A team of scientists grew accurate versions of natural teeth in a laboratory, raising the possibility of an eventual replacement for manmade implants such as dentures, bridges and crowns. The scientists, based at Forsyth Institute, were reportedly the first to grow such a complex tooth structure from a collection of individual cells. The Forsyth scientists manipulated pigs' dental stem cells - primordial cells that differentiate into the various tooth structures - to make enamel, which gives teeth their distinctive, hard exterior.