Still No Verdict from Scientists on Metal Dental Restorations

Scientists specialising in the thermoelectric behavior of materials
have been unable to determine whether or not the thermoelectric
potentials generated by metal dental restorations are large enough to
dissipate electrical energy through the nerves in people's heads.
Experts in thermoelectricity attending the 13th International Forum On
Thermoelectricity held in Kiev, February 2009, undertook to answer
questions regarding the thermoelectric behavior of metal dental
resorations.
However so far there has been no information forthcoming.
The latest developments in the debate can be followed at the website
of the International Thermoelectric society at:

- where the message attached below has just been posted.
Best regards to all,
Keith P Walsh
PS, The thermoelectric effect is a natural phenomenon whereby
dissimilar metals in contact with each other are able to generatee an
electric current whenever their points of contact are subjected to a
temperature difference.
There is no electrolysis involved.
***********************************************
It looks like I was wrong.
It=92s been more than a year now and it appears that the scientific
community, including the International Thermoelectric Society, is
still completely ignorant of the thermoelectric properties of metal
dental restorations. (In any case, I still haven=92t had any answers to
the questions I put to Professor Anatychuk at last year=92s
International forum on the matter.)
Let me explain the issue again.
Metal amalgams are used for filling cavities in people=92s (including
children=92s) teeth.
And there isn=92t anyone anywhere in the world who knows what the
thermoelectric properties or thermoelectric behaviour of these
materials are.
An amalgam is not an alloy.
A dental amalgam is formed by mixing bits of a solid alloy with liquid
mercury and allowing the mixture to harden, and the entire process
normally takes place at room temperature.
Under these circumstances what you get is a material which is
fundamentally different from metallic alloys in the respect that its
internal microstructure displays a much greater degree of
inhomogeneity than an alloy.
The solid amalgam may be accurately described as an inhomogeneous
mixture of dissimilar metals.
For an illustration of the microstructure of a typical dental amalgam
see:

And, as result of its material inhomogeneity you might expect the
thermoelectric behaviour of a dental amalgam to be more pronounced
than that of a true metal alloy (i.e. where the constituent metals are
all raised to a temperature which is above the melting point of each
one, and the mixture is then allowed to cool at a controlled rate to
produce a solid with a much higher degree of material homogeneity than
in amalgams).
The =93cores=94 of unreacted solid alloy in the dental amalgam have a
different composition to that of the solid amalgam matrix in which
they are held. The cores have no mercury in them at all, whilst all of
the mercury used to form the material is contained within the
surrounding matrix.
If you were to subject this material to a thermal gradient you would
expect the difference between the thermoelectric properties of the
cores and the surrounding matrix to give rise to a thermoelectric eddy
current around each of the cores.
For an illustration of this type of thermoelectric eddy current see:

In NDT applications the local electromagnetic fields generated by
these thermoelectric eddy currents are detected at the surfaces of the
materials in which they are induced by very sensitive instruments.
The question arises; is it possible that the very sensitive
neurological tissue in the vicinity of teeth with amalgam dental
fillings may be excited by the local electromagnetic fields associated
with the thermoelectric eddy currents induced in the amalgams whenever
they are subjected to a temperature gradient (e.g. when eating ice-
cream)?
And has anyone ever bothered to carry out experimental investigations
in order to determine whether this effect can be detected with very
sensitive instruments?
Apart from the fact that dental amalgams are inhomogeneous mixtures of
dissimilar metals in their own right, dentists also sometimes screw
metal alloy retaining pins into the root sockets of patients=92 teeth
and encase the heads of the pins in amalgam, thereby creating the
conditions for generating further thermoelectric potentials along the
contours of the interface between the retaining pins and the amalgam.
In this instance there can be no excuse for not recognising the
thermoelectric potential of the arrangement. Metal dental restorations
are continually subjected to thermal gradients. The question arises;
are the thermoelectric potentials generated by metal dental
restorations comprising several different metallic materials in
contact with each other large enough to dissipate electrical energy
through the nerves in people=92s heads?
And has anyone ever bothered to carry out experimental investigations
in order to determine what is the largest thermoelectric potential
that can be generated by metal dental restorations?
Normal levels of electrical potentials generated by metal dental
restorations can be routinely measured, see:

And researchers have measured these potentials with magnitudes of up
to 350 millivolts, see:

