Severe tissue damage and neurological deficit following extravasation of sodium hypochlorite solution during routine endodontic treatment

Key Points Sodium hypochlorite is a toxic material and should be handled with care. Accidents, while rare, can result in distressing and severe complications for the patient. In the event of an accident the patient should be fully informed of the potential sequelae and detailed clinical notes kept. This case highlights the clinical features practitioners should look for, enabling them to decide on how best to manage the patient. For those that require hospital admission a treatment protocol is discussed. A risk assessment should be made prior to using sodium hypochlorite including careful clinical and radiological examination of the tooth, the type of syringe used and the technique employed. Endodontic therapy is a routinely practised clinical procedure with few reported complications. Sodium hypochlorite is often used as an irrigant during this procedure, but severe complications may occur if this solution extravasates beyond the root apex. We present a case demonstrating some of the severe sequelae that can occur following the misuse of sodium hypochlorite during endodontic treatment of an upper lateral incisor, which also resulted in the previously unreported complication of isolated facial nerve weakness.