Amalgam fillings - really bad or not that bad?

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Hi,

I am reading various articles online about the amalgam fillings and am quite shocked on the degree of variation of opinions from "professionals" on weather amalgam fillings are a major health hazzard or not. From what I could gather there are 3 camps. 1st camp says that they are a major health hazzard, that the amount of mercury in one filling is enough to posion all the fish in a small lake, that people with amalgam fillings are cronically poisoned with mercury and all that nasty stuff that comes with the package. 2nd camp says, yes that are toxic for body but the amount one is exposed by the fillings is minimal - you get more mercury from eating tuna than the fillings themselves. But the fillings should be banned not because of the health hazzard but because they pose serious environmental hazzard when they are disposed etc. The 3rd camps say they are perfectly safe, since they are used for more than 150 years and there arent any obvious side-effect deteced. Something like that.

That makes me think that none of this people made any serious scientic study of the matter. Like 3 people would be watching a ball fall from a heigh of h meters and the question asked is how much time does it take for the ball to fall down. Guess these medical studies vary depending on who funded the research. Should the funding from people who are determined that the ball falls really slow they come to the conclusion that it takes t = h^2 * g time for the ball to fall down. On the other hand should they wish to show that balls falls down really fast then they would say that it takes t = sqrt(h/g) time for the ball. The most extremist would just state that ball falls down instantly!?! Should all of this people conduct a totaly scientific experiment they all would come to the matter that it takes exactly t = sqrt(2*h/g) time for the ball to reach the ground provided that the air resistance is neglected, should the air resistance be included then t = .. etc. Soo the opinion would be unanimous.

How can there be such a "variation" in opinions? I ask this question here becose I trust "science" people. Since in science - scientific truth is what matters above all else. What are your opinions on this matter?
 

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  • #2
Janus
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haki said:
Hi,

Guess these medical studies vary depending on who funded the research. Should the funding from people who are determined that the ball falls really slow they come to the conclusion that it takes t = h^2 * g time for the ball to fall down. On the other hand should they wish to show that balls falls down really fast then they would say that it takes t = sqrt(h/g) time for the ball.
All I can do with this is to give a counter example. My wife works for a Dentist. At times, people have come to him to have their mercury fillings removed and replaced. Even though doing so would line his pockets, he tells them that is unnecessary, and that he would advise against it.
 
  • #3
Moonbear
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The only studies on such a topic would be epidemiological, which by their nature, are not controlled well. The best you can do is hope to find age-matched people who never had any fillings at the time when mercury fillings were used and see if they differ in any health problems from those with mercury fillings. The problem is that if you never needed a filling in that time, it could be an indicator that your overall general health was better too, either through better preventative care or the luck of the genetic draw.

Likewise, with biological studies of any kind, and especially with epidemiological studies, the results are not always clear-cut. It's hard to sort out other risk factors, and you have to deal with individual variation. It's much easier to create a vacuum and drop a ball and measure the time it takes to drop with no other variables affecting it than it is to measure something in a population of people who have the freedom to live their life in their manner of choosing. This means that when you get results that are not clear-cut, there conclusions drawn from them can be much more open to interpretation. Usually, one tries to look at a question from multiple directions and in multiple populations before a sufficient body of evidence exists to start drawing stronger conclusions based on common patterns in all the studies rather than the results of just a single study.
 
  • #4
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Thank you for the replies.

Well my point was that there shuldnt be such a huge difference of opinions. They are of a magnitude that is equivalent to the difference of resistance of a conducting material compared to a non-conductive material.

I didnt have in mind a very sofisticated epidemiological study. I would propose a bit simpler study.

Take n dentists out of which they have at least i patients that have no amalgam fillings but have an appointemnt to have them done. The experiment would be as follows: monitor n*i patients before the filling(s) are done - that includes monitoring the levels of metals in the body including mercury in the blood, urine, breath, and saliva. That would give an estimate of the level prior to fillings. And then monitor the patients for 1 week after the fillings are done. Since there are 3 camps there would be 3 hypothesis: 1st hypothesis would be that the mercurty levels in the body would skyrocket after the fillings are done, 2nd hypothesis would be that the levels would be slighty elevated but nothing serious after, 3rd hypothesis would say that there should be no difference after.

