Evaluation of salivary melatonin in preschool children with dental caries

Objectives: The information on salivary melatonin in association with dental caries status is very limited. No prior studies have investigated salivary melatonin levels in children with deciduous dentition. The objectives of this study were to assess melatonin concentrations in saliva in children with high and low caries risk of deciduous dentition, and to determine the correlations between salivary melatonin and clinical parameters of dental caries status.
Methods: Saliva samples were collected from preschool children with deciduous teeth (ages 4-6 years). The group was divided into two categories: high caries risk and low caries risk. The high caries risk had a total of 34 students and low caries risk had a total of 31 students. Salivary total protein concentrations (mg/ml) were measured by Bradford protein assay. Salivary melatonin concentrations (pg/ml) were measured by the competitive enzyme-linked immunosorbent assay (ELISA). Normalized salivary melatonin concentrations (pg/mg) between high and low caries risk groups were compared using Mann-Whitney U test.
Results: Normalized salivary melatonin concentrations in 4-6 year-old children of high caries risk group and low caries risk group were 2007.60±1675.75 pg/mg and 2510.84±2033.84 pg/mg respectively. There were no statistically significant differences in the levels of salivary melatonin between the high and low caries-risk groups of the preschool children (Z=-1.077, p=0.281). No significant correlations were demonstrated between salivary melatonin levels and dental caries status in the preschool children.
Conclusions: Our findings on salivary melatonin concentrations in children with deciduous dentition imply that salivary melatonin may not be associated with dental caries in deciduous dentition. Further investigations are needed to evaluate the association between salivary melatonin and dental caries in other dentitions.