“…In the course of the ongoing endodontic infection, microbes, their antigens and toxins reach the apical periodontal ligament and surrounding tissues through the apical foramen and trigger immunological defence mechanisms (Georgiou et al, 2019; Martinho et al, 2014). A delicate balance between protective and destructive reactions ultimately results in the formation of granulation tissue around the apical foramen, consisting of necrotic, exudative, granulomatous and fibrous zones (Márton & Kiss, 2000, 2014; Morse, 1977; Petean et al, 2022; Yanagisawa, 1980). In the necrotic and exudative zones, abundant neutrophils eliminate the majority of microbes rendering the granulomatous and fibrous zones sterile (Márton & Kiss, 2014).…”