Evaluation of Revitalization Success Using i-PRF in Non-Surgical Root Canal Retreatment

Evaluation of Revitalization Success Using i-PRF in Non-Surgical Root Canal Retreatment: A Clinical Study

The goal of this randomized controlled clinical trial is to determine whether regenerative endodontic treatment can improve healing outcomes in teeth with apical periodontitis following failed root canal treatment. The study includes adult patients who require non-surgical root canal retreatment due to persistent periapical lesions.

The main questions it aims to answer are:

Does regenerative endodontic treatment improve periapical healing compared with conventional non-surgical root canal retreatment? Does regenerative treatment increase long-term treatment success and tooth survival? Researchers will compare conventional non-surgical root canal retreatment with regenerative endodontic treatment using injectable platelet-rich fibrin (i-PRF) to see if the regenerative approach results in better clinical and radiographic outcomes.

Participants will:

Be randomly assigned to receive either conventional retreatment or regenerative endodontic treatment.

Undergo clinical and radiographic evaluations over a two-year follow-up period. Be assessed for pain, sensitivity, pulp vitality, hard tissue formation, and periapical healing.

Study Overview

• Status: Recruiting
• Conditions: Apical Periodontitis; Periapical Diseases
• Intervention / Treatment: Procedure: Non-Surgical Root Canal Retreatment; Procedure: Regenerative Endodontic Treatment

Detailed Description

Apical periodontitis is a common consequence of failed root canal treatment and is primarily associated with persistent intraradicular infection. Although non-surgical root canal retreatment remains the standard treatment approach for failed primary endodontic therapy, reported failure rates range between 23% and 30%. Even after thorough chemomechanical preparation, complete elimination of microorganisms may not always be achieved. In addition, conventional treatment does not restore pulp vitality and may compromise the structural integrity of the remaining tooth tissue.

Regenerative endodontic procedures have emerged as a biologically based alternative aimed at promoting tissue regeneration within the root canal system. By utilizing biological scaffolds and growth factor-rich preparations, regenerative therapy may enhance healing, support revascularization, and potentially restore natural defense mechanisms of the tooth.

This study is designed as a randomized controlled clinical trial comparing conventional non-surgical root canal retreatment with regenerative endodontic treatment. The regenerative protocol incorporates injectable platelet-rich fibrin (i-PRF), an autologous blood-derived biomaterial obtained through low-speed centrifugation. i-PRF contains growth factors and bioactive components that may support angiogenesis, cell migration, and tissue repair.

Following local anesthesia and rubber dam isolation, previously obturated root canal fillings will be removed. Standardized chemomechanical preparation and irrigation protocols will be performed according to the assigned treatment group. In the regenerative group, i-PRF will be applied as a biological scaffold prior to placement of a bioceramic material to achieve coronal sealing. In the conventional retreatment group, canals will be obturated using established root canal filling techniques.

All procedures will be performed under standardized clinical conditions. Radiographic examinations will be obtained using positioning devices to ensure reproducibility and standardization of angulation. Patients will be monitored periodically over a two-year follow-up period to assess healing progression and treatment outcomes.

This study seeks to provide evidence regarding the biological and clinical potential of regenerative endodontic therapy as an alternative to conventional retreatment in teeth with persistent apical periodontitis.

• Study Type: Interventional
• Enrollment (Estimated): 140
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Melike B KAPLANOGLU; Phone Number: 905319330396; Email: melikekaplanoglu37@gmail.com
• Study Contact Backup: Name: Idil OZDEN, PhD; Email: idil.akman94@gmail.com

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye)
    • Recruiting
    • Marmara University
    • Contact: Melike Kaplanoglu, DDS; Phone Number: 905319330396; Email: melikekaplanoglu37@gmail.com
    • Contact: Idil Ozden, DDS, PhD; Email: idil.akman94@gmail.com
    • Principal Investigator: Melike Beyza KAPLANOGLU

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Patients aged between 18 and 50 years.
• Single-rooted maxillary anterior teeth with closed apices.
• Presence of periapical lesion confirmed radiographically.
• Previously treated root canal tooth requiring non-surgical retreatment.
• Tooth has not previously undergone non-surgical root canal retreatment.
• Tooth is considered restorable.
• Patient is systemically healthy.
• Patient is willing to participate and provides informed consent.

