Childhood Lead Exposure and the Risk of Dental Caries in Permanent Teeth: The Cincinnati Lead Study

Dental caries is a significant public health problem in the United States. The evidence on the association between lead exposure and dental caries is conflicting because the impact of childhood lead exposure on the prevalence of caries in young adults has not been evaluated in prospective cohort studies.

To assess the association of prenatal and postnatal childhood lead exposure with dental caries in young adults living in Cincinnati, Ohio, United States.

We examined 206 predominately African American participants aged 16 to 22 y in the Cincinnati Lead Study, a prospective cohort study measuring prenatal and postnatal blood lead levels from the maternal, neonatal, and postnatal periods (from 3-78 mo of age) for dental caries. Caries experience was quantified as the number of decayed, missing, and filled teeth (DMFT) and surfaces (DMFS) in permanent teeth. The impact of average childhood blood lead levels on stimulated and unstimulated salivary flow rate was also assessed.

A significant positive association between average childhood blood lead levels and DMFS and DMFT was observed in young adults. A 2-fold increase in DMFS between 6 and 15 µg/dL, followed by a downturn at the highest blood lead quintile (P < 0.05), was observed. Statistically significant covariates were the number of sealants present, lactobacilli count in saliva, and maternal high school education. When adjusted for mutans streptococci, ever smoking, flossing, and the number of adults and children living in the household, the average childhood blood lead levels were associated with reduced salivary flow rate.

Childhood blood lead levels were associated with an increased DMFS/DMFT in young adulthood.Knowledge Transfer Statement:The results of this study support the need for continued reduction in lead exposure-especially in low- and middle-income countries-to further reduce the risk of dental caries in permanent teeth.