Psychological and medical effects of mercury intake from dental amalgam. A status report for the American Journal of Dentistry.

Studies examining health consequences of the release of mercury from dental amalgams have concluded that there is insufficient mercury released from these restorations to cause a medical problem. Although the mercury vapor generated during removal of amalgams will cause a transient increase in the patient's mercury level in tissue fluids, biochemical assays have demonstrated that the increase is too small to have a negative influence on organ systems. This is true even when patients have all their amalgams removed in a single session. Nevertheless, over the past decade, the release of mercury from dental amalgam has been frequently blamed for a variety of health complaints. A number of sensationalized media reports regarding the mercury issue have no doubt contributed to the public concern that has been aroused. Consequently, patients may present at the dentist's office, either self-diagnosed or looking for a cause implicating mercury. In actuality, these patients may have symptoms of either medical problems or psychological disorders such as depression or anxiety. Unfortunately, the incorrect diagnosis may not only mislead, but actually place the patient in a dangerous situation. Two well-controlled studies have indicated that (1) 89% of the patients with self-reported "amalgam illness" had psychogenic disorders, whereas only 6% of the matched-pair manifested symptoms of these psychological disorders; and (2) these alleged "amalgam illness" patients had preneurotic reactive/defensive mechanisms that did not allow them to recognize aggressive and threatening situations which the control group would quickly and readily regard as potentially difficult to manage. Other studies involving psychological assessment seem to confirm that dental therapy (removal of amalgams) for people with alleged "amalgam illness" may, at best, provide a "placebo effect".