled so 
carefully elsewhere, and is subject to stringent laws governing its 
disposal, is frequently and illegally dumped into the waste water 
system in dental clinics.  Every time you have a mercury restoration 
done and then "just rinse and spit" fragments (sometimes large ones) 
enter the waste water system even if the dentist is responsible with 
his disposal of the amalgam that he does not use at that time.

It has been estimated that approximately 54 grams of mercury escape 
from dental offices each year.  This adds up to a walloping 5400 
Kilograms per year in the U.S. (12,172 pounds).

Richard Simeneaux, president of the Southern Arizona Dental Society 
is on record as saying "There is mercury in the amalgam, but it's OK 
to put amalgam in your mouth and it's OK to put it in a 
landfill…" "We don't want to pollute the environment and we don't 
think what we are doing is wrong – we're dumping amalgam, not free 
mercury."  

But what happens to that mercury once it is cosily packed into your 
cavity?

It leaks.

And what does not pass through the body into the waste water 
disposal system stays in the tissues so that when that person dies, 
whatever is left in the teeth and the tissues eventually 
contaminates the ground around the burial site (or goes up the 
crematorium chimney).

Sources:

http://www.fplc.edu/risk/vol2/spring/royal.htm

http://www.amalgam.org/