Mercury exposure from dental amalgam: 1 year follow-up

Hye-Jin Baek

Department of Dentistry
Graduate School, Kyungpook National University
Daegu, Korea
(Supervised by Professor Youn-Hee Choi)

index: children, dental amalgam, mercury, urine

(Abstract)
Objective. Dental amalgam is a widely used filling material for oral cavity. Released mercury vapor from amalgam could be the systemic adverse effects potentially. The purpose of this study was to evaluate the relationship between dental amalgam and urinary mercury levels in children each for 1 year.
Methods. A total of 463 elementary school children were participating in this study at 1st survey(baseline). One of the trained dentists had oral examination all the teeth to check the decayed, missing, and filled surface index (ds, fs, dfs/DS, FS, DMFS) and all of the dental materials used. Urine samples collected were analyzed for mercury and creatinine level. All tests are administered three times every 6 months. Additionally, general characteristics and oral hygiene habit of subjects were surveyed by questionnaire.
All the collected data were analyzed using t-test, ANOVA, χ2-test, logistic regression analysis, and mixed-model analysis. The statistical analysis was performed using the SPSS 18.0.
Results. The total of 463 elementary school children (male: 240, female: 223) investigated at 1st survey. Affecting factors of newly development dental caries were grade and mother''s education. Amalgam exposure and urinary Hg were mederately correlated. The more amalgam surfaces tended to have higher urinary mercury levels. In the mixed-model analysis, amalgam surfaces was the most relevant factors about urinary mercury levels.
Conclusions. Mercury concentration in urine was associate with dental amalgam. Even a small amount of mercury uptake from dental amalgam has been associated with increasing the mercury concentration of urine in children.