Talk:Amalgam (dentistry)/Archive 1

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How is it used?

I came to this article to find out how this stuff "works." I'm inferring from the text (and it's not at all obvious if true) that amalgam has a very low melting point, and it's heated before it's applied, and sets up by cooling? If so what is the melting point, and what temp is it held at when it's prepared for use? None of this basic stuff is in the article. Could somebody (a dentist?) walk us through what you do when you grab a container of amalgam and fill a tooth with it? 68.42.98.97 (talk) 14:58, 7 July 2008 (UTC)

"Dental" amalgam?

I think "Dental Amalgam" should have its own page or a subsection on a more general "Amalgam" page. This page is ONLY about dental amalgam ... but many mining, metallurgy, and chemistry pages link here, apparently out of context. The disambig link at the top of the page is not useful as the linked section does not have any chemical or mineral expositions of amalgamation. Amalgamation has been used in metal refining since the 1500s, as a dental filling only since 1826 ... why no mention of the chemistry of amalgamation, metals which form amalgams, historical importance in mining, etc.? There sure is a lot of petty detail about the dental application. New Providence (talk) 04:30, 8 April 2008 (UTC)

I agree, why not split the article into "Amalgam" and "Dental Amalgam" pages? The contents of the present article could pretty much be moved directly to "Dental Amalgam" and a section could be left here linking to the main dental article. There isn't much here in the way of general information on amalgam here though as you noted User:NewProvidence; you seem to have done a fair amount of research on this topic so maybe you'd like to draft something up? I'll add the Split-apart tag to the article.--Eloil (talk) 20:32, 29 April 2008 (UTC)
It's not a split -- it's a rename. Rename this article Dental amalgam and begin a new article on Amalgam, placing the removed information (placed somewhere below) into that article. DRosenbach (Talk | Contribs) 03:11, 21 May 2008 (UTC)

Deceitful pure propaganda article

What a deceitful pile of corporate propaganda filth. Brings disgrace and discredit on wikipedia. As for the supposed lack of evidence, See Mats Hanson "Effects of amalgam removal on health" for a start. Also Wojcik, Godfrey, Christie & Haley 2006. -Robin P Clarke

 (I've now put some little changes to counter that misleading.)-rpc
I know I'm listening to a man of detached Olympian reasoning when he uses objective terminology like "corporate propaganda filth." And on that point, which corporation holds the patent on amalgam? Oh that's right, none. Anybody who wanted to make money from dental fillings would be taking your position, amalgam is cheap and anybody can make it.

Propaganda? Not. Splitting? Not.

I am totally against splitting this article because once we split up this article, then there will be stubs. It's not propaganda at all becuase there are some health effects on mercury you know. Joe9320 (talk) 06:53, 17 May 2008 (UTC)

Comment 1

The last paragraph needs NPOVing, but I'm not the person to do it. Who exactly claims amalgam is poisoning patients, who advises the removal of all fillings. Do the dentists have any say in the matter? theresa knott 21:09, 21 Apr 2004 (UTC)

