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Mercury
Dental Amalgams - Analyzing the Debate
by Gary Null
Revised May 2001
Note: The information on this
website is not a substitute for
diagnosis and treatment by a qualified, licensed professional.
A History of Ill Effects
Mercury has a long history of extreme toxicity, which makes its deliberate use in people's mouths all the harder to comprehend. Consider the bare facts: One of the oldest of all recognized poisons - a metal more toxic than lead and even arsenic - is the main ingredient in today's most common dental amalgam, which American dentists place in about 1 million fillings per day. (10,11). Disinfectants, antiseptics, pesticides and insecticides contain this same ingredient because it is hostile to life.(12)
Tales of mercury's damaging effects date to ancient Roman and Spanish history, when imprisoned slaves who worked in mercury mines suffered from acute symptoms of fatigue, dyspnea and epigastric pain on their first day. As time passed, they developed other highly common symptoms of mercury poisoning. These included lesions of the nervous system such as erethismus mercurialis (moodiness and other mental disturbances) and tremor mercurialis (involuntary, choreatic shaking movements).
These slaves were condemned to death in the mines, and they eventually wasted away in the terminal stages of mercury poisoning. By contrast, the small doses of mercury released by dental amalgam cause a chronic mercury poisoning that manifests, for the most part, as mental symptoms. That makes it especially difficult to diagnose.(13)
A more recent example of mercury's dangers comes from the British hatmaking industry of the late 19th century. At the time, the expression "mad as a hatter" characterized workers who used mercury compounds in the shaping of felt hats. The workers exhibited unusual shyness, mood swings and a dwindling intellect, all symptoms of severe mental retardation.(14) But these dangers were recognized for three-quarters of a century before the use of mercury in the U.S. hatmaking industry was banned in 1941.(15)
Mercury got its start in the dental industry in 1826, when a Paris dentist combined it with silver, copper and other metals to create a paste. Seven years later, two brothers in New York City with no dental training began to promote mercury as a cheap alternative to gold fillings.(16) By the end of the 1830s, mercury amalgam's use was commonplace in the U.S. Not only was the material cheap and durable, but it also required less time and skill to place than the trickier gold fillings. (17,18)
Still, traditional dentists were appalled by the very idea of using a known poison in the body.(19) In the 1940s, the American Society of Dental Surgeons required its members to sign a pledge not to use the substance in their practices. But many members refused to sign because they believed mercury's low cost would benefit the poor. The debate caused such a schism in dentistry that the Society eventually folded.
When the American Dental Association formed in 1859, it took a very different stance on the mercury issue. The ADA defended the use of mercury amalgam, helping to establish it as a popular dental filling by the end of the 1800s.(20) The organization's staunch defense of mercury continues to this day.
For example, in January, 1984, the association proclaimed, "When mercury is combined with the metals used in dental amalgam, its toxic properties are made harmless." A 1991 document counsels dentists to tell patients who express concern about the mercury in amalgam fillings that "...the mercury forms a biologically inactive substance when it combines with the other materials used to produce the amalgam."
A somewhat bizarre variant of this explanation is cited by Dr. Hal Huggins in his recent expose of the amalgam controversy, "Integrity vs. Intimidation."(21) In the ADA's Guide to Dental Materials and Devices, the reader is informed that amalgam does release small amounts of mercury, but that "this evaporation stops as soon as the filling is coated by saliva."(22)
"Most scientists from physics chemistry, and toxicology would tell you," Huggins comments, "that when multiple metals are warmed up to mouth temperature and coated with an electrolyte like saliva, you have a perfect condition to form a battery. In this case, the efflux from this filling-battery would be mercury, either as vapor, inorganic mercury…or methyl mercury."(23)
The assurances provided by the ADA have no basis in scientific fact. On the contrary, they frequently fly in the face of scientific reality. Speaking of the ADA's claim that mercury combines with other metals in dental amalgam to form a biologically inactive substance, Dr. Douglas Swartzendruber, chairman and former dean of the biology department at the University of Colorado in Colorado Springs said, "They must have discovered alchemy."(24) Existing scientific evidence strongly supports the conclusion that mercury amalgam fillings are a danger to your health.
"How could mercury be completely harmless when put into a patient's mouth," asks Dr. Boyd Haley, professor and chair of the department of chemistry at the University of Kentucky. "I think the situation would make a great Gilbert and Sullivan musical," Haley notes. "It is absolute silliness for the Environmental Protection Agency (EPA) and OSHA to say that mercury before going in and after coming out of mouth is totally toxic, but inside the mouth is absolutely safe."(25)
Indeed, there is no proof that the volatile substance transforms into an inert ingredient. On the contrary, research shows that amalgams expose people to mercury vapors continuously, especially after fillings are stimulated by chewing, brushing, or heat. These findings are confirmed by Dr. Tano Lucero, a former research chemist and industrial hygienist for OSHA who later became president of Bio-Ethics Medical Center in Scottsdale Arizona. Dr. Lucero became a victim of neurotoxic poisoning from numerous job-related exposures. After beginning a comprehensive program of detoxification, one doctor suggested that he have his dental amalgams removed. A subsequent visit to the dentist revealed, to his amazement, that 25-year-old fillings were adding enormously to his toxic burden. Lucero states, "My intra-oral mercury levels were almost twice the OSHA standard of 50 micrograms per cubic meter. The equipment [used to detect these levels] was the exact make and model of the mercury vapor analyzer I had used to conduct my inspections of hospitals, dental clinics and other industries. The OSHA standard was based on an employee's eight-hour work exposure for a 40-hour work week. My exposure was twice that level over a 24-hour period, seven days a week. If I were doing an OSHA inspection of my mouth, I would be in violation of the OSHA standard and subject to a serious citation which carries a $1,000 penalty!"(26)
"The ADA claims that when mixed with other metals the amalgam fillings form a biologically inactive substance," Lucero continues. "This is simply not true. Is elemental mercury escaping from filling material? The answer is an absolute YES!....Having worked for OSHA for 17 years, never have I witnessed anything of the magnitude of resistance in acknowledging the danger of toxicity in silver amalgams as by the ADA."(27) Says Haley, "I don't want to panic people, but I think we have to be realistic. Mercury comes out of amalgams. It gets into our saliva, and we swallow it. The vapors go through the membranes of our mouth to the nasal mucosa and collect in the brain. There's almost no way that it can't do that. It's not safe."(28)