Copyright 2004 John Fairfax Publications Pty Ltd
Sydney Morning Herald
May 20, 2004 Thursday
SECTION: Health And Science; Pg. 3
LENGTH: 531 words
BYLINE: Deborah Smith

The tooth fairy is facing some stiff competition from scientists - as are the makers of false teeth.

Researchers have predicted that it could become possible to use stem cells from inside discarded baby teeth to repair damaged brains, and to use stem cells from elsewhere in the body to grow new teeth to replace lost ones.

The developments highlight the surprising versatility of adult stem cells in the human body. But the news is not all good for adult stem cell research, with some recent setbacks in heart and diabetes studies at a time when embryonic stem cell research is about to get a boost.

The first licence in Australia to extract embryonic stem cells from surplus IVF embryos was issued last month to a Sydney fertility clinic, Sydney IVF.

In the US, a Harvard University team has skirted around President George Bush's ban on public money being spent on embryonic stem cell research and used private funds to create 17 new embryonic stem cell lines that they are making available to other researchers.

The British team working on growing new teeth will not reveal where in the body they obtain the stem cells they use, because they have recently set up a company, Odontis, to commercialise their discoveries. The team, led by Professor Paul Sharpe, of King's College London, was awarded an $820,000 British grant this month. It has only carried out research on mice so far, but intends to begin human work soon.

The team has been able to coax stem cells to become a small ball of cells known as a tooth bud. When implanted in the mouth of an adult animal, it develops into a new tooth which is anchored into the jaw with bone.

In mice it took only weeks for the new teeth to grow, but in humans it would take a few months, Sharpe says, who adds the prospect of newly grown teeth is at least five years away.

Tests can reveal whether the bud is destined to become a molar or an incisor, so it can be placed in the right position, he says.

In Australia, Dr Stan Gronthos , at Royal Adelaide Hospital's Hanson Institute, is using human stem cells from baby teeth as his starting point to try to grow new teeth, initially in mice.

He believes bioengineering techniques, such as building artificial scaffolds, may be needed to make the teeth develop into the right shape.

"And the big question will be how to create a living root to attach it to the bone," Gronthos says.

The stem cells in baby teeth were discovered unexpectedly after Gronthos's colleague in the US, Dr Songtau Shi, noticed the bloody pulp in his 6-year-old daughter's tooth after it had fallen out.

Shi says the stem cells from children are fast growing and long lived and have the potential to form the dentin in teeth as well as bone, nerve cells and fat.

The big advantage with baby teeth as a source of stem cells, says Gronthos, is that there is an easily accessible supply of them.

While adult stem cells have been collected now from many sources, including umbilical cord blood, bone marrow and fat, new research has dashed hopes of finding adult stem cells in the pancreas to treat diabetes, making embryonic stem cell research look a more promising approach for diabetes.