Sometimes kids trip and fall, and their teeth take the hit. Nearly half of children suffer some injury to a tooth during childhood. When that trauma affects an immature permanent tooth, it can hinder blood supply and root development, resulting in what is essentially a “dead” tooth.
Until now, the standard of care has entailed a procedure called apexification that encourages further root development, but it does not replace the lost tissue from the injury and, even in a best-case scenario, causes root development to proceed abnormally.
Stem cells can regrow dental tissue , new study
New results of a clinical trial, jointly led by Songtao Shi of the University of Pennsylvania and Yan Jin, Kun Xuan, and Bei Li of the Fourth Military Medicine University in Xi’an, China, suggest that there is a more promising path for children with these types of injuries: Using stem cells extracted from the patient’s baby teeth.
Shi has been working for a decade to test the possibilities of dental stem cells after discovering them in his daughter’s baby tooth. He and colleagues have learned more about how these dental stem cells, officially called human deciduous pulp stem cells (hDPSC), work and how they could be safely employed to regrow dental tissue, known as pulp.
The Phase I trial, conducted in China, which has a research track for clinical trials, enrolled 40 children who had each injured one of their permanent incisors and still had baby teeth. Thirty were assigned to hDPSC treatment and 10 to the control treatment, apexification.
Those that received hDPSC treatment had tissue extracted from a healthy baby tooth. The stem cells from this pulp were allowed to reproduce in a laboratory culture, and the resulting cells were implanted into the injured tooth.
Upon follow-up, the researchers found that patients who received hDPSCs had more signs than the control group of healthy root development and thicker dentin, the hard part of a tooth beneath the enamel. Blood flow increased as well.
At the time the patients were initially seen, all had little sensation in the tissue of their injured teeth. A year following the procedure, only those who received hDPSCs had regained some sensation. Examining a variety of immune-system components, the team found no evidence of safety concerns.
As further support of the treatment’s efficacy, the researchers had the opportunity to directly examine the tissue of a treated tooth when the patient reinjured it and had to have it extracted. They found that the implanted stem cells regenerated different components of dental pulp, including the cells that produce dentin, connective tissue, and blood vessels.
It is, however, just a first step. While using a patient’s own stem cells reduces the chances of immune rejection, it’s not possible in adult patients who have lost all of their baby teeth. Shi and colleagues are beginning to test the use of allogenic stem cells, or cells donated from another person, to regenerate dental tissue in adults.
Kun Xuan, Bei Li, Hao Guo, Wei Sun, Xiaoxing Kou, Xiaoning He, Yongjie Zhang, Jin Sun, Anqi Liu, Li Liao, Shiyu Liu, Wenjia Liu, Chenghu Hu, Songtao Shi, Yan Jin. Deciduous autologous tooth stem cells regenerate dental pulp after implantation into injured teeth. Science Translational Medicine, August 22 , 2018; 10 (455): eaaf3227 DOI: 10.1126/scitranslmed.aaf3227
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