Theresa, it doesn't make any difference. This is Wikipedia. This artical, as it is at this time, is both POV and factually inaccurate. Any attempts I make to change it into a balanced, informative article will be reverted. This is how Wikis work. Crusadeonilliteracy
You give up too easily. Wiki's are wonderful things when people work together. theresa knott 11:24, 21 Jun 2004 (UTC)
Don't buy into his whining. He's on a crusade to scare everyone into thinking that mercury is the most toxic substance on earth.
I clarified mercury's toxicity (which is mild) and he immediately went crying to mav [1] who dismissed his complaints like the rubbish they are. I then handed him a plate full of his ass [2] which he responded to thusly [3].
He then made a new account [4] as evidenced by it's contributions [5] compared to his old account [6] and tried to exaggerate mercury's toxicity again [7].
After that, he used a proxy to change this [8], and has been doing similar things ever since. I have largely ignored him, while keeping a watchful eye on him, but now I must speak up about his sockpuppetry and ignorant "crusade".
Darrien 06:23, 22 Jun 2004 (UTC)
Darrien - firstly watch your tone. I then handed him a plate full of his ass is not the kind of thing you should be saying here on Wikipedia.
I'm not aware of any regulations which dictate what tones or words are acceptible on wikipedia, though I doubt it was the words I used seeing as how you don't have a problem with strong language [9].
We have lots of policies related to wikipedia:wikilove,
"Follow this advice..." that is not a policy.
Wikipedia:no personal attacks
What I said was not a personal attack, and that page is not policy either, it is a guidline. I also noticed that this was also a guideline. Interestingly, so was this.
and the like. They all pretty much boil down to - be nice!
Perhaps you should tell that to Crusadeonilliteracy and his various incarnations. It's not "nice" to change articles to reflect your misguided medical beliefs and use sockpuppetry to assist in doing so
I have no problem with the words themselves (well except that it's spelled arse not ass but then again I am english)There is a world of difference between me saying "Rooney is fucking brilliant" and your expression. I was being nice. theresa knott 23:08, 22 Jun 2004 (UTC)
Secondly I'm not convinced that Yggdr%E6sil and crusadeonilliteracy are one and the same person,
I am, and based on the evidence, I'm sure that most other people would too.
but even if they are so what? If people want to start again with a new username that's fine by me, it's only if they use two accounts at once - for example if they vote twice in a poll, once with each account, that is becomes appropriate to bring sockpuppetry to the attention of the community. And finally there is absolutely no evidence whatsoever that a single edit by an anon user, (that changes the spelling of a word) means that crusadeon illeteracy is using proxies to hide his edits.
Sorry, how about this? [10] both usernames and the proxy IP (which resolves to New Zealand) have the same and/or similar articles in their edit history.
As for the article itself, it still reads like an anti alternative medicine article. There is soo much more that could be added
  1. Who first used amalgam in dentistry?
  2. What are the exact propertions of mecury and other metals in dental amalgam?
  3. Why does it set hard within a minute? -what's the physics/chemistry of the process?
  4. What else is amalgam used for? (I have a vague recollection of mecury being used in gold or silver extraction)
Mercury will amalgamate easily with gold and silver. One way this was used was at the "sludge" portion of a mine. After all the usable ore was extracted, the sludge was passed over a copper-mercury amalgam, which bound to the gold. The copper-mercury-gold amalgam was occasionaly scraped off and then distilled to remove the mercury. The result was fairly high purity gold.
Peace! theresa knott 08:42, 22 Jun 2004 (UTC)
Darrien 19:26, 22 Jun 2004 (UTC)
Darrien 08:40, 23 Jun 2004 (UTC)

Darrien we've got off to a bad start. That's my fault, I shouldn't have issued an order to "watch your tone"straight off. you'd think by now I'd have learned not how to get peoples back's up in the opening sentence. Can we start again? theresa knott 08:51, 23 Jun 2004 (UTC)

Sure.
Darrien 09:57, 23 Jun 2004 (UTC)
Great let's look at the issue of proxies. I don't know how transparent proxies work. What I mean is if a user's ISP users a transparent proxy and the user edits wikipedia does the proxy IP address show up?
Yes.
Because if it does then all that's happening is that Crusadeonilliteracy forgot to log in. In fact if you think about it, this is almost certainly what's going on as he has signed his comment above while editing as an non logged in user with IP 203.109.254.49 which resolves to proxy1.ihug.co.nz compare this with the IP you pointed out 203.109.254.40 which resolves to proxy2.ihug.co.nz.
No, I signed it for him.
Now who in their right mind would do this if they were trying to hide their identity? theresa knott 10:47, 23 Jun 2004 (UTC)
Darrien 01:37, 24 Jun 2004 (UTC)
Oh yeah so you did. Still my point remains , no one has to log in if they don't want to. theresa knott 13:26, 24 Jun 2004 (UTC)
When did I say otherwise?
Darrien 06:07, 25 Jun 2004 (UTC)

[my older and now solved concerns were here, except for the monkey study mention transfered below]

