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EndodonticsNCT07721051

The Effect of Using Different Scaffolds in Retreated Teeth on The Clinical and Radiological Success of Regenerative Endodontic Treatment

An observational study of Endodontics and Regenerative Endodontic Procedures, run by Kırıkkale University.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

This clinical study aims to compare the clinical and radiographic outcomes of four different scaffolds used in regenerative endodontic treatment of previously root canal-treated permanent teeth requiring retreatment. Read more about this study

Who is it for?
Ages 16 to 40 years
Type of treatment
Injection or infusion
How many people
60 participants
Where
No sites listed yet
Study dates
1 Oct 2026to 1 Mar 2028
Phase
Observational
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 16 to 40 years
  • All sexes
  • No healthy volunteers
  • Child, Adult

Study population: This study will include patients aged 16-40 with single-canal, closed-apical permanent teeth who presented to the Department of Endodontics at the Faculty of Dentistry, Kırıkkale University, for endodontic retreatment.

Who may be able to join

  • Patients aged 16-40 who are systemically healthy
  • Patients who have a permanent tooth with a single root canal and fully developed root that requires retreatment
  • Patients who may or may not have periapical radiolucency

Who cannot join

  • Patients who require antibiotic prophylaxis
  • Patients with systemic conditions such as diabetes or hematological disorders
  • Patients who have taken antibiotics, anti-inflammatory medications, and/or antidepressants within the past three weeks
  • Patients who are pregnant or suspect they may be pregnant during treatment
  • Patients with heavy plaque and tartar buildup on their teeth
  • Patients with redness and bleeding of the gums
Show all 12Show fewer
  • Patients with severe gingivitis, generalized periodontitis, or a periodontal pocket depth of more than 3 mm
  • Patients with internal or external root resorption
  • Patients for whom complete isolation with a rubber dam cannot be achieved
  • Patients with an open, immature root apex
  • Patients with horizontal or vertical fractures
  • Patients with teeth having multiple roots or root canals

Trial locations and contacts

No sites are listed yet. Contact the study team or a site near you to ask about taking part.

ALİ ERDEMİR, Professor contact

+905325650065

erdemirali@hotmail.com

Sara NAJJARİ HAGH contact

+905525981520

saranajjari1998@gmail.com

About this study

This clinical study aims to compare the clinical and radiographic outcomes of four different scaffolds used in regenerative endodontic treatment of previously root canal-treated permanent teeth requiring retreatment.

Participants will be randomly assigned to one of four groups based on the scaffold used: induced blood clot, injectable platelet-rich fibrin (i-PRF), advanced platelet-rich fibrin (A-PRF), or advanced platelet-rich fibrin plus (A-PRF+). All participants will receive the same root canal disinfection and restorative procedures, with the scaffold type differing between the groups.

Participants will be evaluated clinically and radiographically at 3, 6, and 12 months after treatment. The study will compare the groups in terms of the resolution of clinical signs and symptoms and changes observed on radiographic and cone-beam computed tomography images.

Read the detailed description

This study was designed as a prospective, controlled clinical trial to compare the clinical and radiographic outcomes of four regenerative endodontic approaches applied to permanent teeth requiring single-root retreatment. The sample size was calculated using G*Power v3.1 (Heinrich Heine University, Düsseldorf, Germany) based on an effect size of 0.50, a significance level of 0.05, and a power of 0.80; a total of 60 patients, with 15 patients per group, were planned to be included in the study. The null hypothesis (H0) of this study is that there will be no difference in the clinical and radiographic success of four different regenerative approaches (apically induced blood clot, injected i-PRF, A-PRF, and A-PRF+) applied to necrotic permanent teeth requiring single-root retreatment. The necessary institutional approval and ethics committee approval have been obtained for this study. Patient participation will be voluntary; patients will be informed about the study, and informed consent forms will be obtained from those who wish to participate. Following the application of local anesthesia and a rubber dam, the relevant teeth will be disinfected with 2.5% NaOCl, and the general shape of the cavity will be formed using a sterile diamond bur with a high-speed, water-cooled air turbine. If caries is present, sterile steel burs attached to a low-speed micromotor and an angle piece will be used to remove it. Once the access cavity is complete, the root canal filling material will be removed with retreatment files without chemical agents. The working length will be determined, and mechanical preparation will be kept to a minimum. The apical opening will be enlarged to a diameter equal to the tip diameter of a #40 file. For root canal irrigation, 20 mL of 1.5% sodium hypochlorite, 20 mL of normal saline, and 10 mL of 17% EDTA will be used. After calcium hydroxide is placed in the root canal, the tooth will be sealed with a temporary filling material. Second Session (3 weeks later): If there are no symptoms, the temporary filling material and calcium hydroxide will be removed. A final irrigation will be performed with 20 mL of 17% EDTA. The volunteer patients included in the study will be divided into four groups according to the random assignment determined on the www.randomizer.org website.

