Tooth Regeneration via the Scaffold–Cell–Growth Factor Triad: An Evolution in Regenerative Dentistry

The tooth is a complex biological organ composed of multiple tissues, including enamel, dentine, cementum and pulp. However, dental disease and tooth loss due to periodontitis, caries, or trauma adversely affect most adults at some time in their lives. Tooth regeneration represents a shift in the dental paradigm from removal to repair to regeneration. Tooth regeneration is an extension of the broader field of regenerative medicine, aiming to restore a tissue defect to its original form and function by using biological substitutes to replace lost teeth or tooth tissue, providing a viable alternative to currently available clinical treatments. A full array of cell sources has been trialled for endodontic regeneration, following the basic premise of tissue engineering, including cells–scaffold–bioactive molecules. Several reports have documented dental pulp-like tissue regeneration, either in vitro or following the transplantation of stem cells. Tooth regeneration follows two unique approaches: cell transplantation and cell homing. Cell transplantation has been the predominant approach, whereas cell homing aims to achieve tissue repair and regeneration of the injury site through the chemotaxis of host endogenous cells. This narrative review explores therapeutically viable tooth regeneration approaches by contrasting cell transplantation and cell-to-scaffold methodologies focussing on the cell–scaffold–bioactive molecule triad.