It was nothing personal. It was just that too much needed to be done. You also used phrasing that seemed to indicate a bias. You should almost never use "I" in an article. Also, "START XXX HERE" is not very becoming of an encyclopedia. I'm going to look over your contributions to this article and attempt to NPOV them.
Darrien 02:11, 28 Jun 2004 (UTC)
I'm sorry, but there is very little that I can use. The links you have provided as being "scientific", are anything but. Their methods are not scientific. They did not check the mercury levels in the sheep until after they removed the fillings. That would cause an enormous amount (compared to what would be released if they were left intact) of mercury to be released, and with radioactive tracers, even minute amounts of them will show up brightly on an X-ray image.
You should also know that in a scientific study, one should never present any kind of opinion at all. Their "mercury vapor releasing tooth" presentation was full of opinion and bias. I especially liked this quote: "... even if we don't consider the neurological impairment and the brain damage that they surely cause in dental personnel and the infertility and the heart break that they cause to so many families". They are the same knid of uninformed people. They just attempt to seem more plausible by presenting their evidence in a scintific manner.
Darrien 03:12, 28 Jun 2004 (UTC)
So what about the MONKEY study, (not the SHEEP study)? Can you poke a hole in their credibility so I can ignore it?
"The same experiment was repeated using a monkey..." If they repeated the experiment, then they drilled the fillings out of the monkey too.
I'm talking about this one, not the hyped presentation: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=2227216
Well it's also there... within all the circus!
http://www.iaomt.org/
If you can give me a link to the full text of the study, then I will most certainly try.
Thanks.

Earlier you stated "I clarified mercury's toxicity (which is mild)".

