![[dr. bob]](/dr-bob-sm.gif)
Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 20 of 20. This is the beginning of the thread.
Posted by Cass on June 15, 2004, at 23:43:57
I've been very concerned about the effect of mercury from my amalgam fillings on my physical and emotional health. Within the next few months, I'm going to have all my amalgam fillings removed and replaced by composite fillings. I have asked the dentist to use a rubber dam to prevent any leakage of mercury into my mouth. He has agreed. He's a very good dentist with an excellent reputation.
Have any of you had improvements in your health after having amalgams removed? Have you ever considered it? Do you have any experience, knowledge or advice you'd like to share?
Posted by sooshi on June 16, 2004, at 22:11:28
In reply to Getting my amalgams out, posted by Cass on June 15, 2004, at 23:43:57
Hi Cass,
I had all of mine removed, but I don't think I had it done by a very qualified dentist. One tooth/gum became abcessed, and the mercury poison got into my system...I eventually had to have that tooth pulled, I couldn't stand the pain. I had the rubber dams, but funny enough, the dentist put on goggles, respirator mask thingy, net on her hair, etc., and NOTHING on my eyes, nose, etc. Just the rubber dam over my mouth. I felt nausea and weakness for a full 6 months after this (I had 2 teeth done).
I'm not trying to discourage you from doing it! Just make sure your dentist knows what he/she is doing!!
P.S. I haven't really noticed any great increase in health since having the mercury taken out, but maybe that's because of my bad experience?
Posted by Cass on June 17, 2004, at 15:11:54
In reply to Re: Getting my amalgams out » Cass, posted by sooshi on June 16, 2004, at 22:11:28
The precautions that the dentist takes are a concern for me. He doesn't believe there's any danger in removing them, but he'll use a rubber dam because I have requested it. He didn't mention taking any precautions for himself. I'm not sure what to think. I had been planning on having 4 amalgams replaced at a time, or even having all 8 removed at one time. Perhaps that's a mistake.
Did you do or take anything to help you detox from the mercury? Was there a particular health problem that motivated you to have the mercury removed? If so, didn't you have any improvement?
Posted by Wildflower on June 18, 2004, at 8:54:45
In reply to Getting my amalgams out, posted by Cass on June 15, 2004, at 23:43:57
Cass - I don't know much about this. Are all silver fillings Mercury? I've been having mine removed one by one (whenever I have excess $) because they're deteriorating. I haven't heard much about the affects that these have on your health. Do you have any research that you could point me to?
Posted by Cass on June 18, 2004, at 11:43:11
In reply to Re: Getting my amalgams out » Cass, posted by Wildflower on June 18, 2004, at 8:54:45
Hi Wildflower,
Silver fillings are amalgams, and amalgams contain mercury. There are tons of articles on the internet about mercury poisoning from amalgam fillings. Here's one article: http://www.holisticdentalcare.com/Dentalphilosophy.htm
You can find other by doing a search for "mercury in amalgams". I'm glad you haven't had any ill effects from removing yours. Did the dentist use a rubber dam or any other precaution?
Posted by Larry Hoover on June 19, 2004, at 6:52:40
In reply to Getting my amalgams out, posted by Cass on June 15, 2004, at 23:43:57
> I've been very concerned about the effect of mercury from my amalgam fillings on my physical and emotional health. Within the next few months, I'm going to have all my amalgam fillings removed and replaced by composite fillings. I have asked the dentist to use a rubber dam to prevent any leakage of mercury into my mouth. He has agreed. He's a very good dentist with an excellent reputation.
The dam is an essential part of protecting your safety, but does your dentist have experience in doing amalgam removals? Any dentist has the competency to drill out an old filling, but amalgam removal should really be thought of as a specialization. There are techniques which minimize the risk to both patient and dentist. You really are best off having a dentist who does a lot of these procedures.
> Have any of you had improvements in your health after having amalgams removed? Have you ever considered it? Do you have any experience, knowledge or advice you'd like to share?
I've looked into it (a lot), and I plan to do it (I'm absolutely convinced that having mercury in my mouth is not a good idea (I'm an environmental toxicologist)), but I'm not in a financial position to proceed (currently surviving on a small disability pension).
I'm going to comment in each message on this thread.
Lar
Posted by Larry Hoover on June 19, 2004, at 7:10:23
In reply to Re: Getting my amalgams out » Cass, posted by sooshi on June 16, 2004, at 22:11:28
> Hi Cass,
>
> I had all of mine removed, but I don't think I had it done by a very qualified dentist. One tooth/gum became abcessed, and the mercury poison got into my system...I eventually had to have that tooth pulled, I couldn't stand the pain. I had the rubber dams, but funny enough, the dentist put on goggles, respirator mask thingy, net on her hair, etc., and NOTHING on my eyes, nose, etc. Just the rubber dam over my mouth. I felt nausea and weakness for a full 6 months after this (I had 2 teeth done).It may seem obtuse to see him all goggled up and everything, but he ought to be, and I don't know how he'd protect you any more, considering what is happening in your mouth. (Goggles, maybe?)
The respirator is essential for the dentist, as the friction from the drill heats the amalgam, and vapourizes mercury. He's breathing the air that comes out of your mouth. So are you, but I've never seen a device that isolates the nose while supplying air, except maybe one of those nose-prong oxygen supplementers you see in hospitals. I'd ask if there's anything the dentist has to protect you better. And shower the instant you get home.
There is no way around it, but having the amalgam drilled out of your teeth is going to expose the patient to a huge concentration spike of mercury. You're going to swallow some (despite the dam), you're going to have it absorb from the tissues of your mouth, you're going to breathe it in. This is acute exposure (as opposed to the trickle of mercury coming from the amalgam, day after day). You might want to consider short-term chelation therapy.
Chelators are designed to draw metal ions out of the blood. They do so non-specifically, so you'll lose most of your zinc and iron and so on, as well. But the mercury that gets into your blood hasn't done its damage yet. If you can get it out of the blood before it gets into your tissues, you minimize the impact. This is a medical procedure, and requires some supervision. I do not recommend home chelation kits (available on the net), as you can make yourself quite ill if you don't know what you're doing.
The other thing you can do, and something everyone who has amalgam in their mouth ought to do anyway, is take selenium supplements. Selenium and mercury form a bond that is so strong that it is one of the most insoluble compounds ever discovered. Its solubility is less than one molecule in a litre of water (which is actually zero solubility, from a commonsense perspective). Selenium permanently binds mercury in your body, and the mercury is 100% detoxified (unless you are cremated....darn, I know too much). It doesn't leave your body, but it doesn't gum things up.
So, before amalgam removal, start using selenium. (Like I said, you should be taking some anyway....but...) 200 mcg/day for at least a week. On the day of the procedure, bump to 600 mcg. Then 400 mcg/day for at least two weeks. Then back to 200. (You can go higher....the Upper Limit is 800 mcg/day on a long-term exposure basis.) This will mop up a lot of the mercury spike.
> I'm not trying to discourage you from doing it! Just make sure your dentist knows what he/she is doing!!Essential!
> P.S. I haven't really noticed any great increase in health since having the mercury taken out, but maybe that's because of my bad experience?Quite possible. Hard to know.
Lar
Posted by Larry Hoover on June 19, 2004, at 7:22:53
In reply to Re: Getting my amalgams out » sooshi, posted by Cass on June 17, 2004, at 15:11:54
> The precautions that the dentist takes are a concern for me. He doesn't believe there's any danger in removing them, but he'll use a rubber dam because I have requested it. He didn't mention taking any precautions for himself. I'm not sure what to think.
I am. Find another dentist. I bet that if you did a websearch using the keywords "dentist" "amalgam removal" and your state/province/whatever you'd get a list.
> I had been planning on having 4 amalgams replaced at a time, or even having all 8 removed at one time. Perhaps that's a mistake.
The fewer the removal procedures, the better, in general. I'm not certain if you can go too far, though, in a single event. I'll see if I can find the answer to that.
> Did you do or take anything to help you detox from the mercury?
See my answer to sooshi, above.
> Was there a particular health problem that motivated you to have the mercury removed? If so, didn't you have any improvement?
Lar
Posted by Larry Hoover on June 19, 2004, at 7:31:26
In reply to Re: Getting my amalgams out » Cass, posted by Wildflower on June 18, 2004, at 8:54:45
> Cass - I don't know much about this. Are all silver fillings Mercury?
Yes. There is far more mercury (concentration-wise) than there is silver in an amalgam filling. Mercury content is generally between 48 and 52%.
The mercury, being both a liquid and a metal, is used to dissolve other metals (silver, copper, traces of a couple others), forming an alloy. After a couple minutes, the solution crystallizes, which hardens it (in the tooth).
