Dental Pulp Stem Cells: From Discovery to Clinical Application.

Postnatal stem cells critically maintain tissue homeostasis and possess immense potential for tissue regeneration. These stem cells in the orofacial system were not identified until early 2000s when they were first found in the dental pulp and termed dental pulp stem cells (DPSCs). Isolated from either permanent or deciduous teeth, DPSCs were characterized to be highly clonogenic with multidifferentiation and neurovascular properties. Subsequent studies suggested that the origin of DPSCs may be associated with neural crest-derived cells and localized adjacent to neurovascular bundles as indicated by specific surface markers. DPSCs serve as key contributors to pulp homeostasis and injury repair. Mechanistic studies have revealed a fine-tuning regulatory network composed of both extrinsic and intrinsic factors that orchestrate fates of DPSCs. These findings have shaped our understanding of their biological nature as niche responsive progenitors. As we explore the potential of DPSCs in pulp regeneration, preclinical studies have developed diverse DPSC transplantation-based strategies, among which preconditioned DPSCs and DPSC aggregates have shown particular promise. Confirmed by recent clinical advances, DPSC transplantation after pulpectomy has successfully rebuilt the physiological pulp structure in situ functionalized with neurovascularization, indicating a novel regenerative approach for treating pulp diseases. Here, we summarized the 20-year golden journey on DPSCs from the unprecedented discovery to current clinical breakthroughs, while also suggesting future directions and challenges regarding expansion of regenerative applications and evaluation of in vivo DPSCs in diseases and therapies. The historical perspective of this field will provide a blueprint for the stem cell research and enlighten principles for de novo organ regeneration.