A multinational research team has successfully regenerated tooth root and supporting periodontal ligaments to restore tooth function in a swine model, according to the December 20 issue of the online publication PloS ONE.
Using stem cells harvested from extracted third molars of 18- to 20-year-olds, Dr. Songtao Shi, University of Southern California, School of Dentistry, Los Angeles, and colleagues created sufficient root and ligament structure to support a crown restoration in their mini-pig model. The resulting restoration closely resembled the original tooth in function and strength.
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. Previous studies conducted by Dr. Shi and Stan Gronthos, PhD, at the National Institutes of Health had used dental pulp stem cells. Dr. Shi found the new technique to be superior.
"The apical papilla provides better stem cells for root structure regeneration," said Dr. Shi. "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."
Dr. Shi hopes 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 who would prefer receiving living tissue derived from their own teeth.
"[Patients receiving implants] must have sufficient bone in the jaw to support the implant," said Dr. Shi. "For those who don’t, this therapy would be a great alternative."
The not-so-distant future may be one in which not only third molars but also primary teeth will become valuable therapeutic tools, he added.
"We will be able to provide not only this technique, but other new therapies utilizing a patient’s own stem cells harvested from [his or her] preserved teeth," Dr. Shi said. "This is a very exciting discovery and one that I hope to see in widespread clinical use in the near future."