The chemistry of the crystal is not so stable that mercury cannot migrate to the surface. If the proportions aren't exactly perfect, or it is incompletely mixed, free mercury will remain in the amalgam, increasing the risk of exposure. If you want, I can show you scientific references to show that all amalgams leak mercury, but some much more than others.
> I've been having mine removed one by one (whenever I have excess $) because they're deteriorating.
The tooth surrounding the amalgam is not perfectly sealed by the filling. Bacteria can and do get down between the two, and decay the tooth. If that happens, mercury exposure is increased.
> I haven't heard much about the affects that these have on your health. Do you have any research that you could point me to?
Do you want abstracts?
Lar
Posted by Larry Hoover on June 19, 2004, at 7:33:04
In reply to Re: Getting my amalgams out » Wildflower, posted by Cass on June 18, 2004, at 11:43:11
> Hi Wildflower,
>
> Silver fillings are amalgams, and amalgams contain mercury. There are tons of articles on the internet about mercury poisoning from amalgam fillings.I've got a bunch of references stashed somewhere on my 'puter. Do you want to see them? Big files, I think.
Lar
Posted by Cass on June 19, 2004, at 12:38:57
In reply to Re: Getting my amalgams out » Cass, posted by Larry Hoover on June 19, 2004, at 7:33:04
Dear Larry,
I really appreciate all your input. Even though my dentist seems like a master of dentistry (he's very thorough and thoughtful), I am beginning to believe that he's a little naive about removing amalgam fillings. I know he's had some experience removing them because he said he'd done it for other patients, but he's clearly not concerned about taking many precautions for himself or the patient.
I had been looking into a dentist from Mexico who is an expert in amalgam removal and takes many precautions. His name is Dr. Javier Morales. His website is http://bikerchick.freehomepage.com/photo.html His rates are reasonable, but I know of one lady who saw him a couple years ago and had a bad experience. If you're interested in looking at the website, I'd love your feedback.
I hadn't considered an medical chelation, but I will certainly consume substances that help to detoxify heavy metals. I'm considering chorella and AFA. I already drink wheatgrass juice on a regular basis. Thanks for the tip about selenium and about showering when getting home.
I'd like to see the articles you have on amalgams and mercury and any more input you might have.
Posted by Cass on June 19, 2004, at 20:22:45
In reply to Re: Getting my amalgams out » Cass, posted by Larry Hoover on June 19, 2004, at 7:33:04
Since you mentioned that selenium is good for detoxing mercury, I've been looking for foods that are high in this mineral. A lot of those foods are meat and dairy. I don't eat read meat or fowl, and I eat very little fish and dairy, but I do eat them occassionally. I'm looking for fruits, vegetables and nuts that contain selenium. In searching the web I've found that Brazil nuts, brocoli, brussel sprouts and mushrooms are good sources. Do you know of any others by chance?
Posted by Larry Hoover on June 23, 2004, at 16:10:13
In reply to Re: Getting my amalgams out » Larry Hoover, posted by Cass on June 19, 2004, at 12:38:57
> Dear Larry,
>
> I really appreciate all your input. Even though my dentist seems like a master of dentistry (he's very thorough and thoughtful), I am beginning to believe that he's a little naive about removing amalgam fillings. I know he's had some experience removing them because he said he'd done it for other patients, but he's clearly not concerned about taking many precautions for himself or the patient.That's a serious problem. Some dentists just have blind faith in amalgam as being safe.
> I had been looking into a dentist from Mexico who is an expert in amalgam removal and takes many precautions. His name is Dr. Javier Morales. His website is http://bikerchick.freehomepage.com/photo.html His rates are reasonable, but I know of one lady who saw him a couple years ago and had a bad experience. If you're interested in looking at the website, I'd love your feedback.
I'm less than impressed by the way the information is presented, but I am judging it from a biased position. It is clear English is not the first language of the writer. I don't feel comfortable passing judgment on the quality of the procedures offered there, but there is enough "mercury is scary" type information to make me think they take the issue seriously.
> I hadn't considered an medical chelation, but I will certainly consume substances that help to detoxify heavy metals. I'm considering chorella and AFA.
AFA? That doesn't ring a bell. And chlorella doesn't come to mind when I think of heavy metal detox.
> I already drink wheatgrass juice on a regular basis. Thanks for the tip about selenium and about showering when getting home.
You're welcome.
> I'd like to see the articles you have on amalgams and mercury and any more input you might have.
I'm having trouble accessing them right now. They're on my old computer, which is not working at the moment... :-/ I posted most of it on the net, I think, so I'll see if I can find it all again.
In the meantime, here are a couple links:
http://www.thorne.com/altmedrev/fulltext/enviro5-3.html
http://www.testfoundation.org/amalgampage.htmLar
Posted by Larry Hoover on June 23, 2004, at 16:14:26
In reply to Re: Good food sources of selenium? » Larry Hoover, posted by Cass on June 19, 2004, at 20:22:45
>
> Since you mentioned that selenium is good for detoxing mercury, I've been looking for foods that are high in this mineral. A lot of those foods are meat and dairy. I don't eat read meat or fowl, and I eat very little fish and dairy, but I do eat them occassionally. I'm looking for fruits, vegetables and nuts that contain selenium. In searching the web I've found that Brazil nuts, brocoli, brussel sprouts and mushrooms are good sources. Do you know of any others by chance?The only dependable source for selenium, IMHO, is selenium yeast. It's grown in a specially prepared nutrient solution, and the yeast incorporate the selenium directly into amino acids.
The other sources you mention depend entirely on the soil where they are grown. A recent study of brazil nuts, for example, showed over 1000-fold variation in selenium content, depending on what part of Brazil they were grown. I wouldn't want to bet my health on such an unknown. The others you mention do not contain enough selenium to counteract mercury toxicity.
Lar
Posted by Wildflower on June 24, 2004, at 9:50:38
In reply to Re: Getting my amalgams out » Wildflower, posted by Cass on June 18, 2004, at 11:43:11
Now I'm really worried. He didn't use any type of precaution even though he's one of those high-tech dentists (flat screens, digital xrays, etc.)
I did have one tooth that decayed under the silver filling. My previous dentist neglected to remove all of the decay before filling it. There's a chance mercury could be in my bloodstream from that ordeal. Nevermind all of the times that I had fillings fall out and swallowed them by accident.
I still have one silver filling left. When it's time to remove it, I'll be sure to take precautions.
Posted by joebob on June 29, 2004, at 10:21:33
In reply to Re: Getting my amalgams out » Cass, posted by Larry Hoover on June 19, 2004, at 7:33:04
single most important thing i ever did for my health.......and is what started me looking into health in a more serious way
it was more than 25 years ago....had i not done it i fear i would have lost a kidney by now and have prostatis to die for
best,
joebob
Posted by Cass on June 29, 2004, at 12:16:03
In reply to for the record..getting my amalgams out was the, posted by joebob on June 29, 2004, at 10:21:33
Hi joebob,
Did your dentist take precautions against mercury exposure? If so, do you remember what they were? Also can you elaborate on the health benefits you've experienced?
I'm so glad it's helped you.
Posted by sexylexy on July 9, 2004, at 18:59:12
In reply to Re: for the record..getting my amalgams out was the » joebob, posted by Cass on June 29, 2004, at 12:16:03
Hey Ya'll
Is anyone on the low carb thing? Today is my frist day and I don't have a book. Can someone tell me what book I need to get to know what to eat. Today I have had a some turkey bacon, grilled salmon and asparagus and shelless taco salad with some rotel cheese dip on it? Is that bad? I am a little confused, for those of you on it when did you see results, any side effects?
Thanks a ton!!
Lexy
Posted by Larry Hoover on July 27, 2004, at 11:08:49
In reply to Getting my amalgams out, posted by Cass on June 15, 2004, at 23:43:57
> I've been very concerned about the effect of mercury from my amalgam fillings on my physical and emotional health. Within the next few months, I'm going to have all my amalgam fillings removed and replaced by composite fillings. I have asked the dentist to use a rubber dam to prevent any leakage of mercury into my mouth. He has agreed. He's a very good dentist with an excellent reputation.
>
> Have any of you had improvements in your health after having amalgams removed? Have you ever considered it? Do you have any experience, knowledge or advice you'd like to share?OK, I guess I'm about to put the posting size limit to the test, with this one. It's huge. Sorry about the delay in coming back to this, but I have been unable to access my archives as of yet. I kinda sorta reconstructed what I was gonna post.
