Functional Tooth Regeneration

Fundamental problems in the oral tissues caused by dental caries, periodontal disease and trauma affect the oral and general health issues. Current regenerative medicine has been developed by the accumulation of important findings in embryonic development, stem-cell biology and tissue engineering technology. Tooth regenerative therapy including both of tooth-tissue repair and whole-tooth replacement is expected as a novel therapeutic concept to enable a fully functional recovery of oral and maxillofacial region. Tooth tissue-derived stem cells and cell-activating cytokines are considered to be available approach for tooth-tissue regeneration based on the differentiation potential into several tooth tissues in vitro and in vivo. Whole-tooth replacement regenerative therapy is thought to be an attractive concept for next-generation regenerative therapy as a model of bioengineered organ replacement. To realise the whole-tooth regeneration, we have developed a novel three-dimensional cell-manipulation method designated the ‘organ germ method’. This method involves compartmentalisation of epithelial and mesenchymal stem cells at a high cell density to replicate the epithelial-mesenchymal interactions in organogenesis. The bioengineered tooth germ generates a structurally correct tooth in vitro and erupted successfully with correct tooth structure when transplanted into the oral cavity. Bioengineered teeth were able to perform physiological tooth functions such as mastication, response to mechanical stress and a perceptive potential for noxious stimuli. In this chapter, we describe recent findings and technological development underpinning tooth regenerative therapy.