Dental radiography after age 25 years, amalgam fillings and tumours of the central nervous system.

The aim of the study was to investigate the importance of diagnostic dental radiography and amalgam fillings as risk factors for tumours of the central nervous system (CNS). This population-based case-control study included subjects aged 25-74 years, living in the catchment area of the Neurosurgery Department of Uppsala University Hospital in Sweden. A total of 192 cases of glioma, 99 cases of meningioma and 42 cases of acoustic neurinoma were identified between 1987 and 1990. A control group of 343 subjects was matched on age, gender and parish. Information about dental exposure was obtained by a self-administered questionnaire and from dental records. For those who had a dental radiography at least once a year after age 25 years, a relative risk of 2.1 (95% confidence interval (CI) 1.0-4.3) was seen for meningioma, while for other subgroups of CNS tumours the relative risk was close to unity. No association was observed between the number of amalgam fillings and CNS tumours. In conclusion, there was no clear evidence that dental radiography or amalgam fillings is related to the development of tumours of the CNS.