I'm trained as a chemist, and I've decided to apply that knowledge to specialize in environmental toxicology. I don't claim expert status, but I do consider myself to be familiar with the science and the issues. Mercury is a toxic material. If mercury amalgam was being proposed as a potential dental restorative material today, it would never be approved. Never. Under EPA regulations, amalgam material which is excess of that required to complete a dental restoration (i.e. leftovers) is hazardous waste. Under EPA regulations, the oral rinse water collectors (the things you rinse and spit into) must have mercury collectors installed. Under EPA regulations, amalgam removed for an existing restoration must be treated as hazardous waste. Under EPA regulations, if a whole tooth is extracted which has amalgam still contained within it, it must be treated as hazardous waste. And we are to believe that while amalgam is in our mouths, it is safe? Well, your dentist might have a conflict of interest on this subject. Admitting liability would make a whopper of a class-action lawsuit. The California Dental Association was ordered, by law, to provide the following public notice about amalgam:
`NOTICE TO PATIENTS: PROPOSITION 65 WARNING: Dental Amalgam, used in many dental fillings, causes exposure to mercury, a chemical known to the state of California to cause birth defects or other reproductive harm.'
That's the "watered down" version that the dental association fought against for a number of years. The proposed warning was more explicit than that.
In fact, legislation is going to soon substantially affect access to, and use of, dental amalgam restorative materials throughout the United States. (I think this law passed, but I'm not sure....In any case, it makes clear that there is real concern.) It will not be legal to even use them in children (as of Jan. 1, 2005), or even to permit interstate commerce of amalgam (by 2008).
SEC. 3. PROHIBITION ON INTRODUCTION OF DENTAL AMALGAM INTO INTERSTATE COMMERCE.
(a) PROHIBITION- Section 501 of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 351) is amended by adding at the end the following:
'(j) Effective January 1, 2008, if it contains mercury intended for use in a dental filling.'.
(b) TRANSITIONAL PROVISION- For purposes of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 301 et seq.), effective December 31, 2004, and subject to subsection (a), a device that contains mercury intended for use in a dental filling shall be considered to be misbranded, unless it bears a label that provides as follows: `Dental amalgam contains approximately 50 percent mercury, a highly toxic element. Such product should not be administered to children less than 18 years of age, pregnant women, or lactating women. Such product should not be administered to any consumer without a warning that the product contains mercury, which is a highly toxic element, and therefore poses health risks.'.
I have seen no evidence that mercury has any beneficial effect, even in tiny trace amounts. Although yoru body has some capacity to eliminate mercury, it is toxic in any amount.
A little bit about mercury toxicology.....
First, about organic mercury, from: http://www.ansci.cornell.edu/courses/as625/1998term/Cadmium/cadmium.html
"Mercury (MeHg) (and perhaps Hg 2+) exerts its toxic effects through numerous mechanisms. In neurons, MeHg disrupts calcium homeostasis by affecting both voltage-gated calcium channels as well as disruption of intracellular pools. MeHg, like cadmium, binds to sulfydral groups on cysteine, which may compromise the function of enzymes and ion channels. MeHg also interacts with DNA and RNA, resulting in reductions in protein synthesis, and disrupts the structure of the microtubules of neurons. MeHg poisoning produces oxidative stress in cells. This may occur through multiple mechanisms: decreased expression and activity of anti-oxidant enzymes, participation in a Fenton-like reaction by Hg 2+, or disruption of electron transport in the mitochondria through inhibition of enzymes of the electron transport chain, and subsequent uncoupling of the e- transport chain and ATP synthesis (oxidative phosphorylation). Methylmercury has also been shown to induce programmed cell death (apoptosis) in exposed neurons."Inorganic mercury, as found in amalgams: http://www.calpoison.org/public/mercury.html
"Long-term exposure (usually work-related) of inhaled vapors is generally more dangerous than a one-time short exposure. After long-term inhalation exposure, the nervous system is the main target of toxicity. Symptoms may occur within weeks but usually develop insidiously over a period of years. Neurologic symptoms include tremors, headaches, short-term memory loss, incoordination, weakness, loss of appetite, altered sense of taste and smell, numbness and tingling in the hands and feet, insomnia, and excessive sweating. Psychiatric effects are also seen after long-term exposure."From the Agency for Toxic Substances and Disease Registry: http://www.atsdr.cdc.gov/ToxProfiles/phs8916.html
"A potential source of exposure to metallic mercury for the general population is mercury released from dental amalgam fillings. An amalgam is a mixture of metals. The amalgam used in silver-colored dental fillings contains approximately 50% metallic mercury, 35% silver, 9% tin, 6% copper, and trace amounts of zinc. When the amalgam is first mixed, it is a soft paste which is inserted into the tooth surface. It hardens within 30 minutes. Once the amalgam is hard, the mercury is bound within the amalgam, but very small amounts are slowly released from the surface of the filling due to corrosion or chewing or grinding motions. Part of the mercury at the surface of the filling may enter the air as mercury vapor or be dissolved in the saliva. The total amount of mercury released from dental amalgam depends upon the total number of fillings and surface areas of each filling, the chewing and eating habits of the person, and other chemical conditions in the mouth. Estimates of the amount of mercury released from dental amalgams range from 3 to 17 micrograms per day (µg/day). The mercury from dental amalgam may contribute from 0 to more than 75% of your total daily mercury exposure, depending on the number of amalgam fillings you have, the amount of fish consumed, the levels of mercury (mostly as methylmercury) in those fish, and exposure from other less common sources such as mercury spills, religious practices, or herbal remedies that contain mercury."There are a number of abstracts (posted separately) which reveal just how much we are exposed to mercury via amalgam.
There are three major routes of absorption for mercury from amalgams. The first involves direct absorption of mercury vapour into the brain via the nasal sinuses (abstracts). The second involves direct absorption of mercury vapour via the lungs (the major identified route). The third, and perhaps most variable, involves absorption in the digestive tract of organic mercury from the biotransformation of elemental mercury via gut bacteria (abstracts). Elemental mercury may also be biotransormed (via oxidation) after it is absorbed into our bodies.
Bottom line is: I'm getting my amalgams removed, as soon as I get healthy enough to earn some money so that I can afford the procedure. My disability coverage will not permit the replacement of amalgam restorations.
There's a whole lot more data below (links), and in the abstracts..........................
One source of confusion around mercury content in dental amalgam is that the concentration of mercury in commercial amalgam powders does not take into account the mass of mercury which will be added to the mixture at what is called 'trituration', the mechanical mixing of the amalgam by the dentist. Generally, an equal mass of mercury and amalgam powder are combined with a mortar and pestle to form the alloy, which crystallizes over about a 30 minute period. The chemistry of the crystallization process is exceedingly complex, but there is always free mercury left over. Moreover, the mercury in the crystals is not so
tightly bound that it cannot be released by dissolution, evaporation, or friction. Every moment, mercury is leaving the surface of the amalgam.
In case there was any doubt about mercury content in amalgam, see:http://www.gbg.bonet.se/bwf/art/instab/introduction.html
http://altcorp.com/amalgamcomp.htm
http://www.dentalgentlecare.com/amalgam_filling.htm
http://www.hseh.com/product/amalgam_aristaloy21.asp
http://www.inchem.org/documents/ehc/ehc/ehc118.htm#SectionNumber:3.4
http://www.garynull.com/Documents/Dental/Amalgam/amalgam_Index.htm
The term "quack" comes from a derisive characterisation of doctors (150 years ago, doctors fixed teeth) who used quacksilber (or something close to that) dental materials, the Germanic name for mercury. Quack. Quack.
Oh, and one more thing. Individual sensitivity to metals varies dramatically. Some people become sensitive to nickel, for example. They are so sensitive that the tiny amount in stainless steel causes bit reactions. I can't wear a stainless steel watch band, or my wrist breaks out in pustules. It's gross. Mercury sensitivity seems to be a bit controversial in the literature, but e.g. gold sensitivity, silver sensitivity, cobalt sensitivity, nickel sensitity, etc. are well accepted phenomena. Can you say cover-up?
Regards,
LarThere are few abstracts which address the mercury content of amalgam literally, but let's start with those. Nota bene, many of these abstracts are in the dental trade literature.
Crit Rev Oral Biol Med 1996;7(1):23-35Setting reactions in dental amalgam. Part 2. The kinetics of amalgamation.
Okabe T, Mitchell RJ.
Department of Biomaterials Science, Baylor College of Dentistry, Dallas, Texas 75246, USA.
