Persistent Apical PeriodontitisNaOCl-NPPNCT07453576
Effect Of Different Sodium Hypochlorite Concentrations On Intracanal Substance P, CGRP And Opiorphin Levels And Postoperative Pain During Root Canal Retreatment
A study testing Sodium Hypochlorite 1% Irrigation, Sodium Hypochlorite 2.5% Irrigation and Sodium Hypochlorite 5% Irrigation in people with Persistent Apical Periodontitis, run by KEZBAN MELTEM ÇOLAK at 1 site in Turkey (Türkiye).
Trial summary
This randomized clinical study aims to evaluate the effect of different sodium hypochlorite concentrations (1%, 2.5%, and 5.25%) used during root canal retreatment on intracanal levels of Substance P, CGRP, and Opiorphin, as well as postoperative pain. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Persistent Apical Periodontitis
- What is being tested?
- Sodium Hypochlorite 1% Irrigation, Sodium Hypochlorite 2.5% Irrigation and Sodium Hypochlorite 5% Irrigation
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Oct 2025to 1 Feb 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients aged between 18 and 65 years.
- Systemically healthy individuals (ASA I or II)
- Patients requiring non-surgical root canal retreatment of a previously treated permanent tooth
- Patients who provide written informed consent.
Who cannot join
- Patients with systemic diseases that may affect pain perception or inflammatory response.
- Use of analgesics, anti-inflammatory drugs, or antibiotics within 7 days prior to treatment.
- Pregnant or lactating women.
- Teeth with root fractures, perforations, advanced periodontal disease, or non-restorable teeth.
- Teeth with open apices or immature root development.
- Presence of acute apical abscess with swelling or sinus tract.
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- Patients with known allergy to sodium hypochlorite.
- Inability to achieve adequate isolation with rubber dam.
- Patients unable to attend follow-up or complete pain assessment forms.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Atatürk University Faculty of Dentistry, Department of Endodontics
Erzurum, Erzurum, 25240
GİZEM YAĞMUR ALMALI, DDS, +905535774333, gizemyagmuur@gmail.com
About this study
Official title: Effect Of Different Sodium Hypochlorite Concentrations (%1, %2.5, And %5) On Intracanal Substance P, CGRP, And Opiorphin Levels And Postoperative Pain During Root Canal Retreatment: A Randomized Clinical Trial
This randomized clinical study aims to evaluate the effect of different sodium hypochlorite concentrations (1%, 2.5%, and 5.25%) used during root canal retreatment on intracanal levels of Substance P, CGRP, and Opiorphin, as well as postoperative pain.
Patients requiring non-surgical root canal retreatment will be randomly assigned to one of three irrigation concentration groups. Intracanal samples will be collected before and after irrigation to measure neuropeptide levels. Postoperative pain will be assessed using a visual analog scale (VAS) at predetermined time intervals.
The results of this study may help clarify the relationship between irrigant concentration, inflammatory mediators, and postoperative pain following root canal retreatment.
Read the detailed description
This prospective, randomized, single-center clinical study is designed to investigate the effects of different sodium hypochlorite (NaOCl) concentrations (1%, 2.5%, and 5.25%) used during non-surgical root canal retreatment on intracanal levels of Substance P, calcitonin gene-related peptide (CGRP), and Opiorphin, as well as postoperative pain intensity.
Patients diagnosed with teeth requiring root canal retreatment will be included according to predefined inclusion and exclusion criteria. Following access cavity preparation and removal of previous root canal filling material, intracanal samples will be obtained prior to irrigation. Participants will then be randomly allocated to one of three irrigation protocols using different NaOCl concentrations. A second intracanal sample will be collected after irrigation.
Neuropeptide levels will be quantified using enzyme-linked immunosorbent assay (ELISA). Postoperative pain will be recorded using a visual analog scale (VAS) at specified time intervals following treatment.
The primary outcome measures are the changes in intracanal Substance P, CGRP, and Opiorphin levels. The secondary outcome measure is postoperative pain intensity. This study aims to contribute to a better understanding of the biological and clinical effects of irrigant concentration during root canal retreatment.
