Effect of Intracanal Cryotherapy on Postoperative Endodontic Pain

July 13, 2026 updated by: Medine Ciçek, Recep Tayyip Erdogan University

Effect of Intracanal Cryotherapy on Endodontic Postoperative Pain in Teeth With Asymptomatic Irreversible Pulpitis and Asymptomatic Apical Periodontitis: A Four-Arm Randomized Controlled Trial

This study aimed to evaluate the effects of cooled and room-temperature NaOCl irrigation on postoperative endodontic pain in single-rooted teeth diagnosed with asymptomatic irreversible pulpitis (AIP) or asymptomatic apical periodontitis (AAP).

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
132

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Locations

  • Turkey (Türkiye)
    • Centre
      • Rize, Centre, Turkey (Türkiye)
        • Recep Tayyip Erdoğan University Faculty of Dentistry, Department of Endodontics

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Systemically healthy patients with 18-70 years of age
  2. Single-rooted teeth with a single root canal, diagnosed with either AIP and normal periapical tissues or AAP.

Pulpal and periapical diagnoses were established according to the American Association of Endodontists (AAE) [20] diagnostic terminology. Included teeth were categorized into 2 diagnostic groups: AIP with normal periapical tissues and AAP associated with pulp necrosis. AIP was provisionally diagnosed in teeth with extremely deep caries approximating or reaching the pulp, a positive response to cold testing (Dispodent, Nadu, India), and no clinical symptoms. Periapical radiographs showed a PAI score of 1 without periodontal ligament widening. The diagnosis was confirmed intraoperatively by persistent pulpal bleeding that remained uncontrolled after 10 minutes of application of a sterile cotton pellet moistened with 2.5% sodium hypochlorite. AAP was diagnosed in teeth with a PAI score of ≥3 in the absence of clinical symptoms. None of the included teeth exhibited tenderness to percussion. All periapical radiographs were obtained using a phosphor storage plate system and the paralleling technique (Myray parallel holder, NDental, Imola, Italy) under standardized exposure parameters (70 kV, 8 mA, 0.360 s).

Exclusion Criteria: 1) Teeth with canal calcification, complex or atypical canal anatomy, root resorption, incomplete root development, or a history of endodontic treatment of the study tooth.

2) Teeth initially diagnosed with AIP in which pulpal bleeding was controlled within 10 min after access cavity preparation, as these teeth were considered eligible for vital pulp therapy.

3) Teeth initially diagnosed with AIP in which pulp necrosis was identified after access cavity preparation.

4) Teeth in which root canal treatment could not be completed in a single visit.

5) Patients who had taken analgesics within 12 hours before the appointment or antibiotics within the previous month.

6) Teeth with periodontal probing depths >3 mm or clinical/radiographic signs of periodontal disease.

7) Teeth with insufficient coronal tooth structure to allow an adequate ferrule.