Exclusion Criteria:

• Teeth without radiographic evidence of periapical lesion.
• Teeth with developmental anomalies.
• Patients with systemic diseases that may affect healing.
• Pregnant patients.
• Teeth presenting with internal or external root resorption.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Conventional Non-Surgical Root Canal Retreatment; Participants will receive conventional non-surgical root canal retreatment.	Procedure: Non-Surgical Root Canal Retreatment; Conventional non-surgical root canal retreatment will be performed under local anesthesia and rubber dam isolation. Previous root canal filling materials will be removed, followed by standardized chemomechanical preparation and irrigation. The canals will be obturated using resin-based sealer and gutta-percha with lateral condensation technique, and the tooth will be restored with a permanent coronal restoration.
Experimental: Regenerative Endodontic Treatment With Injectable Platelet-Rich Fibrin; Participants will receive regenerative endodontic treatment using injectable platelet-rich fibrin as a biological scaffold.	Procedure: Regenerative Endodontic Treatment; Regenerative endodontic treatment will be performed under local anesthesia and rubber dam isolation. After removal of previous root canal filling materials and standardized canal preparation, injectable platelet-rich fibrin obtained from the patient's autologous blood will be applied into the canal space as a biological scaffold. Mineral trioxide aggregate will be placed coronally, followed by permanent composite restoration.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Periapical Index (PAI) Score	Periapical healing will be assessed using standardized periapical radiographs and scored according to the Periapical Index (PAI) system. Changes in lesion size and PAI scores from baseline to follow-up visits over a 24-month period will be evaluated.	Baseline and up to 24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Pain Intensity	Postoperative pain intensity will be assessed at follow-up visits using clinical evaluation and patient-reported outcomes when applicable.	Baseline and up to 24 months
Percussion and Palpation Sensitivity	Clinical evaluation of percussion and palpation sensitivity will be performed at scheduled follow-up visits to assess signs of persistent inflammation or tenderness.	Baseline and up to 24 months
Pulp Vitality Response	Pulp vitality will be assessed using standardized vitality testing methods during follow-up visits to determine restoration of tooth vitality.	Baseline and up to 24 months
Proportion of Teeth With Successful Healing (PAI ≤ 2)	Successful healing will be defined as a Periapical Index (PAI) score of 2 or lower at follow-up evaluations. The proportion of teeth achieving successful healing within 24 months will be compared between treatment groups.	Baseline and up to 24 months

Collaborators and Investigators

• Sponsor: Marmara University
• Collaborators: Marmara University Scientific Research Projects Unit
• Investigators: Study Chair: Idil OZDEN, PhD, Marmara University

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2025
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: February 26, 2026
• First Submitted That Met QC Criteria: February 26, 2026
• First Posted (Actual): March 4, 2026

Study Record Updates

• Last Update Posted (Actual): March 4, 2026
• Last Update Submitted That Met QC Criteria: February 26, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Randomized Controlled Trial; regenerative endodontic treatment; apical periodontitis; root canal retreatment; Periapical Healing; Injectable Platelet-Rich Fibrin; Non-Surgical Endodontic Retreatment
• Additional Relevant MeSH Terms: Periodontal Diseases; Mouth Diseases; Stomatognathic Diseases; Jaw Diseases; Periodontitis; Periapical Periodontitis; Periapical Diseases
• Other Study ID Numbers: 2025-KAEK-43 (ISTANBUL PROVINCIAL DIRECTORATE OF HEALTH KOŞUYOLU HIGH SPECIALIZATION EDUCATION AND CLINICAL RESEARCH ETHICS COMMITTEE)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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