Stem cells to push teeth back
In the adult, it is possible to do to grow new perfectly functional teeth from a set of stem cells. This is what a Japanese team has just demonstrated ... on mice. But hope is good to one day adapt this feat to the human being.
The recipe for growing teeth seems simple in principle. Takashi Tsuji and his team of stem cell biology from the Tokyo Science Faculty have just detailed it in the Pnas, American scientific journal. The principle is to cultivate stem cells, an idea that is not new and that has raised hopes and experiments for several years. But the Japanese team, it has succeeded to the end ...
The biologists first took tissues at the origin of the teeth from a very young mouse embryo and isolated two types of cells, epithelial (forming the epithelia, that is to say the skin) and mesenchymal cells, primarily cartilage, bone and connective tissue.
These two cell populations were then fused to obtain a sort of germ, cultured for 5-7 days. The biologists then implanted it in the upper jaw of an adult mouse in place of a tooth that had previously been removed.
After 36 days, the new teeth had pierced the gingiva and, after 49 days, had reached normal size and, well aligned with the teeth of the lower jaw, allowed perfect chewing.
Indiscernible from the original teeth
Upon observation, these new teeth appeared quite normal, with internal innervation, roots and enamel protection. Ligaments have formed, connecting these teeth to the underlying bones and sensory nerves, as in the naturally grown dentition. The new teeth therefore provide a sensitivity to pressure, which is of course impossible with a prosthesis or an implant. In short, the teeth thus generated have, say the researchers, all the characteristics of their counterparts appeared normally.
According to Japanese authors, this technique could very well be applied in humans. The germ would then be made from stem cells taken from the person, since it is now known that such cells, including mesenchymal cells, are not reserved for embryos. It exists in adults in the bone marrow.
The scientific success is very interesting, but, however, if the operation is actually possible in humans, what remains to prove, the technique is still far from the dentists ...