Multidisciplinary examination of patients with illness attributed to dental fillings

In 1993, a special Amalgam Clinic was established at Huddinge University Hospital. Residents in the Stockholm County area with morbidity attributed to dental fillings ('amalgam disease'), were referred to this clinic. Patients were examined by a dentist (n 428), a physician (n 379), and a psychologist (n 360). Sixty-nine per cent were women and 31% men; the mean patient age was 46 years.

Oral symptoms included tender or aching teeth (60%), metallic taste (54%), sore mouth (43%) and dry mouth (43%). Signs of moderate or severe temporomandibular joint dysfunction were found in 81 cases, glossitis in 30 and oral lichen in 26 cases. Common general symptoms included diffuse pain (78%), general weakness (75%), extreme fatigue (68%) and dizziness (68%). Seven per cent of the patients suffered from previously undiagnosed medical conditions (thyroid dysfunction, anaemia, cardiopathy, renal disease, cancer). In 26 subjects, skin patch testing revealed allergy to mercury, gold or palladium. The median concentration of mercury was 10 nmol L-1 in whole blood, 3 nmol L-1 in plasma and 10 nmol L-1 in urine, i.e. normal levels. Earlier mental trauma was common, and in the psychological questionnaire SCL-90, clear tendencies to somatization were found. Only a few cases of severe psychiatric illness were observed. No positive correlation was found between the amount of amalgam and somatic symptoms or psychological effect parameters.

The results do not support the hypothesis that release of mercury from amalgam fillings is the cause of 'amalgam disease', but suggest that there may be various explanations for the patient's complaints.