Via PhysOrg.com, good news for the future of dental medicine: "researchers activated the Wnt signalling pathway in mouse tissue; this signalling pathway is one of those used for cell communication and plays an important role in embryonic development ... one mouse molar developed dozens of new teeth with normal dentin, tooth enamel and developing roots. The crowns were, however, simple and cone-shaped, unlike the typically more complex multiple cusps of mouse molars. ... it became clear they were the result of germination from previously developed teeth, just like the teeth of lower vertebrates. ... The results also suggest that mice have retained incipient potential for continuous tooth generation and that it can be unlocked by activating Wnt signalling. It is reasonable to conjecture that the potential for continuous tooth generation may also have been retained in humans." It seems that a great deal of potential lies in the manipulation of Wnt signalling.