The use of sodium hypochlorite as an irrigant solution during endodontic treatment is generally regarded as safe. However, a case report by Bowden, et al describes life-threatening airway obstruction following extrusion of sodium hypochlorite beyond the apex of the root canal into the surrounding tissues. Endodontic treatment had been initiated on the lower left second molar tooth 8 hours prior to the patient presenting with rapidly worsening swelling in the floor of the mouth. The root canals had been irrigated with sodium hypochlorite solution of unknown volume and concentration, but the irrigation was ceased due to immediate, severe mandibular pain. Two hours later, a swelling involved the submandibular, submental, and sublingual regions bilaterally, and the tongue was markedly elevated. The patient was referred for immediate emergency treatment. Clinical examination revealed trismus, extensive bilateral soft-tissue swelling and edema, and marked ecchymosis of the floor of the mouth and tongue. High-flow oxygen, high-dose intravenous antibiotics, and intravenous dexamethasone were initiated, but the patientís condition deteriorated over the next 2 hours, requiring urgent surgical decompression of the tissue spaces and extraction of the lower left second molar tooth. Nasal-tracheal intubation was performed, and the patient remained intubated for an additional 36 hours in intensive care. He was discharged from the hospital 48 hours later. At one month, the ecchymosis and swelling had fully resolved, and mouth opening was normal. The authors note that sodium hypochlorite is a cytotoxic agent, and when it contacts vital tissues it causes hemolysis and ulceration, inhibits neutrophil migration, and damages endothelial and fibroblast cells. It is likely that the combination of periapical bone destruction due to chronic infection and increased pressure irrigation led to the extrusion of sodium hypochlorite into the adjacent soft tissues.
(Source: Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology. March 2006)