I assume you are refering to Mercury (element)?
Yes. Mild toxicity isn't like the "completely safe" view of the document at the time. Thanks for the "widely regarded as safe".
Since you appear to know about chemistry more than I do, maybe you can document that _mild_ toxicity so that the page is no longer "amalgam never-ever toxic" POV?
See below, I don't see how an amalgam can be toxic.
That will be difficult for me to do. With the knowlege I have of chemistry, Mercury, and metalurgy; I do not believe that amalgam fillings pose any threat to human health whatsoever.
Hmmm. Perhaps the 120 millions US $ amalgam study here will help your toward NPOV. http://www.vimy-dentistry.com/nhanesscreening.htm
Nope. "...mercury is the most toxic non-radioactive element towards human life..." that statement is false.
Perhaps you can tell me about the difference between non-gamma-2 amalgam and gamma-2? The anti-amalgam fans claim non-gamma-2 leaks more, but the German government banned gamma-2 claiming it leaks too much compared to the non-gamma-2. Is there any metallurgic document to help calculate the leak of either?
Sorry, but metallurgy is not my specialty.
The article clearly states that alloys do not exhibit all of the properties that their constituent metals have. Objectively looking at the issue, given that so many people have amalgam fillings, why aren't people dying left and right from mercury poisoning?
Considering the extremely hard diagnosis of mercury poisoning even as an excellent team of toxicology specialists look at an affected town (Minamata, Japan, 30+ year of poisonous fish killed hundreds), it is unclear that people dying from say multiple sclerosis will be mentionned under a mercury poisoning statistic. It's much easier to recognize the multiple sclerosis entity, tell the patient of his impending doom from a disease with no known cause, give him the number of the polluter-funded multiple sclerosis association, and leave it at that. Yet when you want to study neuron-damaging immune disorders like that you expose rats to mercury and lead together and get the same symptoms and you can cure them with lead chelators(which removes mercury as well - at least in rats). The same paradigm existed before lead paint was banned (polluter-funded support groups for patients with a disease "with no known cause" and all that).
So mercury poisoning diagnosis is hard. Let's simplify your question to: why aren't people simply dying left and right?
Mercury poisoning diagnosis is not hard, Mercury poisoning is so rare that it is seldom looked for as a cause of symptoms.
Only what leaks from the alloy is toxic AFAIK, which is certainly not a quick effect like eating a thermometer and being somewhat sickly for a day. A good question is how much amalgam leaks.
Amalgam does leak substantially and neuron growth cone degeneration at low levels covered here: http://www.mindfully.org/Health/Mercurcy-Exposure-Nerves.htm
I think you have misunderstood the purpose of that study. They were not studying what, if any, affect amalgams have on brain tissue, they were studying what affect Mercury ions have on brain tissue.
In the study, they cultured snail neurons, and then put a few drops of Mercury chloride on them. Of course the neurons are going to degrade. Especially because they used a Mercury salt, which are much more dangerous than elemental Mercury or even Mercury (II) oxide. What would you expect to happen if they put a few drops of phosphoric acid on a snail neuron? Probably the same thing, but millions of people drink phosphoric acid on a daily basis (albeit in a dilute form). In fact, if you have ever drank a soda, you have consumed phosphoric acid, which is also used as a metal etchant.
This neuron degeneration is typical of a number of human diseases.
Also many forms of mercury are delayed effects. You can have 80 times the fatal level in your blood from a single exposure and look/feel healthy for months at a time. Then go sick and even die(with the same neuron damage shown in the video at http://www.iaomt.org/ ). The link with the original exposure is rarely made because of the months between the exposure and effects, and the strong symptoms appearing all of a sudden hinting wrongly at a recent cause(which is never found).
http://www.uh.edu/admin/srmd/mercurypoison.html
Yes, that was the dimethylmercury poisoning case where Dr. Wetterhahn died. A professor at my college knew her personally, but how does this apply to the article? We are not debating the fact that some merucy compounds are toxic, we are debating whether or not amalgams are.
Key research here would be what mercury does when it enters the body as a vapor or thru lymphatic draining(a quick way to administer certain drugs under the tongue).
I wouldn't imagine that much would happen. Elemental Mercury needs to oxidise to present any danger to the human body. I don't think lymph would be very rich in oxidsers.
In amalgam the effect certainly doesn't affect all of the population(hence the counter-indications of the manufacturer), usually requires blood-brain barrier to be weakened by another process (fluoridation come to mind), and the varieties of symptoms or mercuric compounds involved or claimed are astonishingly numerous. Some people having the complete set of statistical factors against them are doing fine, just like with cigarettes.
Why is the human lifespan longer now than at any point in human history, given all the "toxic" chemicals that are being used in our food, water, clothes, medical treatments?
Modern hygiene, vaccines(even those mercury-controversial ones), a few chemical bans (leaded paint and gasoline banned, etc), addition of vitamins/minerals to some food because having everyone taking vitamins is too hard(vitamin D in milk, enriched wheat flour, etc). Less wars deaths, welfare so the poor don't just starve, better public education about health, more condom use, various medical breakthrus, and probably 20 more factors.
Your question is very generic, so I researched from the amalgam point of view first.
Rising is the lifespan of the average individual. And maybe even the one of the person covered in amalgam counter-indications, or those who have a disease that has a synergic toxicity with mercury(for lead poisoning there are proof) because of all the other factors.
I've researched the diet-type that would cause the fewest cavities, therefore the fewest amalgam in theory(could not verify historics but Japan no longer does amalgam in dental schools); I've found Japan with the highest life expectancy despite high pollution necessiting gas masks for the sick at street corners. The Okinawa island near Japan, far away from urban pollution, has the longest-lived group of centenarians per capita on earth by a wide margin. They also have extremely low rates of handicaps, and a very low crime rate.
Yes, pollution affects life expectancy and such; But I'd like to stick to the topic of amalgam in the mouth of people, but not other products or amalgam bits as sewer waste.
I'm still trying to verify the amalgam use in Japan. Anecdotal evidence from my Japaneese-born friends has been good but not wikifiable.

