Tissue engineering regenerates tooth crowns in animal model

Tissue engineering regenerates tooth crowns in animal model
June 28, 2004
By Mark Berthold
American Dental Association
Boston ÇƒÓ Researchers from the Forsyth Institute have regenerated tooth crowns in rats, according to a new study.
"Bioengineered teeth from cultured rat tooth bud cells," which appears in July's Journal of Dental Research, reports maintaining individual tooth-forming cells in culture for six days before implanting them.
According to the researchers ÇƒÓ from Forsyth, Massachusetts General Hospital in Boston and the Universidade Federal de Sao Paulo in Brazil ÇƒÓ this demonstrates that adult dental stem cells can give rise to tooth crowns containing dentin and enamel. It may also be possible to expand enough such cells in culture to grow full-sized teeth.
"We are very excited because mammalian systems tend to operate in similar ways," says principal investigator Pamela Yelick, Ph.D. "Having regenerated teeth of a second mammalian species allows us to hope for similar success with human teeth."
In bioengineering the rat teeth, the researchers used techniques similar to when Forsyth regenerated pig tooth crowns in 2002. In both experiments, the researchers "seeded" adult dental stem cells ÇƒÓ not embryonic stem cells ÇƒÓ from the immature teeth of animals onto biodegradable polymer scaffolds. The scaffolds were then implanted in the abdomen of rat hosts, forming small but recognizable tooth crowns.
In the previous pig study, researchers could not rule out the possibility that the new teeth hadn't emerged from clumps of incompletely dissociated tooth tissue. But in the latest rat study, they grew individual, dissociated tooth bud cells in culture before implanting them.
"Our results show that individual tooth progenitor cells can interact on scaffolding to form tooth crowns, and that it might be possible to culture enough dental stem cells to grow full-sized teeth," says co-author Dr. Monica T. Duailibi.
Adds Dr. Yelick, "Within a year, we expect to determine whether the methods we use to regrow animals' teeth will be useful in regenerating human teeth. If the methods prove effective, it will be at least seven years before they can be tested clinically in humans."