Stem cells are considered to be the most valuable cells for regenerative medicine. Research on stem cells is providing advanced knowledge about how an organism develops from a single cell, and how healthy cells replace damaged ones in adult organisms. Stem cells have the ability to continuously divide to either replicate themselves (self-replication), or produce specialized cells that can differentiate into various other types of cells or tissues. Although current root canal treatment modalities offer high levels of success for many conditions, an ideal form of therapy might consist of regenerative approaches in which diseased or necrotic pulp tissues are removed and replaced with healthy pulp tissues to revitalize the teeth. The creation and delivery of new tissues to replace diseased , missing, or traumatized pulp is referred to as regenerative endodontics. This approach provides an innovative and novel range of biologically-based clinical treatments for endodontic disease to bring smiles on millions of faces. The purpose of this book is to give a prior insight of the unprecedented opportunities of oral and tooth tissue regeneration.