Comparing Two Root Canal Cleaning Solutions (Chlorhexidine vs. Sodium Hypochlorite) for Pain After Treatment (CHXvsNaOCl-Pai)

Comparison of Postoperative Pain Using 2% Chlorhexidine Versus 5.25% Sodium Hypochlorite as Root Canal Irrigants in Non-surgical Root Canal Treatment: A Randomized Controlled Trial

Brief Summary (A short description for the lay public)

This study aims to find out if the type of cleaning solution used during a root canal affects the pain a patient feels the next day. A root canal procedure involves cleaning the inside of the tooth. Two common cleaning solutions are chlorhexidine (CHX) and sodium hypochlorite (NaOCl, also known as bleach). While both are effective, it is not clear if one causes more discomfort than the other.

In this research, half of the participants will have their root canal cleaned with CHX, and the other half with NaOCl. We will then ask all participants to rate their pain 24 hours after the procedure using a simple pain scale. Our goal is to see if there is a difference in pain levels between the two groups. The results will help dentists choose the best solution to make their patients more comfortable after treatment

Study Overview

• Status: Not yet recruiting
• Conditions: Postoperative Pain
• Intervention / Treatment: Procedure: Chlorhexidine gluconate 2%; Drug: Sodium hypochlorite 5.25%

Detailed Description

Detailed Description (Extended technical description of the protocol)

This study is designed as a randomized controlled trial to compare the intensity of postoperative pain 24 hours after non-surgical root canal treatment using two different irrigating solutions: 2% chlorhexidine (CHX) and 5.25% sodium hypochlorite (NaOCl). The central hypothesis is that the type of irrigant influences early postoperative pain, but that this effect may be modified by patient-specific factors such as gender and age.

Methodology:

Following ethical approval and informed consent, 90 adult patients indicated for non-surgical root canal treatment will be enrolled using a non-probability consecutive sampling technique. Participants will be randomly allocated to one of two parallel groups (n=45 per group): Group A (2% CHX) and Group B (5.25% NaOCl). The sample size was calculated a priori using the pwr package in R, assuming a 95% confidence level, 80% power, and a moderate effect size based on previous studies.

A standardized endodontic protocol will be followed for all participants to ensure consistency and minimize bias:

Procedure: After administering local anesthesia (2% lignocaine with 1:80,000 adrenaline), the operative field will be isolated with a rubber dam. Standard endodontic access will be prepared, and the working length will be determined using digital radiography.

Instrumentation and Irrigation: Chemo-mechanical preparation will be performed. Irrigation will be carried out using 2 ml of the assigned solution after each instrument. The solution will be delivered using a 27-gauge side-vented needle (Max-i-Probe) kept 1-2 mm short of the working length and maintained in motion to prevent apical extrusion. The flow rate will be controlled at 2-4 ml/min.

Obturation and Follow-up: Canals will be dried with sterile paper points and obturated with gutta-percha and sealer. Participants will be provided with a questionnaire to record their pain after 24 hours using a Visual Analog Scale (VAS). Pain scores will be categorized as no pain (0), mild (1-30), moderate (31-50), or severe (51-100).

Data Analysis:

Data will be analyzed using R software (version 4.3.3). Descriptive statistics (mean, SD, frequencies) will be calculated. Comparative analyses between the two groups will be conducted using the Student's t-test for mean pain scores and the Chi-square test for categorical pain types. Statistical significance will be set at p < 0.05. A key aspect of the analysis plan includes pre-planned subgroup analyses stratified by gender and age to explore their interaction with the irrigant used.

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Faiz Rahman, BDS; Phone Number: +923451505838; Email: faizr3702@gmail.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

Adults aged 18-65 years

• Any gender
• Requiring non-surgical root canal treatment
• Willing to provide written informed consent
• Able to report postoperative pain using a validated pain assessment scale -

Exclusion Criteria:Known hypersensitivity or allergy to chlorhexidine or sodium hypochlorite

• Systemic conditions affecting pain perception (e.g., diabetes with neuropathy, fibromyalgia)
• Medications affecting pain perception (e.g., chronic analgesics, corticosteroids, antidepressants)
• Preoperative dental pain in the tooth scheduled for treatment
• Pregnancy or lactation
• Teeth with resorbed roots
• Mobile teeth (pathological mobility)
• Open apices