Montrealer 17:02, 28 Jun 2004 (UTC)

In 1984, human autopsy studies were published which demonstrated that the amount of mercury found in brain and kidney tissue was directly related to the amount of mercury amalgam fillings in the teeth. This contradicts the previous position that mercury in fish was the largest contributor to mercury in the brain of the average person.
This needs a reliable reference.
OK. Seeking...
In the 1980s, significant research at the University of Calgary School of Medicine demonstrated that mercury from dental amalgam fillings could be found in the blood and tissues of pregnant mothers and their babies within a few days. Neither of those studies make claims regarding the safety or toxicity of mercury in the brain at the levels detected in the study.
This needs a reliable reference.
OK. Seeking...
In this case the government worries about much smaller quantities of mercury than are contributed by amalgam user brains.
I am very skeptical of this statement. Elemental mercury is extremely unreactive, you could drink a shot glass of mercury and remain unharmed. Any exposure to elemental mercury will cause only negligible amounts to be absorbed by the body.
True; proven in cases where children eat broken thermometers. In this case the mercury comes out.
The very point I am researching right now is that amalgam-leaded mercury ISN'T a liquid it's a vapor. And it ISN'T swallowed, it is leeched thru the lymphatic drain under the tongue which bypasses the digestive system and the liver(used as such as the administration route of certain drugs). I could not find any internet-available documents on it so far.
As I've stated above, I don't think that lymph would affect Mercury in any significant way.
However, very large amounts of mercury are absorbed by the body when it is exposed to organic mercury compounds. See dimethylmercury.
Which is why I mentionned the fish advisory is misleading people to think mercury of amalgam is as toxic as fish mercury. You left the fish advisory by itself, which is meaningless by itself - it should have been removed if the rest of that argument is removed.
Chemical reactions causing the amalgam alloy to break down have long been claimed to make the mercury bound to something else. I lack chemistry competence to prove or disprove it.
This is a widely misunderstood position because mercury in fish is 80% methylmercury(a known neurotoxin), which is not present in amalgam. The ADA claims that the mercury in amalgam is not neurotoxic at all.
This makes no sense without the above text.
Scrap the ADA reference; the ADA has changed it so I'm no longer using it (for the same reason I'm not using their 1800's arguments that mixing amalgam in the office is nontoxic. They have evolved beyond that one too).
However the extreme anti-amalgam POV people consider the fish advisory proves that mercury is poisonous at that level, and that amalgam is a level superior to that so it must be even more toxic therefore banned. This misconception must be addressed. The misconception that disease is automatic when you go above the government standards and automatically safe when less than that standard is also a common illusion.
A medical research team at the University of Kentucky established a probable relationship of mercury exposure from silver amalgam dental fillings to Alzheimer's disease and cardiovascular disease.
This needs a reliable reference.
OK
University of Georgia microbiologists determined that mercury from fillings inhibits the effectiveness of antibiotics.
This needs a reliable reference.
OK
Hair analysis for mercury is doubly untrustworthy because it sometimes fails to find mercury in the hair of individuals who have died of chronic mercury poisoning from fish or from chronic exposure in mines. There is no way to reliably test the presence of mercury in a human body part while it is alive. The only reliable tests are done after autopsy and, more ralely, an amputation.
From a chemical standpoint, this seems wrong, but I cannot comment on it from a medical standpoint.
People who died from 40 years of being fisherman and eating fish in Minamata, Japan(as recognized by Japan) sometimes have no mercury in their hair. This mirrors the study of Amy Holmes in Autism:talk that some individuals (autistics) do not excrete mercury thru hair at a normal rate(the most autistic had 19 times less mercury in hair than the age matched non-autistic control with the least mercury in hair).
Furthermore urine/blood/hair tests never shows mercury in the brain. No test on a living person ever does, according to many doctors.
World Health Organization reported that exposure to mercury from amalgams is higher than from fish, seafood, water and air.
This needs a reliable reference.
OK
The FDA has claimed it could not condemn amalgam, but asked for more studies to be done on the subject.
This needs a reliable reference.
OK - will make all reference when I have time.
P.S. Removing any text from a talk page is greatly frowned upon.
Darrien 07:52, 2004 Jun 29 (UTC)
Ok - but how do we prevent a talk page from becoming very very long?
Don't bother, the wiki has plenty of storage space. If and when the page becomes so long that it hinders reading, someone will come by and archive it.
I feel wikilove is within sight...

-Montrealer (somehow I got logged off during edit??)