The literature on the setting mechanisms of dental amalgams made from powders of silver-rich alloys of tin and/or copper has been critically reviewed. Part 2 is a review of the kinetics of the reactions that convert the mixture of alloy powder and liquid mercury to hardened amalgam containing the phases and microstructures described in Part 1. It is emphasized that amalgamation is a non-equilbrium process in which hardened microstructures are determined as much by kinetics as by chemistry. The setting reaction begins with dissolution of silver and tin into liquid mercury; most of the product phases precipitate in the liquid mercury. The processes that produce supersaturation in the liquid mercury and the subsequent nucleation and growth of solid phases are considered. Mass balance relationships that provide insight into the factors that control the volume fraction of the undesirable gamma 2 Sn-Hg phase are described. The nucleation and growth of eta' Cu-Sn crystals are also discussed; it is found that these crystals nucleate on copper-rich phases and grow into the liquid mercury. Finally, aspects of the setting reaction that are controlled by intergranular and interphase diffusion in the solid are discussed. These aspects include: the supersaturation of silver and tin within the liquid mercury, nucleation and growth of the beta 1 Ag-Hg phase in the surfaces of alloy particles, and the decomposition of initially formed gamma 2 Sn-Hg.
J Dent Res 1995 Jul;74(7):1414-7Mercury vaporization from amalgams with varied alloy compositions.
Ferracane JL, Adey JD, Nakajima H, Okabe T.
Department of Biomaterials and Biomechanics, Oregon Health Sciences University, Portland 97201, USA.
The fact that mercury is released from dental amalgam restorations after abrasion provides a source of continued controversy over the safe use of this material. Studies have shown that the amount and rate of mercury release vary for different amalgam products. The objective of this study was to determine how alloy composition affects mercury vaporization from experimental amalgams with similar alloy particle size and shape and percent residual mercury. An hypothesis to be tested was that mercury release is dependent upon the concentration of tin in the silver-mercury matrix phase of the amalgam. Seven spherical amalgam alloys (two low-copper and five high-copper) were made by a dental manufacturer (Tokuriki Honten, Japan). Trituration conditions were adjusted so that all set amalgams had the same residual Hg (47.3%). ADA-type amalgam cylinders were aged for 14 days at 37 degrees C, then lightly wet-abraded on #600 silicon carbide, dried, and placed into a tube through which air was blown at a rate of 750 mL/min. Mercury vaporization was monitored with a gold film analyzer (Jerome 411) for 30 min. Total Hg release was determined by integration. We analyzed polished specimens via electron microprobe to determine composition, volume fraction of silver-mercury matrix (gamma 1), and amount of tin in the gamma 1. The results showed a strong negative correlation (r2 = 0.941) between the log of total mercury released and the amount of tin in the gamma 1. The effect of alloy composition, specifically the presence or absence of zinc in the amalgam, could not be definitively determined.(ABSTRACT TRUNCATED AT 250 WORDS)
J Dent Res 1976 Nov-Dec;55(6):1001-3Influence of amalgam, alloy, and Hg on the in vitro growth of Streptococcus mutans: III. Effect of specimen age and composition.
Nunez LJ, Schmalz G, Hembree JH.
We will now summarize the conclusions from parts I, II and III of this study. A test procedure has been developed that provides a simple, quick, and nondestructive means of monitoring the in vitro growth of S mutans in the presence of amalgams and alloys. The spectrophotometric readings are related in a simple way to growth expressed as dry weight of bacteria and metabolic products. Results are expressed as growth relative to controls which represent bacteria growing under identical conditions but not in contact with metals. The %RA60 value that represents growth after 60 hours relative to controls is used as a measure of growth in the presence of alloys or amalgams. Spherical, fine cut, and dispersion alloys were studied as well as amalgams prepared from these alloys. The dispersion alloy inhibits growth less than the spherical alloy which in turn inhibits growth less than the fine cut alloy. The results for amalgams prepared from the alloys are reversed. At an aging time of two hours, dispersion alloy amalgams inhibit growth more than spherical alloy amalgams and fine cut alloy amalgams. Aging time of amalgams greatly influences the growth inhibition. Immediately after trituration growth is inhibited, but this inhibition is lost with aging. Different types of amalgams seem to lose growth inhibition at different rates. Hg composition in the range of 48 to 52% seems to have little effect on growth inhibition. It remains for clinical studies, which are concerned with the incidence of secondary caries associated with amalgams, to demonstrate that the age and nature of the amalgam are significant.
And, some abstracts detailing mercury exposure from amalgam restorations, and its effects:FASEB J 1995 Apr;9(7):504-8
Comment in: FASEB J. 1995 Nov;9(14):1499-500.
Mercury exposure from "silver" tooth fillings: emerging evidence questions a traditional dental paradigm.
Lorscheider FL, Vimy MJ, Summers AO.
Department of Medical Physiology, Faculty of Medicine, University of Calgary, Alberta, Canada.
For more than 160 years dentistry has used silver amalgam, which contains approximately 50% Hg metal, as the preferred tooth filling material. During the past decade medical research has demonstrated that this Hg is continuously released as vapor into mouth air; then it is inhaled, absorbed into body tissues, oxidized to ionic Hg, and finally covalently bound to cell proteins. Animal and human experiments demonstrate that the uptake, tissue distribution, and excretion of amalgam Hg is significant, and that dental amalgam is the major contributing source to Hg body burden in humans. Current research on the pathophysiological effects of amalgam Hg has focused upon the immune system, renal system, oral and intestinal bacteria, reproductive system, and the central nervous system. Research evidence does not support the notion of amalgam safety.
Toxicology 1995 Mar 31;97(1-3):19-22The dental amalgam mercury controversy--inorganic mercury and the CNS; genetic linkage of mercury and antibiotic resistances in intestinal bacteria.
Lorscheider FL, Vimy MJ, Summers AO, Zwiers H.
Department of Medical Physiology, Faculty of Medicine, University of Calgary, Alberta, Canada.
Mercury (Hg) vapor exposure from dental amalgam has been demonstrated to exceed the sum of all other exposure sources. Therefore the effects of inorganic Hg exposure upon cell function in the brain and in the intestinal bacteria have recently been examined. In rats we demonstrate that ADP-ribosylation of tubulin and actin brain proteins is markedly inhibited, and that ionic Hg can thus alter a neurochemical reaction involved with maintaining neuron membrane structure. In monkeys we show that Hg, specifically from amalgam, will enrich the intestinal flora with Hg-resistant bacterial species which in turn also become resistant to antibiotics.
Toxicol Appl Pharmacol 1997 May;144(1):156-62Mercury in saliva and feces after removal of amalgam fillings.
Bjorkman L, Sandborgh-Englund G, Ekstrand J.
Department of Basic Oral Sciences, Karolinska Institutet, Stockholm, Sweden.
The toxicological consequences of exposure to mercury (Hg) from dental amalgam fillings is a matter of debate in several countries. The purpose of this study was to obtain data on Hg concentrations in saliva and feces before and after removal of dental amalgam fillings. In addition Hg concentrations in urine, blood, and plasma were determined. Ten subjects had all amalgam fillings removed at one dental session. Before removal, the median Hg concentration in feces was more than 10 times higher than in samples from an amalgam free reference group consisting of 10 individuals (2.7 vs 0.23 mumol Hg/kg dry weight, p < 0.001). A considerable increase of the Hg concentration in feces 2 days after amalgam removal (median 280 mumol Hg/kg dry weight) was followed by a significant decrease. Sixty days after removal the median Hg concentration was still slightly higher than in samples from the reference group. In plasma, the median Hg concentration was 4 nmol/liter at baseline. Two days after removal the median Hg concentration in plasma was increased to 5 nmol/liter and declined subsequently to 1.3 nmol/liter by Day 60. In saliva, there was an exponential decline in the Hg concentration during the first 2 weeks after amalgam removal (t 1/2 = 1.8 days). It was concluded that amalgam fillings are a significant source of Hg in saliva and feces. Hg levels in all media decrease considerably after amalgam removal. The uptake of amalgam mercury in the GI tract in conjunction with removal of amalgam fillings seems to be low.
J Dent Res 1998 Apr;77(4):615-24Mercury in biological fluids after amalgam removal.
Sandborgh-Englund G, Elinder CG, Langworth S, Schutz A, Ekstrand J.
Department of Basic Oral Sciences, Karolinska Institutet, Huddinge, Sweden.