Now that ough to be a valid indicator weather or not amalgam fillings affect the biochemistry of the body after the fillings are done.

The second step would be to have the levels analysed by a few good toxiologist. That would be a pretty decent experiment if you ask me. Sadly I couldnt find any published details of studies regarding amalgam fillings online. Just a bunge of articles that quote different studies.
 
  • #5
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It is not advised to handle mercury with bare skin. Why would it be ok to have mercury as a permanent resident in your mouth?

wicipedia said:
Mercury poisoning, also known as mercuralism, is the phenomenon of toxication by contact with mercury.
If its in your teeth, you are in contact with it. This doesn't take a 2 million dollar study to figure out whether or not its good or bad for you.

For a list of symtoms see:

The Poisoning of Minamata (Japan)

http://www1.umn.edu/ships/ethics/minamata.htm [Broken]
 
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  • #6
Ouabache
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That makes me think that none of this people made any serious scientic study of the matter.
There are serious scientific studies on this subject. Here are three I found
just in Apr 2006 issue of JAMA (Journal of the Americal Medical Association)

Down Timothy A. DeRouen; Michael D. Martin; Brian G. Leroux; Brenda D. Townes; James S. Woods; Jorge Leitão; Alexandre Castro-Caldas; Henrique Luis; Mario Bernardo; Gail Rosenbaum; Isabel P. Martins
Neurobehavioral Effects of Dental Amalgam in Children: A Randomized Clinical Trial
JAMA, 295: 1784 - 1792.

Conclusions: In this study, children who received dental restorative treatment with amalgam did not, on average, have statistically significant differences in neurobehavioral assessments or in nerve conduction velocity when compared with children who received resin composite materials without amalgam. These findings, combined with the trend of higher treatment need later among those receiving composite, suggest that amalgam should remain a viable dental restorative option for children.
Down David C. Bellinger; Felicia Trachtenberg; Lars Barregard; Mary Tavares; Elsa Cernichiari; David Daniel; Sonja McKinlay
Neuropsychological and Renal Effects of Dental Amalgam in Children: A Randomized Clinical Trial
JAMA, 295: 1775 - 1783.

Conclusions In this study, there were no statistically significant differences in adverse neuropsychological or renal effects observed over the 5-year period in children whose caries were restored using dental amalgam or composite materials. Although it is possible that very small IQ effects cannot be ruled out, these findings suggest that the health effects of amalgam restorations in children need not be the basis of treatment decisions when choosing restorative dental materials.

Here are some more references you check out, they were given
in the following article:
Down Herbert L. Needleman
Mercury in Dental Amalgam—A Neurotoxic Risk?
JAMA, 295: 1835 - 1836.

