A study involved seeding cells from the immature teeth of six-month old pigs onto biodegradable polymer scaffolds. The researchers then placed these structures into rat hosts. Within 30 weeks, small, recognizable tooth crowns had formed. These contained dentin; odontoblasts, cells that secrete dentin-forming protein; a well-defined pulp chamber; Hertwig’s root sheath epithelia; cementoblasts, which form a mineralized tissue that covers the roots; and a morphologically correct enamel organ. The results, demonstrated in some two dozen experiments, represent the first successful generation of mature tooth crowns containing both dentin and enamel. They also suggest that it may be possible to grow teeth of a particular size and shape, according to principal investigator Pamela Yelick, Harvard School of Dental Medicine instructor in oral and developmental biology at the Forsyth Institute and an assistant member of the Forsyth staff. The research was reported in the Oct. 1, 2002, Journal of Dental Research.