Objective: The aim of this article was to investigate whether there is evidence for a specific syndrome of health problems attributed to dental amalgam.
Material and methods: A secondary and retrospective analysis of two different databases was performed: (a) 90 patients (47% female, mean (SD) age 34 (6) years) of a clinical trial to remove amalgam fillings who attribute their health complaints to dental amalgam, and (b) 116 patients (62% female, mean (SD) age 37 (8) years) from an outpatient unit for environmental medicine who attribute their symptoms to environmental sources other than amalgam.
Results: The samples differed in age, sex, and educational level. No statistically significant differences between either of the groups were found in overall psychological distress, intensity of the symptoms, or in numbers of self-reported symptoms in the Symptom Check List after controlling for age, sex, and education (Mean Global Severity Index 0.62 versus 0.63). Patients from the amalgam group showed mean values for private and public self-consciousness similar to the population norm, while patients from the comparison group had statistically significantly decreased mean values. While the amalgam group more frequently reported mental symptoms, patients from the comparison group had a higher prevalence of somatic symptoms.
Conclusions: The results showed some differences in symptomatology, while general psychological distress was similar in both groups, indicating no strong evidence for an amalgam-specific syndrome.