Development of a Core Outcome Set in Endodontics (COS-ENDO): Part 2 – COS-ENDO for Studies of Nonsurgical Root Canal Treatment and Retreatment in Permanent Teeth

Introduction
Methodological heterogeneity and reporting bias complicate interpreting endodontic outcomes. Supported by the American Association of Endodontists and its Foundation, this study developed the Core Outcome Set in Endodontics (COS-ENDO) to standardize reporting for studies of Nonsurgical Root Canal Treatment/Retreatment, Surgical Endodontics, Vital Pulp Therapy, Apexification, and Regenerative Endodontics. This article, Part 2 of a 5-part series, focuses on COS-ENDO for Nonsurgical Root Canal Treatment/Retreatment, while other parts address the remaining treatments.
Methods
Outcomes were identified through scoping reviews, a qualitative study with patients, and a web-based survey of American Association of Endodontists practicing members. In a 2-round Delphi survey, clinicians, patients, and researchers rated outcomes on a 9-point scale. Ratings were assessed against consensus criteria, and a virtual meeting finalized COS-ENDO.
Results
Of the 97 invited participants to Round 1, 77 registered, and 73 (24 Academicians/Researchers, 26 Clinicians, and 23 Patients (or their parents/caregivers)) assessed 39 outcomes, with 18 excluded. The remaining outcomes—7 achieving consensus for inclusion and 14 lacking consensus—advanced to Round 2 for re-rating by 70 participants. This resulted in 9 outcomes achieving consensus for inclusion, and 12 lacking consensus. In the final meeting, 16 participants finalized the COS-ENDO for Nonsurgical Root Canal Treatment/Retreatment, including Tooth survival, Pain, Signs of infection, Radiographic evidence of periradicular healing, Success, Functional tooth, Need for further intervention, and Adverse events/Complications.
Conclusions
COS-ENDO is an important step in standardizing outcome reporting in endodontics, ensuring consistent reporting and enhancing research utility. Further efforts are needed to establish optimal measurement methods.

Contributors

Maryam Zanjir, Elaine Cardoso, Nicola L. Harman, Ava Khansari, Hamid Jafarzadeh, Gevik Malkhassian, Mike Sabeti, Anita Aminoshariae, Anil Kishen, · Joanna E.M. Sale, Prakesh S. Shah, Amir Azarpazhooh

Publication

Journal: Journal of Endodontics
Volume: 51
Issue: 4
Pages: 412 - 426
Year: 2025
DOI: 10.1016/j.joen.2025.01.010

Further Study Information

Current Stage: Completed
Date: July 2023 - March 2025
Funding source(s): American Academy of Endodontists/Foundation for Endodontics


Health Area

Disease Category: Dentistry & oral health

Disease Name: Endodontics

Target Population

Age Range: 18 - 120

Sex: Either

Nature of Intervention: Procedure

Stakeholders Involved

- Clinical experts
- Consumers (caregivers)
- Consumers (patients)
- Journal editors
- Researchers
- Service providers

Study Type

- COS for clinical trials or clinical research
- COS for practice

Method(s)

- Consensus meeting
- Delphi process
- Survey

Delphi survey and consensus meeting with key stakeholders