8) Pregnant or breastfeeding patients and patients with systemic conditions or regular medication use that could affect treatment outcomes.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Other: GROUP 1- Asymptomatic irreversible pulpitis - control
20 mL of 2.5% NaOCl was kept in a glass beaker at room temperature and monitored with a digital thermometer to maintain a temperature of 22°C. Final irrigation in Groups 1 was performed using this solution.
Other: root canal treatment and cryotherapy
All endodontic procedures were completed in a single visit by one operator with 6 years of clinical experience. Only 1 tooth per patient was included. Local anesthesia was administered using 2 mL articaine HCl containing 1:100,000 epinephrine. After rubber dam isolation and access cavity preparation, working length was determined using an electronic apex locator and confirmed radiographically. Root canals were prepared with Endoart Smart Gold files to size 40/.04 and, when needed, up to 2 larger sizes according to canal anatomy. Apical patency was maintained 1 mm beyond the working length using a size 10 K-file. Between instruments, canals were irrigated with 2 mL of 2.5% NaOCl using a 30-gauge side-vented needle. NaOCl was ultrasonically activated three times for 20 seconds to aid smear-layer removal. Canals were then irrigated with saline, followed by 5 mL of 17% EDTA for 1 minute.
Experimental: GROUP 2- Asymptomatic irreversible pulpitis- cryotherapy
For Group 2, 20 mL of 2.5% NaOCl was divided into eight 2.5-mL syringes and cooled to 2 °C in a refrigerator. The syringes were then placed in an insulated container filled with ice to maintain the target temperature during transport to the clinic and until use. A digital thermometer was used to verify that the solution remained at 2 °C. Each syringe was removed individually immediately before irrigation and delivered over approximately 40 seconds.
Other: root canal treatment and cryotherapy
All endodontic procedures were completed in a single visit by one operator with 6 years of clinical experience. Only 1 tooth per patient was included. Local anesthesia was administered using 2 mL articaine HCl containing 1:100,000 epinephrine. After rubber dam isolation and access cavity preparation, working length was determined using an electronic apex locator and confirmed radiographically. Root canals were prepared with Endoart Smart Gold files to size 40/.04 and, when needed, up to 2 larger sizes according to canal anatomy. Apical patency was maintained 1 mm beyond the working length using a size 10 K-file. Between instruments, canals were irrigated with 2 mL of 2.5% NaOCl using a 30-gauge side-vented needle. NaOCl was ultrasonically activated three times for 20 seconds to aid smear-layer removal. Canals were then irrigated with saline, followed by 5 mL of 17% EDTA for 1 minute.
Other: GROUP 3- Asymptomatic apical periodontitis - control (n=33)
20 mL of 2.5% NaOCl was kept in a glass beaker at room temperature and monitored with a digital thermometer to maintain a temperature of 22°C. Final irrigation in Groups 1 and 3 was performed using this solution.
Other: root canal treatment and cryotherapy
All endodontic procedures were completed in a single visit by one operator with 6 years of clinical experience. Only 1 tooth per patient was included. Local anesthesia was administered using 2 mL articaine HCl containing 1:100,000 epinephrine. After rubber dam isolation and access cavity preparation, working length was determined using an electronic apex locator and confirmed radiographically. Root canals were prepared with Endoart Smart Gold files to size 40/.04 and, when needed, up to 2 larger sizes according to canal anatomy. Apical patency was maintained 1 mm beyond the working length using a size 10 K-file. Between instruments, canals were irrigated with 2 mL of 2.5% NaOCl using a 30-gauge side-vented needle. NaOCl was ultrasonically activated three times for 20 seconds to aid smear-layer removal. Canals were then irrigated with saline, followed by 5 mL of 17% EDTA for 1 minute.
Experimental: GROUP 4- Asymptomatic apical periodontitis - cryotherapy
For Group 4, 20 mL of 2.5% NaOCl was divided into eight 2.5-mL syringes and cooled to 2 °C in a refrigerator. The syringes were then placed in an insulated container filled with ice to maintain the target temperature during transport to the clinic and until use. A digital thermometer was used to verify that the solution remained at 2 °C. Each syringe was removed individually immediately before irrigation and delivered over approximately 40 seconds.
Other: root canal treatment and cryotherapy
All endodontic procedures were completed in a single visit by one operator with 6 years of clinical experience. Only 1 tooth per patient was included. Local anesthesia was administered using 2 mL articaine HCl containing 1:100,000 epinephrine. After rubber dam isolation and access cavity preparation, working length was determined using an electronic apex locator and confirmed radiographically. Root canals were prepared with Endoart Smart Gold files to size 40/.04 and, when needed, up to 2 larger sizes according to canal anatomy. Apical patency was maintained 1 mm beyond the working length using a size 10 K-file. Between instruments, canals were irrigated with 2 mL of 2.5% NaOCl using a 30-gauge side-vented needle. NaOCl was ultrasonically activated three times for 20 seconds to aid smear-layer removal. Canals were then irrigated with saline, followed by 5 mL of 17% EDTA for 1 minute.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Between- and Within-Group Comparisons of Postoperative Pain Scores Over Time
Time Frame: During the first week after treatment
During the first week after treatment

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Recep Tayyip Erdogan University

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 11, 2026

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 26, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 3, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 13, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 13, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 17, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 17, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 13, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 12 (Israel lung Association)

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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