Dental amalgam is the major source of inorganic mercury (Hg) exposure in the general population. The objective of the present study was to obtain data on changes in Hg levels in blood, plasma, and urine following removal of all amalgam fillings during one dental session in 12 healthy subjects. The mean number of amalgam surfaces was 18 (range, 13 to 34). Frequent blood sampling and 24-hour urine collections were performed up to 115 days after amalgam removal, and in eight subjects additional samples of plasma and urine were collected up to three years after amalgam removal. A transient increase of Hg concentrations in blood and plasma was observed within 48 hours after amalgam removal. In plasma, the peak concentrations significantly exceeded the pre-removal plasma Hg levels by, on average, 32% (1.3 nmol/L; range, 0.1 to 4.2). No increase in the urinary Hg excretion rate was apparent after amalgam removal. An exponential decline of Hg was seen in all media. Sixty days after the amalgam removal, the Hg levels in blood, plasma, and urine had declined to approximately 60% of the pre-removal levels. In seven subjects, who were followed for up to three years, the half-lives of Hg in plasma and urine were calculated. In plasma, a bi-exponential model was applied, and the half-life was estimated at median 88 days (range, 21 to 121). The kinetics of Hg in urine (nmol/24 hrs) fit a mono-exponential model with a median half-life of 46 days (range, 35 to 67). It is concluded that the process of removing amalgam fillings can have a considerable impact on Hg levels in biological fluids. After removal, there was a considerable decline in the Hg levels of blood, plasma, and urine, which slowly approached those of subjects without any history of amalgam fillings.
Dent Mater 1997 Sep;13(5):297-304Mercury levels in plasma and urine after removal of all amalgam restorations: the effect of using rubber dams.
Berglund A, Molin M.
Department of Dental Materials Science, Umea University, Sweden.
Anders.Berglund@denmatsc.umu.seOBJECTIVE: The aim of the present study was to determine whether removal of all amalgam restorations might significantly affect mercury levels in plasma and urine and whether the use of rubber dams might reduce patient exposure to mercury during amalgam removal. METHODS: All amalgam restorations were removed from 18 subjects during a single treatment session in which a rubber dam was used and from 10 subjects when a rubber dam was not used. All amalgam restorations were removed by the same dentist using high-speed cutting, water coolant, and high-volume evacuation. The levels of mercury in plasma and urine were analyzed both before and during the subsequent twelve months after amalgam removal. In order to determine whether removal of all amalgam restorations might cause an exposure large enough to significantly increase the mercury levels in two indicator media for mercury exposure, i.e., plasma and urine, and to determine if the removal might cause a significant decrease in the mercury levels found over time, the one-tailed, paired Students' t-test was used. For each individual, the pre-removal levels were compared with both the levels found in plasma on d 1 and in urine on d 10, and also with the levels found 1 y after removal. Furthermore, in order to examine whether the use of rubber dams had any effect on the mercury levels found after removal, the changes in the mercury levels found were compared between the groups using the Wilcoxon-Mann-Whitney rank sum test. RESULTS: After removal of all amalgam restorations, only the non-rubber dam group showed significant increases in the mercury levels found in plasma (p = 0.012) and urine (p = 0.037). However, one year later, the mercury levels in plasma and urine had sunk significantly below the pre-removal levels for both groups. When the changes in the mercury levels found were compared between the groups, the non-rubber dam group showed a significantly higher increase of mercury in plasma than the rubber dam group the day after removal (p = 0.0010). Compared to the pre-removal mercury levels in plasma and urine, the levels found 1 y after removal of all amalgam restorations were on average 52 +/- 23% (range 4-89%) lower in plasma and 76 +/- 21% (range 20-94%) lower in urine. SIGNIFICANCE: The study showed that dental amalgam had a statistically significant impact on the mercury levels found in plasma and urine in the patients tested, and that the use of a rubber dam during removal of all amalgam restorations significantly reduced the peak of mercury in plasma following removal.
Stomatologiia (Mosk) 1997;76(4):9-11[Patterns of mercury release from amalgam fillings into the oral cavity]
[Article in Russian]
Motorkina AV, Barer GM, Volozhin AI.
Seventy-five subjects aged 20 to 57 with 1 to 15 fillings of silver amalgam were examined. The level of mercury vapors in the oral cavity was assessed using an AGP-01 device and the method developed by the authors. Emission of mercury vapors in the oral cavity increased with the number of fillings. The concentration of mercury in the oral cavity depends largely on the number of silver amalgam fillings and less so on these fillings' length of service.
Occup Environ Med 1995 Feb;52(2):124-8People with high mercury uptake from their own dental amalgam fillings.
Barregard L, Sallsten G, Jarvholm B.
Department of Occupational Medicine, Sahlgrenska University Hospital, Goteborg, Sweden.
OBJECTIVES--To describe people with high mercury (Hg) uptake from their amalgam fillings, and to estimate the possible fraction of the occupationally unexposed Swedish population with high excretion of urinary Hg. METHODS--Three case reports are presented. The distribution of excretion of urinary Hg in the general population was examined in pooled data from several sources. RESULTS--The three cases excreted 23-60 micrograms of Hg/day (25-54 micrograms/g creatinine), indicating daily uptake of Hg as high as 100 micrograms. Blood Hg was 12-23 micrograms/l, which is five to 10 times the average in the general population. No other sources of exposure were found, and removal of the amalgam fillings resulted in normal Hg concentrations. Chewing gum and bruxism were the probable reasons for the increased Hg uptake. Extrapolations from data on urinary Hg in the general population indicate that the number of people with urinary excretion of > or = 50 micrograms/g creatinine could in fact be larger than the number of workers with equivalent exposure from occupational sources.
CONCLUSION--Although the average daily Hg uptake from dental amalgam fillings is low, there is a considerable variation between people; certain people have a high mercury uptake from their amalgam fillings.
Arch Environ Health 1994 Sep-Oct;49(5):384-94Human exposure to mercury and silver released from dental amalgam restorations.
Skare I, Engqvist A.
National Institute of Occupational Health Stockholm, Sweden.
In 35 healthy individuals, the number of amalgam surfaces was related to the emission rate of mercury into the oral cavity and to the excretion rate of mercury by urine. Oral emission ranged up to 125 micrograms Hg/24 h, and urinary excretions ranged from 0.4 to 19 micrograms Hg/24 h. In 10 cases, urinary and fecal excretions of mercury and silver were also measured. Fecal excretions ranged from 1 to 190 micrograms Hg/24 h and from 4 to 97 micrograms Ag/24 h. Except for urinary silver excretion, a high interplay between the variables was exhibited. The worst-case individual showed a fecal mercury excretion amounting to 100 times the mean intake of total Hg from a normal Swedish diet. With regard to a Swedish middle-age individual, the systemic uptake of mercury from amalgam was, on average, predicted to be 12 micrograms Hg/24 h.
Arch Environ Health 1994 Sep-Oct;49(5):384-94Human exposure to mercury and silver released from dental amalgam restorations.
Skare I, Engqvist A.
National Institute of Occupational Health Stockholm, Sweden.
In 35 healthy individuals, the number of amalgam surfaces was related to the emission rate of mercury into the oral cavity and to the excretion rate of mercury by urine. Oral emission ranged up to 125 micrograms Hg/24 h, and urinary excretions ranged from 0.4 to 19 micrograms Hg/24 h. In 10 cases, urinary and fecal excretions of mercury and silver were also measured. Fecal excretions ranged from 1 to 190 micrograms Hg/24 h and from 4 to 97 micrograms Ag/24 h. Except for urinary silver excretion, a high interplay between the variables was exhibited. The worst-case individual showed a fecal mercury excretion amounting to 100 times the mean intake of total Hg from a normal Swedish diet. With regard to a Swedish middle-age individual, the systemic uptake of mercury from amalgam was, on average, predicted to be 12 micrograms Hg/24 h.
Eur J Oral Sci 1996 Jun;104(3):320-1A case of high mercury exposure from dental amalgam.
Langworth S, Stromberg R.
Dept. Occupational Medicine, Huddinge University Hospital, Sweden.
This report describes a patient who suffered from several complaints, which by herself were attributed to her amalgam fillings. Analysis of mercury in plasma and urine showed unexpectedly high concentrations, 63 and 223 nmol/l, respectively. Following removal of the amalgam fillings, the urinary excretion of mercury became gradually normalized, and her symptoms declined.
Sci Total Environ 1990 Dec 1;99(1-2):1-22Does mercury from amalgam restorations constitute a health hazard?
Weiner JA, Nylander M, Berglund F.
National Board of Occupational Safety and Health, Solna, Sweden.
