Sodium hypochlorite (NaOCl) has been the most frequently used irrigant in endodontic therapy. Your properties include antimicrobial effect and tissue dissolution capacity (Estrela). However, some accidents can happen due NaOCl extrusion to the buccal tissues. Extrusion of NaOCL may occur because of extreme pression of irrigation solution, widening of the apical foramen, incorrect working length, areas of external resorption or root perforations (references). Sodium hypochlorite is caustic to the cancellous bone, degrading the organic matrix, (Kerbl, 2012) and to the soft tissues causing cell injury in endothelial cells and fibroblasts and ulcerations (Gatot,
