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

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.