Darrien 04:54, 2004 Jun 30 (UTC)
(When the talk page gets too long (not yet IMO but when it get's say twice as long as it is now) I'll archive it) theresa knott 12:30, 30 Jun 2004 (UTC)

The current entry for "Amalgam" was informative, but had four limitations: (a) accuracy: in certain places it was factually inaccurate; (b) language: there remained some basic linguistic mistakes; (c) incompleteness: there were certain key areas of information which had not been included yet; (d) links: only two links were provided for what is a broad subject with many excellent website resources in existence.

As this is my area of specialist research, and I have a library of books, papers, articles, studies and clippings on it, and have been writing about it for years, and am one of the leading experts in this field in Ireland and Britain, I decided to try and and address these four issues all at once.

Although I gave a lot of thought to it, and spent many days putting together carefully re-edited or new paragraphs where appropriate, I found that all of my changes were immediately reverted. This reversion was made completely indiscriminately, since even my basic corrections of a few spelling and grammatical errors had been reversed to their previous linguistically inaccurate versions. This therefore leads me to conclude that the reversion took place more or less automatically, without any particular attention being given to the specific proposed changes and additions individually.

In other words, this is against the community spirit of Wikipedia. I still hope that we can work together to improve this "Amalgam" entry, and so I have two suggestions:

(i) I could reinstate the changes I proposed all at once, but this time one by one, in small degrees. In this way, each one could be considered in its own right, rather than multitudinous changes being reverted all at once indiscriminately;

and/or (ii) If the person who reverted the entry would like to enter discussion with me with regard not to my entire proposed changes as a whole, but with regard to individual aspects of the changes I proposed, then perhaps we can try to come to some compromises, and together work to improve this entry. Likewise, others could join in the discussion if they wish.

My intention would be that in both the discussion and in the entry itself there would be an academic attempt to come as far as possible to objective statements, rather than statements of opinion.

My logic is that this is very clearly a controversial topic (just see the history and discussion pages!) and, correspondingly, there exist two (or more) very different schools of thought on the matter. Since both of these camps have appeared before the U.S. House of Representatives (April 2002) to discuss the issue, as well as before courts of law in many protracted lawsuits, in neither case with any clear conclusion one way or the other yet, then in an objective knowledge base like an encyclopedia we, as a result, should do our best likewise to reflect both sides of the conflict, if we have any pretension to objectivity.

In other words, from a scientific perspective, the matter is not decided, since there is no conclusive proof of either safety or danger from amalgam which has been submitted either in scientific, legal or government circles. Correspondingly, it is our duty to report on both sides in an objective fashion, i.e. with phrases such as "Some dentists argue. . . while others claim. . . " or "Some studies have shown. . . while others have suggested. . . " or "Dental associations in some countries (e.g. x, y and z) maintain. . . while those in some countries (e.g. p, q and r) have stated. . .. " etc. Some paragraphs of the current entry do not currently report on both sides in this objective fashion, but instead reflect the opinions of one side only.

It is not that I wish any parts of the entry to be changed to an opposite opinion. I would much rather that opinions were left out (including my own, which I have already done my best to put aside for the sake of academic reporting), and that instead these opinions were given equal mention as two sides of what is an ongoing scientific, political and legal debate at large in dozens of countries, still without conclusive resolution.

P.S. I am Simon K - but my proposed changes appeared under "212.2.175.179". I don't know how this happened, unless my log-in session had accidentally expired, since I would have liked it to appear under my username "Simon K". Simon K 16:11, 2 Nov 2004 (UTC)

I would like to keep this article as scientific as possible, so I have created Dental amalgam controversy to hold the bulk of information relating to the mercury scare. I have copied this version [11] verbatim, minus the introduction, to it.
Darrien 14:19, 2004 Nov 3 (UTC)

I was unable to look at these pages for a long time, but returning now to Wikipedia I am very pleased at the solution, which strikes me as an admirable one, to have created two pages. Thank you for finding this good resolution to the dilemma. The new ‘dental amalgam controversy’ page was a good idea, and it seems to me to be a good compromise/balance, describing both sides of this controversial topic in a fairly objective manner, combining contributions from different people. Simon K 17:00, 9 Dec 2004 (UTC)

There is no controversy, there is discussion about the toxicity and the impact of such on the body. Psilocin 23:42, 31 December 2006 (UTC)

D.C./Marvel

Why/How do amalgams harden?

