Mercury Fillings Report - Silver Mercury Fillings

[Disclaimer: Please note that a dentist is not a medical doctor and thus isn’t licensed to diagnose or treat medical problems or predict medical consequences, good or bad, for his/her patient related to this topic of mercury toxicity. They put their license to practice dentistry at risk, or at least will be required to submit to correction and censure from peers if they cross the line and begin “practicing medicine” when it comes to issues related to this subject. What is said herein is not meant to diagnose or set forth specific diseases or pathologies, nor to claim that mercury in dental fillings cause medical related problems. There are many books available in the popular and scientific press which better address this subject which you are encouraged to read if you wish further information. Any such discussion or decisions related to medical issues related to mercury toxicity should be discussed with a competent physician knowledgeable on these issues.]

There is little debate today that mercury is a potent neurotoxin and a significant problem in both biologic systems as well as in the environment. But in dentistry the use of mercury in fillings represents one of the most hotly debated subjects. Those opposed to using mercury in dental fillings claim that mercury is released from fillings and can be toxic to the human biological system. Defenders cite its 150+ years in use as evidence of its safety. Those opposed to using it in fillings say that the debate should be settled by medical toxicology, and defenders easily dismiss any toxicology information as irrelevant, claiming that the mercury is “bound” in the amalgamated filling material, and again citing its “long successful” track record and the fact that more people aren’t “sick.”

Those defending the use of mercury allow that 1% of the population is “allergic” to the material, which tends to minimize or discount the severity of the problem for those who do have problems. (This would mean that they believe it’s okay for 2.5 million people in the US to be affected! Ironically, if 1% of the people were ill-affected by the use of a toothpaste, it would immediately be removed from the market.) Additionally, the defenders of the status-quo with mercury filling use cite the fact that it would be nigh impossible to meet the needs of our populations around the world if mercury fillings were not employed as a dental restorative material. This is because mercury fillings are inexpensive, readily available, and easily placed.

But the question still remains begging – with such a huge debate and such serious allegations being leveled, why is it still used and defended, especially with the advent of modern dental materials that do not have mercury and have so many other advantages. Good question! Indeed, there is a growing movement politically, legally, and scientifically, that is trying to discredit the use of mercury fillings. Perhaps the jury is still out on this issue, at least as far as public policy is concerned.

Those opposed to its use are adamant that no mercury of any form should be implanted or used in the body. And the arguments can be compelling. If a HAZMAT unit has to clean up a broken mercury thermometer, if the dentist has to handle the mercury filling material in a special way before it goes into the tooth, if there are special environmental methods for handling mercury filling waste products after use, how could it be safe while in the mouth? In other words, why is the human mouth the only safe place for mercury? On the surface of the argument it doesn’t make sense. Why is it that older generation scientists used to calibrate their mercury sensing equipment by chewing gum?

So much has changed in dentistry. One of the biggest revolutions has been the arrival of modern materials. Silver Mercury Amalgam fillings have been around since the early 1800’s when mercury was combined with metal filings to form a type of metal cement or amalgamation that was easy to handle and readily available. Without question, if silver mercury fillings weren’t seen as being “grand fathered” in, there would be no way even the same modern scientific processes that are used to justify its continued use, would allow it to become a “new” medical/dental material.

Some of the disadvantages of silver mercury fillings include expansion, corrosion, and esthetics. In short silver mercury filings expand in size over a lifetime of use in a tooth. This creates stresses in a tooth structure that propagate through the tooth structure and generally must be relieved at some point in time, resulting in fracturing and cracking of enamel and tooth structure. When a tooth does break apart, it can necessitate a root canal or gum surgery. Silver mercury fillings do not seal shut or tight against a tooth interface. Ironically, due to its toxic properties, bacteria don’t tend to thrive well and hence less decay will occur and be slower growing over time, than around similar defects in non-silver fillings. Silver mercury fillings oxidize or “rust” in the wet environment of the mouth. This tarnishing or corrosion further breaks down the filling materials especially at the “margins” or edges of the filling materials. Added to this is the dark gray or black color of the fillings and the graying it produces in the filled teeth. (For further information on cracked teeth, see the report on this web site about Cracked Teeth.)

“Amalgam” is the word used to describe the mixture of various metals like tin, silver, copper, and zinc, along with elemental mercury (a liquid at room temperature) to form a dental filling. Fifty percent of the filling is mercury, and when these metals are mixed together it becomes hard and is referred to as a “silver filling.” Silver mercury fillings have been used since the early 1800’s when barber-dentists began using them in America after their introduction from Europe. To their credit, they are quick, cheap, easy to handle, and readily available – all which have paved the way for the historical and universal use of this dental material.

