Maintaining the viability and avoiding necrosis of dental pulp are crucial to preserving the structural integrity and functioning of teeth. In recent years, cell-based regenerative endodontics has emerged as a promising approach to achieve this goal and has gained increasing attention in scientific research; however, in the confined space of the root canal system, hypoxic conditions can be both beneficial and detrimental, as they may promote angiogenesis in the graft to some extent but also lead to tissue necrosis if prolonged. Dental pulp stem cells (DPSCs) have been verified as multipotent cells that can promote angiogenesis and are therefore ideal candidates for realising real dental pulp regeneration within root canals. Thus, we focus on the underlying mechanisms of DPSCs to promote angiogenesis and summarise some preclinical studies and clinical trials involving transplanting of DPSCs to achieve real dental pulp regeneration, in the hope that this intractable source of perplexity in regenerative endodontics may be resolved sooner.