Single-Visit and Two-Visit Endodontic Treatments (RCT)

The Efficacy of Single-Visit and Two-Visit Endodontic Treatments for Necrotic Teeth With Apical Periodontitis

You are being asked to participate in this research study because you are being treated at the UCSF Graduate Endodontics department for an endodontic procedure. We are trying to determine the treatment outcomes of one v. two-visit endodontic treatments. .If you decide to continue, we would like to request your consent for a follow up period of 1 year to observe the healing of the abscess. Observation periods occur at 6 months following the completion of the root canal and at 12 months and are a part of the standard of care. We will review findings in the Axium chart, which will be recorded by the treating doctor

Study Overview

• Status: Completed
• Conditions: Periapical Periodontitis; Endodontic Infection
• Intervention / Treatment: Other: control group; Other: Calcium Hydroxide (CH)

Detailed Description

This research study includes patients who are receiving endodontic treatment within the UCSF Graduate Endodontics Department. The purpose of the study is to evaluate and compare treatment outcomes between one-visit and two-visit root canal procedures. Participants who choose to continue in the study will be followed for a period of one year so that healing of the periapical abscess can be monitored. Follow-up appointments are scheduled at six months and twelve months after treatment completion, both of which are part of routine standard care. Clinical and radiographic findings documented in the Axium chart by the treating provider will be reviewed as part of the study analysis.

• Study Type: Interventional
• Enrollment (Actual): 59
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • San Francisco, California, United States, 94143
      • University of California San Francisco School of dentistry

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Classified as American Society of Anesthesiologists (ASA) Class I or II
• presenting with radiographic evidence of apical periodontitis-defined as a Cone-Beam Computed Tomography Periapical Index (CBCTPAI) score of 3 or greater according to the Estrela classification

Exclusion Criteria:

• Exclusion criteria included patients with uncontrolled chronic systemic conditions (e.g., diabetes, hypertension, chronic obstructive pulmonary disease), cardiovascular disease, renal or hepatic impairment, and autoimmune disorders
• History of smoking
• Periodontal disease with probing depths ≥ 3 mm.
• Root fractures
• Immature apices
• Resorption
• perforations
• Inability to achieve rubber dam isolation
• Lack of informed consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: One-visit endodontic treatment; In this arm, obturation will be completed using a single-cone technique after cleaning and shaping.	Other: control group; control group- no intervention
Experimental: multiple visits endodontic treatment; in this arm the endodontic therapy will be completed in multiple visits.	Other: Calcium Hydroxide (CH); calcium hydroxide will be used as interim medication in the first visit and patients will return for the obturation in the second visit.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical and Radiographic Healing	The primary outcome was defined using a combined clinical and radiographic healing based on the Cone-Beam Computed Tomography Periapical Index (CBCT-PAI)	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Volumetric Change in Periapical Lesion Size	The secondary outcome was defined as the change in lesion volume (mm³) between baseline and follow-up CBCT scans, serving as a quantitative metric of periapical healing	12 months

Collaborators and Investigators

• Sponsor: University of California, San Francisco

Publications and helpful links

General Publications

• 1. Siqueira JF Jr, Rôças IN. Clinical implications and microbiology of bacterial persistence after treatment procedures. J Endod 2008;34:1291-1301. 2. Tait C, Camilleri J, Blundell K. Non-surgical endodontics: obturation. Br Dent J 2025;238:487-496. 3. Schwendicke F, Göstemeyer G. Cost-effectiveness of single- versus multistep root canal treatment. J Endod 2016;42:1446-1452. 4. Makanjuola JO, Umesi DC, Oderinu OH. Comparison of the incidence of flare-up and time efficiency in single-visit root canal treatment employing either rotary or manual step-back canal preparatory technique. Niger Postgrad Med J 2018;25:100-104. 5. Ricucci D, Siqueira JF Jr. Biofilms and apical periodontitis: prevalence and association with clinical and histopathologic findings. J Endod 2010;36:1277-1288. 6. Siqueira JF Jr. Reaction of periradicular tissues to root canal treatment: benefits and drawbacks. Endod Topics 2005;10:123-147. 7. Shuping GB, Ørstavik D, Sigurdsson A, Trope M. Reduction of intracanal bacteria using nickel-titanium rotary instrumentation and various medications. J Endod 2000;26:751-755. 8. Sjögren U, Figdor D, Spångberg L, Sundqvist G. The antimicrobial effect of calcium hydroxide as a short-term intracanal dressing. Int Endod J 1991;24:119-125. 9. Tronstad L, Andreasen JO, Hasselgren G, et al. pH changes in dental tissues after root canal filling with calcium hydroxide. J Endod 1981;7:17-21. 10. Ng YL, Mann V, Rahbaran S, et al. Outcome of primary root canal treatment: systematic review-Part 2. Influence of clinical factors. Int Endod J 2008;41:6-31. 11. Mergoni G, Ganim M, Lodi G, et al. Single versus multiple visits for endodontic treatment of permanent teeth. Cochrane Database Syst Rev 2022;12:CD004450. 12. Schulz KF, Altman DG, Moher D. CONSORT 2010 statement: updated guidelines for reporting parallel group randomized trials. J Pharmacol Pharmacother 2010;1:100-107. 13. Estrela C, Bueno MR, Azevedo BC, et al. A new periapical index based on cone-beam computed tomogr

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2021
• Primary Completion (Actual): July 1, 2023
• Study Completion (Actual): July 1, 2025

Study Registration Dates

• First Submitted: December 5, 2025
• First Submitted That Met QC Criteria: January 14, 2026
• First Posted (Actual): January 21, 2026

Study Record Updates

• Last Update Posted (Actual): January 21, 2026
• Last Update Submitted That Met QC Criteria: January 14, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Periodontal Diseases; Mouth Diseases; Stomatognathic Diseases; Periapical Diseases; Jaw Diseases; Periodontitis; Periapical Periodontitis; Investigative Techniques; Epidemiologic Research Design; Epidemiologic Methods; Research Design; Methods; Inorganic Chemicals; Anions; Ions; Electrolytes; Hydroxides; Alkalies; Calcium Compounds; Control Groups; Calcium Hydroxide
• Other Study ID Numbers: Ucsfendo

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No