Periodontal regeneration remains a major clinical challenge because of the complex, multiphasic architecture of the periodontium (cementum, periodontal ligament, alveolar bone). Stem cell–based strategies (autologous/allogeneic mesenchymal/dental-derived stem cells, cell sheets, cell-free approaches such as secretome/exosomes and cell homing) and they aim to restore structure and function beyond what conventional guided tissue regeneration achieves. Several preclinical studies and an increasing number of randomized clinical trials (RCTs) and meta-analyses report superior improvements in clinical attachment level (CAL), probing pocket depth (PPD) and radiographic bone fill when stem-cell approaches are added to standard therapy, although effect sizes remain modest and study heterogeneity is high. Translation requires consensus on cell source, manufacturing (GMP), scaffold/delivery method, outcome definitions, and regulatory/ethical oversight. This review summarizes current evidence, mechanisms, delivery strategies, safety, limitations, and recommendations for authors preparing manuscripts for publication.