Researchers from King’s College London, UK have developed a new method that replaced missing teeth with bioengineered material made from a patient’s own gum cells.
If a patient loses a tooth, the dentist or oral surgeon will typically replace it with an implant. The vast majority of dental implants used today are root-form endosseous implants. Such implants have a similar look to an actual tooth root and are placed within the bone of the jaw. The bone of the jaw fuses the surface of the implant with the surrounding bone (a process known as osseointegration). Because dental implants lack the periodontal ligament they will feel slightly different from natural teeth during chewing. Also, the friction from chewing and from other jaw movements can cause loss of bone around the implant.
Research by members of Paul Sharpe‘s laboratory at King’s College London has brought us closer to the reality of bioengineered teeth to replace toss teeth. Bioengineered tooth research has focussed primarily on producing immature teeth that can grow into adult teeth. Typically, such tooth buds are grown in culture and then transplanted into the gums. The gum actually provides and adequate environment for embryonic tooth buds to develop and form adult teeth. Therefore, the prospect of forming bioteeth certainly seems viable. The only question is identifying the cells and materials that can combine to properly form a normal adult tooth.
Sharpe noted, “What is required is the identification of adult sources of human epithelial and mesenchymal cells that can be obtained in sufficient numbers to make biotooth formation a viable alternative to dental implants.”
Sharpe and his colleagues surmised that gum tissue might provide the right cells for this project. Therefore, they isolated adult human gum tissue samples from patients at the Dental Institute at King’s College and grew it in culture in the laboratory. Next, Sharpe’s group combined this gum tissue with mouse embryonic tooth mesenchyme cells, which are stem cells that can induce tooth formation. This gum-tooth combination created teeth with surrounding gum tissue that could be transplanted into the mouths of mice. The teeth had dentine, enamel and viable roots.
The epithelial cells from human gum were able to respond to tooth-inducing signals from the embryonic tooth mesenchymal cells in a manner that allowed them to contribute to the tooth crown and the roots, and formed all the available cell types necessary for normal tooth formation. Thus, it appears that gum biopsies can provide a realistic source for human biotooth production.
The next step in this research is the formidable challenge of finding a mesenchymal stem cell population that can induce tooth formation. Presently, only embryonic mesenchymal cells can do this, according to Sharpe, but it is possible that adult mesenchymal stem cells can be manipulated to become tooth-inducing cells.