The effect of root canal preparation using single versus multiple endodontic rotary files on post-operative pain, a randomised clinical trial

Objective The purpose of this randomised clinical trial study was to compare the incidence and intensity of post-operative pain following the use of single-file and multi-file rotary instruments with continuous rotational motion for root canal preparation in asymptomatic permanent human teeth. Methods A total of 105 healthy consenting patients who fulfilled specific inclusion criteria and had premolar or molar teeth diagnosed with asymptomatic irreversible pulpitis without periapical pathosis requiring endodontic treatment participated in this study. The patients were randomly allocated by stratification into five groups of 21 according to the instruments and systems used for root canal preparation: (a) Neoniti A1 (#25) single file, (b) RaCe #25/.06 single file, (c) Mtwo #25/.06 single file, (d) Easy RaCe, (e) and Mtwo multifile. Endodontic treatment was carried out in a single appointment. The severity of post-operative pain was assessed by numerical rating scale scores until complete pain relief was achieved. Analgesic consumption and the incidence of pain were also evaluated. Data were analysed by one-way ANOVA and Tukey HSD tests. Results When comparing different instruments and systems for canal preparation, the analgesic consumption, incidence and intensity of post-operative pain did not differ (p>0.05). The highest levels of post-operative pain were experienced after 6 h in all groups. Conclusion The post-operative pain did not differ between the single and multi-file root canal preparation techniques evaluated in this study.