Amalgam fillings are perhaps one of the most controversial topics in dentistry. The ongoing concern regarding the safety of this type of metal filling seems to easily ignite a very passionate debate, mainly from those opposed to the use of amalgam - more specifically mercury - in dentistry. There has been several studies published by reputable institutions that state amalgam fillings are safe for use, however those opposed to the use of mercury in dentistry continue to stand behind their belief that mercury is dangerous.
Now, to add more fuel to the already smoldering mercury issue comes a study recently published in the online journal of the American Chemical Society, Chemical Research in Toxicology. The study, "The Chemical Forms of Mercury in Aged and Fresh Dental Amalgam Surfaces", conduced by Graham George, Satya Singh, Jay Hoover, and Ingrid Pickering, from the University of Saskatchewan's Department of Geological Sciences and College of Dentistry, examined both freshly placed amalgam and fillings that were placed about 20 years ago. Using a special x-ray technique to examine the fillings, the scientists found the fresh amalgam contained metallic mercury, which is known to be toxic. The aged fillings contained a form of mercury known as beta-mercuric sulfide (metacinnabar). This form of mercury is considered unlikely to be toxic to the body. The scientists noted that the surface of the older fillings lost up to 95% of the mercury overtime, due to considerations such as eating certain foods, dental cleanings, and evaporation, to name a few. Here is the fire-starer: the scientists caution that "human exposure to mercury lost from fillings is still of concern."
Now, even I am starting to become confused. Do you remember back in July 2009 when the Food and Drug Administration (FDA) issued their final regulation on dental amalgam, assuring us that amalgam fillings are indeed safe for use? The FDA agrees with the American Dental Associations position on amalgam fillings. I will let you read their position on amalgam for yourself, but I am really starting to wonder if amalgam fillings really are safe? Where is the evaporated metallic mercury going as it is converted into beta-mercuric sulfide? Would I stand by and watch one of my children have an amalgam filling placed in their mouth? I must admit that my position on amalgam has remained rather conservative, trusting the American Dental Association and the FDA. Now, I'm starting to wonder...
It used to be thought that mercury was ‘locked into’ tooth fillings, but now dentists admit that consuming hot food and drinks can release mercury into the body. In tests mercury from tooth fillings was found in many body organs, such as the brain, kidneys etc.
If anyone ever had any doubts about the safety of “mercury fillings” you can be re-assured by the findings of this study. The fact that up to 95% of the mercury in your mouth is unaccountable after 20 years has me feeling better already!!! No wonder old fillings are considered SAFE because all the poison has already gone. When I say gone I mean from the tooth not the body!!!
Please read the article!
The original spin on this was that old amalgam fillings are less toxic than new ones based on measuring the surface and a few micrometers deep. The authors found that the surface contained only 5% Hg and that it was in the form of a compound that is not bioavailable. They have not looked at the bulk of the material. New and old amalgam fillings releases mercury and for this reason dental amalgam is an unsuitable biomaterial from a toxicological point of view.
The conclusions of the investigation are based on ONE SINGLE old filling of unknown history the article reveals. It is also a fact that the university that provided the tooth and filling stores extracted teeth fully submerged in “Carolina solution”. Exactly what chemicals this solution consists of is unknown at present.
Who took the initiative to the press release and free access to the article spreading the “news” that old amalgam fillings are less toxic than new ones is unclear at present.
/Ulf
The U.S. Food and Drug Administration (FDA) has evaluated research on the safety of dental amalgam and has not found any reason to limit its use.
Elemental mercury is harmful when inhaled over long periods of time. (See Hatter’s disease.) Elemental mercury is NOT harmful when swallowed. In fact historically, it was used as a laxative because it is so poorly absorbed. Ingestion of mercury in fish is not elemental mercury, but an entirely different compound unrelated to dental amalgam. Elemental mercury can be released from fresh amalgam under pressure and friction. How much mercury can be inhaled while at the same time creating pressure and friction on new fillings? Is the released mercury being inhaled, exhaled or even swallowed? Safe or not? Vast amounts of good scientific research supports the use of amalgam.
I had practiced dentistry for 37 years before retiring in 2005. I used both amalgam and composites in my practice. Both have a place and both can get recurrent decay. I have had 4 occlusal amalgams in my mouth for 57 years. never been replaced. The FDA and FDA are okay with this. I wonder if dentists like doing composites because it gives them more income????
It’s cost effective, easy to place and inhibits decay.
It’s also toxic, and it’s because of its toxicity that even bacteria won’t even grow around these fillings.
It’s ugly, leaks out mercury, and weakens your teeth. I haven’t used the stuff in over 15 years.
The controversy won’t die. Old dogs hang onto their old ways.
Shawn, your ability to deftly handle these controversial topics is impressive.
It’s always easier to back off and not say a word, but then the loudest voice always wins.
Your concern for what goes into the mouths of your own children captures the essence of this controversy.
I don’t want amalgam in my child’s teeth.
