In December 2010, the FDA Dental Products Panel conducted a hearing to review several “citizen’s petitions” about a minor reclassification of amalgam that the FDA made last year. Some press reports may lead people to believe that the hearing was a big deal and that the American public is at great risk from amalgam fillings. Medscape, for example, reported testimony from both sides but headlined its article “Mercury Exposure Due to Dental Fillings of Superfund Site Magnitude: Biologist.” The simple truth is that there is no significant risk because amalgam fillings are safe.
I was one of the original experts who testified before the FDA Panel in 1991 and have followed this issue for more than 20 years. The basic science has not changed. We just have more studies that reinforce what was known then. Anti-mercury advocates continue to be dissatisfied with the evidence, even though studies have addressed, in significant detail, all the issues that were raised then, including any risks of exposure of children to dental amalgam.
Because mercury is ubiquitious in the Earth’s crust, the general public gets exposed to mercury every day in air, water and food. Lead is equally ubiquitous in the environment from a variety of sources. All people have some of each in their bodies.
Having dental amalgams does raise total exposure to inorganic mercury to about twice that normally encountered from food, air and water. This is like owning a penny stock. If it doubles in value you have two cents. People who eat large fish may get slightly more exposure. Exposure does not equal morbidity or mortality at these levels.
Dose makes a poison, not it’s name. That is true for mercury, lead, cadmium, epoxides, and any other material that “might” be poisonous.
Statements that there are “no safe levels” of either mercury or lead belie the fact that all indiviudals on the Earth have both in them. I put such statements in the category of “distortional science.” No study has ever shown any adverse effect (other than occasional allergies, often to other ingredients than mercury) from having amalgam fillings. Claims of medical effects are not proven by evidence-based objective studies. Most such claims show other illnesses, including somatiform disorders.
Identifying a “risk” requires that the risk be quantified. It is risky to ride in an airplane, ride a bicycle, have sex, and many other “normal human activities.” The risks, if any, from amalgam, are far outweighed by its benefits in saving teeth at reasonable cost. Cost includes cavity preparation, longevity, anti-cariogenicity of the product, placement time, and durability. No other filling material is safer by any criteria. Composite resins, often touted as “safer,” are now under increased scrutiny. There is no “perfect” dental material.
The promotion of anti-amalgamism is regularly linked with fringe practitioners, people with financial interests in promoting something else, and pseudoscience. Based on past practices, and rhetoric, I’m one of many who conclude that the anti-amalgamists resemble more a religious cult than a group of serious, objective scientists searching for the truth.
Attempting to legislate science shows that this is not about science at all.
Precious research dollars might be better spent on learning more about diseases which have real and significant impact, such as oral cancer.
This page was posted on December 18, 2010.