Difference Between Pro- and Anti-Inflammatory Interleukins in Saliva of Children with Early Childhood Caries

Background: Early childhood caries (ECC) is a common chronic disease in young children, influenced by multiple factors, including the activity of bacteria and other microorganisms, diet, and immune response. Pro-inflammatory cytokines like interleukin-8 (IL-8) and anti-inflammatory cytokines like interleukin-10 (IL-10) play crucial roles in the inflammatory process of caries. However, their relationship with ECC severity remains unclear. This study aimed to compare salivary IL-8 and IL-10 levels in children with and without ECC and analyze their association with caries severity using the International Caries Detection and Assessment System (ICDAS). Children with and without central obesity were included to evaluate the potential influence of nutritional status on cytokine expression. Methods: A cross-sectional study was conducted from March 2022 to December 2023 in San Luis Potosí, México, including 76 children aged 3 to 5 years (40 with ECC and 36 caries-free). Anthropometric measurements were taken to classify children as centrally obese or non-centrally obese. Unstimulated saliva samples were collected, and IL-8 and IL-10 levels were measured using ELISA. Statistical analysis included the Mann–Whitney U test, Spearman’s rank correlation coefficient, and binary logistic regression analysis, considering p < 0.05 as statistically significant. Results: IL-8 levels were higher in the ECC group (85 ± 119 pg/mL) than in the control group (45 ± 74 pg/mL), but this difference was not significant (p = 0.3613). IL-10 levels were lower in the ECC group (3 ± 2 pg/mL) than in the control group (11 ± 44 pg/mL; p = 0.6481). The difference between IL-8 and IL-10 levels was greater in the ECC group (27 ± 41 pg/mL) than in the control group (17 ± 33 pg/mL; p = 0.1709). No significant correlation was found between cytokine levels and ICDAS scores (p > 0.05), and binary logistic regression did not show an association between IL-8, IL-10, WHtR, and cavitated caries lesions. Conclusions: Although IL-8 tended to be elevated and IL-10 reduced in children with ECC, the differences were not statistically significant. The observed trend suggests a possible local immunological imbalance in children with caries, which may contribute to disease progression independently of bacterial activity or behavioral influences.