Factors Affecting the Outcome of Non-Surgical Root Canal Treatment

Method: A case series study of NSRCTs completed by undergraduate or post-graduate students at the School of Dentistry, University of Otago during 2008. Success was based on both radiographic and clinical healing. Putative risk factors that were assessed included: patient gender and age, operator experience, tooth factors (number of canals, tooth type) and restorative factors (quality of root filling, coronal seal and type of restoration). Clinical history and radiographs were retrieved from patient records. Data analyses were conducted in IBM SPSS 20.0 using the Chi-square and Fisher’s Exact tests.

Result: One hundred NSRCT cases were included. The overall success rate was 87%. Although not statistically significant, marginally greater NSRCT success rates were observed among females, older patients, single-canal teeth and those performed by postgraduate students. Obturation length within 2 mm of the apex was a main predictor of success at 93.8% (p<0.05) compared to those terminating more than 2 mm from the apex (64.7%), or those extruding through the apex (33.3%). The success rate was the lowest for maxillary molar teeth at 69% compared to mandibular molars at 92.3% (p<0.05).

Conclusion: Obturation length and tooth type were the strongest predictors of NSRCT success/failure.