(The resting potential of the human neurological synapses only 70
millivolts.)
Dental materials scientists, and members of the dental profession in
general, have a tendency to assume that these potentials are the
result of =93galvanic activity=94, or electrolysis, and that they are only
generated when the amalgam is in contact with an electrolyte, which is
normally presumed to be saliva. So, when researchers William
Schriever
of the University of Oklahoma and Louis E. Diamond of the University
School of Medicine, Oklahoma City measured amalgam potentials of
comparable magnitude when they had taken care to ensure that they were
not in contact with any saliva at all, they deduced that the
electrolytic agent in the generation of the measured potentials must
have been =93bone fluid=94 in contact with the hidden surfaces of the
amalgam under the fillings. See:
questions arise; is there any such =93bone fluid=94 with the necessary
acidic properties to justify this presumption? Is there any evidence
that the required degree of electrolysis can be produced by the action
of =93bone fluid=94 to explain these electrical potentials (dentists are
sometimes keen to explain that under initial galvanic action the
surfaces of newly placed amalgam fillings quickly form a protective
coating of metal oxide which adheres to those surfaces and, once it
has formed, effectively PREVENTS any further electrolysis from taking
place =96 and yet the presence of the electrical potentials in the
amalgams can still be measured)? And is it not possible that these
potentials are more accurately explained by thermoelectric and/or
associated electromagnetic effects which do not involve any
electrolysis at all?
I first asked questions about the thermoelectric behaviour of metal
dental restorations in this forum more than ten years ago. In
response, I received a series of what I thought were rather
unscientific and condescending replies from Cronin B Vining, a
prominent member of the thermoelectric community at the time. Mr
Vining freely admitted that the substance of his replies was based
largely on guesswork, see:

Guesswork is an important part of the scientific process but it must
always be supported by, and be consistent with, scientific (i.e.
experimental) evidence in order for it to be accepted as scientific
fact. Guesswork on its own does not constitute science, no matter who
makes the guess. This is because in the absence of any corroborative
experimental evidence there is always a possibility that the guess is
wrong. And if experimental evidence contradicts the guess then
according to the established principles of scientific understanding,
it is wrong. (The celebrated American physicist Richard P Feynman was
a committed proponent of this important principal, see YouTube =931993
Horizon No Ordinary Genius Pt 1 - 1 of 5=94, 5 minutes in.)
Cronin Vining=92s judgements on the thermoelectric behaviour of dental
amalgams were made after only taking into account the percentage
composition of the constituent metals which he had found in his
search. He had completely ignored any consideration of the
inhomogeneous nature of how these constituents are arranged in the
material, a factor which we have already seen is of major significance
to its thermoelectric behaviour.
And on subsequent questioning he also failed to address the question
of how the combination of an alloy retaining pin with amalgam might
behave under thermal gradients.
Professor Anatychuk of the Institute of Thermoelectricity in the
Ukraine believes that Alessandro Volta was the first person to
demonstrate a thermoelectric effect when he re-produced Luigi
Galvani=92s experiments with the frog=92s leg. (Presumably Galvani doesn=92=
t
warrant the credit for it because he had offered a spurious
explanation based on =93animal electricity=94).

