This systematic review was designed to evaluate and compare successful cases of regenerative endodontic treatment (RET) in terms of etiology, diagnosis, treatment protocols, and signs of success. An electronic search was performed in the PubMed and Google Scholar databases. The search was completed by 2 independent reviewers following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. All in vivo studies in humans that reported at least 1 successful case of RET were included in this review. Successful RET cases were defined as any case that involved the absence of clinical signs/symptoms of periapical inflammation and the presence of continued root maturation, especially apical closure, after the completion of the initial RET. A total of 250 successful cases of RET from 18 studies were selected in this review. A total of 98 (39%) successful cases were detected at least 2.5 years after the initiation of RET. A total of 239 (96%) successful RET cases were presented with the healing/absence of periapical lesions, and no further treatment was required. Furthermore, 45% of the successful RET cases showed root development maturation (stage V). Finally, the clinical outcomes of these RET cases are presented in this systematic review. Prudent case selection and excellent operative protocols are considered to be essential to achieve successful RET outcomes. Future studies are needed to identify a variety of relevant data, including preoperative, intraoperative and postoperative factors, in order to provide a better understanding of successful cases after RET.
Keywords: endodontic regeneration; immature necrotic teeth; outcome assessment; systematic review.