REFERENCES

1. Bellinger DC, Trachtenberg F, Barregard L, et al. Neuropsychological and renal effects of dental amalgam in children: a randomized clinical trial. JAMA. 2006;295:1775-1783. FREE FULL TEXT
2. DeRouen TA, Martin MD, Leroux BG, et al. Neurobehavioral effects of dental amalgam in children: a randomized clinical trial. JAMA. 2006;295:1784-1792. FREE FULL TEXT
3. Ratcliff HE, Swanson GM, Fisher LJ. Human exposure to mercury: a critical assessment of adverse health effects. J Toxicol Environ Health. 1996;49:221-270. FULL TEXT | ISI | PUBMED
4. Vimy MJ, Lorscheider FL. Intra-oral air mercury released from dental amalgam. J Dent Res. 1985;64:1069-1071. FREE FULL TEXT
5. Shapiro IM, Cornblath DR, Sumner AJ, et al. Neurophysiological and neuropsychological function in mercury-exposed dentists. Lancet. 1982;1:1147-1150. FULL TEXT | ISI | PUBMED
6. Thompson CM, Markesbery WR, Ehmann WD, Mao YX, Vance DE. Regional brain trace-element studies in Alzheimer's disease. Neurotoxicology. 1988;9:1-7. ISI | PUBMED
7. Echeverria D, Woods JS, Heyer NJ, et al. The association between a genetic polymorphism of coproporphyrinogen oxidase, dental mercury exposure and neurobehavioral response in humans. Neurotoxicol Teratol. 2006;28:39-48. FULL TEXT | ISI | PUBMED
8. Oshima H, Nakamura M, Yasuda K, Yamagishi N, Hatayama T. Stress protein assay for the evaluation of cytotoxicity of dental amalgam. J Mater Sci Mater Med. 2004;15:1-5. FULL TEXT | ISI | PUBMED
9. Pendergrass JC, Haley BE, Vimy MJ, Winfield SA, Lorscheider FL. Mercury vapor inhalation inhibits binding of GTP to tubulin in rat brain: similarity to a molecular lesion in Alzheimer diseased brain. Neurotoxicology. 1997;18:315-324. ISI | PUBMED
10. Needleman H. Lead poisoning. Annu Rev Med. 2004;55:209-222. FULL TEXT | ISI | PUBMED
11. Needleman HL, Gunnoe C, Leviton A, et al. Deficits in psychological and classroom performance of children with elevated dentine lead levels. N Engl J Med. 1979;300:689-695. [correction in N Engl J Med. 1994;331:616-617]. ABSTRACT
12. Lanphear BP, Hornung R, Khoury J, et al. Low-level environmental lead exposure and children's intellectual function: an international pooled analysis. Environ Health Perspect. 2005;113:894-899. ISI | PUBMED
13. Lorscheider FL, Vimy MJ, Summers AO. Mercury exposure from "silver" tooth fillings: emerging evidence questions a traditional dental paradigm. FASEB J. 1995;9:504-508. FREE FULL TEXT
 
  • #7
Moonbear
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quantumcarl said:
It is not advised to handle mercury with bare skin. Why would it be ok to have mercury as a permanent resident in your mouth?
In dental amalgam, the mercury is incorporated as part of the compound material, and is not as freely available as if you were just handling pure mercury with your bare hands.

Dental amalgam (silver filling) is considered a safe, affordable and durable material that has been used to restore the teeth of more than 100 million Americans. It contains a mixture of metals such as silver, copper and tin, in addition to mercury, which chemically binds these components into a hard, stable and safe substance. Dental amalgam has been studied and reviewed extensively, and has established a record of safety and effectiveness.
From:http://www.ada.org/prof/resources/positions/statements/amalgam.asp [Broken]

Quackwatch has a good explanation too. http://www.quackwatch.org/01QuackeryRelatedTopics/mercury.html
 
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  • #8
Curious3141
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In his schooldays (1960s), my dad had ended up with a mouthful of mercury when mouthpipetting it in the lab (safety standards were terrible in those days). No apparent ill effects. He has an IQ over 170.
 
  • #9
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Moonbear said:
In dental amalgam, the mercury is incorporated as part of the compound material, and is not as freely available as if you were just handling pure mercury with your bare hands.


From:http://www.ada.org/prof/resources/positions/statements/amalgam.asp [Broken]

Quackwatch has a good explanation too. http://www.quackwatch.org/01QuackeryRelatedTopics/mercury.html
Sorry, apparently I put the wrong link with "see list of symtoms". But, Minamata is a fairly obtuse symtom.

Here's a better description:

Clinical Signs and Pathology

Depending upon the amount of mercury ingested, the clinical signs can either be peracute, acute, or chronic. Ingestion of large amounts of mercury results in almost immediate death due to heart attack. Symptoms of acute poisoning include severe abdominal pains, vomiting and diarrhea. The intestinal mucosa is destroyed and if the animal survives this first stage, hemorrhagic gastroenteritis is followed by ulcerative colitis with destruction of the kidney tubules. Chronic exposure results in soreness, swelling, bleeding and ulceration of the gums, tongue and oral mucosa with anemia, edema, and body wasting ending in death. Chronic mercury poisoning may be accompanied by mental disturbances due to degeneration of nerve tracts and may result in blindness, weakness, incoordination and coma.
From:http://www.michigan.gov/dnr/0,1607,7-153-10370_12150_12220-26953--,00.html

And here is an article perfectly suited to this thread from the Journal of the American Medical Association (JAMA). Please read this and critique if you have the time!

