Evaluation of the relationship between salivary levels of Streptococcus mutans, statherin, and cathelicidin LL-37 and early childhood caries

Background: Although caries is known to be influenced by diet and oral hygiene factors, susceptibility to the disease may be reduced by host factors, such as saliva antimicrobial peptides (AMPs). However, the relationship between salivary AMPs and early childhood caries (ECC) remains limited. Among the AMPs, cathelicidin LL-37 is mentioned in the literature for its bactericidal activity against oral pathogens, while statherin is recognized for its mechanism of reducing hydroxyapatite demineralization on the tooth surface. Cathelicidin LL-37 is a significant class of proteins within the immune system, and statherin prevents the precipitation of calcium phosphate in saliva, maintaining high levels of calcium for enamel remineralization and high phosphate levels for buffering. Aim: This study aimed to compare the salivary levels of statherin, cathelicidin LL-37, and Streptococcus mutans (S. mutans), as well as the oral hygiene and dietary habits, of children with and without early childhood caries (ECC). Design: A total of 24 children with ECC and 34 children without ECC were selected to participate in this study. The levels of S. mutans in unstimulated saliva collected from the children were measured by real-time polymerase chain reaction (PCR), and the levels of statherin and cathelicidin LL-37 in saliva were measured using an enzyme-linked immunosorbent assay (ELISA). Results: There was no statistically significant difference in salivary statherin levels between the two groups, but salivary cathelicidin LL-37 levels were significantly higher in the ECC group (p = 0.024). The ECC group had significantly elevated S. mutans levels compared to the non-ECC group (p < 0.05). The frequency of sugar-containing foods and/or beverages consumed more than three times a day between meals was statistically significantly higher in the ECC group compared to the non-ECC group (p = 0.021). The statistical analysis also revealed a positive correlation between the dmfs score and age (p = 0.022).