Association between Low blood lead levels and increased risk of dental caries in children: a cross-sectional study

Abstract

BackgroundThe objective of this study was to examine the association between low blood lead levels of <5 μg/dL and the development of dental caries among children.MethodsThe Children’s Health and Environment Research (CHEER) group recruited a cohort of 7,059 school-aged children from six Korean cities. The final study populations in the permanent and deciduous teeth groups were 1,564 and 1,241 children, respectively, after excluding 4 children with blood lead levels of >5 μg/dL. Compared with the children who did not have dental caries, the risk of having dental caries according to blood lead level was estimated by using the zero-inflated negative binomial model.ResultsThe geometric mean (geometric standard deviation, maximum) blood lead level was 1.53 μg/dL (1.57, 4.89 μg/dL), and 74.4% of children had a level of <2 μg/dL. Blood lead level was significantly higher in the children with than in those without deciduous dental caries (1.59 vs. 1.51 μg/dL), similarly with permanent dental caries (1.65 vs. 1.51 μg/dL). After adjustment for covariates, deciduous teeth surfaces that were decayed and filled increased significantly with increasing blood lead levels in a dose-dependent manner (prevalence ratio, 1.14; 95% confidence interval: 1.02–1.27). However, the risk of having dental caries in permanent teeth was not linearly associated with the increase in blood lead level.ConclusionsIn the sum of decayed and filled surfaces, we found a significant increase in risk of dental caries of the deciduous teeth with an increase in blood lead levels (<5 μg/dL) but found no statistical significance in the association with decayed and filled surfaces of caries separately.

Association Between Environmental Health, Ecosystem Vitality, and Early Childhood Caries

“…One study highlighted that exposure to carbon oxide ambient air contamination results in changes in the composition of saliva and teeth based on the severity of exposure (13). Exposure to lead can result in lead accumulation in teeth and may increase the risk for caries (14,15), including ECC (2,16).…”

The associations between lead exposure at multiple sensitive life periods and dental caries risks in permanent teeth

“…Among 543 urban U.S children 6-10 years old, blood Pb levels in childhood were positively associated with number of caries, after adjustment for demographic and maternal factors and oral care practices [9]. However, these and other studies [7,8,9,15] have several limitations, including cross-sectional study designs [7,8,15]; Pb measurements in blood or salivawhich may not represent long-term exposure [8,9]; and a limited number of tooth samples collected from each individual [7].…”

“…Several population-based studies [7,8,9,15] suggest an association between Pb levels and dental caries. For example, a cross-sectional epidemiologic study conducted among 1,564 Korean children showed that the prevalence of decayed, missing and filled surfaces (DMFS) in deciduous, but not permanent teeth, increased with each mg/dl of childhood blood Pb exposure [15]. Among 543 urban U.S children 6-10 years old, blood Pb levels in childhood were positively associated with number of caries, after adjustment for demographic and maternal factors and oral care practices [9].…”

Primary teeth microhardness and lead (Pb) levels

“…There have been several studies suggesting that environmental exposure to lead (Pb) also contributes to disparities in childhood caries, particularly in primary teeth [7, 8, 9, 10, 11, 12, 13]. A 2017 study of 1,564 Korean children showed that each μg/dL of blood Pb was associated with a 1.16 (95% CI: 0.91–1.49) greater prevalence of decayed, missing and filled surfaces in deciduous, but not permanent teeth, after adjustment for age, sex, mother's education, household income and urinary cotinine [7]. Further, in an Egyptian study of teeth from children and adults, Pb levels were higher in the teeth pulp from carious teeth (n = 62) than healthy teeth (n = 39) (77 versus 29 ppm, p = 0.004).…”