The cutting edge of stem cell research

A team from King's College London has grown teeth from transplanted cells in the jaws of mice. In the first experiment of its kind, the researchers, lead by Professor Paul Sharpe, grew the teeth by transplanting tooth buds from embryos, which then grew into normal teeth. In a separate experiment, the research team demonstrated the ability to make tooth buds from stem cells and that these stem cells grow in the kidneys of mice. Sharpe hopes that stem cell derived tooth buds will be used to grow teeth in the mouths of dental patients.

A second study, published in the same issue of the Journal of Dental Research, concentrates on adult dental stem cells. The team, from the Forsyth Institute (Boston, US), grew engineered teeth on a scaffold, then transplanted them into rats. Pamela Yelick, lead investigator, said, 'ideally what would happen is you would implant a [material] seeded with these dental stem cells and just implant that in the jaw. It would be similar to growing a baby tooth'.

There are hopes of clinical trials within a decade, but many obstacles remain. Extracting bone marrow stem cells is a painful surgical procedure, so Sharpe may have to switch to using dental stem cells. Taking lining cells from the mouths of human embryos is not without ethical controversy, and the cells may be rejected or lead to cancer. And there is also the difficulty of growing the cells to the correct shape and size, although this should be overcome using scaffolds or the right combination of molecular signals.

Replacing lost teeth is big business. With the average over 50 year old in the western world missing twelve teeth, the market is currently estimated at around US$ 900 million and expected to grow 15-20% per annum for the next 5-6 years. Sharpe, hoping to commercialise the stem cell technique, set up Odontis Ltd, which received £100,000 in funding from NESTA (National Endowment for Science, Technology and the Arts) earlier this year. He said: 'A key medical advantage of our technology is that a living tooth can preserve the health of the surrounding tissues much better than artificial prosthesis'.