- Conditions
- Persistent Apical Periodontitis
- Being tested
- Sodium Hypochlorite 1% Irrigation, Sodium Hypochlorite 2.5% Irrigation, Sodium Hypochlorite 5% Irrigation
- Keywords
- Root Canal Retreatment, Sodium Hypochlorite, Substance P, CGRP, Opiorphin, Postoperative Pain
- Medical subject headings
- Pain, Postoperative
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Sodium Hypochlorite 1% IrrigationDrug
Irrigation with 1% sodium hypochlorite solution during chemomechanical preparation in non-surgical root canal retreatment. The solution will be used according to standardized irrigation protocols, and intracanal samples will be collected before and after irrigation for neuropeptide analysis.
Sodium Hypochlorite 2.5% IrrigationDrug
Irrigation with 2.5% sodium hypochlorite solution during chemomechanical preparation in non-surgical root canal retreatment. Intracanal samples will be collected before and after irrigation to evaluate changes in Substance P, CGRP, and Opiorphin levels.
Sodium Hypochlorite 5% IrrigationDrug
Irrigation with 5% sodium hypochlorite solution during chemomechanical preparation in non-surgical root canal retreatment. Intracanal samples will be obtained before and after irrigation, and postoperative pain will be assessed using a visual analog scale (VAS).
| Study group | Role | What they receive |
|---|---|---|
| 1% Sodium Hypochlorite Irrigation | Experimental | Participants assigned to this arm will undergo non-surgical root canal retreatment using 1% sodium hypochlorite as the irrigating solution during chemomechanical preparation. Intracanal samples will be collected before and after irrigation to evaluate changes in Substance P, CGRP, and Opiorphin levels. Postoperative pain will be recorded using a visual analog scale (VAS) at predetermined time intervals. Receives: Drug: Sodium Hypochlorite 1% Irrigation |
| 2.5% Sodium Hypochlorite Irrigation | Experimental | Participants assigned to this arm will undergo non-surgical root canal retreatment using 2.5% sodium hypochlorite as the irrigating solution during chemomechanical preparation. Intracanal samples will be collected before and after irrigation to evaluate changes in Substance P, CGRP, and Opiorphin levels. Postoperative pain will be recorded using a visual analog scale (VAS) at predetermined time intervals. Receives: Drug: Sodium Hypochlorite 2.5% Irrigation |
| 5% Sodium Hypochlorite Irrigation | Experimental | Participants assigned to this arm will undergo non-surgical root canal retreatment using 5% sodium hypochlorite as the irrigating solution during chemomechanical preparation. Intracanal samples will be collected before and after irrigation to evaluate changes in Substance P, CGRP, and Opiorphin levels. Postoperative pain will be recorded using a visual analog scale (VAS) at predetermined time intervals. Receives: Drug: Sodium Hypochlorite 5% Irrigation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Intracanal Substance P, CGRP, and Opiorphin Levels
The primary outcome is the change in intracanal levels of Substance P, CGRP, and Opiorphin before and after irrigation with different sodium hypochlorite concentrations during non-surgical root canal retreatment. Neuropeptide levels will be quantified using ELISA.
Measured: Before irrigation and immediately after irrigation during the same treatment session
Change in Intracanal Substance P, CGRP, and Opiorphin Levels
The primary outcome is the change in intracanal levels of Substance P, CGRP, and Opiorphin before and after irrigation with different sodium hypochlorite concentrations during non-surgical root canal retreatment. Neuropeptide levels will be quantified us
Measured: Before irrigation and immediately after irrigation during the same treatment session
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Mar 2026
- Study start1 Oct 2025
- Primary completion1 Dec 2026 (estimated)
- Study completion1 Feb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Persistent Apical PeriodontitisStudies of the same condition, open and under way.
- 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
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants will be randomly assigned to one of three parallel groups according to the sodium hypochlorite concentration used during root canal retreatment (1%, 2.5%, or 5%). Each participant will receive only one irrigation protocol.
