This study evaluated the regenerative outcomes of immature permanent teeth with necrotic pulps treated using three scaffold types-blood clot, platelet-rich fibrin (PRF), and concentrated growth factor (CGF)-combined with either 5% or 17% EDTA as the final irrigant. Thirty teeth were randomly assigned to six treatment groups and followed clinically and radiographically for 12 months. Cone-beam computed tomography (CBCT) was used to assess root development parameters, including root length increase, apical diameter change, hard tissue formation, and periapical lesion volume. Clinical assessments included pain, swelling, sinus tract formation, percussion sensitivity, and pulp sensitivity testing. The study aimed to determine whether different scaffold materials and EDTA concentrations influence regenerative healing responses in immature necrotic teeth.

This prospective randomized clinical study investigated regenerative endodontic treatment approaches for immature permanent teeth diagnosed with pulp necrosis and associated periapical pathology. Thirty teeth were allocated into six treatment subgroups based on two variables: scaffold type (blood clot, platelet-rich fibrin [PRF], or concentrated growth factor [CGF]) and final irrigation protocol (5% EDTA or 17% EDTA). All procedures were performed using a standardized regenerative protocol that included sodium hypochlorite irrigation, intracanal antibiotic medication, induction of apical bleeding when applicable, placement of the assigned scaffold, coronal sealing with mineral trioxide aggregate (MTA), and final composite restoration.

Radiographic evaluation involved cone-beam computed tomography (CBCT) at baseline and 12 months to measure root length development, apical diameter changes, hard tissue formation, and volumetric alterations in periapical lesions. Periapical radiographs were taken at baseline, 6 months, and 12 months to complement CBCT findings. Clinical follow-up included assessment of symptoms such as pain, swelling, sinus tract presence, tenderness to percussion, and pulp sensitivity using cold testing and electric pulp testing.

The primary aim of this study was to compare the effects of scaffold type and EDTA concentration on the biological and radiographic outcomes of regenerative endodontic treatment. The study sought to clarify how these variables may influence root maturation, apical closure, pulp vitality responses, and periapical tissue healing within a regenerative framework. This research was designed to contribute to the optimization of clinical protocols for managing immature teeth with necrotic pulps.

Inclusion Criteria:

• Immature permanent teeth with open apices
• Diagnosis of pulp necrosis
• Radiographic evidence of periapical pathology
• Teeth suitable for isolation and restoration
• Patients aged 9 to 25 years
• No systemic diseases that contraindicate dental treatment
• Willingness to attend follow-up visits
• Signed informed consent by patient or guardian

Exclusion Criteria:

• Teeth with root fractures
• Teeth with severe canal curvature (>30°)
• Teeth with advanced root resorption
• Periodontal pocket depth >3 mm
• Previous endodontic treatment or retreatment
• Pregnancy
• Use of antibiotics or analgesics within the last 7 days
• Nonrestorable crowns
• Uncooperative patients unable to attend follow-up

Individual participant data (IPD), including CBCT images and clinical records, will not be shared due to patient confidentiality and ethical restrictions stated by the institutional review board.

No blinding was possible because the type of scaffold (blood clot, PRF, or CGF) and the EDTA concentration (5% or 17%) were visibly identifiable during the clinical procedure. Operators could not be masked, and participants were aware of the treatment steps, making the study open label.