Regrowing Teeth

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"If you think about it, you are transplanting a tooth under the soft tissue, in the gums," says Sharpe. "That tooth has to erupt and form roots so it's connected. If you can't form a root, there's no point doing any of it."

Indeed, a group of researchers from the University of Southern California (USC) recently regrew tooth roots in pigs using adult stem cells from wisdom teeth. The team, led by Songtao Shi, assistant professor of USC's School of Dentistry, isolated stem cells from the extracted wisdom teeth of 18-to-20-year-old humans. From these cells, the researchers successfully recreated a tooth's root and periodontal ligament, which, when transplanted into the oral cavity of a pig, could support a synthetic crown. Shi says it is a promising start, and his team hopes to begin human trials within the next few years. Eventually, he envisions being able to isolate stem cells from sources such as wisdom teeth, then store them for future use should the patient require dental attention down the line.

In the next few years, Shi, Sharpe, and others anticipate great strides in the area of tooth regeneration. As Sharpe sees it, the work being done in his field may help researchers in other areas of tissue engineering.

"I like to think that the fact that we are working on an organ where the surgery is easy to do and accessible will mean we can iron out some of the problems more easily in a patient," says Sharpe. "If we do something in a patient and it doesn't work, it's very easy to correct: the patient just has to come in and open his mouth. If doing that with a liver or a heart, it's not quite so easy. So we might prove certain principles of organ engineering."