Faradaic Activity in Dental Amalgams

Nothing has a constant resistance. For example ,if you took a standard resistor and examined it micrometer by micrometer you would see large changes in the properties and fluctations in the resistance/meter.

The point is that within a ciruit amalgam can be characterised as having an overall resistance. For example, suppose you took a 9v batter and connected it to amalgam. A certain current flows. It matters little to the external environment what happens in every microscopic part of the amalgam. All that matters is the amount of current, which comes out of the resistor, what the net result is. The external voltage appled , divided by the current coming into (and leaving) the amalgam.(assuming the amalgam isn't a voltage source) IS the resistance of the amalgam.

Obviously the physical properties of amalgam may vary because it is a mixture which is not uniform and it may have some very unusual properties which are not understood. We obviously don't even understand all the phase changes and how to predict the amount of Hg vapor. But even so all properties such as capacitance, any generated voltage, any inductance etc can basically be "characterized" with one number as far as any "external" electric or biological circuit is concerned at a given point in tiem. Circuits aren't designed based on how their components behave internally, though this may help explain variations in measured bulk properties. They are designed using the black box principle.

"what matters" is how these components affect the circuit they are connected to..interanlly they can be thought of as a black box, because a neuron will never see what is happening inside the amalgam. It will only respond to the net current and voltage,fields, capacitance, etc produced externally by the amalgam.

I just did.

Well, I just touched the two leads of my ohm meter to one of mine, and=20 the result was indistinguishable from just touching the leads together=20 (0.3 ohms, in each case). Such a test doesn't quantify the=20 resistivity very well, but it puts an upper bound on it. It is=20 definitely not only a conductor, but a good one.

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As I said before "amalgam" does not have a single value of=20 resistivity, because it is a rather arbitrary mixture of elemental=20 metals, and each recipe has a different resistivity.

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Keith has been banging the same old tired drum for the last five years and he doesn't even understand how little his posts have to do with Faraday's Law, Gauss' Law or Maxwell's corresponding equations...

FWIW, in layman's terms, Faraday's Law: "Any change in the magnetic environment of a coil of wire will cause a voltage (emf) to be "induced" in the coil. No matter how the change is produced, the voltage will be generated. The change could be produced by changing the magnetic field strength, moving a magnet toward or away from the coil, moving the coil into or out of the magnetic field, rotating the coil relative to the magnet, etc. "

All this reminds me of the old Gilligan's Island episode where Gilligan's mouth turned into a radio...

yes

But when challenged to go to the physics department of your local college/university where they could easily put this question to rest for you, you continue to ignore this avenue of research

yes

see above. the question is: having provided you with an experimental procedure by which the electrical resistivity of a typical dental amalgam CAN be measured, why do you refuse to perform the experiment?

The physics department of your local college/university.

Yes, go see Prof. XXX in the physics department at your local college/university.

Keith makes Gilligan look like a genius.

Lithium Carbonate (600mg X2 per day) degausses amalgam

Keith: I'll write this backwards so maybe you can understand it easier:

!!!!tnemtraped scisyhP egelloc lacol eht enohP

OK SP

Sigh. You beat me to posting. I got 0.4 ohms.

True, that's why dental filling materials are in a state of flux.

Joel

I had been away this past 6 weeks and had only checked in various NG's occasionally. Ah ... I see the entertainment provided by the gentleman troll Mr. Keith P. Walsh has returned.

Always well spoken, never uses profanity, a true icon of trolls!!

Nice to see some levity return.

MA Sonjariv

Even when he was alive.

carabelli

New keyboard again. I had to read it twice - absolutely perfect!!

carabelli

Same keyboard, but thanks anyway :*)

I was beginning to wonder at his absence. I'm glad he's still standing. What DOES he get from this amalgam obsession anyway? Hell, I'll get some amalgam for him and build a biological mockup and test the stuff nine ways from Sunday, if he'll just give it a rest.

"New keyboard" means what ever beverage I had at the moment, coffee, water, pick your adult beverage - got spewed on the keyboard because I was laughing so hard.

A Kansas euphemism :-)

Thanks for the laugh

carabelli

Why bother? It's simple enough for him to get the answer, it's apparent the answer isn't important.

But if you do it, charge him $1000 for the answer.

billkatz is incorrect. My mercury amalgam fillings conduct just fine.

Nop.e, but I am not a dentist either.

the softrat Sometimes I get so tired of the taste of my own toes. mailto: snipped-for-privacy@pobox.com

-- Dough, the stuff, that buys my beer, Ray, the guy that tends the bar, Me, the guy, who drinks my beer, Far, the distance to the bar, So, I think I'll have a beer, La, Laa lAA lAh LaH LAA LAAAH! Tea, no thanks I want a beer, which brings us back to Dough Dough Dough!