**5. Conclusions**

Clinicians should consider employing the REP in cases when the root development is severely deficient, with insufficient dentine, and where the tooth's prognosis is hopeless even with an apexification procedure. With moderate to high certainty, APCs used in the REP procedure significantly improved apical closure and response to vitality pulp tests. However, overall both APCs and BC showed similar successful outcomes in the regeneration procedure. In the apexification procedure with moderate certainty, it can be concluded that both MTA and Ca(OH)2 are equally effective in forming the calcific barrier. With moderate certainty, it can be concluded that both regeneration and apexification procedures are equally comparable interventions and result with similar overall outcomes.

**Author Contributions:** Conceptualization, L.M. and P.P.; methodology, P.P.; software, S.P.; validation, L.M., P.P. and S.G.; formal analysis, B.L.; investigation, P.P.; resources, B.L.; data curation, S.P.; writing—original draft preparation, L.M.; writing—review and editing, L.M. and B.L.; visualization, P.P.; supervision, S.G.; project administration, L.M.; funding acquisition, B.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable for secondary research.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.
