The sodium hypochlorite accident: experience of diplomates of the American Board of Endodontics.

To better understand the etiology associated with sodium hypochlorite accidents, we surveyed diplomates of the American Board of Endodontics. Of the 314 diplomates who responded, 132 reported experiencing a sodium hypochlorite accident. Questions were asked about the age and sex of the patient as well as the tooth being treated, preoperative signs, symptoms, diagnosis, and radiographic appearance. Data were analyzed by chi-square tests. Significantly more women experienced sodium hypochlorite accidents compared with men (p < 0.0001). More maxillary teeth than mandibular teeth (p < 0.0001) and more posterior than anterior teeth (p < 0.0001) were involved. A diagnosis of pulp necrosis with radiographic findings of periradicular radiolucency were positively associated with such accidents (p < 0.0001). Most respondents reported that patient signs and symptoms completely resolved within a month. The occurrence of an accident, by itself, did not adversely affect the endodontic prognosis of the involved tooth. Anatomic variations may contribute significantly to the occurrence of a sodium hypochlorite accident.