Amalgam is the most extensively used implant material in dentistry. There have been no clinical trials of this substance and there are no epidemiological studies that allow any conclusions on the safety of amalgam fillings. Amalgam restorations continuously emit mercury vapour, which is absorbed in considerable quantities via the lungs. A comparison with dose-effect relationships, obtained in occupational studies, for certain effects on the kidneys and central nervous system (CNS), suggests that individuals with unusually high emission of mercury from amalgam fillings are at risk. It is unclear whether or not clinically significant effects could be expected. The limited sensitivity of available occupational studies, together with insufficient knowledge of possible host factors affecting resistance to mercury, implies that other more severe effects in susceptible individuals cannot be excluded. Information on long-term effects on organs other than brain or kidney is sparse. Animal studies suggest the possibility of immune system reactions to mercury, i.e. development of autoimmunity, that are not primarily dose-dependent, but rather depend on genetic susceptibility. From a toxicological point of view, amalgam is an unsuitable material for dental restorations.
Int Arch Allergy Immunol 1995 Mar;106(3):180-203Does amalgam affect the immune system? A controversial issue.
Enestrom S, Hultman P.
Department of Pathology I, Linkoping University, Sweden.
Although in use for more than 150 years, dental amalgam has been questioned more or less vigorously as a dental restoration material due to its alleged health hazard. Humans are exposed to mercury and the other main dental amalgam metals (Ag, Sn, Cu, Zn) via vapour, corrosion products in swallowed saliva, and direct absorption into the blood from the oral cavity. Dental amalgam fillings are the most important source of mercury exposure in the general population. Local, and in some instances, systemic hypersensitivity reactions to dental amalgam metals, especially mercury, occur at a low frequency among amalgam bearers. Experimental and clinical data strongly indicate that these and other subclinical systemic adverse immunological
reactions to dental amalgam metals in humans will be linked to certain MHC genotypes, and affect only a small number of the exposed individuals. These individuals will be very difficult to detect in a mixed population of susceptible and resistant individuals, including persons with alleged symptoms due to dental amalgam fillings, where many of the individuals are likely to suffer from conditions with no proven immunological background such as multiple chemical sensitivity syndrome. Intensified studies should be performed to identify such susceptible MHC genotypes, taking advantage of the reported cases of more heavily metal-exposed humans with systemic autoimmune reactions. Further studies will also be needed to ascertain whether the combined exposure to the metals in dental amalgam may lower the threshold for adverse immunological reactions, since recent studies have shown that the metals in alloy, especially silver, may induce autoimmunity in genetically susceptible mice.
Biometals 1999 Sep;12(3):227-31Dental amalgam mercury exposure in rats.
Galic N, Prpic-Mehicic G, Prester L, Blanusa M, Krnic Z, Ferencic Z.
Department of Dental Pathology, School of Dentistry, Zagreb, Croatia.
The aim of this study was to measure the distribution of mercury, in tissues of rats exposed to amalgam over a two months period. Possible interaction of mercury with copper and zinc in organs was also evaluated. Rats were either exposed to mercury from 4 dental amalgams, or fed the diet containing powdered amalgam during two months. Mercury was measured in the kidney, liver and brain, copper in kidney and brain and zinc in kidney. The results showed significantly higher concentrations of mercury in the kidneys and the brains of rats in both exposed groups compared to control. Even after two
months of exposure to mercury brain mercury concentration in rats with amalgam fillings was 8 times higher than in the control and 2 times higher than in rats exposed to amalgam supplemented diet. The highest mercury concentration in the latter group was found in the kidneys and it was 5 times higher than in the control group. We found no significant differences
between mercury levels in exposed and control rat's liver. Exposure to mercury from dental amalgams did not alter the concentrations of copper and zinc in the tissues. Histopathological analyses of rats tissues did not show any pathological changes. These results support previously proposed nose-brain transport of mercury released from dental amalgam fillings.
Journal of Nephrology, 2002 Mar-Apr;15(2):171-6Mercury in dental restoration: is there a risk of nephrotoxicity?
Mortada WL, Sobh MA, El-Defrawy MM, Farahat SE.
Urology and Nephrology Center, Mansoura University, Faculty of Science, Egypt.
BACKGROUND: Concern has been voiced about exposure to mercury (Hg) from dental amalgam fillings, and there is a need to assess whether this leads to signs of nephrotoxicity. METHODS: A total of 101 healthy adults (80 males and 21 females) were included in this study. The population as grouped into those having amalgam fillings (39 males and 10 females) and those without (41 males and 11 females). Hg was determined in blood, urine, hair and nails to assess exposure. Urinary excretion of beta2-microglobulin (beta2M), N-acetyl-beta-D-glucosaminidase (NAG), gamma- glutamyltransferase (gammaGT) and alkaline phosphatase (ALP) were determined as markers of tubular damage. Albuminuria was assayed as an early indicator of glomerular dysfunction. Serum creatinine, beta2M and blood urea nitrogen (BUN) were determined to assess glomerular filtration. RESULTS: Hg levels in blood and urine were significantly higher in persons with dental amalgam than those without; in the dental amalgam group, blood and urine levels of Hg significantly correlated with the number of amalgams. Urinary excretion of NAG, gammaGT and albumin was significantly higher in persons with dental amalgam than those without. In the amalgam group, urinary excretion of NAG and albumin significantly correlated with the number of fillings. Albuminuria significantly correlated with blood and urine Hg. CONCLUSION: From the nephrotoxicity point of view, dental amalgam is an unsuitable filling material, as it may give rise to Hg toxicity. Hg levels in blood and urine are good markers of such toxicity. In these exposure conditions, renal damage is possible and may be assessed by urinary excretions of albumin, NAG, and gamma-GT.
J Dent Res 1985 Aug;64(8):1069-71Intra-oral air mercury released from dental amalgam.
Vimy MJ, Lorscheider FL.
Intra-oral air was analyzed for mercury (Hg) vapor concentration in 46 subjects, 35 of whom had dental amalgam restorations. Measurements were made with a Jerome Hg detector both before and ten min after chewing stimulation. Subjects with dental amalgams had unstimulated Hg vapor concentrations that were nine times greater than basal levels in control subjects with no
amalgams. Chewing stimulation in subjects with amalgams increased their Hg concentration six-fold over unstimulated Hg levels, or a 54-fold increase over levels observed in control subjects. Concentrations of Hg measured in intra-oral air larger than those reported in expired air were attributed to the rate and direction of air passage across amalgam surfaces. There were significant correlations between Hg vapor released into intra-oral air after chewing stimulation and the numbers and types of amalgam restorations. It is concluded that intraoral air is a reliable physiological indicator of Hg released from dental amalgam that may reflect a major source of chronic Hg exposure.
J Dent Res 1985 Aug;64(8):1072-5Serial measurements of intra-oral air mercury: estimation of daily dose from dental amalgam.
Vimy MJ, Lorscheider FL.
Serial measurements of Hg concentration in intra-oral air were made during and after chewing stimulation in 35 subjects with occlusal amalgam restorations. Hg concentrations remained elevated during 30 min of continuous chewing and declined slowly over 90 min after cessation of chewing. By curve-fitting and integration analysis of data during these time periods (including corrections for respiratory volume, retention rate of inspired Hg, oral-to-nasal breathing ratios, and consumption of three meals and three snacks per day), we calculated that all subjects received an average daily Hg dose of approximately 20 micrograms. Subjects with 12 or more occlusal amalgam surfaces were estimated to receive a daily Hg dose of 29 micrograms, whereas in subjects with four or fewer occlusal amalgam surfaces, the dose was 8 micrograms. These Hg dosages from dental amalgam were as much as 18-fold the allowable daily limits established by some countries for Hg exposure from all sources in the environment. The results demonstrate that the amount of elemental Hg released from dental amalgam exceeds or comprises a major percentage of internationally accepted threshold limit values for environmental Hg exposure. It is concluded that dental amalgam Hg makes a major contribution to total daily dose.
Clin Prev Dent 1991 May-Jun;13(3):5-7Long-term dissolution of mercury from a non-mercury-releasing amalgam.
Chew CL, Soh G, Lee AS, Yeoh TS.
National University of Singapore.
The hazards of mercury from dental amalgams have long been recognized. This study examined the mercury release from a "non-mercury-releasing" dental amalgam, Composil, over a 104-week period. Four cylindrical specimens were incubated in 10 ml of purified water at 37 degrees C. The incubate was changed at the end of each 24-hour period and assayed for its mercury content at biweekly intervals. Mercury estimation was carried out using cold-vapor, atomic absorption spectrophotometry over a 104-week period. Results showed that the overall mean release of mercury was 43.5 +/- 3.2 micrograms/cm2/24 hr, and the amount of mercury released remained fairly constant during the duration of the experiment. This study showed that Composil releases mercury in quantities that far exceed those detected in other amalgam systems.
J Prosthet Dent 1987 Dec;58(6):704-7Correlation of dental amalgam with mercury in brain tissue.
Eggleston DW, Nylander M.
Department of Restorative Dentistry, University of Southern California, School of Dentistry, Los Angeles.