JAMA said:
Neurobehavioral Effects of Dental Amalgam in Children

A Randomized Clinical Trial

Timothy A. DeRouen, PhD; Michael D. Martin, DMD, PhD; Brian G. Leroux, PhD; Brenda D. Townes, PhD; James S. Woods, PhD, MPH; Jorge Leitão, MD, MS; Alexandre Castro-Caldas, MD, PhD; Henrique Luis, MS; Mario Bernardo, DMD, PhD; Gail Rosenbaum, MS; Isabel P. Martins, MD, PhD

JAMA. 2006;295:1784-1792.

Context Dental (silver) amalgam is a widely used restorative material containing 50% elemental mercury that emits small amounts of mercury vapor. No randomized clinical trials have determined whether there are significant health risks associated with this low-level mercury exposure.

Objective To assess the safety of dental amalgam restorations in children.
http://jama.ama-assn.org/cgi/content/abstract/295/15/1784

I realize that the mercury in compound fillings is part of the compound and not "pure mercury". It is however, 50% of the amalgam... along with silver and small portions of other metals.

This amalgamation and the process of amalgamation does not change the toxicity of mercury... it only bonds it to some other elements like silver. Upon "gassing off" in the mouth, the mercury remains a toxic threat and a risk to overall health.

Although mercury/silver amalgam is the most cost effective and one of the most maliable yet strong materials discovered (in the 1700s by the Chinese) to fill a cavity........ these arguments resemble the sort of argument that the Romans might have used to justify transporting their drinking water through lead piping. And we know the rest of that story. koo:surprised koo
Thanks!
 
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  • #10
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Curious3141 said:
In his schooldays (1960s), my dad had ended up with a mouthful of mercury when mouthpipetting it in the lab (safety standards were terrible in those days). No apparent ill effects. He has an IQ over 170.
IQ of over 170!!!... this is quite possibly a symtom of mercury-induced neurological hyperactivity!

Unless your dad was mouthpipetting mercury everyday he does not make a good subject of study with regard to the effects of amalgamated mercury residing in a person's oral cavity 24/7.

Don't get me wrong. I believe the old "what don't kill ya, don't kill ya..." type of reasoning. You know... like how you need a bit of arsnic every week to live through a full dose if it happens... and so on.
 
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Thank you very much for the replyies.

"...did not, on average, have statistically significant differences..." yes we all love statistics.

But anyway, guess the camp 2 is correct. Thanks again.
 
  • #12
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quantumcarl said:
And here is an article perfectly suited to this thread from the Journal of the American Medical Association (JAMA). Please read this and critique if you have the time!

Originally Posted by JAMA
Neurobehavioral Effects of Dental Amalgam in Children - A Randomized Clinical Trial; Timothy A. DeRouen, PhD et al.; JAMA. 2006;295:1784-1792.

Context Dental (silver) amalgam is a widely used restorative material containing 50% elemental mercury that emits small amounts of mercury vapor......
http://jama.ama-assn.org/cgi/content...ct/295/15/1784 [Broken]

Hmmmm déjà vu :uhh: ........ (my last post - 1st ref.)
 
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  • #13
Curious3141
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quantumcarl said:
IQ of over 170!!!... this is quite possibly a symtom of mercury-induced neurological hyperactivity!

Unless your dad was mouthpipetting mercury everyday he does not make a good subject of study with regard to the effects of amalgamated mercury residing in a person's oral cavity 24/7.

