The aim of this study was to evaluate the intensity and duration of postoperative pain after
the removal of root canal filling material in retreatment procedures of upper incisor teeth
with chronic apical periodontitis, using different techniques.
The patients were assigned to three groups of 45 patients, according to the method used to
remove old canal filling material. The presence of postoperative pain was assessed after 6,
12, 24, 48, and 72 hours, 7 days, and finally after 10 days.
The hypothesis of this study: there would be no difference in postoperative pain intensity
among the groups.