Stem Cells Generate Replacement Tooth in a Mouse Model
BY LAUREN UZDIENSKI, AUGUST 13, 2009
Researchers in Japan have successfully used stem cells to grow a tooth in a mouse model in what the Wall Street Journal calls "the first time scientists have developed a fully functioning three-dimensional organ replacement." The replacement tooth's structure, hardness and responsiveness to mechanical stress and pain were found to be equivalent to a natural tooth.
The study was conducted by delivering "tooth germ," which was derived from epithelial and mesenchymal cells, into the site of a missing tooth in an adult mouse. By 11 weeks, after the tooth erupted, it was found to have identical characteristics to a natural tooth: structural components like enamel, ameloblast, dentin, odontoblast, dental pulp, alveolar bone and blood vessels were in place, as were mechanical characteristics, like sufficient hardness for chewing and responsiveness to "noxious stimulation."
The authors did not give the number of mice that were evaluated for the study, though they said that instances of non-erupted explants were not frequent. These cases were attributed to transplantation issues, including "transplantation with the reverse direction or the falling off [of] the explants."
Though early, these pre-clinical results have some implication for human tissue engineering, with the authors stating that their work can serve as a model for organ replacement. To further their research, the authors say further examination is needed to identify available adult tissue stem cells and better understand how the cells differentiate.
