Incidence of postoperative pain after intracanal procedures based on an antimicrobial strategy.

The purpose of this prospective study was to evaluate the incidence of postoperative pain after intracanal procedures based on an antimicrobial strategy. Data were examined from 627 teeth that had necrotic pulps or required retreatment. Information was obtained for each patient treated with regard to presence of preoperative pain. Occurrence of periradicular bone destruction detected by radiographs was also recorded. The operators consisted of undergraduate students, who were in their first year of clinical training. Root canals were instrumented and then medicated with a calcium hydroxide/camphorated paramonochlorophenol paste. No systemic medication was prescribed. Approximately 1 week after the initial appointment, patients were asked about the occurrence of postoperative pain and the level of discomfort was rated as no pain, mild pain, moderate pain, or severe pain. Data were statistically analyzed using the Chi-square test. Mild pain occurred in 10% of the cases, moderate in 3.3%, and severe (flare-up) in 1.9%. Postoperative pain was significantly associated with the treatment of previously symptomatic teeth without periradicular lesions (p < 0.01). No other correlations were detected between the occurrence of postoperative discomfort and other clinical conditions. There was also no difference regarding the incidence of postoperative pain between treatment and retreatment (p > 0.01). The intracanal procedures used in this study to control root canal infections showed a small incidence of postoperative pain, particularly flare-ups, even performed by inexperienced undergraduate dental students.