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

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.

Inclusion Criteria: * 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 Exclusion Criteria: * 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 * 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