Endodontic interappointment emergencies in a Singapore private practice setting: a retrospective study of incidence and cause-related factors.

One thousand and sixteen consecutive records of patients treated by the author for endodontic treatment was surveyed for the incidence of endodontic interappointment emergencies (EIE) and the major factors contributing to it. The overall incidence of EIE was 3.15% and unrelated to the patients' sex or tooth location. Caucasians were more likely to experience flare-ups than Chinese (p < 0.01). Patients < 20 years and > 60 years were less likely to experience EIE (p < 0.05). EIE was significantly higher in necrotic teeth than in vital teeth (p < 0.01). A clinical diagnosis of necrotic pulp with acute apical abcess (NP/AAA) increased the incidence of flare-ups significantly (p < 0.05). Retreatment cases also had a higher incidence of EIE and this was statistically significant (p < 0.01). The possibility of EIE was the highest after the first visit (p < 0.01) and this was reduced significantly with subsequent visits.