BABY TEETH
The New Scientist reports that baby teeth contain stem cells that can turn into fat cells, neural cells, or " tooth-forming cells called ondontoblasts."
Previous work by [NIH pediatric dentist Songtao] Shi in 2000 had already shown that extracted adult wisdom teeth contain stem cells in the pulp at the centre of the tooth (PNAS, vol 97, p 13625). So when his six-year old daughter and her friends started losing their baby teeth, he decided to see if they also contained stem cells.
Whenever a tooth fell out, instead of putting it under the pillow, the parents stored the tooth in a glass of milk in the refrigerator overnight.
To isolate the stem cells, Shi extracted the pulp and cultured the cells for several days, then tested the survivors for markers of stem cell activity. About 12 to 20 cells from a typical incisor tooth turn out to be stem cells.
By culturing the cells in various growth factors, Shi could differentiate the cells into tooth-forming cells, fat cells or neural cells. The differentiated cells survived when implanted under the skin and in the brain of immunocompromised mice.
Shi also found that the cells promote the growth of bone. He suspects the stem cells may play a role in preparing the way for adult teeth. "We don't have evidence at the moment, but we think these stem cells do have a reason to be there."
The discovery of stem cells in baby teeth could give a big boost to oral surgery, says oral biologist Bjorn Reino Olsen, at Harvard Medical School. The cells, once differentiated into odontoblasts, could secrete dentine. This bone-like material could then replace the less biocompatible metal posts that are currently used to anchor implants to the jaw.
Take it from someone with too many crowns, any serious attempt to extend healthy life will have to deal with decrepit teeth. This development is definitely good news.