Effect of Intracanal Cryotherapy Versus Laser Application on Postoperative-pain and Bacterial Load Reduction in Single Visit Root Canal Treatment in Patients With Symptomatic Irreversible Pulpitis in Mandibular First Molar Teeth (Randomized Control Trial)

This randomized controlled clinical trial investigates the Effect of Intracanal Cryotherapy Versus Laser Application on Post-Operative Pain and Bacterial Load Reduction in Single-Visit Root Canal Treatment in Patients with Symptomatic Irreversible Pulpitis in Mandibular First Molars. Sixty patients aged 18-40 years with restorable mandibular first molars diagnosed with symptomatic irreversible pulpitis will be enrolled at the Endodontic Department, Faculty of Oral and Dental Medicine, Future University in Egypt. Participants will be randomly allocated into four groups: Group 1 (control) will receive final irrigation with 2.6% sodium hypochlorite (NaOCl) at room temperature (24°C), Group 2 will receive cryotreated NaOCl (2-4°C), Group 3 will receive preheated NaOCl (60°C), and Group 4 will receive laser-activated NaOCl, each applied for one minute. The study will be double-blind for both the operator and the patient. Post-operative pain will be assessed using a Numerical Rating Scale (0-10) at 6, 12, 24, 48, and 72 hours post-treatment. Bacterial load reduction will be measured microbiologically at three stages: after access cavity preparation, after instrumentation, and after final irrigation. Statistical analysis will be performed using SPSS version 24 and Minitab version 16, with a significance level of p < 0.05. The study has received ethical approval from the Future University Ethics Committee and is conducted without external funding.

Study Overview

• Status: Active, not recruiting
• Conditions: Symptomatic Irreversible Pulpitis (SIP)
• Intervention / Treatment: Procedure: final irrigation by preheated NaOcl; Procedure: final irrigation by NaOCI activated by laser; Procedure: final irrigation by Cryotreated NaOcl; Procedure: final irrigation by NaOcl at room temperature

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • New Cairo
    • Cairo, New Cairo, Egypt, 11835
      • Future University in Egypt

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Patients aged 18 to 40 years.
• Patients able to understand and sign the informed consent form.
• Patients who positively accept to participate in the study.
• Patients diagnosed with symptomatic irreversible pulpitis in a restorable mandibular first molar.
• The affected tooth must have a mesial and distal root canal configuration classified as Type III according to Vertucci's classification.
• The root curvature of the involved canals must be mild to moderate (5-20°), as measured by Schneider's method.
• No sex predilection.

Exclusion Criteria:

• Patients who are pregnant or lactating.
• Medically compromised patients (e.g., with systemic conditions that contraindicate dental treatment or affect pain perception).
• Patients who have taken any analgesic medication within 8 hours prior to the appointed treatment.
• Patients who have taken antibiotics within the two weeks prior to the preoperative assessment.
• Patients with parafunctional habits such as bruxism or clenching.
• Patients with severe malocclusion associated with traumatic occlusion.

• Teeth exhibiting any of the following:

  • Pain on percussion.
  • A diagnosis of peri-apical periodontitis or a peri-radicular lesion.
  • Internal or external root resorption.
  • Pulp stones or significant canal calcifications.
  • Evidence of previous endodontic treatment.
  • Teeth with non-patent canals or canals that cannot be negotiated.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Final irrigation by NaOCI at room temperature; final irrigated using NaOCI (2.6%) at room temperature 24°C for 1 min.	Procedure: final irrigation by preheated NaOcl; final irrigation by preheated NaOcl (2.6%) at 60°C for 1 min.
Active Comparator: Final Irrigation by Cryotreated NaOCI; final irrigated using NaOCI (2.6%) that Cryotreated at 2-4°C for 1 min.	Procedure: final irrigation by NaOCI activated by laser; final irrigation by NaOCI (2.6%) activated by laser for 1 min.
Active Comparator: Final Irrigation by Preheated NaOCI; final irrigated using NaOCI (2.6%) Preheated at 60°C for 1 min.	Procedure: final irrigation by Cryotreated NaOcl; final irrigation by Cryotreated NaOcl (2.6%) at 2-4°C for 1 min.
Active Comparator: Final Irrigation by Laser Activated NaOCI; finally irrigated using NaOCI (2.6%) activated by laser for 1 min.	Procedure: final irrigation by NaOcl at room temperature; final irrigation by NaOcl (2.6%) at room temperature 24°C for 1 min.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Post-operative pain after each activation method in comparison to control group	measuring Post-operative pain by Numerical rate scale and pain level will be assigned to one of 4 categorical score: none (0): mild (1-3), severe (7-10).	from 6 to 72 hours from the treatment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
bacterial load change after final irrigation protocol.	Recording the percentage of bacterial load reduction by collecting samples by paper points, first sample after access cavity and before Root canal treatment. second sample after mechanical instrumentation third sample after final irrigation.	immediately after the intervention

Collaborators and Investigators

• Sponsor: Future University in Egypt

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2025
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: May 31, 2026
• First Submitted That Met QC Criteria: May 31, 2026
• First Posted (Actual): June 4, 2026

Study Record Updates

• Last Update Posted (Actual): June 4, 2026
• Last Update Submitted That Met QC Criteria: May 31, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: ARummani

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