Professor Imad About, researcher of Marseille's faculty of orthodontics, examines an image of original dental cells on a screen in his laboratory in Marseille, March 12, 2010. Professor About has been conducting research to regenerate dental tissue with the hopes of running clinical tests in five years that will allow him to grow teeth from bone marrow. REUTERS/Jean-Paul Pelissier (FRANCE - Tags: HEALTH SCI TECH)