Postoperative pain perception and associated risk factors in children after continuous rotation versus reciprocating kinematics: A randomised prospective clinical trial.

To compare the postoperative pain of continuous rotation and reciprocating movements after pulpectomy of non-vital primary molars and determine associated risk factors. 146 children aged 4-8 years with one primary molar indicated for pulpectomy were randomly assigned to two equal groups: those instrumented with continuous rotation motion (Hyflex EDM Coltene/Whaledent) and reciprocating motion (Reciproc R25 (VDW)). A 4-point pain scale was used to assess postoperative pain frequencies, which were compared at different intervals using the Chi-square test. Postoperative pain risk factors were determined using logistic regression analysis. There was no statistically significant difference between the follow-ups. Gender, pulp status, and radiographic radiolucency increased the risk of postoperative pain incidence. Postoperative pain likelihood in children with chronic apical periodontitis was 8.72 times that of children with necrotic pulps. Postoperative pain after instrumentation with both kinematics was comparable. Postoperative pain incidence is increased by preoperative pulp condition, radiographic radiolucency, and gender.