Joe Bulger DDS
Visit my dental blog – Toronto Dentist Smile Blog
Sorry – forgot to reply to Beverly’s comment…
Beverly, you said “I wonder if dentists like doing composites because it gives them more income????”
Here’s the bottom line: While I charge a slightly higher fee for Direct Resin Restorations, they take more time, skill and the materials cost considerably more.
I probably make far less profit on them, except for the times I can provide multiple small restorations at once.
While profit can be a motivator for some dentists. I think providing services that you believe are the better for your patients is the bigger motivator.
For me the key question remains, “What’s the best I can do for this patient TODAY?”
I try not to get stuck hanging onto old familiar ways. If something comes along that I truly believe is better, I’ll drop tried and true techniques in a heartbeat. Doesn’t matter if I’ve done it a certain way for 20 years. Better is better.
Otherwise we would still all be using rubber base and zinc phosphate cements.
I stopped doing amalgams years ago. I remember purchasing an Intra-Oral Camera and my new amalgams looked embarrassingly ugly on the big screen.
Joe Bulger DDS
Visit my dental blog – Toronto Dentist Smile Blog
we already know the truth about amalgam it is ridiculously toxic and should not be used unfortunately dentists are greedy self serving people who put their own lust for money ahead of peoples health do not trust them they are maggots!!!!
Looks like we have a true Dentist-Hater in Peter. Wonder how many teeth he has left?
Amalgam is a cheap, strong, durable and easy to apply material. That’s why dentists use it.
I don’t use it and I can tell you the alternatives are more expensive and more challenging to apply.
Joe
FDA & CDC Don’t Agree On The Danger of Amalgam Fillings
While the FDA only as recently as 2009 decided to reclassify elemental mercury from Class I (low risk) to Class II (moderate risk), the FDA 2009 statement only recommended that the product labeling of amalgam include:
* A warning against the use of dental amalgam in patients with mercury allergy;
* A warning that dental professionals use adequate ventilation when handling dental amalgam;
* A statement discussing the scientific evidence on the benefits and risk of dental amalgam, including the risks of inhaled mercury vapor. The statement will help dentists and patients make informed decisions about the use of dental amalgam.
Meanwhile, the CDC’s Agency for Toxic Substances and Disease Registry (ATSDR) published a Public Health Statement CAS#: 7439-97-6 back in 1999, containing the summary chapter of the Toxicological Profile for Mercury.
Under Section 1.3 – “How I Might Be Exposed To Mercury”, it states the following:
“A potential source of exposure to metallic mercury for the general population is mercury released from dental amalgam fillings… 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. However, it should be kept in mind that
exposure to very small amounts of mercury, such as that from dental amalgam fillings, does not necessarily pose a health risk.
U.S. government summaries on the effects of dental amalgam conclude that there is no apparent health hazard to the general population, but that further study is needed to determine the possibility of more subtle behavioral or immune system effects, and to
determine the levels of exposure that may lead to adverse effects in sensitive populations. Sensitive
populations may include pregnant women, children
under the age of 6 (especially up to the age of 3),
people with impaired kidney function, and people
with hypersensitive immune responses to metals. If
you belong to this group, you should discuss your
medical condition with your dentist prior to any
dental restoration work. Removal of dental
amalgams in people who have no indication of
adverse effects is not recommended and can put the
person at greater risk, if performed improperly.
Because metallic mercury evaporates into
the air… anyone breathing the air in the room [is] at risk of exposure to mercury. The longer people breathe the contaminated air, the greater their risk will be.
Very small amounts of metallic mercury (for example, a few drops) can raise air concentrations of mercury to levels that may be harmful to health. The longer people breathe the contaminated air, the greater the risk to their health. Metallic mercury and its vapors are extremely difficult to remove from clothes, furniture, carpet, floors, walls, and other such items. If these items are not properly cleaned, the mercury can remain for months or years, and continue to be a source of exposure.
Workers are mostly exposed from breathing air that
contains mercury vapors, but may also be exposed
to other inorganic mercury compounds in the
workplace. Dentists and their assistants may be
exposed to metallic mercury from breathing in
mercury vapor released from amalgam fillings and
to a much lesser extent from skin contact with
amalgam restorations. Family members of workers who have been exposed to mercury may also be
exposed to mercury if the worker’s clothes are
contaminated with mercury particles or liquid.”
And all of the above CDC info is just from section 1.3! Here is the link to the PDF document: http://www.atsdr.cdc.gov/ToxProfiles/tp46-c1-b.pdf
Maybe the CDC will finally be able to convince the FDA after all of these years just how risky it is to place a toxic substance like Mercury in the mouths of our children and fellow Americans. Dental amalgam fillings have already been banned in a number of countries across the globe for the danger involved with using mercury in humans. The FDA is lobbied heavily by the ADA (a private organization) to push the “safety” of these so called “silver fillings” and refuse to inform the public of the dangerous mercury content contained in these “silver fillings”. The ADA needs to ban this outdated method of treatment which dates back to the 1800’s. The longevity of the use of mercury appears to be the ADA and the FDA’s reasoning of “proof” of it’s long proven record of “safety”.