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: 2% Chlorhexidine Group; Root canal irrigation with 2% chlorhexidine gluconate solution. 2 mL after each instrument, 27-gauge side-vented needle, 1-2 mm short of working length, passive flow 2-4 mL/min.	Procedure: Chlorhexidine gluconate 2%; 2% chlorhexidine gluconate solution used as root canal irrigant. Clear, colorless, odorless liquid. Broad-spectrum antimicrobial with substantivity (binds to dental tissues, prolonged effect up to 72 hours). Does not dissolve organic tissue. Lower cytotoxicity than NaOCl. Applied at 2 mL per instrument, delivered via 27-gauge side-vented Max-i-Probe needle placed 1-2 mm short of working length, passive flow at 2-4 mL/min, continuous needle motion. Room temperature. Final irrigation with same solution; Drug: Sodium hypochlorite 5.25%; 5.25% sodium hypochlorite solution used as root canal irrigant. Pale yellow liquid with characteristic chlorine odor. Broad-spectrum antimicrobial with rapid bactericidal action. Dissolves organic pulp tissue and necrotic debris. Cytotoxic to periapical tissues if extruded. No substantivity. Applied at 2 mL per instrument, delivered via 27-gauge side-vented Max-i-Probe needle placed 1-2 mm short of working length, passive flow at 2-4 mL/min, continuous needle motion. Room temperature. Final irrigation with same solution.
Active Comparator: 5.25% Sodium Hypochlorite Group; Root canal irrigation with 5.25% sodium hypochlorite solution. 2 mL after each instrument, 27-gauge side-vented needle, 1-2 mm short of working length, passive flow 2-4 mL/min.	Procedure: Chlorhexidine gluconate 2%; 2% chlorhexidine gluconate solution used as root canal irrigant. Clear, colorless, odorless liquid. Broad-spectrum antimicrobial with substantivity (binds to dental tissues, prolonged effect up to 72 hours). Does not dissolve organic tissue. Lower cytotoxicity than NaOCl. Applied at 2 mL per instrument, delivered via 27-gauge side-vented Max-i-Probe needle placed 1-2 mm short of working length, passive flow at 2-4 mL/min, continuous needle motion. Room temperature. Final irrigation with same solution; Drug: Sodium hypochlorite 5.25%; 5.25% sodium hypochlorite solution used as root canal irrigant. Pale yellow liquid with characteristic chlorine odor. Broad-spectrum antimicrobial with rapid bactericidal action. Dissolves organic pulp tissue and necrotic debris. Cytotoxic to periapical tissues if extruded. No substantivity. Applied at 2 mL per instrument, delivered via 27-gauge side-vented Max-i-Probe needle placed 1-2 mm short of working length, passive flow at 2-4 mL/min, continuous needle motion. Room temperature. Final irrigation with same solution.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative pain intensity at 24 hours	Pain intensity measured using a 4-point Visual Analog Scale (VAS): 0 = no pain, 1 = mild pain, 2 = moderate pain (required analgesics with relief), 3 = severe pain (analgesics no relief). Patient-reported 24 hours post-treatment.	24 hours after root canal treatment completion
Postoperative pain intensity at 24 hours	Pain intensity measured using a 4-point Visual Analog Scale (VAS): 0 = no pain, 1 = mild pain, 2 = moderate pain (required analgesics with relief), 3 = severe pain (analgesics no relief). Patient-reported 24 hours post-treatmen	24 hours after root canal treatment completion

Collaborators and Investigators

• Sponsor: College of Physicians and Surgeons Pakistan

Study record dates

Study Major Dates

• Study Start (Estimated): February 15, 2026
• Primary Completion (Estimated): June 15, 2026
• Study Completion (Estimated): June 15, 2026

Study Registration Dates

• First Submitted: February 12, 2026
• First Submitted That Met QC Criteria: March 3, 2026
• First Posted (Actual): March 5, 2026

Study Record Updates

• Last Update Posted (Actual): March 5, 2026
• Last Update Submitted That Met QC Criteria: March 3, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Postoperative pain; Root canal treatment
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative
• Other Study ID Numbers: SCOD-endo-2025-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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