Scientists use stem cells to grow replacement teeth in mice

A study published this week in Proceedings of the National Academy of Sciences reported that scientists in Tokyo have successfully grown teeth in mice using stem cells.
The research team, led by Etsuko Ikeda at the Tokyo University of Science, used tissue from a mouse Embryo called 'tooth germ' and were able to separate out two cells which were later combined to create a bioengineered tooth germ. This newly engineered tissue was then implanted into the jaw of mice which had previously had their teeth removed. The researchers also engineered a florescent protein into the tooth germ to make it easier to track the progress of the growing teeth.
Originally, the tooth germ tissue implanted into the sockets measured 500 micrometers. However, within 37 days, the tissue had formed into visible sprouting teeth - made easier to see by the florescent protein. The protein also allowed the researchers to see that during the period of growth the genes  normally activated during tooth growth were also activated during the bioengineered tooth growth. The paper reported not only success in the growth of the teeth being as hard and durable as the mice's previous teeth, but also that the new teeth had connected with the existing nerve fibres, allowing for the mice to feel pain in the teeth.
While this research signifies a hopeful step for those suffering from severe dental problems, the wider implications are for the growth of human organs such as livers and kidneys using similar methods. However, Yasuhiro Ikeda, an expert in the field, cautioned against letting this research overly heighten expectations, saying that 'each organ is different, so it may take a long time before we can actually use this system in a clinic.'

 Source : BioNews http://www.bionews.org.uk/page_46465.asp