Group 1: (Blood Clot Group) Bleeding will be induced by exiting the apical foramen with sterile Type K files to ensure the canal is filled with blood.

Group 2: (i-PRF Group) 10 cc of venous blood drawn from the patient's antecubital vein will be centrifuged at 700 rpm for 3 minutes. The upper yellow layer will be drawn up with a syringe and injected into the root canal.

Group 3: (A-PRF group) The 10 cc of venous blood obtained as in Group 2 will be centrifuged at 1500 rpm for 14 minutes. The upper yellow layer will be removed from the tube and applied to the root canal using sterile pluggers.

Group 4: (A-PRF+ group) The 10 cc of venous blood obtained as in Group 2 will be centrifuged at 1300 rpm for 8 minutes. The yellow layer on top will be removed from the tube and applied to the canal using sterile applicators.

In all groups, after a bioceramic-based covering material is placed over the scaffold, a glass ionomer base material will be applied, and the teeth will be restored with a bonding agent and composite. Post-treatment, periapical X-rays will be taken of all patients, and a KIBT scan will be performed. Patients will be evaluated clinically and radiographically at 3-, 6-, and 12-month follow-up visits. The clinical evaluation will assess spontaneous pain, percussion sensitivity, palpation sensitivity, the presence of a fistula, and mobility. Vitality tests will be performed using a cold test and an electrical pulp test. At the 12-month follow-up, a KIBT scan will be performed to examine changes in lesion size, root wall thickness, or hard tissue formation.

Measurement of Dentin Thickness KIBT images will be acquired using an I-CAT (Imaging Sciences, Hatfield, PA, USA) tomography device in accordance with the standard imaging protocol. During imaging, the Frankfurt horizontal plane will be positioned parallel to the floor. In contrast, the midsagittal plane will be positioned perpendicular to the floor using the jaw support unit and laser alignment beams. Images will be acquired using standard parameters: an 8x8 cm field of view (FOV) of the relevant jaw, 120 kVp, 8 mA, a voxel size of 0.25 mm³, and a scan time of 14.7 seconds. Dentin thickness measurements for the relevant tooth will be performed on axial sections. Measurements will be determined in millimeters at three regions-4, 6, and 8 mm from the radiographic apex-based on the distance between the root canal wall and the external root surface.

Root Canal Volume Measurement Root canal volume measurements for the teeth will be performed using the ITK-SNAP software. KIBT images will be imported into the program in DICOM format. The region of interest will be delineated as a rectangular area using a semi-automatic segmentation method. During segmentation of all images, the minimum and maximum threshold values will be optimized based on the gray density distribution. Minimal manual adjustments will be made for each tooth as necessary. A region-growing algorithm will be applied, and a manual spread point will be placed at the root canal midpoint. The segmentation process will spread outward from the selected spread point and automatically terminate when it exceeds the predefined threshold boundaries. Segmentation areas extending beyond the anatomical boundaries will be manually corrected. The resulting volume values will be recorded in mm³ via the software's "Volume and Statistics" tab.

Measurement of Periapical Lesion Dimensions Periapical lesion dimensions will be assessed in millimeters along three axes. The bucco-lingual and mesio-distal widths of the lesion will be measured on the axial section where the lesion appears widest. The vertical dimension will be determined from the sagittal section at which the lesion appears widest.

