Effect Of Different Sodium Hypochlorite Concentrations On Intracanal Substance P, CGRP And Opiorphin Levels And Postoperative Pain During Root Canal Retreatment (NaOCl-NPP)

March 2, 2026 updated by: KEZBAN MELTEM ÇOLAK

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.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

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 Type

Interventional

Enrollment (Estimated)

60

Phase

  • Not Applicable

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

  • Name: KEZBAN MELTEM ÇOLAK, Prof. Dr
  • Phone Number: +905325744027
  • Email: meltem25@gmail.com

Study Locations

  • Turkey (Türkiye)
    • Erzurum
      • Erzurum, Erzurum, Turkey (Türkiye), 25240
        • Recruiting
        • Atatürk University Faculty of Dentistry, Department of Endodontics
        • Contact:

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • 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.

Exclusion Criteria:

  • 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.
  • 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.

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
Intervention / Treatment
Experimental: 1% Sodium Hypochlorite Irrigation
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.
Drug: Sodium Hypochlorite 1% Irrigation
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.
Experimental: 2.5% Sodium Hypochlorite Irrigation
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.
Drug: Sodium Hypochlorite 2.5% Irrigation
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.
Experimental: 5% Sodium Hypochlorite Irrigation
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.
Drug: Sodium Hypochlorite 5% Irrigation
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).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.
Before irrigation and immediately after irrigation during the same treatment session
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
Before irrigation and immediately after irrigation during the same treatment session

Collaborators and Investigators

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

Sponsor

KEZBAN MELTEM ÇOLAK

Investigators

  • Principal Investigator: KEZBAN MELTEM ÇOLAK, Atatürk University, Faculty of Dentistry, Department of Endodontics

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)

October 1, 2025

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

February 1, 2027

Study Registration Dates

First Submitted

March 2, 2026

First Submitted That Met QC Criteria

March 2, 2026

First Posted (Actual)

March 6, 2026

Study Record Updates

Last Update Posted (Actual)

March 6, 2026

Last Update Submitted That Met QC Criteria

March 2, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • B.30.2.ATA.0.01.00/698

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

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.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

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.

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