Postoperative pain after 1- and 2-visit root canal therapy.

OBJECTIVES The factors that influence postoperative pain after root canal treatment are not completely understood. The purpose of this prospective clinical study was to evaluate postoperative pain after root canal therapy performed in 1 appointment versus 2 appointments. STUDY DESIGN Seventy-two patients requiring root canal therapy on permanent molars were included in this study. Patients were randomly assigned to either the 1-appointment or the 2-appointment group. Both vital and nonvital teeth were included. The standardized protocol for all teeth involved local anesthesia, isolation and access, engine-driven rotary nickel-titanium canal instrumentation to a minimum size #5 (.028 mm).04 taper Profile with step-back flaring, and irrigation with 2.5% NaOCl. Teeth in group 1 (n = 39) were obturated at the first appointment by using laterally condensed gutta-percha and Roth 811 sealer. Teeth in group 2 (n = 33) were closed with a sterile dry cotton pellet and Cavit restoration and were obturated at a second appointment 7 to 14 days later. A modified Visual Analogue Scale was used to measure preoperative pain and pain at 6, 12, 24, and 48 hours after the first appointment. Statistical analysis was performed to compare groups at each interval by using an independent-samples t test with Bonferroni adjustment. RESULTS There was no statistically significant difference between groups at preoperative intervals or at any of the 4 postoperative intervals (P <.01). CONCLUSIONS There was no difference in postoperative pain between patients treated in 1 appointment and patients treated in 2 appointments. The majority of patients in both groups reported no pain or only minimal pain within 24 to 48 hours of treatment.