Effect of Different Apical Actions on Local Inflammatory Mediators and Pain

Effect of Different Apical Actions on Local Inflammatory Mediators and Pain During Root Canal Preparation: A Randomized Clinical Study

The goal of this clinical trial is to determine patients' the inflammation and pain response to different apical actions used in rotary instrumentation during root canal shaping process. The main questions it aims to answer are:

1. How the different apical actions of endodontic motors influence the pain and inflammatory mediator release from the periapical region of related tooth?
2. Does the perceived pain differ among the used apical action methods after the root canal preparation?
3. Are the perceived pain and local pain mediator levels coherent?

Participants will:

Attend to the root canal treatment in the endodontics clinic. The treatment will be two visits.

Answer the Visual Analog Scale questionnaire on day 0 (first appt.) and Day 3 (second appt.) Keep a diary of their symptoms and the number of times they use an anti-inflammatory drug.

Study Overview

• Status: Completed
• Conditions: Postoperative Dental Pain; Pulp Disease, Dental; Pulpitis - Irreversible
• Intervention / Treatment: Procedure: Root canal shaping with Continuous Rotation; Procedure: Root canal shaping with Apical Reverse; Procedure: Root canal shaping is conducted with Apical slow-down kinematic.

Detailed Description

Study Protocol

This study will include patients aged 18-49 years who present to the İzmir Katip Çelebi University, Department of Endodontics, requiring root canal treatment for vital, lesion-free mandibular first and second molars. Patients with systemic diseases will be excluded. The study will involve 66 patients. The sample size was calculated according to the effect size of 0,25 recommended by Cohen (1988).

Pre-Treatment Assessment:

• Patients will be asked about spontaneous pain and percussion pain related to the affected tooth prior to the session.
• These pain levels will be recorded using the Visual Analog Scale (VAS).

Group Allocation:

• After rubber dam isolation and access cavity preparation, patients will be randomly assigned to one of four groups using a four-sided die.

• Each group will consist of 22 patients and will undergo root canal shaping using an endomotor with one of the following techniques:

  1. Continuous Rotation
  2. Apical Reverse
  3. Apical Slow-Down

Questionnaire:

Patients will be given a pen and will be asked to mark the current and percussion-provoked pain of the related tooth by a numbered linear Visual Analog Scale (VAS) before treatment on Day 0 and Day 3.

Root Canal Shaping:

1. Working Length Determination: Establish the working length and create a glide path using a #10 K-file.
2. Instrumentation Sequence: Enlarge the canals sequentially using rotary files of sizes 15.04, 20.04, 25.06, 30.06, and 35.06.
3. Irrigation: Use 2 ml of 2.5% sodium hypochlorite (NaOCl) for irrigation after each file change.

Sample Collection (First Session):

• After completing the first session:
• Rinse the canals with distilled water.
• Remove remaining liquid with #45 paper points.
• Insert sterile #20.02 paper points into the canals and leave them for 30 seconds to collect periapical exudates.
• Collect three samples per canal. Cut the apical 5 mm of the paper points and place them in 1.5 ml Eppendorf tubes for storage at -80°C.
• The canals will then be rinsed again with 2.5% NaOCl. Patients will be dismissed without using intra-canal medication and instructed to return for the filling session after three days. Patients will be advised to take 800 mg ibuprofen if they experience pain. The medication use will be documented.

Second Session:

• The questionnaire will be held again with the VAS scores and percussion sensivity.

  • After local anesthesia the intermediate restorative material is removed and root canal irrigation with distilled water.
  • Working length is confirmed again with a file. Collect three additional samples per canal using #20.02 paper points as in the first session.
  • Proceed to finalize the root canal treatment.

Final Root Canal Treatment:

1. Perform the final irrigation using 2.5% sodium hypochlorite and 17% EDTA.
2. Fit gutta-percha cones. 35.06 cone or fitting .02 tapered cones will be selected as the master cone according to the anatomy and fit.
3. Fill the canals using a resin-based root canal sealer with lateral condensation utilizing #25 spreader and accessory #20.02 gutta-percha cones.
4. After cutting the excess gutta-percha, clean the cavity and complete the treatment with composite resin restoration.

Sample Handling:

• All collected samples will be stored in a -80°C freezer for biochemical analysis. The analysis will be based on ELISA tests which will investigate the Substance P, IL-1ß, TNF alpha and IL-6 on Day 0 and Day 3.

