Encapsulated Acellular System From Mesenchymal Stem Cells for Dental Pulp Regeneration

Inclusion Criteria: * Systemically healthy patients (ASA I). * Patient presenting with a maxillary or mandibular incisor/canine and mandibular premolar with mature apex, pulpal necrosis, and apical radiographic evidence of apical periodontitis (PAI ≥2 and CBCTPAI ≥1). * Patient presents with a tooth that does not respond to electrical and thermal pulp testing. * Patients with restorable teeth (considering the definition of class A or B, according to Samet and Jotkowitz classification) without the need for a single fine prosthesis (crown) or major restoration. Exclusion Criteria: * Patients not available for the follow-up period (27 weeks). * Patients who will undergo orthodontic treatment in the next six months. * Patients with reports of allergies to any material or medication used in the study. * Pregnant patients. * Heavy smokers (more than 10 cigarettes per day). * Patients with a history of systemic diseases that impair immune function, such as diabetes mellitus, immunodeficiency, leukemia, Addison's and Cushing's disease. * Patients who have used immunosuppressive drugs or chemotherapy, 3 months before the study. Or that they will be irradiated or undergo chemotherapy. * Patients who have endodontically treated teeth. * Patients who have teeth with signs of severe root resorption. * Patients who have teeth with mobility class III or Dens invaginatus. * Patients who have teeth with a history of avulsion-type dentoalveolar trauma. * Patients who have teeth with clinical and/or radiographic evidence of root fracture. * Patients who have teeth that cannot be completely isolated with rubber dam. * Patients who have teeth with more than one root or root canal.