Bio tooth replacement 'a step closer'
New advance reported in replacing missing teeth with those generated from human cells
9th March 2013 - Losing a tooth and growing a new one from your own dental stem cells may be a step closer after British researchers refined the technique in the laboratory.
It is still much too early for use in humans, but the basic principle involves taking the cells and growing more of them under laboratory conditions to produce a very small, immature tooth, similar to what a tooth would look like when it starts to grow in an embryo.
"It's very immature and very small," says Professor Paul Sharpe, an expert in craniofacial development and stem cell biology at King’s College, London who led the work. "These are transplanted directly into the mouth where they get their blood supply and they start to grow and gradually form a complete tooth," he tells BootsWebMD.
Although the technique is unlikely to allow scientists to specifically choose between canines, incisors and molars, dentists would be able to re-shape the tooth crown according to its position in the jaw.
Hybrid human teeth in mice
In the latest work, the team from the Dental Institute at King’s College were able to combine human gum cells with the cells in mice responsible for teeth growth and transplant this combination of cells into mice. The result was hybrid human/mouse teeth containing dentine and enamel, as well as viable roots.
The ability to produce a tooth replacement with roots would be a major step forward in dental surgery. Replacement of missing or damaged teeth currently involves fixed or removable prostheses or dental implants. Dental implants involve drilling a hole into the jawbone into which a titanium rod is screwed that is capped by a plastic or ceramic ‘tooth’ crown.
Putting down roots
Although in general implants work well, the continual impact from chewing can result in bone loss around the titanium rod. This is not a problem with natural teeth. "A normal tooth root is connected to the bone via soft tissue called the periodontal ligament," Professor Sharpe says, "and that soft tissue is really important because it provides a shock absorber, so that when you eat or when you move your teeth together you don't get any kind of sensation going through your jaws - it buffers the shock, basically."
The latest advance made by Professor Sharpe and his team bring the prospect of bioengineered teeth with their own root system a step closer. However, the next step will be finding adult sources of human cells that can be obtained in sufficient numbers to make biotooth formation a viable alternative to dental implants.
"It's one thing like we and others have done to prove a principle in a laboratory," says Professor Sharpe. "Taking that into a clinic is a long way off because the cells we use and the way we manipulate those cells showing that this will work in the lab context are not ways that you can use in a clinical context."
Professor Sharpe believes that even with proper funding the first patient trials of the technique would be unlikely to happen for at least five years.
The latest study, which appears in the Journal of Dental Research, was funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London.