Advancing dentin-pulp regeneration: clinical perspectives and insights from stem/progenitor cell transplantation (part II)

This systematic review evaluates clinical studies investigating regenerative endodontic procedures for mature/immature teeth utilizing stem cell transplantation. An electronic search of Scopus, PubMed, ISI Web Science, and Google Scholar was conducted up to January 2023. Outcome measures encompassed radiographic (periapical lesion, root length, apical foramen width, volume of the regenerated pulp) and clinical (post-operative pain, sensibility test) parameters. Among 3250 identified articles, five clinical studies were selected, comprising two randomized controlled trials (RCTs) for mature/immature teeth, and three case reports/series for mature teeth. Despite the promising potential, the included studies exhibited a notable risk of bias. The diversity in stem cells (e.g., dental pulp stem cells [DPSCs], umbilical cord mesenchymal stem cells [UC-MSCs]), scaffolds (Atecollagen, collagen membrane, platelet-poor plasma [PPP], leukocyte platelet-rich in fibrin [L-PRF]), and growth factors (granulocyte colony-stimulating factor [G-CSF]) emphasized the heterogeneity across interventions. In RCTs, DPSCs application increased root length and reduced apical foramen width in immature teeth, while UC-MSCs transplantation reduced apical lesions in mature teeth. Transplantation of DPSCs aggregates or UC-MSCs/PPP also elicited positive pulp responses and increased blood flow. In case reports/series, DPSCs application in teeth with irreversible pulpitis resulted in mineralization and increased the regenerated pulp' volume. Furthermore, transplantation of DPSCs with G-CSF/atelocollagen or L-PRF/collagen membrane led to positive pulp responses. While underscoring the potential of stem cell transplantation for regenerative endodontics in mature/immature teeth, the overall evidence quality and the limited number of available studies emphasize the need for cautious interpretation of results. Future welldesigned clinical studies are essential to validate these findings further.