N-Acetyl Cysteine Protects Pulpal Stem Cells in Endodontic Revascularization (NAC)

January 17, 2026 updated by: David C. Han, DDS, MS, University of California, Los Angeles

N-Acetyl Cysteine Helps Pulp Stem Cells Differentiate During Endodontic Revascularization

Pulp re-vascularization/regeneration is a procedure performed to allow pulpal stem cells to survive and/or differentiate to allow immature tooth root structures to grow to full maturity. Currently, the procedure includes disinfection of the necrotic root canal space and induction of bleeding to potentiate pulpal stem cell differentiation to allow root growth on an immature root. A number of studies conducted previously demonstrate that N-acetyl cysteine (NAC) potentiates differentiation of pulpal stem/stromal cells and protects pulpal cells from apoptosis. 14-18 human subjects will be recruited forming two groups where pulp re-vascularization/regeneration procedures will be performed with or without the use of NAC treatment prior to induction of bleeding. Recall follow-up appointments will be done at 6 months and 1 year post treatment with subsequent yearly appointments until full root growth has been achieved.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Terminated

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

We will recruit 14-18 patients under the age of 18 by means of advertising at UCLA. Two groups will be formed, one with NAC treatment during endodontic revascularization and one without. Each patient will have an adult tooth where the following criteria are met:

  • Tooth with necrotic pulp and immature apex(apices)
  • Pulp space is not needed for post/core, final restoration
  • Compliant patient who is willing to come for at least 2-3 treatment appointments and 2-3 follow-up recall appointments.
  • Patients are not allergic to calcium hydroxide intra-canal medicament

Appropriate consent forms will be obtained by the patient and the patient's parent or legal guardian. If we recruit 18 patient, 9 patients will be under regenerative endodontic therapy/re-vascularization with NAC and 9 patients without NAC.

The following procedures will be applied to the patients.

First Appointment:

  • Local anesthesia administration, dental dam isolation and access
  • Copious, gentle irrigation with 20mL NaOCL (sodium hypochlorite) using an irrigation system that minimizes the possibility of extrusion of irrigants into the periapical spaces. The concentration of NaOCL will be low (1.5%, 20mL/canal for 5 minutes). Afterwards, irrigation with 17% EDTA (20mL/canal for 5 minutes) will be done. Irrigating needle position should be about 1mm from root end, to minimize cytotoxicity to stem cells in the apical tissues.
  • Dry canals with paper points
  • Place calcium hydroxide into canal(s) delivered via syringe
  • Seal access with 3-4mm of a temporary restorative material such as CavitTM, IRMTM or glass ionomer. Dismiss patient for 2-4 weeks.

Second Appointment:

  • Assess response to initial treatment. If there are signs/symptoms of persistent infection, consider repeating the procedures of the First appointment.
  • Anesthesia with 3% mepivacaine without vasoconstrictor, dental dam isolation
  • Copious gentle irrigation with 20mL of 17% EDTA
  • Take a radiograph to ensure previous calcium hydroxide has been fully removed form the canal system
  • Dry with paper points
  • For study patients only: Irrigate canal system with NAC (20mM NAC, 30mL/canal) gently for 10 minutes and then dry canal(s) with paper points
  • Create bleeding into the canal system by over-instrumenting (endo file, endo explorer). Induce bleeding by rotating a pre-curved (approximately 45 degrees at the apical 1-2mm of file) K-file at 2mm past the apical foramen with the goal of having the entire canal filled with blood to the level of the cemento-enamel junction.
  • Stop the bleeding at a level that allows for 3-4mm of restorative material. Place a resorbable matrix (CollaPlugTM, CollacoteTM, CollatTapeTM) over the blood clot if necessary to achieve a better stop for mineral trioxide aggregate (MTA) or Bioceramic fast set putty (BC). Place white MTA as capping material on top of the resorbable matrix.
  • The access is closed with 3-4mm layer of glass ionomer (Fuji IXTM, GC America, Alsip, IL), composite or alloy over the capping material. For resin modified glass ionomers and composite, 40 seconds of light curer will be done.

Follow-up recall appointments: Clinical and Radiographic exam

  • Extra-oral examination: No pain, extra-oral swelling nor extra-oral sinus tract
  • Intra-oral examination: No pain, intra-oral swelling of mucosa nor intra-oral sinus tract
  • Take 1 straight on periapical radiograph and 1 angled periapical radiograph. Resolution of apical radiolucency (often observed within 6-12months).
  • Record any increased width of root walls (this is generally observed before apparent increase in root length and often occurs 12-24 months after treatment)
  • Record any increase in root length (in mm)
  • Test vitality of pulp with Endo-Ice and Electric pulp tester (EPT).
  • Record which goals have been attained (primary, secondary and/or tertiary)

The degree of success of RET is measured by the extent to which it is possible to attain primary, secondary and tertiary goals:

  • Primary goal: The elimination of symptoms and the evidence of bony healing
  • Secondary goal: Increased root wall thickness and/or increased root length
  • Tertiary goal: Positive response to vitality testing

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
7

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • California
      • Los Angeles, California, United States, 90095
        • University of California, Los Angeles Dept of Graduate Endodontics

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

2 years to 14 years (Child, Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Inclusion criteria include the following:

    1. Subjects will be self and parent-reported as healthy individuals with no significant medical issues.
    2. Radiographic assessment will determine that root(s) have not grown to completion

    2) Vitality tests (cold testing with Endo ice and Electric pulp testing) will determine the tooth to be necrotic 3) Palpation and percussion tests may or may not be positive 4) Probings will be within 1-5mm 5) Patient will commit to coming to 2-3 treatment appointments lasting 1-3 hours each. Thereafter, patient will commit to come for followup recall appointments 6 and 12 months following last treatment appointment.

    6) Patient must be able to tolerate sitting in a dental chair for 1-3 hours. 7) Patient will be in the age range of 6 to 18 years

Exclusion Criteria:

  • Exclusion criteria include patients who cannot tolerate sitting in a dental chair due to anxiety for 1-2 hours.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
No Intervention: Control
No intervention will be administered in this group as it serves as a control group.
Experimental: NAC Treatment
N-Acetyl Cysteine treatment during root canal revascularization
Drug: N acetyl cysteine
N acetyl cysteine at 20mM will be utilized as the final stage of irrigation prior to induction of bleeding during endodontic revascularization procedure.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change of Root length
Time Frame: 6 months and 1 year
Change of root length in millimeters over time
6 months and 1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of California, Los Angeles

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: David C Han, DDS, MS, University of California, Los Angeles

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 15, 2018

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 1, 2019

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 1, 2019

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 23, 2018

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 23, 2018

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 1, 2018

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 21, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 17, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 17-001024

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

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Endodontic Disease

Clinical Trials on N acetyl cysteine

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings