Mercury derived from dental amalgams and neuropsychologic function.
There is widespread concern regarding the safety of silver-mercury amalgam dental restorations, yet little evidence to support their harm or safety. We examined whether mercury dental amalgams are adversely associated with cognitive functioning in a cross-sectional sample of healthy working adults. We studied 550 adults, 30-49 years of age, who were not occupationally exposed to mercury. Participants were representative of employees at a major urban medical center. Each participant underwent a neuropsychologic test battery, a structured questionnaire, a modified dental examination, and collection of blood and urine samples. Mercury exposure was assessed using a) urinary mercury concentration (UHg); b) the total number of amalgam surfaces; and c) the number of occlusal amalgam surfaces. Linear regression analysis was used to estimate associations between each marker of mercury exposure and each neuropsychologic test, adjusting for potential confounding variables. Exposure levels were relatively low. The mean UHg was 1.7 micro g/g creatinine (range, 0.09-17.8); the mean total number of amalgam surfaces was 10.6 (range, 0-46) and the mean number of occlusal amalgam surfaces was 6.1 (range, 0-19). No measure of exposure was significantly associated with the scores on any neuropsychologic test in analyses that adjusted for the sampling design and other covariates. In a sample of healthy working adults, mercury exposure derived from dental amalgam restorations was not associated with any detectable deficits in cognitive or fine motor functioning.
Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York 10032, USA. prf1@columbia.edu
Pam
P
Factor-Litvak
Gunnar
G
Hasselgren
Diane
D
Jacobs
Melissa
M
Begg
Jennie
J
Kline
Jamie
J
Geier
Nancy
N
Mervish
Sonia
S
Schoenholtz
Joseph
J
Graziano
D000328:Adult; D003072:Cognition Disorders / Q000209:etiology*; D003430:Cross-Sectional Studies; D003723:Dental Amalgam / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male; D008628:Mercury / Q000009:adverse effects* / Q000097:blood; D008875:Middle Aged; D019957:Motor Skills Disorders / Q000209:etiology; D009483:Neuropsychological Tests
D003723:Dental Amalgam; D008628:Mercury