Assessment of inflammatory cytokines in gingival crevicular fluid for diagnostic differentiation of apical periodontitis

Introduction : Apical periodontitis (AP) is a chronic inflammatory condition resulting from microbial infection of the dental pulp. The host immune response and microbial interactions play a significant role in the disease’s progression. Gingival crevicular fluid (GCF) provides a valuable, non-invasive source for detecting inflammatory biomarkers involved in AP, such as IL-1β, IL-10, and IL-23. Aim : To evaluate the levels of IL-1β, IL-10, and IL-23 in GCF among individuals with symptomatic apical periodontitis (SAP), asymptomatic apical periodontitis (AAP), and healthy controls, and to assess their potential as diagnostic biomarkers. Materials and methods : This cross-sectional study included 90 participants aged 20–50 years, divided into three groups: SAP (n=30), AAP (n=30), and healthy controls (n=30). GCF samples were collected using Periostrips, and cytokine levels were measured using enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed using SPSS version 26, with significance set at p 0.05. Results : IL-1β, IL-10, and IL-23 levels were significantly elevated in the SAP group compared to the AAP and control groups ( p 0.01). IL-10 showed the highest diagnostic accuracy (AUC=0.806), followed by IL-1β (AUC=0.714). IL-23, although significantly elevated in SAP, had lower diagnostic value (AUC=0.636). Strong positive correlations were observed between IL-1β and IL-10, as well as IL-1β and IL-23. Conclusion : The elevated levels of IL-1β, IL-10, and IL-23 in GCF reflect their involvement in the inflammatory processes of apical periodontitis. IL-10 demonstrated the greatest potential as a diagnostic biomarker. These findings support the clinical utility of GCF cytokine profiling for non-invasive diagnosis and monitoring of AP progression.