Don't get me wrong. I believe the old "what don't kill ya, don't kill ya..." type of reasoning. You know... like how you need a bit of arsnic every week to live through a full dose if it happens... and so on.
No, I know it's just an anecdotal one-off thing. Just throwing it in there, since it seemed half-way relevant.:biggrin:
 
  • #14
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Curious3141 said:
No, I know it's just an anecdotal one-off thing. Just throwing it in there, since it seemed half-way relevant.:biggrin:
Oops. I thought things felt duplicated today!... my apologies Ouabache.

I certainly can't argue with the JAMA party paper since they have done the study and I haven't. I'll have to bow to the research and personally avoid toxic poisons like mercury and floride on my own. There are other poisons I'd rather expose myself to at any rate.
 
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  • #15
DocToxyn
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quantumcarl said:
This amalgamation and the process of amalgamation does not change the toxicity of mercury... it only bonds it to some other elements like silver. Upon "gassing off" in the mouth, the mercury remains a toxic threat and a risk to overall health.
Your first statement is not necessarily true. If we are defining toxicity in terms of what deleterious effects the mercury will have to the exposed organisms, one major factor in this is bioavailability. In other words, in its current state how much of the toxicant in question is absorbed and interacting with the system. In this case, since it is bound in the amalgam, it has little chance to accumulate to toxic levels and elicit damage. Another example of this would be if I gave a person a capsule containg a lethal dose of cyanide that was coated in a material that could not be digested by the gi tract. Obviously the cyanide is still toxic, but it will not harm the person because it was not available.

Another interesting aspect of this was brought up by the Minamata incident you mentioned. This was a tragic event the occurred in Japan when numerous people died or were seriously affected following the consumption of shellfish from the waters surrounding their home harbor. The mercury was dumped into the harbor by industrial processes and ended up in the sediments. This mercury in its metal ion state is indeed toxic, but not particularly so. In the sediments it was methylated by certain bacteria, which made it much more soluble and available for accumulation by shellfish and other animals. Once these were ingested the more toxic methyl mercury exacted its toll on the people. Very unfortunate situation, but again stressing that not all poisons are created equal. Perhaps if the people had only been exposed to the industrial waste mercury, things wouldn't have been so bad (pure speculation).
 
  • #16
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DocToxyn said:
Your first statement is not necessarily true. If we are defining toxicity in terms of what deleterious effects the mercury will have to the exposed organisms, one major factor in this is bioavailability. In other words, in its current state how much of the toxicant in question is absorbed and interacting with the system. In this case, since it is bound in the amalgam, it has little chance to accumulate to toxic levels and elicit damage. Another example of this would be if I gave a person a capsule containg a lethal dose of cyanide that was coated in a material that could not be digested by the gi tract. Obviously the cyanide is still toxic, but it will not harm the person because it was not available.

Another interesting aspect of this was brought up by the Minamata incident you mentioned. This was a tragic event the occurred in Japan when numerous people died or were seriously affected following the consumption of shellfish from the waters surrounding their home harbor. The mercury was dumped into the harbor by industrial processes and ended up in the sediments. This mercury in its metal ion state is indeed toxic, but not particularly so. In the sediments it was methylated by certain bacteria, which made it much more soluble and available for accumulation by shellfish and other animals. Once these were ingested the more toxic methyl mercury exacted its toll on the people. Very unfortunate situation, but again stressing that not all poisons are created equal. Perhaps if the people had only been exposed to the industrial waste mercury, things wouldn't have been so bad (pure speculation).
I see what you are pointing out. That's fantastic information! So where I say the toxicity doesn't change in an amalgam you say the exposure to that toxicity is measurabley less than were it fully exposed as methyl mercury.

I suppose my inclination is that if you have mercury in your mouth... you have mercury in your mouth and mercury is a class (x) toxin (effects will vary from person to person). If there is a viable alternative to having mercury in your mouth it sounds as though it would be a reasonably better choice than having a highly toxic metal firmly embedded in one's skull.

I know the dental physicians who support this technique do so out of concern for the general populice. However, where one hand of the dentist offers the composite filling as an alternative... the other hand is defending the amalgam program. I guess that's marketing.
 

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