Salivary lead in relation to caries, salivary factors and cariogenic bacteria in children.

Saliva has been suggested as a useful biomarker of environmental contamination, including exposure to lead. The study examined the associations between salivary lead level and the following factors: blood lead level, the number of decayed and filled surfaces (dfs) on deciduous and permanent teeth (DMFS), salivary flow rate, pH, buffer capacity, lactobacilli and mutans streptococci counts. One hundred and twenty saliva samples of children living in a shipyard area (known to be an area contaminated with lead) were analysed for lead. Clinical oral examination was conducted to define carious lesions in accordance with the criteria of the World Health Organisation. The analysis revealed detectable levels of lead in a range of 0.16-28.52 μg/dl with a mean concentration of 2.26 ± 3.67 μg/dl. No significant differences in salivary lead concentrations were found in relation to gender and age. The salivary lead level significantly correlated with the blood lead level (Rs = 0.18, P = 0.05). There was no association between the salivary lead levels and dfs or DMFS. The results indicated that children with high salivary lead levels did not differ in flow rate, pH, buffer capacity of saliva from those with low lead levels. However, the number of mutans streptococci were reduced in the high salivary lead groups, while the lactobacilli count was not associated with the salivary lead levels. The current finding suggests that saliva may not have potential to be an appropriate alternative for biological monitoring of lead exposure.