PRF-Assisted Regenerative Endodontic Retreatment of an Immature Tooth: A 4-Year Follow-Up.

Regenerative endodontic retreatment can be a viable nonsurgical option for previously treated immature teeth with persistent periapical pathology. With proper case selection, meticulous disinfection, and preservation of stem cell viability, long-term healing and continued root development can be achieved even in complex retreatment cases.