(PO73) Changes in Biomarkers in Gingival Crevicular Fluid and Periapical Fluid Following Cleaning and Shaping for Apical Periodontitis

Abstract: The purpose of this study was to measure inflammatory and bone and tissue degrading markers from teeth with apical periodontitis through gingival crevicular fluid (GCF) and periapical fluid (PF) to capture the host response after root canal therapy. Participants with pulpal necrosis and radiographic signs of periapical pathology, requiring primary root canal treatment (RCT), were recruited for the study. Clinical/radiographic data were collected at each visit. GCF was collected from a healthy control tooth and a diseased tooth pre-operatively (first visit), at the second treatment visit, and at 1-month and 6-month follow-up visits. PF samples were collected at the first visit after cleaning and shaping and at the second visit before obturation. Samples were analyzed using multiplex immunoassays (Meso Scale Discovery) for multiple targets. For this analysis, samples from 11 participants were analyzed. Proinflammatory cytokine levels in the GCF decreased between visit 1 and visit 2 (mean values in pg/µL): TNFα (p = 0.49), IL1β (p = 0.21), IL8 (p = 0.11). Bone resorptive activity (RANKL/OPG ratio) decreased between visits in the GCF (p = .03) and in the PF (p = .06) significantly. There was also a reduction in MMP-8 and MMP-9 levels between visit 1 and visit 2. Analysis of GCF and PF showed that levels of proinflammatory cytokines and bone and tissue degrading markers reduce quickly following initial cleaning and shaping. Thus, we conclude that the host response during root canal therapy can be investigated by the analysis of GCF and PF.