Postoperative Pain Following Single-Visit Nonsurgical Retreatment Using Minimally Invasive Rotary vs. Reciprocating Nickel-Titanium File Systems: A Two-Arm Parallel Randomized Clinical Trial

Abstract

Objective: This study aimed to compare postoperative pain following the single-visit retreatment procedures of asymptomatic and symptomatic teeth using two different nickel-titanium file systems. Materials and Methods: Eighty patients were divided into symptomatic and asymptomatic groups, each further subdivided based on the use of rotary or reciprocating files. Retreatment involved removal of filling material with one flare and MicroMega REMOVER files, followed by shaping with one curve mini (rotary) or One RECI (reciprocating) files. Postoperative pain was recorded using a visual analogue scale (VAS) at 24 h, 48 h, 72 h, 7 days, and 14 days. Data were analyzed using Shapiro-Wilk, Mann-Whitney U, Kruskal-Wallis, Dunn-Bonferroni, and Pearson chi-square tests (p < 0.05). Results: No significant differences in postoperative pain were found among the four groups. Pain levels were not associated with sex, age, or tooth position. Analgesic use significantly decreased over time in all groups except the asymptomatic rotary group. Patients requiring analgesics reported higher pain scores within the first 48 h (p < 0.05). Conclusions: Postoperative pain was low and comparable across all groups. File kinematics (rotary vs. reciprocating) did not influence pain outcomes. Single-visit retreatment is a viable alternative to multivisit procedures for both symptomatic and asymptomatic cases. Clinical Relevance: This study supports the clinical feasibility of single-visit root canal retreatment, potentially improving patient comfort and reducing chair time. Trial Registration: ClinicalTrials.gov identifier: NCT06357481.

Keywords: apical periodontitis; minimally invasive files; postoperative pain; retreatment; single visit treatment.

Figure 1

Flowchart of study participants during the inclusion, exclusion, and grouping processes.

Figure 2

Case 1. ST-OCM group. (a) Lower second premolar tooth that had root canal treatment 3 years ago. The patient was diagnosed with symptomatic apical periodontitis. Periapical lesion and an unsuccessful restoration are present. (b) The image shows the intraoral condition of the tooth before the retreatment. (c) After the proximal walls have been made, the root canal filling was removed using MicroMega REMOVER, one flare, and one curve mini files. (d and e) The complete removal of the root canal filling was confirmed through the use of an operating microscope and periapical radiography. (f and g) Intraoral view and postoperative periapical radiography image after root canal filling was completed. Case 2. ST-OR group (h) lower second premolar tooth with symptomatic apical periodontitis, root canal treatment was performed 4 years ago. A periapical lesion is present. (i) Intraoral view after removal of the old coronal restoration. (j) Build up the proximal wall with composite resin. Checking using an operating microscope that the root canal filling has been completely removed with MicroMega REMOVER, one flare, and one RECI. (k) İrrigation activation with ultrasonic device. (l) The complete removal of the root canal filling was confirmed through the periapical radiography. (m and n) Intraoral view and postoperative periapical radiography image after root canal filling was completed.

Figure 3

Percentage of postoperative pain levels between the different times.