One of the interesting things about amalgams is that they are plastic when made, but quickly harden. What's going on in terms of chemistry/physics? Seems like it would be a good addition to this article.

Mercury apparently acts as a solvent for the other components of dental amalgams, by altering or breaking some bonds, and by rearranging or disrupting the crystalline and/or other structual forms that would exist in the components of the mixture. It seems likely that the components other than mercury harden as the mercury becomes isolated in pockets as the alteration of the structure of other components takes place, leaving distinct, isolated pockets of liquid and vaporized mercury, which subsequently leaks, in its elemental form, into the mouth due to wear and during removal. There seems to be little evidence that the resulting mixture contains any types of alloys incorporating mercury, which is why the term amalgam is used for these mixtures, in order to distinguish the blend from 'true' alloys wherein all the components are chemically bonded. Unless evidence is provided indicating that more than a fraction of any alloys that are produced by the solvent (or other chemical activity upon components of the amalgam mixture) actually incorporate mercury, then it can only be assumed that labeling dental amalgams (what the FDA calls a 'device') as 'alloys' is purely POV. While amalgams may or may not contain some alloys incorporating other components of the mixtures used, it needs to be resolved whether or not mercury is incorporated in these presumed 'alloys'. It is implied, by the general meaning of amalgam, that a heterogenous mixture remains after hardening, rather than what is generally implied by the term 'alloy'. If the term is to be used, then there needs to be clarification on this matter, or a pov tag is needed. Ombudsman 22:52, 23 September 2006 (UTC)


There is no controversy, there is discussion about the toxicity and the impact of such on the body. Psilocin 23:42, 31 December 2006 (UTC)

Mining?

At the top of the article it says that this article is about amalgams in dentistry. Why has the mining section been included. As far as I can see, it does not appear to be relevant to amalgams in dentistry at all; the section appears to be about uses of mercury in mining, should that not be located on the mercury page?. The only link is the mercury. If mining is to be included (which I oppose), then perhaps the mining of all the components of amalgams should be included, as mercury is only one of the materials used. Bouncingmolar 00:53, 23 May 2007 (UTC)

Who knows. I do not believe the mining section really needs to be mentioned in this article either. It could go. - Dozenist talk 03:05, 23 May 2007 (UTC)
==Chemical analysis==
Mercury is the preferred electrode material for the analysis of metals by anodic stripping voltammetry. The formation of amalgams facilitates the reduction of most metal ions in aqueous solutions that is normally not possible because their reduction potentials are more negative than the potential for the reduction of the solution.
==Use in organic chemistry==
Formation of amalgams is used to increase the reactivity of metals. In the Grignard reaction, amalgamation of the magnesium makes the reaction more facile. In the Barbier reaction and other reactions using aluminum, it is absolutely necessary, as the surface oxide coating normally makes aluminum inert.
==Mining==
Mercury has been used in the gold and silver mining processes due to the ease with which mercury will amalgamate with them. In gold placer mining, in which small particles of gold are washed from sand or gravel deposits, mercury was often used to separate the gold from other heavy minerals.
After all of the usable metal had been extracted from the ore, mercury was poured down a long copper trough which formed a thin coating of mercury on the surface. The waste ore was then poured down the trough, and any gold in the waste amalgamated with the mercury. This coating was occasionally scraped off and distilled to remove the mercury, leaving behind fairly high-purity gold.
Mercury amalgamation was first applied to silver ores with the invention of the patio process in Mexico in 1557. Other amalgamation processes were invented for processing silver ores, including pan amalgamation and the Washoe process.
With the invention of mercury amalgamation to treat silver ore, mercury became essential to the silver mines of the New World. The Spanish Empire transported mercury from Almadén across the Atlantic to supply the silver mines of Zacatecas and Potosí. Another source for mercury in the Spanish Empire was the mine of Huancavelica in Peru, discovered in 1563. In 1648, the Viceroy of Peru declared that Potosí and Huancavelica were "the two pillars that support this kingdom and that of Spain."[1]
Today, mercury amalgamation has been replaced by other methods to recover gold and silver from ore. Dangers of mercury pollution have played a part in the near-disappearance of mercury amalgamation processes. Mercury amalgamation is still commonly used by small-scale gold placer miners, especially in less-developed countries, most notably Brazil.
The amalgam table is used in gold productions and was the main way to collect fine particles of gold during the 1800s. The table is simply a sloped, smooth surface with a copper sheet overlaid and smeared with mercury. The pulp from the stamp battery is directed over the table. The finely crushed gold chemically bonds with the mercury, and hence sticks to the table for later collection. However, if there is any oil in the water, it will surround the gold and cause it to float away and not bond properly with the mercury.
==Other uses==
Thallium amalgam is used as liquid for thermometers, because it freezes at -58°C[citation needed], whereas pure mercury freezes at -38°C.

