Dental fillings unlikely to cause mercury poisoning

Mercury has been used in dentistry for about 150 years but some believe that dental fillings can give off harmful vapours that can be dangerous for dentists and patients. But dental associations say it is safe when mixed with other metals and there is no scientific evidence for a link between the material and health problems. A range of ailments that some people attribute to the mercury in 'silver' dental fillings are more likely to be caused by other factors. Researchers at the University of Giessen, Germany studied 40 patients with amalgam fillings and health problems they attributed to amalgam, and 40 similar 'controls' with the same number of fillings but no complaints. Participants were given a dental examination to measure the quantity, surface area and quality of their amalgam fillings. Then the researchers measured the amount of mercury in their blood and urine and assessed their allergy to amalgam. They also gave the study participants a series of questionnaires to assess coping strategies, interpersonal problems, self-consciousness, depression and other problems. It was found that patients and controls had similar levels of mercury in their blood and urine. Only one patient tested positive for allergy to amalgam, while 28% were found to be allergic to other things, such as house dust, pollen or animal hair. Patients had higher levels of psychic distress, a higher incidence of depression and somatization disorders as well as different styles of coping with anxiety compared to the controls. Hence, no indication for mercury intoxication or amalgam allergy as a cause of the patients' complaints could be found. The theory that amalgam-related complaints are an expression of the underlying psychic problems was supported in the study. Conclusively, treatment should focus on somatization and changing the coping and attribution styles of patients.