Dental amalgam is a dental filling used to fill cavities that has been used for more than 150 years in hundreds of millions of people around the world. Some have raised concerns that dental amalgam, as silver fillings are technically known, contains elemental mercury that has adverse effects.
At the same time, the Food and Drug Administration, known for lax oversight, bad decision making and even making decisions based on politics, has reviewed the "best available scientific evidence" to determine whether the low levels of mercury vapor associated with dental amalgam fillings are a cause for concern. They consider dental amalgam fillings safe for adults and children ages 6 and above.
I've had some
for over 60 years that were put in by an old German dentist and they're
still holding up and there never was any physical ailments associated
with them. These fillings are supposed to last 10-15 years before they need to be replaced. So they say, but I had one fall out about 30 years ago and one is starting to show signs of wear and tear and needs to be replaced. The other 5-6 are still good.
Dental amalgam is a mixture of metals, consisting of liquid elemental mercury and a powdered alloy composed of silver, tin, and copper. Approximately 50 percent of dental amalgam is mercury by weight. The chemical properties of elemental mercury allow it to react with and bind together the silver/copper/tin alloy to form an amalgam. Dental amalgam fillings are also known as “silver fillings” because of their silver-like appearance.
When placing dental amalgam, the dentist first drills the tooth to remove the decay and then shapes the tooth cavity. Next, the dentist mixes the powdered alloy with the liquid mercury to form an amalgam putty and this softened amalgam putty is placed and shaped in the cavity where it rapidly hardens into a solid filling.
The first known use of amalgam was recorded in the Chinese literature in the year 659, but it wasn’t until 1819 that a mercury-based dental amalgam as we know it today was invented by an English chemist named Bell. However, it wasn’t until 1826 that the filling was first used in England and France. When they were first used in the United States in 1830, numerous harmful effects were soon widely reported.
In 1840 the American Society of Dental Surgeons denounced the use of amalgams due to concerns about mercury poisoning and members of the society were required to pledge to avoid mercury amalgam fillings. Nevertheless, many dentists continued using amalgams since they were cheaper, faster and easier to place than gold materials.
As early as 1850, some U.S. dentists claimed that removing amalgam fillings could bring miraculous cures in patients with chronic disease. Today, some dentists remove amalgam fillings from patients as a result of claims that such fillings result in serious adverse health effects.
The controversy continued and in 1859, those who were determined to continue using the mercury amalgam in the United States formed its own dental society, first called the National Dental Association; it later became the American Dental Association.
In 1926, a prominent German chemist, Alfred Stock, discovered that mercury was the source of his own health problems and after having his own amalgams removed, Stock then studied the health problems of many of his friends and advised them to have their amalgams removed.
He studied the release of mercury vapor from amalgams and published his findings in over thirty scientific papers. Stock led an international movement to halt the use of mercury amalgam fillings.
In the 1930s, Stock’s laboratory and most of his records were destroyed in a World War II bombing raid, derailing the anti-amalgam mercury movement that he had led.
In 1957, Dr. Karl Frykholm of Sweden published a study claiming (some say wrongly) that when saliva covers an amalgam filling, the mercury is no longer released and ever since then, the ADA has cited his paper as a proof that amalgam fillings are stable and safe.
A dentist suffering from multiple sclerosis named Hal Huggins met a Brazilian dentist, Olympia Pinto, at a conference in Mexico City in 1973. Dr. Pinto shocked Huggins by telling him that amalgam fillings are unstable and mercury from them can trigger illnesses like Hodgkin’s disease and sickle cell anemia. After learning about the amalgam health issues from papers Dr. Pinto sent him, Dr. Huggins researched and wrote a book on the hazards of amalgams.
In 1979, researchers at the University of Iowa reported there was a measurable release of mercury vapor from amalgam fillings and when they were stimulated by chewing, brushing or hot beverages the release was far greater. Those findings were confirmed in 1981 by research at Ohio State University.
Researchers in Sweden and the United States, in 1987, did autopsy studies on victims of sudden unexpected death in which they confirmed a strong correlation between brain levels of mercury and the number of amalgam filling surfaces in the teeth.
Researchers published an autopsy study in 1989 showing that mercury levels were much higher in the pituitary glands and the thyroid glands of dental staff as compared to a non- dentist control group.
The mercury level in the pituitary glands of the dental group was about forty times higher than that of the controls.
Other studies found dentists to have a higher rate of irritability, depression and mood disorders. Dentist have a much higher suicide rate than other white collar professionals.
In 1990 researchers at the University of Calgary School of Medicine placed amalgam fillings with radioactive mercury into pregnant sheep and monkeys. After 29 days the mercury was found in the kidneys, the liver, the gastrointestinal tract, the brain and many other parts of the body including the unborn fetus. For both the mother and the fetus, the highest mercury level was in the pituitary gland, explaining the clinical association between amalgams and depression and mood disorder.
The same year the CBS television show Sixty Minutes exposed the hazards of mercury amalgams. According to the source, the program also exposed the biased attacks by state dental licensing boards on mercury free, holistic dentists. The ADA spokesman squirmed under cross-examination by the host. This sort of dental amalgam expose was never repeated again on any TV network.
A 1991 survey
conducted by the American Dental Association, which revealed that nearly
half of the 1,000 American adults surveyed believed that health
problems could develop as a result of dental amalgam.
The largest German manufacturer of amalgam, Degussa AG, stopped making amalgam in 1993 and the following year Sweden announced phase-out of amalgam fillings, starting with pregnant women and children. Also in 1994, researchers reported that elemental mercury vapor from amalgams fillings is toxic to brain neurons. Low dose mercury causes the neurofibrillary tangles in the brain regarded as a key marker of Alzheimer’s disease.
In another 1994 report, human autopsy studies on babies who had died of Sudden Infant Death Syndrome (SIDS) was published at the University of Munich in Germany. They found a strong correlation between the mercury levels in the brains and kidneys of the babies and the number of amalgam fillings in the mother’s teeth. These findings were confirmed by another autopsy study conducted in 1996 that showed mercury from a mother’s amalgam fillings is typically the major source of mercury for the unborn child.
The German government then acted to curb the use of amalgams in children and women of childbearing age.
In 1996 Health Canada established guidelines for dentist cautioning against the use of amalgams in children, pregnant women, people with kidney disorders and other vulnerable people.
Health Effects of Mercury Exposure