Encapsulated Mesenchymal Stem Cells for Dental Pulp Regeneration.

Inclusion Criteria: Patient inclusion criteria: * Age: 16 - 58 years old. * Signed the informed consent. * Non-smoking. * Systemically healthy patients Tooth inclusion criteria: * Upper and lower incisors, upper and lower canines and lower premolars teeth with mature apex and apical lesion (greater than 2 PAI and 1 CBCTPAI). * Teeth that do not response to both electrical and thermal pulp test * Teeth that can be restored (as defined by Class A or Class B using Samet and Jotkowitz classification) without the need of a stainless steel crown. Exclusion Criteria: Patient exclusion criteria: * Patients without a phone number for contact during the study. * Subjects not available for follow up period (12 months). * Patients who are or will undergo orthodontic treatment over the next 12 months. * Patients with an allergy to any material or drug used in the study. * Patients who are pregnant or lactating. * Patients with a history of systemic diseases that alter immune function, such as diabetes mellitus, immunodeficiency, leukemia, Addison's disease and Cushing. * Patients who have used immunosuppressive drugs or chemotherapy, 3 months before the study. Tooth exclusion criteria: * Endodontically treated teeth * Teeth with signs of severe root resorption. * Teeth with mobility class III or Dens invaginatus. * Teeth with avulsion history and conservation in a dry extraoral medium for more than 1 hour. * Teeth with clinical and / or radiographic evidence of root fracture. * Teeth that can not be absolutely isolated with rubber dam. . Teeth with more than one root or root canal.