Association between Salivary Cortisol, Secretory IgA, and Inflammatory Cytokines with Early Childhood Caries: A Cross-sectional Analytical Study

A bstract Objectives: Early childhood caries (ECC) is a multifactorial disease driven by biological and psychosocial determinants. Identifying noninvasive biomarkers could improve risk stratification and personalized prevention. The aim of the study is to evaluate the association of salivary cortisol, total secretory immunoglobulin A (sIgA), and pro-inflammatory cytokines (interleukin-6 [IL-6], interleukin-1β [IL-1β], and tumor necrosis factor-alpha [TNF-α]) with ECC in preschool children.IL-1β. Mathods: This cross-sectional analytical study included 120 children aged 3–6 years (60 ECC; 60 caries-free). Unstimulated saliva was collected via passive drooling. Biomarkers were quantified using high-sensitivity enzyme-linked immunosorbent assay kits. Multivariable logistic regression and receiver operating characteristic (ROC) curve analysis were performed, adjusting for age, sex, feeding practices, oral hygiene, and socioeconomic status (SES). Results: Children with ECC exhibited significantly higher levels of salivary cortisol (8.92 + ˗2.11 vs. 5.21 + ˗1.98 ng/mL, P < 0.001), IL-6 (42.81 + ˗10.29 vs. 26.44+ ˗9.87 pg/mL, P < 0.001), and TNF-α ( P = 0.002) compared to controls. Conversely, sIgA levels were significantly lower in the ECC group (11.34 + ˗4.12 vs.18.25 + ˗5.03 mg/dL, P < 0.001). ROC analysis identified cortisol (area under the curve [AUC] = 0.89) and sIgA (AUC = 0.86) as excellent diagnostic indicators. In the final multivariable model, cortisol (OR 3.94, 95% confidence interval [CI] 2.11–7.35) and sIgA (OR 0.44, 95% CI 0.28–0.70) remained independently associated with ECC after adjusting for SES and behavioral covariates. Conclusions: Salivary cortisol, sIgA, and inflammatory cytokines are significantly associated with ECC, reflecting complex interactions between stress physiology, mucosal immunity, and oral dysbiosis. While these biomarkers show promise as early-warning indicators, longitudinal data are required to establish their discriminatory utility for caries onset.