Post-Treatment:

• The occlusion will be checked using articulation paper, and adjustments will be made if primary contact is present to ensure no traumatic occlusion.

This standardized protocol ensures consistent data collection and optimal treatment outcomes for all participants.

• Study Type: Interventional
• Enrollment (Actual): 75
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey
  • Çiğli
    • İzmir, Çiğli, Turkey, 35649
      • İzmir Katip Çelebi Üniversitesi

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Mild, moderate pulpitis and pulpal expose patients in need of root canal -treatment to their mandibular premolars.
• Healthy periodontal tissue with Periapical Index under 2.
• Helathy adjacent teeth.

Exclusion Criteria:

• Systemic diseases
• Percussion pain
• Patients who did not consent to a vital pulp therapy
• Radiologically seen open apex, root resorption, calcification
• Periodontal pocket beyond 4mm in length
• Consumption of Antibiotics or Corticosteroids 1 month before the treatment
• Consumption of antiinflammatory drugs 2 days before the treatment

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Continuous Rotation; The apical root canal shaping mode of the apex locator integrated endodontic motor is "Continuous Rotation" which is the standard and mostly used option in endodontics. Works as a Control group also	Procedure: Root canal shaping with Continuous Rotation; The root canal shaping is conducted with a continuous rotation kinematic.
Experimental: Apical Reverse; The apical root canal shaping mode of the apex locator integrated endodontic motor is "Reverse". The motor makes a reverse movement to prevent the file over the working length	Procedure: Root canal shaping with Apical Reverse; The root canal shaping is conducted with a apical reverse kinematic.
Experimental: Apical Slow-down; The apical root canal shaping mode of the apex locator integrated endodontic motor is "Apical Slow-down". The motor slows down the rotation to preserve the working length and apical constriction.	Procedure: Root canal shaping is conducted with Apical slow-down kinematic.; The root canal shaping is conducted with a apical slow-down kinematic.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Substance P	The local Substance P amount will be assesed with ELISA kits	From Day 0 to Day 3. The last measurement will be taken just before the end of the interventional treatment.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual Analog Scale	Visual Analog Scale (VAS) questionnaire of perceived pain. A visual linear scale starting from 0 to 10. 0 represents no pain and 10 is the highest pain patient ever endured. Patient is asked to mark the pain in the scale.	From Day 0 to Day 3. The last measurement will be taken just before the end of the interventional treatment.
Inflammatory Mediator: IL-1ß	Local IL-1ß will be assessed with local collection from apical site.	From Day 0 to Day 3. The last measurement will be taken just before the end of the interventional treatment.
Inflammatory Mediator: IL-6	Local IL-6 will be assessed with local collection from apical site.	From Day 0 to Day 3. The last measurement will be taken just before the end of the interventional treatment.
Inflammatory Mediator: TNF alpha	Local TNF-alpha will be assessed with local collection from apical site.	From Day 0 to Day 3. The last measurement will be taken just before the end of the interventional treatment.

Collaborators and Investigators

• Sponsor: Izmir Katip Celebi University
• Investigators: Study Chair: Emrah Karataşlıoğlu, PhD, İzmir Katip Çelebi Üniversitesi; Principal Investigator: Mustafa Mert Tulgar, Dmd, İzmir Katip Çelebi Üniversitesi; Principal Investigator: Yağmur Kılıç, Dmd, İzmir Katip Çelebi Üniversitesi

Publications and helpful links

General Publications

• Cohen, J (1988) Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale, NJ: Erlbaum

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2024
• Primary Completion (Actual): May 1, 2025
• Study Completion (Actual): July 1, 2025

Study Registration Dates

• First Submitted: December 30, 2024
• First Submitted That Met QC Criteria: December 30, 2024
• First Posted (Actual): January 6, 2025

Study Record Updates

• Last Update Posted (Actual): July 16, 2025
• Last Update Submitted That Met QC Criteria: July 12, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: Inflammation; postoperative pain; Substance P; continuous rotation; apical kinematics; apical action; apical reverse; apical slow-down
• Additional Relevant MeSH Terms: Tooth Diseases; Pulpitis; Dental Pulp Diseases; Stomatognathic Diseases
• Other Study ID Numbers: 2023-KAE-0080

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: The patients' written consent also required that the data, which involves biological markers, be used only within the experiment and not shared with a third party.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No