Scientists have persuaded adult stem cells to develop into complete tooth crowns in rats, furthering their goal of growing replacement teeth for humans, according to a study in the current issue of the Journal of Dental Research.
Using dental stem cells from juvenile rats placed on a sponge-like polymer mold, researchers at the Forsyth Institute, a dental research facility in Boston, and Universidade Federal de Sao Paulo grew well-formed crowns with all three normal tooth layers: enamel, dentin and pulp.
Because the scientists have also regrown pig tooth crowns, they are optimistic the process will work for people, paving the way for regenerating missing human teeth.
"We're very excited because it might be applicable to all mammals, including humans," said Pamela Yelick, the principal investigator from the Forsyth Institute.
The technique uses two types of adult dental stem cells, primordial cells that differentiate and develop into whole teeth in the jaw. The interaction of the two types leads to the different layers in both normal teeth and the engineered crowns.
To provide the growing teeth with blood and nutrients, researchers implanted the cell molds not in the rats' jaws, but in their abdomens -- a seemingly strange choice, but actually a standard procedure in tissue engineering. The process took about 12 weeks.
"We're working on a way to grow teeth right in the jaw," Yelick said.
If the scientists succeed, "the tooth would erupt exactly the way a natural tooth would," Yelick said.