Effect of Apical Third Enlargement to Different Preparation Sizes and Tapers on Postoperative Pain and Outcome of Primary Endodontic Treatment: A Prospective Randomized Clinical Trial

J Endod. 2021 Sep;47(9):1345-1351. doi: 10.1016/j.joen.2021.05.010. Epub 2021 May 29.

Abstract

Introduction: The purpose of this study was to evaluate the effect of apical preparation size and taper on postoperative pain and healing after primary endodontic treatment.

Methods: One hundred and twenty patients with asymptomatic mandibular first molars with radiographic evidence of periapical pathology and with a periapical index (PAI) score ≥3 were randomly assigned to 2 groups, group 1 and 2, based on apical enlargement to 2 and 3 sizes larger than the initial apical binding file (IABF), respectively. Each group was further divided into subgroups A and B depending on the apical enlargement taper of 4% and 6%, respectively. Endodontic treatment was performed, and the final apical enlargement in all the groups was performed as follows: group 1A, 2 sizes larger than the IABF with a 4% taper; group 1B, 2 sizes larger than the IABF with a 6% taper; group 2A, 3 sizes larger than the IABF with a 4% taper; and group 2B, 3 sizes larger than the IABF with a 6% taper. Postoperative pain was assessed at 6, 12, 24, 48, and 72 hours. Clinical evaluation and the change in the PAI score on radiographs were assessed at the 3-, 6-, and 12-month follow-ups.

Results: No significant difference in postoperative pain was found. The success rate was lowest (57.1%) in group 1 subgroup A as evidenced by the significant change in the PAI score between group 1 subgroup A and the rest of the groups at the 6- and 12-month follow-ups.

Conclusions: Apical preparation to 2 sizes larger than the IABF with a 4% taper is insufficient and results in significantly lower success rates compared with larger preparation sizes and tapers.

Keywords: Apical enlargement; apical periodontitis; periapical healing; postoperative pain; preparation taper.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Humans
  • Molar / diagnostic imaging
  • Molar / surgery
  • Pain, Postoperative / etiology
  • Periapical Periodontitis* / diagnostic imaging
  • Periapical Periodontitis* / surgery
  • Prospective Studies
  • Radiography
  • Root Canal Preparation