Thermoelectric Effect in Metal Dental Fillings

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Keith P Walsh

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Jan 14, 2021, 11:42:54 AM1/14/21
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It was first reported in 1823 that when a material consisting of an inhomogeneous mixture of dissimilar electrical conductors is subjected to a temperature difference, an electromagnetic disturbance can be detected near the surfaces of the material. There is no electrolysis involved in this phenomenon. A typical dental amalgam may be accurately described as an inhomogeneous mixture of dissimilar electrical conductors. However, and in spite of the fact that amalgam fillings are placed in children's teeth, it appears that experimental studies to investigate the thermoelectric behavior of a typical dental amalgam have never been carried out. Further discussion of this omission from our scientific understanding of the nature of metallic dental materials can be viewed securely in the "Public Health Dentistry" group of the LinkedIn website via the following link:
https://www.linkedin.com/feed/update/urn:li:activity:6690597301850906624
Best regards,
Keith P Walsh
keith....@btinternet.com


Steven Bornfeld

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Jan 14, 2021, 4:35:56 PM1/14/21
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I would prefer the term "heterogeneous" to inhomogeneous, but I get it.

Best,
Steve

Keith P Walsh

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Jan 17, 2021, 10:49:15 AM1/17/21
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On Thursday, January 14, 2021 at 9:35:56 PM UTC, Steven Bornfeld wrote:

> >
> I would prefer the term "heterogeneous" to inhomogeneous, but I get it.
>
> Best,
> Steve

Hi Steve,

Thank you for your reply.

Both "heterogeneous" and "inhomogeneous" are in common use in thermoelectrics and, as can be seen from the following example, they are often taken to mean the same thing.

"Thermoelectric properties of heterogeneous, many-phase and composite materials. (Y. Goryachev; M. Siman; L. Fiyallra; O. Shvartsman)

The model of formation of the thermoelectric properties of inhomogeneous materials and the system classification of different structural classes and types of the materials is worked out. The analysis of the concentration dependences of thermoelectric properties is performed on the basis of this method. It is found that the thermoelectric properties of inhomogeneous materials are connected with their composition and internal structural characteristics (such as the coefficient of leakage, the leakage threshold, the contact potential difference and the coefficients of skeletonivity, matrixivity, chainivity). The principal possibility of getting a higher thermoelectric figure of merit (TFM), Z, (in comparison with that of the initial material components) is shown."

When a material comprising an inhomogeneous mixture of dissimilar electrical conductors is subjected to a temperature differential, the only way that the material can maintain electrical equilibrium is by the circulation of thermoelectric eddy currents at the interfaces of the regions of dissimilar composition. It is the circulation of these currents which gives rise to the electromagnetic disturbance near the surfaces of the material, and the effect is continuous for as long as the temperature difference is maintained. (And of course there is no electrolysis involved. It is not necessary for the material to be in contact with any electrolytic fluid, and the material shows no sign of any electrochemical corrosion.)

In view of the fact that amalgam dental fillings are placed in children's teeth, I find it surprising that the dental profession has never sought to establish the extent to which this phenomenon occurs in dental amalgams. I'm sure that no-one would seriously suggest that the materials used in restorative dentistry are exempt from the laws of nature. However it does rather give the impression that the dental profession is not particularly interested in science.

Keith P Walsh

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Jun 29, 2021, 6:02:28 AM6/29/21
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Actually I thought I was boosting this thread earlier - see "Dental Amalgam Phased Out in Norway, Sweden and Denmark - Calls for Further Research". But what the heck, I'll do it anyway.

The interest shown in "Thermoelectric Eddy Current in Dental Amalgams" by members of the LinkedIn group "Thermoelectrics" can be viewed at:

https://www.linkedin.com/feed/update/urn:li:activity:6808698956672045056

And here's my guess again.

Metal amalgam dental fillings are able to dissipate electrical energy through the nerves in people's heads as a result of their thermoelectric behavior, and in so doing they have been the cause of a large proportion of the neurological and so-called "psychiatric" disorders suffered by countless individuals over the last couple of centuries.

What Richard P Feynman actually said was, " - if it disagrees with experiment, or if it disagrees with experience, it's wrong."

What we now need is an experiment, or an experience, which would demonstrate if my guess is wrong or not.

But wait! In recent years the use of dental amalgam has been phased out in the countries of Norway, Sweden and Denmark. Surely this represents an experience which would give an indication if my guess is wrong or not. All we need to do is examine the records of incidences of neurological and so-called "psychiatric" disorders in those countries to see if there has been any significant reduction since amalgam was phased out.

Can anyone offer any rational scientific explanation as to why it appears that this has not been done?

I think I can. See article, "Dental Amalgam Phased Out in Norway, Sweden and Denmark - Calls for Further Research", which was posted to the LinkedIn Group "Public Health Dentistry" in June 2020:

https://www.linkedin.com/feed/update/urn:li:activity:6680802023035715584

Brian Sandle

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Jun 29, 2021, 8:44:16 PM6/29/21
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Note you quote:" the contact potential difference"
What is contacting what?

Keith P Walsh

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Jul 4, 2021, 9:37:53 AM7/4/21
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Hi Brian,

I haven't cited "contact potential difference" anywhere in my description of thermoelectric eddy currents in dental amalgams.

I'll explain it to you again.

When a material which consists of an inhomogeneous mixture of dissimilar electrical conductors is subjected to a temperature difference the only way that it can maintain electrodynamic equilibrium is by the circulation of thermoelectric eddy currents at the interfaces of the regions of dissimilar composition. These eddy currents continue for as long as the temperature difference is maintained and they are responsible for the electromagnetic disturbance which can be detected close to the surfaces of the material. (And of course, there is no electrolysis involved.)

If you think that you know of any reason why any part of this description is incorrect, I would be interested to hear it.

For my part I believe that individuals will never understand this properly if they continue to regard an amalgam as having the same degree of material homogeneity as a true alloy. It doesn't.

I'd also like to take this opportunity to put forward further guesswork of my own which at present is not contradicted by the evidence of any known experiment or experience.

The electromagnetic disturbances generated by metal amalgam dental fillings are able to dissipate electrical energy through the nerves in people's heads and, in so doing, they have been responsible for a large proportion of the neurological and so-called "psychiatric" disorders suffered by countless individuals over the last couple of centuries.

In order to fulfil our obligation to the established principles of scientific understanding, what we now need is an experiment, or an experience, which will give an indication as to whether my guess is wrong or not.

But wait! In recent years the use of metal amalgams in restorative dentistry has been phased out in the countries of Norway, Sweden and Denmark. Surely this represents such an experience. All we need to do is find out if there has been any corresponding reduction in the incidence of neurological or so-called "psychiatric" disorders in those countries.

Can anyone offer any rational explanation as to why it appears that this has not been done - other than perhaps, "The metals companies who make large amounts of money supplying the world's dentists with the components for dental amalgams would rather it wasn't done"?

Regards,

Keith P Walsh
keith....@btinternet.com

Keith P Walsh

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Jul 10, 2021, 12:45:04 PM7/10/21
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"All we need to do is find out if there has been any corresponding reduction in the incidence of neurological or so-called "psychiatric" disorders in those countries. Can anyone offer any rational explanation as to why it appears that this has not been done?"

No takers?

It looks like everyone is content to wallow in ignorance.

(And I expect some of you like to imagine yourselves scientists.)

Keith P Walsh

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