Regenerative Endodontic Procedures in Immature Permanent Teeth: Biological Mechanisms and Clinical Outcomes.

Necrotic immature permanent teeth with open apices pose a difficult management problem in clinical endodontics. Conventional apexification techniques resolve infection but do not support continued root development, leaving the tooth structurally vulnerable. Regenerative endodontic procedures (REPs) have emerged as a biologically oriented alternative that harnesses stem cells, scaffolds, and growth factors to form new tissue within the root canal space and encourage root maturation. This narrative review discusses the biological principles underlying REPs, the clinical protocols currently in use, the reported treatment outcomes, the key prognostic factors, and the limitations of current evidence. Overall, REPs demonstrate favorable rates of periapical healing and continued root development, with platelet-rich plasma and platelet-rich fibrin scaffolds showing advantages over blood clot alone for dentinal wall thickening. Pulp sensibility recovery is variable and does not reliably confirm true pulp regeneration. Current outcomes more closely reflect biologically supported repair than consistent, predictable pulp regeneration. Standardized protocols and longer-term follow-up studies are needed to fully establish the evidence base for these procedures.