Clinical study of refractory apical periodontitis treated by apicectomy. Part 1. Root canal morphology of resected apex.

The morphology of the root apex was analysed by observation of the anatomy of specimens obtained by apicoectomy in cases of refractory apical periodontitis that did not respond to nonsurgical root canal treatment. Apical ramifications were present in 19 (70%) of the roots, while one were found in the remaining eight (3%) roots. This frequency is far higher than that reported by other investigators, suggesting that there is a close relationship between the anatomical complexity of the root canal and the occurrence of refractory apical periodontitis.