Postoperative pain after primary molar pulpectomy using rotary or reciprocating single files: A superior, parallel, randomized clinical trial.

Aim: To compare postoperative pain intensity between two single‐file systems with different kinetics (the OneShape file with continuous rotation vs. the WaveOne Gold file with reciprocation movement) after primary molar pulpectomy. Design: This superiority, parallel, randomized clinical trial included 164 healthy children aged 6 to 8 years with asymptomatic, necrotic, maxillary primary second molars due to caries. An equal number of children were assigned to the two groups. The teeth of children in Group 1 were instrumented with the OneShape rotary system (Micro‐Mega), whereas teeth of children in Group 2 were instrumented with the WaveOne Gold reciprocating system (Dentsply Maillefer). Postoperative pain intensity was assessed using a 4‐point pain scale at 6, 12, 24, 48 and 72 h and 1 week after treatment. The parent of each participant received 6 flashcards that included four faces and a word describing each face. A chi‐square test was used to compare postoperative pain intensity. The level of significance was set to 5%. Results: Over the follow‐up period, no significant difference in postoperative pain intensity was found between the two groups (p >.05). Although the absolute risk reduction maximum limit of 95% CI equal or exceeded the predetermined proportional difference of 0.15, pain intensity was inconclusive at 6, 24, and 48 hours denoting that the superiority of the OneShape single‐file over the WaveOne Gold single‐file could not be declared. Conclusions: Postoperative pain intensity associated with a rotary vs. reciprocating file system was nearly similar. [ABSTRACT FROM AUTHOR]