Endodontic DiseaseEarly Phase 1NACNCT03451435
N-Acetyl Cysteine Protects Pulpal Stem Cells in Endodontic Revascularization
A Early Phase 1 study testing N acetyl cysteine in people with Endodontic Disease, run by University of California, Los Angeles at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 6 to 18 yearsHealthy volunteers can take part
- Conditions the study is for
- Endodontic Disease
- What is being tested?
- N acetyl cysteine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 7 participants
- Where
- 1 siteUnited States
- Study dates
- 15 Jun 2018to 1 Apr 2019
- Phase
- Early Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 6 to 18 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Who may be able to join
- Subjects will be self and parent-reported as healthy individuals with no significant medical issues.
- 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
Who cannot join
- Exclusion criteria include patients who cannot tolerate sitting in a dental chair due to anxiety for 1-2 hours.
Trial locations and contacts
1 site in 1 country.
United States1 site
University of California, Los Angeles Dept of Graduate Endodontics
Los Angeles, California, 90095
About this study
Official title: 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.
Read the 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
- Conditions
- Endodontic Disease
- Being tested
- N acetyl cysteine
- Medical subject headings
- Dental Pulp Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
N acetyl cysteineDrug
N acetyl cysteine at 20mM will be utilized as the final stage of irrigation prior to induction of bleeding during endodontic revascularization procedure.
| Study group | Role | What they receive |
|---|---|---|
| Control | No intervention | No intervention will be administered in this group as it serves as a control group. |
| NAC Treatment | Experimental | N-Acetyl Cysteine treatment during root canal revascularization Receives: Drug: N acetyl cysteine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change of Root length
Change of root length in millimeters over time
Measured: 6 months and 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Mar 2018
- Study start15 Jun 2018
- Primary completion1 Apr 2019
- Study completion1 Apr 2019
Why it stopped: Enrollment difficulties
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Endodontic DiseaseStudies of the same condition, open and under way.
- More trials run by University of California, Los AngelesThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 7 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of California, Los Angeles
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, David C. Han, DDS, MS, University of California, Los Angeles
- Investigators
- David C Han, DDS, MS, Principal investigator, University of California, Los Angeles
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03451435
- Sponsor's protocol ID
- 17-001024
- Acronym
- NAC
- Status last verified
- Jan 2026
- First submitted
- 23 Feb 2018
- Last updated
- 21 Jan 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- N-Acetyl Cysteine Helps Pulp Stem Cells Differentiate During Endodontic Revascularization
- ClinicalTrials.gov ID
- NCT03451435
- Acronym / sponsor ID
- NAC / 17-001024
- Conditions
- Endodontic Disease
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Enrollment difficulties
- Enrolment
- 7 participants (actual)
- Lead sponsor
- University of California, Los AngelesUniversity, hospital or other
- Study start
- 15 Jun 2018 (actual)
- Primary completion
- 1 Apr 2019 (actual)
- Study completion
- 1 Apr 2019 (actual)
- First posted
- 1 Mar 2018 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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 design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Control | No intervention | –No intervention will be administered in this group as it serves as a control group. |
| NAC Treatment | Experimental | Drug: N acetyl cysteineN-Acetyl Cysteine treatment during root canal revascularization |
Who may qualify
- Ages
- 6 to 18 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
Key inclusion criteria (4 listed)
- 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
Key exclusion criteria (1 listed)
- Exclusion criteria include patients who cannot tolerate sitting in a dental chair due to anxiety for 1-2 hours.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| N acetyl cysteineN acetyl cysteine at 20mM will be utilized as the final stage of irrigation prior to induction of bleeding during endodontic revascularization procedure. | Drug | NAC Treatment |
Primary outcome
Change of Root length
Time frame: 6 months and 1 year
Change of root length in millimeters over time
Results and safety
The study was stopped early (reason given: Enrollment difficulties). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Jan 2026.
- Individual participant dataSharing planned: No
Related trials for Endodontic Disease
Recruiting
Effects of Different Activation Techniques on Antimicrobial Photodynamic Therapy in Apical Periodontitis
Apical Periodontitis, Endodontic Retreatment
Not yet recruiting
Post-operative Pain and Clinical Outcome After Single-cone Obturation With a Calcium Silicate-based Versus Epoxy Resin Sealer
Post Operative Pain, Acute, Irreversible Pulpitis (Toothache)
Not yet recruiting
PRP-Assisted Regenerative Endodontics Versus Conventional Root Canal Treatment in Mature Necrotic Teeth
Pulp Necrosis, Apical Periodontitis
Not yet recruitingPhase 3
Submucosal Cryotherapy and Anti-inflammatory Drugs for Postoperative Pain Following Root Canal Treatment in Maxillary Molars
Pulpitis
Not yet recruiting
Clinical and Inflammatory Outcomes of Regenerative Endodontic Treatment Using Injectable Platelet-Rich Fibrin in Mature Necrotic Teeth With Chronic Apical Periodontitis.
Chronic Apical Periodontitis, Pulp Necrosis
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
David C Han, DDS, MS principal investigator
University of California, Los Angeles
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing N acetyl cysteine in people with Endodontic Disease, run by University of California, Los Angeles at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 21 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study was stopped early (reason given: Enrollment difficulties). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change of Root length (time frame: 6 months and 1 year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Jan 2026.