Your Third Set of Teeth

Here's something I've long been talking about to my dentist and one of my friends who's a professor at UCSF. The idea is to grow a new set of teeth instead of getting dentures, and researchers now say it should be pretty simple. They've already done it in mice.

Instead of false teeth, a small ball of cells capable of growing into a new tooth will be implanted where the missing one used to be.

The procedure needs only a local anaesthetic and the new tooth should be fully formed within a few months of the cells being implanted.

A few months isn't bad at all, is it? Especially not for a brand new tooth. It will just be a bit weird to cut a new molar at that age, but it's something other animals can already do.

The procedure is fairly simple. Doctors take stem cells from the patient. These are unique in their ability to form any of the tissues that make up the body. By carefully nurturing the stem cells in a laboratory, scientists can nudge the cells down a path that will make them grow into a tooth. After a couple of weeks, the ball of cells, known as a bud, is ready to be implanted. Tests reveal what type of tooth - for example, a molar or an incisor - the bud will form.

There are different sets of genes that get activated in the upper versus the lower jaw, and in the back versus the front. I'd hope they would know where in the jaw they'd been planted, but the scientists already know how to turn some of them on and off, for example to cause a molar to grow where an incisor should be.

Tests have shown the technique to work in mice, where new teeth took weeks to grow. "There's no reason why it shouldn't work in humans, the principles are the same," said Prof Sharpe.

His team has set up a company, Odontis, to exploit the technique, and has won £400,000 from the National Endowment for Science, Technology and the Arts and the Wellcome Trust.

Ah, don't you just love capitalism? Now just think how this will impact dentistry as people opt for a third tooth instead of massive fillings and caps. Sign me up.