Tooth grown from human gum and mouse stem cells

For the first time, teeth have been grown from human gum cells, in combination with stem cells from mouse embryos.

'The advance here is we have identified a cell population you could envisage using in the clinic', said Professor Paul Sharpe to BBC News, who led the study at King's College London's Dental Institute.

Researchers took cells from adult human gums, grew more of these cells in the lab and then mixed them with mouse embryonic stem cells. This combination of cells were then transplanted into mouse kidneys, where they grew into recognisable teeth, complete with enamel and viable roots.

Bioengineered teeth have previously been grown from mouse stem cells in the lab (see BioNews 616). However, this study, published in the Journal of Dental Research, is the first example of cells isolated from human gums being used in the process of engineering teeth.

The development of teeth involves a combination of epithelial cells that form 'surface linings' like the gums, and mesenchymal stem cells that form a variety of different tissues such as bone and cartilage. In this study, epithelial cells were taken from adult human gums, but the mesenchymal stem cells, which instructed the epithelial cells to contribute to the formation of teeth, had to be taken from mouse embryos.

Professor Sharpe explained: 'The next major challenge is to identify a way to culture adult human mesenchymal cells to be tooth-inducing, as at the moment we can only make embryonic mesenchymal cells do this'.

The hope is that these techniques will eventually lead to the use of bioengineered teeth or 'bioteeth' instead of the dental implants currently available. These implants do not form a proper root structure, which can result in them wearing away the surrounding jawbone.

Bioengineered teeth could in principle form a natural root structure that could avoid this problem. However, speaking to BBC News, Professor Sharpe noted that 'if it's going to work it has to be about the same price as a dental implant so we have to find a way to do it that is easy and cheap'.

Professor Alistair Sloan from Cardiff University's School of Dentistry, who was not involved in the study, told BBC News: 'We are still some way from engineering a whole organ like a tooth but the knock-on effect of research like this is developing bio-fillings, so some aspects of the technology are feasible within the next 10 to 15 years'.