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- KEZBAN MELTEM ÇOLAK
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, KEZBAN MELTEM ÇOLAK, Ataturk University
- Investigators
- KEZBAN MELTEM ÇOLAK, Principal investigator, Atatürk University, Faculty of Dentistry, Department of Endodontics
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07453576
- Sponsor's protocol ID
- B.30.2.ATA.0.01.00/698
- Acronym
- NaOCl-NPP
- Status last verified
- Mar 2026
- First submitted
- 2 Mar 2026
- Last updated
- 6 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data (IPD) will not be shared due to patient confidentiality and institutional data protection policies. The dataset contains identifiable clinical information collected as part of a single-center academic thesis study.
Study at a glance
From the registry record, last updated by the sponsor on 6 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect Of Different Sodium Hypochlorite Concentrations (%1, %2.5, And %5) On Intracanal Substance P, CGRP, And Opiorphin Levels And Postoperative Pain During Root Canal Retreatment: A Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT07453576
- Acronym / sponsor ID
- NaOCl-NPP / B.30.2.ATA.0.01.00/698
- Conditions
- Persistent Apical Periodontitis
- Keywords
- Root Canal Retreatment, Sodium Hypochlorite, Substance P, CGRP, Opiorphin, Postoperative Pain
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- KEZBAN MELTEM ÇOLAKUniversity, hospital or other
- Study start
- 1 Oct 2025 (actual)
- Primary completion
- 1 Dec 2026 (estimated)
- Study completion
- 1 Feb 2027 (estimated)
- First posted
- 6 Mar 2026 (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.
This randomized clinical study aims to evaluate the effect of different sodium hypochlorite concentrations (1%, 2.5%, and 5.25%) used during root canal retreatment on intracanal levels of Substance P, CGRP, and Opiorphin, as well as postoperative pain.
Patients requiring non-surgical root canal retreatment will be randomly assigned to one of three irrigation concentration groups. Intracanal samples will be collected before and after irrigation to measure neuropeptide levels. Postoperative pain will be assessed using a visual analog scale (VAS) at predetermined time intervals.
The results of this study may help clarify the relationship between irrigant concentration, inflammatory mediators, and postoperative pain following root canal retreatment.
Detailed description
This prospective, randomized, single-center clinical study is designed to investigate the effects of different sodium hypochlorite (NaOCl) concentrations (1%, 2.5%, and 5.25%) used during non-surgical root canal retreatment on intracanal levels of Substance P, calcitonin gene-related peptide (CGRP), and Opiorphin, as well as postoperative pain intensity.
Patients diagnosed with teeth requiring root canal retreatment will be included according to predefined inclusion and exclusion criteria. Following access cavity preparation and removal of previous root canal filling material, intracanal samples will be obtained prior to irrigation. Participants will then be randomly allocated to one of three irrigation protocols using different NaOCl concentrations. A second intracanal sample will be collected after irrigation.
Neuropeptide levels will be quantified using enzyme-linked immunosorbent assay (ELISA). Postoperative pain will be recorded using a visual analog scale (VAS) at specified time intervals following treatment.
The primary outcome measures are the changes in intracanal Substance P, CGRP, and Opiorphin levels. The secondary outcome measure is postoperative pain intensity. This study aims to contribute to a better understanding of the biological and clinical effects of irrigant concentration during root canal retreatment.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 3
- Model description
- Participants will be randomly assigned to one of three parallel groups according to the sodium hypochlorite concentration used during root canal retreatment (1%, 2.5%, or 5%). Each participant will receive only one irrigation protocol.
| Arm | Type | Receives |
|---|---|---|
| 1% Sodium Hypochlorite Irrigation | Experimental | Drug: Sodium Hypochlorite 1% IrrigationParticipants assigned to this arm will undergo non-surgical root canal retreatment using 1% sodium hypochlorite as the irrigating solution during chemomechanical preparation. Intracanal samples will be collected before and after irrigation to evaluate changes in Substance P, CGRP, and Opiorphin levels. Postoperative pain will be recorded using a visual analog scale (VAS) at predetermined time intervals. |
| 2.5% Sodium Hypochlorite Irrigation | Experimental | Drug: Sodium Hypochlorite 2.5% IrrigationParticipants assigned to this arm will undergo non-surgical root canal retreatment using 2.5% sodium hypochlorite as the irrigating solution during chemomechanical preparation. Intracanal samples will be collected before and after irrigation to evaluate changes in Substance P, CGRP, and Opiorphin levels. Postoperative pain will be recorded using a visual analog scale (VAS) at predetermined time intervals. |
| 5% Sodium Hypochlorite Irrigation | Experimental | Drug: Sodium Hypochlorite 5% IrrigationParticipants assigned to this arm will undergo non-surgical root canal retreatment using 5% sodium hypochlorite as the irrigating solution during chemomechanical preparation. Intracanal samples will be collected before and after irrigation to evaluate changes in Substance P, CGRP, and Opiorphin levels. Postoperative pain will be recorded using a visual analog scale (VAS) at predetermined time intervals. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Patients aged between 18 and 65 years.
