2007 WINNER

By Matthew Jones
Grange School, Cheshire

Winner of the 15-19 category

Growing human teeth in the lab

In today's society, where capitalism runs rampant, you can't just be smart; you have to look the part. So, you've got the haircut and the shoes, you've done the diets and got the body to prove it and you've got the clothes.

Everything looks good - you've had plastic surgery to make sure that it does -and then you smile. Too much red wine, too much social smoking and too much good food at those high-powered business parties have taken their toll and your teeth are a mess.

But, as they say, money solves everything. Recently, cosmetic dentistry has become one of the most rapidly-growing markets. Alistair Kennedy, a dentist at Gaskall Avenue Dental Practice in Knutsford, said "The market for cosmetic dentistry is growing almost exponentially. It's a huge area of growth, in an already multi-million pound industry". He said: "Prices start at around £60 for a tooth-whitening process, but can reach £20,000 or more for major changes, such as the implantation of titanium slugs as substitute teeth."

An alternative to the metal slug procedure may soon become commercially available, due to pioneering research into the field of stem cells by Professor Paul Sharpe, of King's College London.

His research explores the possibility of producing new teeth that can be grown in the lab or even inside the mouth as a replacement for lost, damaged or discoloured teeth. Say goodbye to your malignant mouthful, and say hello to those perfect pearly whites. Such an idea would have been outlandish even 15 years ago, a testament to how far biotechnology has come.

The research utilises a property of stem cells - that they are pluripotent, or able to develop into any cell type in the species from which they were taken, given the right chemical stimuli.

Professor Sharpe's team has been primarily working with mice and their stem cells in order to prove that the principle of growing a biologically-engineered tooth is sound. This is one of four theoretical ways to produce a "BioTooth" - the others are: to reconstruct the mature tooth as it appears in the mouth; to induce a third dentition, or natural tooth growth; to create a biological "scaffold" and attempt to culture the tooth layers on this foundation. However, the stem cell method seems to be the most successful, and the techniques could pave the way for more vital organ replication. Professor Sharpe's team is working to reproduce the conditions found when teeth are first produced by the body. They are trying to grow new teeth in a tooth bed, a specialised collection of tissues in which teeth develop. This is done by implanting a pellet of stem cell-derived mesenchymal cells - the cells which produce the soft tissues - before coating this in epithelial tissue from the mouth, again stem-cell derived, and implanting it into a region of plentiful blood supply in an animal host, such as the kidney, and allowing it to develop for 25 to 30 days.

The professor said culturing such cells in the lab was the most difficult part, especially because of the lack of diverse, healthy stem cell lines from human sources. However, his team has grown a human tooth in a mouse entirely from cultured cells. The teeth were of an appropriate size, surrounded by new bone and connective tissue, and showed evidence of root formation.

However, all this occurred in stable, controlled environments with few stresses. Prof Sharpe wanted to see if the same would occur in the mouth, and so tooth beds were implanted into the mouths of mice. After three weeks, despite the more demanding environment, teeth were easily identifiable in the region, and they had oriented and affixed themselves.

Matthew Jones
Matthew Jones is from The Grange School.