Association of dental cavies and blood lead levels

Context Experiments show that dental caries rates are higher among lead-exp osed animals, but this association has not been established in humans. Objective To examine the relationship between blood lead levels and dental caries. Design Cross-sectional survey conducted from 1988 to 1994 that included a d ental examination and venipuncture blood lead assay. Setting and Participants A total of 24 901 persons aged 2 years and older w ho participated in the Third National Health and Nutrition Examination Surv ey, which assessed the health and nutritional status of children and adults in the United States. Main Outcome Measures For children aged 2 to 11 years, the sum of decayed a nd filled deciduous or primary surfaces; for persons aged 6 years and older , the sum of decayed and filled permanent surfaces; for those 12 years and older, the sum of decayed, missing, and filled surfaces. Results The log of blood lead level was significantly associated with the n umber of affected surfaces for both deciduous and permanent teeth in all ag e groups, even after adjusting for sociodemographic characteristics, diet, and dental care. Among children aged 5 to 17 years, a 0.24-mu mol/L (5-mu g /dL) change in blood lead level was associated with an elevated risk of den tal caries (odds ratio, 1.8; 95% confidence interval, 1.3-2.5). Differences in blood lead level explained some of the differences in caries prevalence in different income levels and regions of the United States. We estimated the population attributable risk of lead exposure to be 13.5% and 9.6% of d ental caries occurring in 5- to 17-year-olds exposed to the high and modera te levels, respectively. Conclusions Environmental lead exposure is associated with an increased pre valence of dental caries in the US population, Findings may help explain th e distribution of caries by income and region of the United States.