Data from this project demonstrate a positive correlation between the number of occlusal surfaces of dental amalgam and mercury levels in the brain (p less than .0025 in white matter). This is indirect evidence suggesting that mercury from dental amalgam fillings may contribute to the body burden of mercury in the brain. The toxic levels of mercury in human tissues have not been sufficiently investigated and the amount of mercury in human brain tissue from dental amalgam may or may not be clinically significant. Nevertheless, dental amalgam exposure should be considered in monitoring sources of mercury accumulation in human brain tissue.
Caries Res 2001 May-Jun;35(3):163-6Dental amalgam fillings and the amount of organic mercury in human saliva.
Leistevuo J, Leistevuo T, Helenius H, Pyy L, Osterblad M, Huovinen P, Tenovuo J.
The National Public Health Institute, Antimicrobial Research Laboratory, Turku University, Turku, Finland.
We studied differences in the amounts of organic and inorganic mercury in saliva samples between amalgam and nonamalgam human study groups. The amount of organic and inorganic mercury in whole saliva was measured in 187 adult study subjects. The mercury contents were determined by cold-vapor atomic absorption spectrometry. The amount of organic and inorganic mercury in paraffin-stimulated saliva was significantly higher (p<0.001) in subjects with dental amalgam fillings (n = 88) compared to the nonamalgam study groups (n = 43 and n = 56): log(e) (organic mercury) was linearly related to log(e) (inorganic mercury, r(2) = 0.52). Spearman correlation coefficients of inorganic and organic mercury concentrations with the number of amalgam-filled tooth surfaces were 0.46 and 0.27, respectively. Our results are compatible with the hypothesis that amalgam fillings may be a continuous source of organic mercury, which is more toxic than inorganic mercury, and almost completely absorbed by the human intestine.
FASEB J 1994 Nov;8(14):1183-90Adverse immunological effects and autoimmunity induced by dental amalgam and alloy in mice.
Hultman P, Johansson U, Turley SJ, Lindh U, Enestrom S, Pollard KM.
Department of Pathology, Linkoping University, Sweden.
Dental amalgam fillings are the most important source of mercury exposure in the general population, but their potential to cause systemic health consequences is disputed. In this study, inbred mice genetically susceptible to mercury-induced immune aberrations were used to examine whether dental amalgam may interfere with the immune system and cause autoimmunity. Female
SJL/N mice were implanted in the peritoneal cavity with 8-100 mg silver amalgam or silver alloy for 10 weeks or 6 months. Chronic hyperimmunoglobulinemia, serum IgG autoantibodies targeting the nucleolar protein fibrillarin, and systemic immune-complex deposits developed in a time- and dose-dependent manner after implantation of amalgam or alloy. Splenocytes from mice implanted with amalgam or alloy showed an increased expression of class II molecules. The functional capacity of splenic T and B cells was affected in a dose-dependent way: 10 weeks of low-dose and 6 months of high-dose amalgam implantation strongly increased mitogen-induced T and B cell proliferation, whereas 10 weeks of high-dose implantation
decreased the proliferation. Not only mercury but also silver accumulated in the spleen and kidneys after amalgam implantation. In conclusion, dental amalgam implantation in a physiological body milieu causes chronic stimulation of the immune system with induction of systemic autoimmunity in genetically sensitive mice. Implantation of silver alloy not containing mercury also induced autoimmunity, suggesting that other elements, especially silver, have the potential to induce autoimmunity in genetically susceptible vertebrates. Accumulation of heavy metals, from dental amalgam and other sources, may lower the threshold of an individual metal to elicit immunological aberrations. We hypothesize that under appropriate conditions of genetic susceptibility and adequate body burden, heavy metal exposure from dental amalgam may contribute to immunological aberrations, which could lead to overt autoimmunity.
FASEB J 1990 Nov;4(14):3256-60Comment in:
FASEB J. 1991 Feb;5(2):236.Whole-body imaging of the distribution of mercury released from dental fillings into monkey tissues.
Hahn LJ, Kloiber R, Leininger RW, Vimy MJ, Lorscheider FL.
Department of Radiology, University of Calgary, Faculty of Medicine,
Alberta, Canada.The fate of mercury (Hg) released from dental "silver" amalgam tooth fillings into human mouth air is uncertain. A previous report about sheep revealed uptake routes and distribution of amalgam Hg among body tissues. The present investigation demonstrates the bodily distribution of amalgam Hg in a monkey whose dentition, diet, feeding regimen, and chewing pattern closely resemble those of humans. When amalgam fillings, which normally contain 50% Hg, are made with a tracer of radioactive 203Hg and then placed into monkey teeth, the isotope appears in high concentration in various organs and tissues within 4 wk. Whole-body images of the monkey revealed that the highest levels of Hg were located in the kidney, gastrointestinal tract, and jaw. The dental profession's advocacy of silver amalgam as a stable tooth restorative material is not supported by these findings.
Antimicrob Agents Chemother 1993 Apr;37(4):825-34Comment in:
Antimicrob Agents Chemother. 1993 Aug;37(8):1730-1.Mercury released from dental "silver" fillings provokes an increase in mercury- and antibiotic-resistant bacteria in oral and intestinal floras of primates.
Summers AO, Wireman J, Vimy MJ, Lorscheider FL, Marshall B, Levy SB, Bennett S, Billard L.
Department of Microbiology, University of Georgia, Athens 30602.
In a survey of 640 human subjects, a subgroup of 356 persons without recent exposure to antibiotics demonstrated that those with a high prevalence of Hg resistance in their intestinal floras were significantly more likely to also have resistance to two or more antibiotics. This observation led us to consider the possibility that mercury released from amalgam ("silver") dental restorations might be a selective agent for both mercury- and antibiotic-resistant bacteria in the oral and intestinal floras of primates. Resistances to mercury and to several antibiotics were examined in the oral and intestinal floras of six adult monkeys prior to the installation of amalgam fillings, during the time they were in place, and after replacement of the amalgam fillings with glass ionomer fillings (in four of the monkeys). The monkeys were fed an antibiotic-free diet, and fecal mercury concentrations were monitored. There was a statistically significant increase in the incidence of mercury-resistant bacteria during the 5 weeks following installation of the amalgam fillings and during the 5 weeks immediately following their replacement with glass ionomer fillings. These peaks in incidence of mercury-resistant bacteria correlated with peaks of Hg elimination (as high as 1 mM in the feces) immediately following amalgam placement and immediately after replacement of the amalgam fillings. Representative mercury-resistant isolates of three selected bacterial
families (oral streptococci, members of the family Enterobacteriaceae, and enterococci) were also resistant to one or more antibiotics, including ampicillin, tetracycline, streptomycin, kanamycin, and chloramphenicol. While such mercury- and antibiotic-resistant isolates among the staphylococci, the enterococci, and members of the family Enterobacteriaceae have been described, this is the first report of mercury resistance in the oral streptococci. Many of the enterobacterial strains were able to transfer mercury and antibiotic resistances together to laboratory bacterial recipients, suggesting that the loci for these resistances are genetically linked. Our findings indicate that mercury released from amalgam fillings can cause an enrichment of mercury resistance plasmids in the normal bacterial floras of primates. Many of these plasmids also carry antibiotic resistance, implicating the exposure to mercury from dental amalgams in an increased incidence of multiple antibiotic resistance plasmids in the normal floras of nonmedicated subjects.
J Dent Res 1998 Jun;77(6):1415-25Activation of the immune system and systemic immune-complex deposits in Brown Norway rats with dental amalgam restorations.
Hultman P, Lindh U, Horsted-Bindslev P.
Department of Health and Environment, Linkoping University, Sweden.
Dental amalgam restorations are a significant source of mercury exposure in the human population, but their potential to cause systemic health effects is highly disputed. We examined effects on the immune system by giving genetically mercury-susceptible Brown Norway (BN) rats and mercury-resistant Lewis (LE) rats silver amalgam restorations in 4 molars of the upper jaw, causing a body burden similar to that described in human amalgam-bearers (from 250 to 375 mg amalgam/kg body weight). BN rats with amalgam restorations, compared with control rats given composite resinous restorations, developed a rapid activation of the immune system, with a maximum 12-fold increase of the plasma IgE concentration after 3 wks (p <
0.001; Mann-Whitney's test). LE rats receiving amalgam restorations showed no significant increase of plasma IgE (p > 0.05). After 12 wks, BN rats with amalgam restorations showed significantly increased (p < 0.05) titers of immune-complex (IC) deposits in the renal glomeruli and in the vessel walls of internal organs. These rats also showed a significant (p < 0.05), from six- to 130-fold, increase in tissue mercury concentration in the concentration order kidney > spleen > cerebrum occipital lobe > cerebellum > liver > thymus, and the tissue silver concentration was significantly (p < 0.05) increased from three- to 11-fold. Amalgam-implanted BN rats showed a significant (p < 0.05) increase in copper concentration in the kidney and spleen, and in kidney selenium concentration. We conclude that dental amalgam restorations release substantial amounts of their elements, which accumulate in the organs and which, in genetically susceptible rats, give rise to activation of the immune system and systemic IC deposits.
