Introduction: This study was aimed to evaluate the effect of XP-endo shaper file and F-One blue files on the degree of the experienced postoperative pain. Methods: 20 male patients complaining of acute pulpitis without apical periodontitis related to the mandibular molars were divided into 2 groups: group 1: treated with XP-endo shaper and group 2: treated with F-One file. The postoperative pain scores were recorded at 6,24,48,72h and 7days using the modified verbal descriptor scale. Mann-Whitney U test was used to compare between the two groups. Dunn's test was used for pair-wise comparisons when Friedman's test is significant. The significance level was set at P ≤ 0.05. Results: there was no statistically significant difference between the two groups at different time intervals except at 48h in which the F-One showed statistically significant lower mean pain scores than the XP-endo shaper file.
Conclusions: Both XP-endo shaper and F-One blue files showed nearly the same amount of postoperative pain over time.