Urinary mercury excretion following amalgam filling in children.
OBJECTIVE
Dental amalgam is the major source of inorganic mercury exposure in the general population. Dental amalgam contains approximately 50% mercury, which is a toxic element. Since children are more at risk for mercury toxicity, we aimed to study prospectively the effects of amalgam filling on urinary mercury excretion in 5- to 7-year-old children.


METHODS
Children admitted to the Pedodontics Department with no previous amalgam filling, and in a good state of health with one or more carious posterior teeth, were selected. All fillings were placed in one session for each child using Sina (Iran) amalgam powder and Degussa (Germany) mercury, which were mixed by an automated electric amalgamator (Dentomate 3, Germany). Urinary mercury concentrations were estimated before and 9-12 days after amalgam filling by atomic absorption using the mercuric hydride system.


RESULTS
Forty-three children (20 male, 23 female) aged 5.95+/-0.92 years and weighing 19.09+/-3.10 kg were studied. Urinary mercury concentrations before and after amalgam filling were 3.83+/-2.45 and 5.14+/-3.14 microg/L, respectively (p = 0.001). There were no statistically significant correlations between the urinary mercury concentrations and any other variables, including the number and surfaces of filled teeth, weight, age, and sex.


CONCLUSIONS
Although there were highly significant increases in urinary mercury concentrations after amalgam filling, no significant correlation was found between the urinary mercury concentration and the amounts of filled amalgam. Additional investigation is required concerning the effects of mercury release from amalgam.
Khordi-Mood
M
M
Department of Pedodontics, Imam Reza Hospital, Mashhad University of Medical Sciences, Iran. mkhordimood@yahoo.com
Sarraf-Shirazi
A R
AR
Balali-Mood
M
M
D002648:Child; D002675:Child, Preschool; D003723:Dental Amalgam / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008452:Maximum Allowable Concentration; D008628:Mercury / Q000652:urine*; D008630:Mercury Poisoning / Q000652:urine*; D010865:Pilot Projects; D011446:Prospective Studies; D013054:Spectrophotometry, Atomic
D003723:Dental Amalgam; D008628:Mercury