Regrow your teeth

A lot of us will lose an adult tooth during our lives, should be this after a trip, a skateboard trick that didn’t quite go as planned, and so on. Dental technology has progressed since the ancient Etruscans fabricated denticles from oxen bones, but not all that much in the wider scheme of things.

Across the world, almost seven per cent of people over 20 years of age have lost all their teeth, while this figure goes up to 23 per cent for the over-60s. So the market is certainly there.

Titanium implants are presently the treatment of choice but they have their disadvantages. No sensation is generated during deployment – you can’t feel yourself chewing, while there is also a greater load on the jaw because of the absence of ligaments between the tooth and bone to absorb some of the stress. Cue the multi-pronged approach to regrowing our own chompers.

Alas, regrowing a natural tooth is no simple matter. You need two types of cell to interact, being dental epithelial cells to form the hard enamel coating on the tooth, and mesenchymal cells to produce the inner workings of a tooth such as dentin below the enamel and the pulp. Mesenchymal cells can be relatively simply obtained from the pulp of an adult tooth, but epithelial cells virtually disappear when your adult teeth are proudly in place so would need to be extracted from children. Then these latter cells need a medium suitable to grow into something bearing resemblance to a tooth.

Work started on assembling a “scaffold” made up of fluffy fibres that could be seeded with a mix of dental cells. Moderate success was achieved with tiny tooth structures resulting after several months.

Another approach involves attempting to trick adult cells into behaving like embryonic cells from which all our cells originate. Biologists at Kyoto University in Japan demonstrated that adult cells could be “reprogrammed” to act like pluripotent cells (the most flexible version of the embryonic cell) by adding a number of transcription genes. In theory, any cell type desired could then be created to also grow new teeth.

Yet another concept entails coercing adult cells to themselves grow into teeth. But there is a major stumbling block here – when the different dental cells join up to form a tooth they send complicated series of chemical signals to and fro among themselves and at least one type needs to be embryonic. So work is now taking place to map out the chemical signals to eventually introduce them into the cell combination.

It is now generally accepted that biological tooth replacement should be in place in around 10 years’ time, but we could have already been there some time ago. An issue that has always held dental research back is funding. Pharmaceutical companies, venture capitalists and the ilk have been somewhat reluctant to fund such research because you can’t live without an adequately functioning heart or brain, but you can live without teeth. The work goes on nonetheless.