If professor Anatychuk is correct, and a single thermoelectric
junction acting at ordinary temperature differentials generates a
thermoelectric potential which is large enough to excite neurological
cells in animal tissue, then this above all demonstrates the
unquestionable necessity for investigating and establishing the size
and effect of the thermoelectric potentials generated by metal dental
restorations.
In my experience it is at this point in the argument that the
apologists for dental amalgam begin to put forward the excuse that =93if
dental amalgams were causing anyone any harm we would have recognised
it=94.
Would we?
How would we?
It is ironic that dental amalgams were first introduced as a treatment
for tooth decay around about the time that Thomas Johann Seebeck
became the first person to demonstrate that the application of a
temperature gradient to dissimilar metals in contact with each other
gives rise to a local electromagnetic effect (and that this happens in
the absence of any electrolytic action).
It can be reasonably argued that the widespread adoption of metal
amalgams for treating cavities in teeth was quickly followed by the
rise to prominence of psychiatric =93medicine=94 in our societies. And as
far as I can tell no-one has any convincing scientific argument for
concluding that the two things are not linked by the relationship of
cause and effect.
If the thermoelectric potentials generated by metal dental fillings
are large enough to dissipate electrical energy through the nerves in
people=92s heads, then this would provide a perfectly plausible causal
link between the two. And in the absence of any experimental evidence
to indicate one way or the other, no-one has any idea whether the
proposal of such a causal link is accurate or not.
Alternative valid explanations for the large rates of affliction from
so-called =93psychiatric disorders which still persist today do not
exist. Those of us alive today have all grown up in an era where the
presence of amalgam fillings in teeth is commonplace, and the high
incidence mental illness is regarded as =93natural=94.
Millions, if not billions, of dollars have been spent on research
attempting to =93prove=94 that the causes of psychiatric disease are
=93genetic=94 (so far without success), whilst at the same time nothing at
all has been spent on investigating the physiological effects of
thermoelectric batteries (metal dental fillings) in people=92s teeth.
The upper and lower mandibles where the teeth of human beings are set
do not have any muscle tissue, but there are very sensitive organs
nearby. The medical profession is also unable to explain the causes of
a class of disorders affecting the area of the lower head which may be
described as neurological rather than psychological, disorders such as
tinnitus (ears), Meniere=92s disease (balance) and facial neuralgia.
Developing drugs which are partially successful in treating the
symptoms of disorders such as these does not mean that their causes
are understood. (And it can be demonstrated that the complaint of a
permanent =93ringing in the ears=94 has a much longer history than that of
loud rock music - many tinnitus sufferers apparently do not
acknowledge that their condition has anything to do with listening to
loud music =96 see:

Meanwhile dentists ignorant of the thermoelectric behaviour of metal
amalgams continue to place amalgam fillings in people=92s teeth.
Dentists don=92t know what thermoelectricity is.
They are taught in dental schools to believe that metals can only
generate electrical potentials when they are involved in electrolytic
reactions, see,

The International Thermoelectric Society has a duty to point out that
dentists are mistaken in this belief.
Many years ago I also contacted Professor Rowe in Cardiff about the
question of the thermoelectric properties of dental amalgams, and he
glibly replied that these properties would be easy to measure (it=92s so
long ago that I no longer have a copy of his e-mail, but I expect that
he remembers it as well as I do). So come on someone at ITS, take up
the challenge and measure these properties. And publish the results.
Measure the largest thermoelectric potential that can be generated by
a metal dental restoration (but don=92t forget that dentists sometimes
screw metal alloy retaining pins into the root sockets of patient=92s
teeth and encase the heads of the pins in dental amalgam).
Don=92t wait for Professor Rowe to do it. He=92s too busy posing by his
car.
In recent postings I=92ve made insinuations against Professor Anatychuk
which were perhaps unfair. I know he=92s not a young man, and if he has
now retired or is perhaps ill then I wish him well and acknowledge the
importance of his work in thermoelectricity. But it looks as though,
for whatever reason, he will not now be able to do the experimental
work necessary to answer my questions (for example, what would have
been the minimum temperature differential necessary for Volta to have
applied to his apparatus in order to make the frog=92s leg jump, using
only a single thermocouple junction?).
And from what I can gather Cronin B Vining is disillusioned with
thermoelectricity altogether (can=92t say I=92m surprised).
What=92s needed is a young scientist with integrity who understands
thermoelectricity from a scientific point of view and does not lack
the courage to tackle a potentially controversial scientific issue
with honesty, intelligence and fortitude.
Remember no scientist ever made a name for himself simply by
regurgitating what others had told him (or her). Anyone who ever
established a lasting reputation as a scientist did so by pursuing
answers to things that they DIDN=92T understand.
Towards the end of 1992 I wrote a series of five letters enquiring
about the electrical behaviour of metal amalgam dental fillings.
You can find them at:

As a result of the response to these letters, and of my own personal
experiences both before and after they were written, I have come to
believe that the electrical potentials generated by metal amalgam
dental fillings are able to dissipate electrical energy through the
nerves in people's heads and, in so doing, make people unhappy.
And in extreme though not uncommon cases they are also able to cause
permanent neurological injury which cannot be repaired simply by the
removal of the fillings.
Metal amalgams are used for filling cavities in children=92s teeth.
And there isn=92t anyone anywhere in the world who knows what the
thermoelectric properties of these materials are.
It=92s idiotic.
Keith P Walsh