Because of its unique physical properties, Mercury metal has many uses. Because of its high density, it is used in barometers. Because it has a high rate of thermal expansion which is fairly constant over a wide temperature range, it is used extensively in thermometers. As a liquid at room temperature, Mercury is used as a contact material for electric switches. In mercury-vapor lamps, it emits a light rich in ultraviolet radiation; (street lighting, sun lamps, "black lights"). It has been used as an insecticide, pesticide, fungicide and in rat poison, and as a disinfectant. It can mix with scrapings or powders of other metals (silver, tin, copper, zinc) to form a special type of alloy called an amalgam, which is used in dentistry for filling teeth.

However, as mentioned above, few subjects have polarized the profession of dentistry like that of amalgam mercury fillings. From a potential health point of view, the concern is that mercury interferes with the tissues and nerve cells of the body. Mercury vapor comes out of the fillings and is breathed into the lungs. This is the main way dental mercury gets into the body. Once inside, it is mainly stored in fat tissue, including the brain and central nervous system.

Mercury has long been known to be toxic; the phrase "mad as a hatter" refers to the 19th-century occupational disease that resulted from prolonged contact with the mercury used in the manufacture of felt hats. Despite evidence and experience to the contrary, proponents of its use in dental fillings claim the mercury is “locked up” with the other metals and therefore is harmless in humans. The truth is that mercury vapor escapes for the life of the filling, especially when chewed on or heated.

Mercury poisoning occurs when biological tissue is damaged resulting from exposure to mercury, or its compounds. Elemental mercury, like that found in thermometers and dental fillings, is the most common occupational and medical source. Exposure typically comes from inhaling mercury vapors. Elemental mercury can be converted into methylmercury by microorganisms (which can then enter the food chain, i.e. contaminated fish), and by gastrointestinal bacteria. This more toxic organic compound can easily cross cell membranes.

Mercury poisoning can cause severe neurological and kidney damage. In acute cases of gross exposure, Mercury can cross the blood-brain barrier and cause irreversible nervous system and brain damage, e.g., loss of motor control, numbness in limbs, blindness, and inability to speak. Some studies have connected maternal mercury exposure to fetal damage. Acute mercury poisoning can be confirmed by urine tests, and chronic exposures show up in hair analysis. For more long term exposure (such as with dental fillings) the manifestations can take longer and be more subtle, if at all. In most people the effects are negligible or at least minimal due to a variety of reasons which include: healthy host defense system, strong immune system, “good” genetics, etc. For others who are affected, the effects can be devastating. They can be “primary” (mercury toxicicity itself) or they can be “secondary” – meaning that they manifest only after an already weakened immune system or host defense mechanism is in play. An amount that may be “safe” for one person, may “pull the rug out” from another person.

They are also thought by many to “trigger” other medical problems. While as many claim, the jury may still be out on all of mercury’s effects on the body, we can at least say that it is unwise to use it in or around the body. At a minimum, there is simply too much question and debate. At worst, it must be recognized for what it is – a toxic neurological poison!

In summary:
It is well known that silver mercury dental fillings are still the predominant filling material. Their use is staunchly defended by a large contingent of dentists including the American Dental Association. While the trend is shifting away from its use, 60-70% of dentists still use it in their practice. There is no question that mercury is toxic to humans and can cause tremendous problems. The debate is whether dental fillings are a source of mercury contamination.

While this debate rages, and without going over the edge into medical diagnosis or treatment, many dentists including Dr. Ostler, have decided to focus on higher quality dental restorative procedures such as porcelain ceramics and resins, newer zirconium substrates, and gold (although gold or other metals are seldom used or needed anymore). In our considered opinions, these are superior restorations which provide a more durable and strong solution to repairing the tooth and holding it together in a strong fashion. While using modern dental techniques and materials are highly technique sensitive and require advanced training to be successful, they completely avoid the mercury debate, and instead offer dental restorations which are stronger and more durable, more esthetic and more natural looking. Because of the ongoing debate, and the extreme negative consequences of potential mercury toxicity, it seems unconscionable to place or implant mercury containing materials in the human body which have at least the potential of causing problems, instead of using modern alternatives available.

For a article on Mercury Amalgams in the Chicago Tribune click here.

For more information about mercury fillings in dentistry, including summaries of clinical research, visit:

www.amalgam.org

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