Research: THE BIOTOOTH

After the age of 50, people in Western countries lose an average of 12 teeth. At present the options are to replace them with dentures or an artificial implant. Researchers are investigating the possibility of replacing a lost or damaged tooth with a living, natural tooth created from the patient's own tissue, and grown in its intended location in the patient's mouth.

To achieve this, in 2002, Professor Paul Sharpe at the Dental Institute, King's College London, founded a regenerative dentistry company, Odontis Ltd, with a Wellcome Trust technology transfer grant. The company is dedicated to growing human teeth by studying the complex formative processes that produce teeth in a developing embryo – and combining this understanding with advances in stem cell biology and tissue engineering.

Experiments in mice have shown that if the two different types of cell that produce a tooth bud in an embryo – epithelial and mesenchymal cells – are combined in culture, then implanted in an adult mouth, new teeth start to form. Moreover, the teeth form in the correct orientation, are the right size and shape for their location (molars are shaped like molars, incisors like incisors and so on), and even attach themselves to the jawbone by soft connective tissue. If left long enough, the teeth form roots and erupt.

Having demonstrated the feasibility of this technology in the mouse, the researchers now aim to move the science established in the mouse into commercial product development – and test the 'BioTooth' in humans.

Crucial to the success of the BioTooth is the need to identify an effective and easily accessible source of the individual's own cells to use as raw material. This avoids rejection by the immune system, and because tooth size, shape and colour are genetically determined, it also means the engineered teeth will more closely match the person's natural teeth.

Having tested the potential of various cell types, the researchers found that adult stem cells derived from bone marrow can replace embryonic mesenchyme in the tooth formation process. Other research suggests that progenitor stem cells capable of generating a variety of tooth tissues, including enamel, could be present within teeth themselves.

External links

• Modina S, Sharpe PT. Tissue engineering of teeth using adult stem cells. Arch Oral Biol 2005;50(2):255–8.