- Systemically healthy individuals (ASA I or II)
- Patients requiring non-surgical root canal retreatment of a previously treated permanent tooth
- Patients who provide written informed consent.
Key exclusion criteria (9 listed)
- Patients with systemic diseases that may affect pain perception or inflammatory response.
- Use of analgesics, anti-inflammatory drugs, or antibiotics within 7 days prior to treatment.
- Pregnant or lactating women.
- Teeth with root fractures, perforations, advanced periodontal disease, or non-restorable teeth.
- Teeth with open apices or immature root development.
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 |
|---|---|---|
| Sodium Hypochlorite 1% IrrigationIrrigation with 1% sodium hypochlorite solution during chemomechanical preparation in non-surgical root canal retreatment. The solution will be used according to standardized irrigation protocols, and intracanal samples will be collected before and after irrigation for neuropeptide analysis. | Drug | 1% Sodium Hypochlorite Irrigation |
| Sodium Hypochlorite 2.5% IrrigationIrrigation with 2.5% sodium hypochlorite solution during chemomechanical preparation in non-surgical root canal retreatment. Intracanal samples will be collected before and after irrigation to evaluate changes in Substance P, CGRP, and Opiorphin levels. | Drug | 2.5% Sodium Hypochlorite Irrigation |
| Sodium Hypochlorite 5% IrrigationIrrigation with 5% sodium hypochlorite solution during chemomechanical preparation in non-surgical root canal retreatment. Intracanal samples will be obtained before and after irrigation, and postoperative pain will be assessed using a visual analog scale (VAS). | Drug | 5% Sodium Hypochlorite Irrigation |
Primary outcome
Change in Intracanal Substance P, CGRP, and Opiorphin Levels
Time frame: Before irrigation and immediately after irrigation during the same treatment session
The primary outcome is the change in intracanal levels of Substance P, CGRP, and Opiorphin before and after irrigation with different sodium hypochlorite concentrations during non-surgical root canal retreatment. Neuropeptide levels will be quantified using ELISA.
Change in Intracanal Substance P, CGRP, and Opiorphin Levels
Time frame: Before irrigation and immediately after irrigation during the same treatment session
The primary outcome is the change in intracanal levels of Substance P, CGRP, and Opiorphin before and after irrigation with different sodium hypochlorite concentrations during non-surgical root canal retreatment. Neuropeptide levels will be quantified us
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Mar 2026.
- Individual participant dataSharing planned: No. Individual participant data (IPD) will not be shared due to patient confidentiality and institutional data protection policies. The dataset contains identifiable clinical information collected as part of a single-center academic thesis study.
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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.
KEZBAN MELTEM ÇOLAK principal investigator
Atatürk University, Faculty of Dentistry, Department of Endodontics
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Sodium Hypochlorite 1% Irrigation, Sodium Hypochlorite 2.5% Irrigation and Sodium Hypochlorite 5% Irrigation in people with Persistent Apical Periodontitis, run by KEZBAN MELTEM ÇOLAK at 1 site in Turkey (Türkiye).
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 9 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: looking for participants now, as of the sponsor's last update on 6 Mar 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 Turkey (Türkiye). 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.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact KEZBAN MELTEM ÇOLAK, Prof. Dr (+905325744027, meltem25@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Intracanal Substance P, CGRP, and Opiorphin Levels (time frame: Before irrigation and immediately after irrigation during the same treatment session). The study lists 2 primary outcomes in all. 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 6 Mar 2026.