A serious complication following the inadvertent injection of sodium hypochlorite outside the root canal system.

During an attempt to negotiate a calcified root canal in a maxillary lateral incisor, a midroot distobuccal perforation was created, and sodium hypochlorite (NaClO) was extruded through the opening into the supporting tissues. This procedural accident caused an immediate burning sensation, severe pain, and marked facial swelling, with the subsequent loss of the tooth.