(PR002) Evaluation of Microbiological and Immunological Content of Periapical Lesions Collected During Endodontic surgery

Conventional or surgical retreatment may be indicated when primary endodontic fails. Few studies have identified the presence of microorganisms and pro-inflammatory cytokines (PIC) in the periapical lesions (PL) of teeth indicated for endodontic microsurgery (EMS). This study aimed to investigate the prevalence of bacterial species in PL of teeth with endodontic infections and the levels of PIC including IL-1β, IL-6 and TNF-α. Forty patients (n=40) scheduled for endodontic microsurgery were selected. Of these, 20 cases involved teeth with primary endodontic treatment, while the remaining 20 teeth involved teeth with endodontic retreatment. Bacterial and cytokine samples were from PL. Microbial analysis used checkerboard DNA-DNA hybridization, and cytokine levels were measured by ELISA. All 40 bacterial species investigated were detected in the LP of retracted teeth, however Tanannerella socranskii and Treponema denticolawere absent in the PL of teeth primary treatment. The bacteria most frequently detected all PL were S. epidermidis, F. periodonticum, E. faecium, P. nigrescens, L. buccalis and E. hirae. The most frequently detected cytokine was IL-1β, followed by IL-1α and IL-6 with TNF-α being the least frequently detected. Teeth that had undergone primary treatment exhibited higher cytokine levels than those that had been retreated. It was concluded that bacterial species are present in LP of both treated and retreated teeth undergoing EMS. The levels of PIC detected were associated with clinical conditions, in descending order of frequency: IL-1β, IL-1α, IL-6 and TNF-α.