Scand J Dent Res 1983 Apr;91(2):150-2Methylation of mercury from dental amalgam and mercuric chloride by oral streptococci in vitro.
Heintze U, Edwardsson S, Derand T, Birkhed D.
The capacity of the oral bacteria Streptococcus mitior, S. mutans and S. sanguis to methylate mercury was investigated in vitro. Mercuric chloride and pulverized dental amalgam in distilled water, respectively, were used as sources of mercury. Methylmercury was found in the bacterial cells of all three tested strains. The results indicate that organic mercury compounds may be formed in the oral cavity.
Occup Environ Med. 2004 Jun;61(6):535-40.
Evaluation of the mercury exposure of dental amalgam patients by the Mercury Triple Test.Hansen G, Victor R, Engeldinger E, Schweitzer C.
Laboratoire d'Hygiene du Milieu et de Surveillance Biologique, Laboratoire National de Sante, Luxembourg. gilbert.hansen@lns.etat.lu
AIMS: To establish and analyse reference data for the mercury burden of patients with and without amalgam fillings. METHODS: Atomic absorption spectroscopy was used to quantify Hg concentrations in the scalp hair and urine (before and after application of dimercaptopropane sulphonate), and Hg release from dental amalgams (using a newly developed, amalgam specific chew test), in 2223 subjects. RESULTS: 50th centiles were 1.3 microg Hg/g creatinine in basal urine, 32 microg Hg/g creatinine after DMPS application, 454 ng Hg/g in hair, and 27 microg Hg per g of chewing gum, which corresponds to about 1 micro g Hg released per minute of chewing. Total Hg intake (from ambient air, drinking water, food, and amalgams) of most patients is well below the provisioned tolerable weekly intake (PTWI) defined by the WHO, unless extremely Hg rich food is consumed on a regular basis. However, for patients exceeding the 75th centile in chew tests, total Hg intake exceeds the PTWI by about 50%, even at the low limit of intake from food. In the absence of occupational exposure, significant Hg release from dental amalgams is a necessary but insufficient condition to obtain a high long term body burden. After removal of dental amalgams, chew tests no longer exhibit oral Hg exposure, while basal urine Hg content and DMPS induced excretion display a exponential decrease (half life about 2 months in both cases). CONCLUSIONS: A standardised procedure for evaluation of the magnitude and origin of the Hg burden of individuals has been developed, which, by comparison with the database presented here for the first time, can serve as a diagnostic tool.
Toxicol Sci. 2004 Jul;80(1):69-73. Epub 2004 Apr 07.
Susceptibility of metallothionein-null mice to the behavioral alterations caused by exposure to mercury vapor at human-relevant concentration.Yoshida M, Watanabe C, Satoh M, Yasutake A, Sawada M, Ohtsuka Y, Akama Y, Tohyama C.
Department of Biochemistry, Division of Chemistry, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki 261-8511, Japan.
While recent human studies suggested adverse neurobehavioral outcomes of low-level exposure to mercury vapor (Hg0) as found among those having dental amalgam fillings and dental personnel, past animal experiments only dealt with exposure at much higher mercury concentrations. The present study aimed to examine neurobehavioral effects of prolonged, low-level Hg0 exposure in mice and to evaluate the protective role of metallothionein-I,II (MT-I,II) against Hg0-induced neurotoxicity, using a knock-out strain of mice. Adult female metallothionein-I,II-null (MT-null) and wild-type OLA129/C57BL6 mice were exposed to 0.06 mg/m3 of Hg0 for 8 h per day for 23 weeks. Neurobehavioral effects were evaluated at 12 and 23 weeks of exposure using open-field test and passive avoidance test. Subcellular distribution of mercury and the induction of MT were also assessed. The Hg0 exposure resulted in significantly enhanced locomotion in the open-field test and poorer performance in the passive avoidance test at a brain Hg concentration less than 1 ppm. These effects were slightly exaggerated in MT-null mice, which showed less induction of MT, lower brain Hg concentration, and lower calculated concentration of MT-unbound cytosolic Hg. The results showed, for the first time, that a concentration of Hg0 relevant to human exposure level could cause neurobehavioral effects in adult mice. The higher susceptibility of MT-null mice suggested that MT-I,II have protective roles in the metal-induced neurobehavioral toxicity, which cannot be entirely explained by kinetic mechanisms, thus suggesting an involvement of nonkinetic mechanisms.
Gen Dent. 2003 Jul-Aug;51(4):356-9; quiz 360.The effect of bleaching agents on mercury release from spherical dental amalgam.
Certosimo A, Robertello F, Dishman M, Bogacki R, Wexel M.
Virginia Commonwealth University, Department of General Practice, Richmond, USA.
To investigate the effect of carbamide peroxide, hydrogen peroxide, and over-the-counter home bleaching products on the release of mercury from spherical dental amalgam, 150 uniform amalgam specimens were prepared in clear acrylic blocks, aged for one week at 37 degrees C, and placed into individual polystyrene jars containing 20 mL of sterile saline. The specimens were divided into three groups of 50 and bleached in eight-hour cycles. All groups exposed to bleach showed increased mercury release over time.
Environ Res. 2004 Mar;94(3):283-90.
Childhood urine mercury excretion: dental amalgam and fish consumption as exposure factors.Levy M, Schwartz S, Dijak M, Weber JP, Tardif R, Rouah F.
Montreal Public Health Department, 1301 Sherbrooke Street East, Montreal, Canada H2L 1M3. mlevy@santepub-mtl.qc.ca
The authors investigated the effect of amalgam fillings and fish consumption on urine mercury level (UHg), in children aged 4-8 years old inclusive. Using a sample of 60 children, we found that children with amalgam fillings had significantly higher UHg levels than children without amalgams (geometric mean=1.412microg Hg/g versus 0.436 microg Hg/g, respectively, P = 0.0001). Subjects with reported higher fish consumption also had significantly higher UHgs (P = 0.004). Univariate analyses provide evidence of an association between elevated UHg level and young age (P = 0.009), short height (P = 0.024), and low weight (P = 0.049) in children with amalgam chewing surfaces. We also found a negative correlation between urine mercury and age (-0.378), height (-0.418), and weight (-0.391). A multiple logistic regression model shows that the presence of amalgam fillings leads to increased odds of high UHg in children (OR=47.18), even after adjusting for high fish consumption (OR=8.66) and height (OR=11.36).
Altern Med Rev 1998 Aug;3(4):262-70Cysteine metabolism and metal toxicity.
Quig D.
Doctor's Data, Inc., West Chicago, IL, USA. dquig@doctorsdata.com
Chronic, low level exposure to toxic metals is an increasing global problem. The symptoms associated with the slow accumulation of toxic metals are multiple and rather nondescript, and overt expression of toxic effects may not appear until later in life. The sulfhydryl-reactive metals (mercury, cadmium, lead, arsenic) are particularly insidious and can affect a vast array of biochemical and nutritional processes. The primary mechanisms by which the sulfhydryl-reactive metals elicit their toxic effects are summarized. The pro-oxidative effects of the metals are compounded by the fact that the metals also inhibit antioxidative enzymes and deplete intracellular glutathione. The metals also have the potential to disrupt the
metabolism and biological activities of many proteins due to their high affinity for free sulfhydryl groups. Cysteine has a pivotal role in inducible, endogenous detoxication mechanisms in the body, and metal exposure taxes cysteine status. The protective effects of glutathione and the metallothioneins are discussed in detail. Basic research pertaining to
the transport of toxic metals into the brain is summarized, and a case is made for the use of hydrolyzed whey protein to support metal detoxification and neurological function. Metal exposure also affects essential element status, which can further decrease antioxidation and detoxification processes. Early detection and treatment of metal burden is important for successful detoxification, and optimization of nutritional status is paramount to the prevention and treatment of metal toxicity.
Posted by KaraS on July 27, 2004, at 14:37:16
In reply to Re: amalgams...huge reply » Cass, posted by Larry Hoover on July 27, 2004, at 11:08:49
Larry,
What should those of us with amalgams (who can't afford to get them taken out) be doing?
Thanks,
Kara
This is the end of the thread.
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