Fig. 8: Ef.LTA together with NaB cooperatively increases IL-1β expression around the root apex in rat apical periodontitis model.

Six-week-old female pathogen-free Sprague-Dawley rats were anesthetized and the pulp of bilateral first mandibular molars was exposed. A collagen sheet soaked with PBS, 10 μg of Ef.LTA, 10 mM of NaB, or Ef.LTA/NaB was inserted into the pulp chamber and then plugged with a sterile cotton pellet. A After 4 weeks, the mandibles were fixed and decalcified. Decalcified mandibles were embedded in paraffin, sectioned longitudinally and attached to glass slides. The sections of the mandibular molars were stained with H&E, and the expression of IL-1β was identified by immunofluorescence staining using anti-rat IL-1β antibody. Nuclei were stained with Hoechst 33258. The samples were observed using fluorescence microscopy. DIC = differential interference contrast. Scale bars = 200 μm. B The pulp necrosis level was assessed histometrically for the root canal of each tooth. Score 0 indicates no pulp cell necrosis in the entire root. Scores of 1, 2, and 3 indicate partial necrosis in the coronal one-third of the root canal, necrosis in two-thirds of the whole root canal, and full necrosis of the root canal, respectively. C, D Quantitative analysis of the relative fluorescence intensity was performed using ZEN software. *p < 0.05.