postoperative pain after endodontic treatment of asymptomatic teeth using rotary instruments: a randomized clinical trial

introduction: the aim of the present study was to compare the effect of two different rotary instruments on postoperative pain in teeth with asymptomatic irreversible pulpitis. methods and materials: a total of 78 mandibular first and second molars were divided into two groups ( n =39) and their root canal preparation was carried out with either race or protaper rotary instruments. all the subjects underwent one-visit root canal treatment and the severity of postoperative pain was evaluated using visual analog scale (vas) at 4-, 12-, 24-, 48- and 72-h and 1-week intervals. in addition, the need for taking analgesics was recorded. data were analyzed with the repeated-measures anova and the mann-whitney u test was used for two-by-two comparison. statistical significance was set at 0.05. results: comparison of mean pain severity between the two groups at various postoperative intervals did not reveal any significant differences ( p =0.10). the difference in amount of analgesics taken by each groups was not statistically significant ( p =0.25). conclusion: there were no significant differences in the postoperative pain reported between the two groups; which indicates the clinical acceptability of both systems.