Moved here from article -- to be placed elsewhere upon later determination. DRosenbach (Talk | Contribs) 00:37, 18 February 2008 (UTC)

Dentistry

Why does the dentistry section have two paragraphs discussing things other than amalgam and one paragraph discussing the topic of the article? DRosenbach (Talk | Contribs) 16:40, 15 February 2008 (UTC)

Could this article be split into dental amalgam vs. other amalgam? DRosenbach (Talk | Contribs) 20:59, 17 February 2008 (UTC)

Updated article

I removed secondary information about non-dental amalgam to the talk page pending a determination of where this information would perhaps be more useful, as this article is an article on dental amalgam.

Seconday, I added what seemed to be entirely missing sections on the the history of amalgam as well as modern use of amalgam.

Thirdly, I wish to debate whether or not the last line of the section entitled "dental malgam controversy" should be allowed to remain. If the scientific community is thoroughly convinced of anything after running clinical studies and controlled trials, why is it that dental amalgam is faced with the objection of the opposition that "long-term studies have yet to conclude that amalgam is safe." Is any drug safe? What's the longest study performed on any medication? 5 years? 10 years? If three 5-7 year studies (Casa Pia, NECAT and the Lisbon one mentioned in the JAMA article ending in the 2000's) all established amalgam safety, why is safety being harped on? If the science isn't there, what is their opposition resting on when it inserts that there have been no long term-studies? I think this sentence should be removed, because it pushes a POV agenda. DRosenbach (Talk | Contribs) 17:26, 18 February 2008 (UTC)

Composition of Amalgam

Currently, dental amalgams are composed of about 40% mercury, and 60% powder where the powder is made up of silver (~65%), tin (~29%), copper (~10%), and zinc (~2%).

The powder composition has over 100% of contents: 65 + 29 + 10 + 2 = 106%, so that is not correct. As I know nothing of the subject, I am not able to correct this, but hopefully someone else can. Punksmurf (talk) 08:16, 7 May 2008 (UTC)

That little "squiggle" means approximately. Different manufacturers use different amounts

I am currently transferring some information which would be better described on this page from the dental restorative materials page bare with me as it contains other stuff that should probalby go on this page as well. Bouncingmolar (talk) 16:04, 21 November 2008 (UTC)
I have finished for the moment but I think this page needs a big cleanup. Bouncingmolar (talk) 17:58, 21 November 2008 (UTC)

Direction proposal for this page

While cleaning up the Dental restorative materials page I noticed this page. I propose the following future structure:

  • description (looks good atm)
    • composition (fair condition)
    • Advantages (requires cleanup)
      • Physical properties
      • Longevity
      • Ease of use
      • Cost
    • Disadvantages
      • aesthetics
      • Galvanic shock
      • controversy/mercury content (with links to main page)

The advantages/disadvantages section is kind of there atm but it needs restructuring. I started but I want to focus on the restoration page for the moment. Bouncingmolar (talk) 17:58, 21 November 2008 (UTC)

  1. ^ Arthur Preston Whitaker, The Huancavelica Mercury Mine: A Contribution to the History of the Bourbon Renaissance in the Spanish Empire, Harvard Historical Monographs 16 (Cambridge, MA: Harvard University Press, 1941).