May 16th, 2013
Originally shared by Dental Tribune International: ‘Bioteeth’ a step closer to becoming clinical reality
NEW YORK, N.Y., USA: Researchers at the Dental Institute at King’s College London say they’re a step closer to growing human teeth in the lab using cells from the individual who would ultimately receive the tooth as a natural implant. Led by Professor Paul Sharpe, the research team isolated adult human gingival tissue from dental patients at the institute, grew more of the tissue in the lab, and then combined the tissue with mesenchyme (tooth-forming) cells from mice.
The combination of cells were transplanted into mice renal tissue, where they grew into hybrid human/mouse teeth that contained dentine and enamel — and formed viable roots.
The root formation is seen as a key breakthrough, because bioengineered teeth with natural root structure could eliminate one of the challenges sometimes seen with tooth-implant technology to date: a risk of bone loss in the area of the jaw that anchors an artificial implant. Such bone loss has been attributed to friction that occurs when eating or because of other jaw movement.
The goal is creation of a viable root that would be integrated into the jaw as if it was the recipient’s natural tooth. There’s no need for the crown of the tooth to match the bite, because technology exists to create a man-made alternative that integrates appropriately into the bite and appearance — and functions comparably to a natural crown.
The King’s College London Dental Institute reports that previous efforts to produce bioengineered teeth (bioteeth) have focused primarily on the generation of immature teeth (teeth primordia) that mimic those in the embryo. Such teeth could be transplanted as small cell ”pellets” into the adult jaw to develop into functional teeth. It has been demonstrated that embryonic teeth primordia can develop normally in the adult mouth, so if suitable cells can be identified and combined in such a way to produce an immature tooth, there is a realistic prospect that bioteeth can become a clinical reality.
Subsequent studies have largely focused on the use of embryonic cells; and although it is clear that embryonic tooth primordia cells can readily form immature teeth following dissociation into single cell populations and subsequent recombination, such cell sources are considered impractical to use in a general therapy.
Sharpe, an expert in craniofacial development and stem cell biology, said, “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. … Epithelial cells derived from adult human gum tissue are capable of responding to tooth-inducing signals from embryonic tooth mesenchyme in an appropriate way to contribute to tooth crown and root formation and give rise to relevant differentiated cell types, following in vitro culture. These easily accessible epithelial cells are thus considered a realistic source for consideration in human biotooth formation. 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.”
Sharpe’s findings were published in the Journal of Dental Research. The team’s efforts were 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, United Kingdom. The research report became available online in early March at jdr.sagepub.com. Categorized under “Research Reports – Biological,” the article is titled, “Adult Human Gingival Epithelial Cells as a Source for Whole-tooth Bioengineering.”
(Source: Dental Institute at King’s College London)