Objective To assess the two-year outcome of initial endodontic treatment and evaluate the relationship between the treatment outcome and relevant factors. Methods A total of 296 patients with 371 teeth received initial endodontic treatment between January 2005 and December 2007 were included in the study. The teeth were treated using crown down technique, and followed for two years. The outcome was examined clinically and radiographically. The relevant factors, including pulp vitality, apical periodontitis, the number of tooth root, and state of root canal obturation, were analyzed. Results 143（176 teeth） from 296 patients（371 teeth） were followed for two years. 152 teeth （86.36%） with normal limits were assessed as“healed”（no apical periodontitis, no signs or symptoms）. 24 teeth were assessed as “disease”, 12 teeth were extracted and 12 teeth were retreated. The healing rate（HR） was statistically higher for vital teeth（95.38%） than that for devital teeth（81.08%）. The HR of teeth without apical periodontitis（95.24%） was significantly higher than that with apical periodontitis（73.24%）. Other factors were associated with different HR, but no statistical significance（P>0.05）. Conclusion Apical periodontitis and pulp vitality may be prognostic factors for outcome of initial endodontic treatment.
