innovations report notes a recent technology demonstration in dental regenerative medicine: "Utilizing stem cells harvested from the extracted wisdom teeth of 18- to 20-year olds, [researchers] have created sufficient root and ligament structure to support a crown restoration in their mini-pig (animal) model. ... The technique relies on stem cells harvested from the root apical papilla, which is responsible for the development of a tooth's root and periodontal ligament. ... The apical papilla provides better stem cells for root structure regeneration. With this technique, the strength of the tooth restoration is not quite as strong as the original tooth, but we believe it is sufficient to withstand normal wear and tear. ... [Researchers hope] to move the technique to clinical trials within the next several years, a potential boon for dental patients who are not appropriate candidates for dental implant therapy or would prefer living tissue derived from their own teeth."