Statistical Analysis All data will be analyzed using SPSS Statistics 17.0 for Windows (SPSS Inc., Chicago, IL), and a P-value of < 0.05 will be considered statistically significant. Lesion size and dentin thickness will be analyzed using a t-test. Volumetric changes in the root canal before and after regenerative endodontic treatment will be tested using the Wilcoxon signed-rank test.

Keywords
Regenerative endodontic procedures, retreatment, A-PRF, A-PRF plus, i-PRF

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT07721051
Study groupRoleWhat they receive
Blood clot groupBleeding will be induced by removing the apical opening with sterile Type K files to ensure the canal fills with blood. The blood clot induced apically will be used as the scaffold material.
i-PRF group10 cc of venous blood drawn from the patient's antecubital vein will be centrifuged at 700 rpm for 3 minutes. The yellow layer on top will be drawn up with a syringe and injected into the canal. i-PRF will be used as the scaffold material.
A-PRF groupThe 10 cc of venous blood obtained as in Group 2 will be centrifuged at 1500 rpm for 14 minutes. The yellow layer on top will be removed from the tube and applied into the canal using sterile applicators. A-PRF will be used as the scaffold material.
A-PRF+ groupAs in Group 2, 10 cc of venous blood will be centrifuged at 1300 rpm for 8 minutes. The yellow layer on top will be removed from the tube and applied into the canal using sterile pluggers. A-PRF+ will be used as the scaffold material.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Proportion of Teeth Achieving Clinical and Radiographic Success at 12 Months

    Clinical and radiographic success will be assessed as a composite binary outcome for each treated tooth at the 12-month follow-up. A tooth will be classified as successful if both clinical and radiographic success criteria are met. Clinical success will be defined as the absence of spontaneous pain, tenderness to percussion, tenderness to palpation, swelling, sinus tract, and pathological mobility. Radiographic success will be defined as reduction or complete resolution of the baseline periapical lesion without the development of a new periapical lesion. The outcome will be reported as the proportion of teeth achieving clinical and radiographic success at 12 months.

    Measured: 12 months after treatment

Secondary outcomes (3)
  1. CBCT-Based Change in Aggregate Periapical Lesion Size From Baseline to 12 Months

    Periapical lesion size will be assessed on cone-beam computed tomography images at baseline and at the 12-month follow-up. The mesiodistal, buccolingual, and vertical dimensions of the lesion will be measured in millimeters. These three linear measurements will be summed to obtain one aggregate periapical lesion size value for each tooth. The change in aggregate periapical lesion size from baseline to 12 months will be compared among the scaffold groups.

    Measured: From baseline to 12 months after treatment

  2. CBCT-Based Change in Mean Dentinal Wall Thickness From Baseline to 12 Months

    Dentinal wall thickness will be measured in millimeters on cone-beam computed tomography images at baseline and at the 12-month follow-up. Measurements will be performed at predefined levels from the radiographic apex, and the mean of these measurements will be calculated to obtain one dentinal wall thickness value for each tooth. The change in mean dentinal wall thickness from baseline to 12 months will be compared among the scaffold groups.

    Measured: From baseline to 12 months after treatment

  3. CBCT-Based Change in Root Canal Volume From Baseline to 12 Months

    Root canal volume will be measured in cubic millimeters on cone-beam computed tomography images at baseline and at the 12-month follow-up using image analysis software. The change in root canal volume from baseline to 12 months will be compared among the scaffold groups.

    Measured: From baseline to 12 months after treatment

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted22 Jul 2026
  2. Study start1 Oct 2026 (estimated)
  3. Primary completion1 Dec 2027 (estimated)
  4. Study completion1 Mar 2028 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Other
Time perspective
Cross-sectional
Enrolment
60 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07721051
Sponsor's protocol ID
2026/08-2026.06.25
Status last verified
Jul 2026
First submitted
9 Jul 2026
Last updated
22 Jul 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided

Questions about this trial

What is this clinical trial studying?

An observational study of Endodontics and Regenerative Endodontic Procedures, run by Kırıkkale University.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 22 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact ALİ ERDEMİR, Professor (+905325650065, erdemirali@hotmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Proportion of Teeth Achieving Clinical and Radiographic Success at 12 Months (time frame: 12 months after treatment). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Jul 2026; AzTrials last refreshed its copy on 6 Nov 2026.

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