comparison of single visit post endodontic pain using mtwo rotary and hand k-file instruments: a randomized clinical trial

objectives: pain is an unpleasant outcome of endodontic treatment that can be unbearable to patients. instrumentation techniques may affect the frequency and intensity of post-endodontic pain. this study aimed to compare single visit post endodontic pain using mtwo (niti) rotary and hand k-file instruments. materials and methods: in this randomized controlled trial, 60 teeth with symptomatic irreversible pulpitis in 53 patients were selected and randomly assigned into two groups of 30 teeth. in group a, the root canals were prepared with mtwo (niti) rotary instruments. in group b, the root canals were prepared with hand k-file instruments. pain assessment was implemented using visual analog scale (vas) at four, eight, 12 and 24 hours after treatment. the acquired data were analyzed using chi-square, mann-whitney u and student’s t-test (p<0.05). results: patients treated with rotary instruments experienced significantly less post-endodontic pain than those treated with hand instruments (p<0.001). conclusion: the use of mtwo (niti) rotary instruments in root canal preparation contributed to lower incidence of postoperative pain than hand k-files.