A research group from the Guangzhou Institutes of Biomedicine and Health, headed by Dr. Duanqing Pei, has recently reported a successful attempt to grow teeth out of human urine.
During a laboratory experiment they extracted pluripotent stem cells (iPSCs) out the urine through the coaxing procedure. Afterwards, they forced iPSCs into mimicking both epithelial cells (which eventually become enamel) and mesenchymal cells, which eventually grow into the other three components in teeth: dentin, cementum, and pulp.
Laboratory mice were the first ones to take a blow of raging scientific imagination. Dr. Duanqing Pei’s team implanted them with a mixture of the epithelial and mesenchymal cells, and to their (scientists') glorious joy, only three weeks later teeth-resembling structures were formed. They were containing almost everything that a decent tooth needs: dental pulp, dentin, enamel space, and enamel organ.
To our regret, it looks like it’s too early to rush to the dentistry with a jar full of pee, in hopes to get affordable jaws. Professor Chris Mason, a stem cell scientist at the University College London, flatly commented that human urine is "probably one of the worst sources" to make tooth implants, considering quantity and quality of expelled cells. Using urine also involves a high risk of bacterial contamination.
Even so, this experiment could be put to good use as a personal hygiene horror for kids: one naughty girl did not want to brush her teeth…and guess what happened.