Reattaching Teeth Using Stem Cells

A new approach to anchor teeth back in the jaw using stem cells has been developed and successfully tested in the laboratory for the first time by researchers at the Uni­versity of Illinois at Chicago (UIC). In the Brodie Lab­oratory for Craniofacial Ge­netics at the UIC College of Den­tistry, reseachers used stem cells ob­­­tain­­ed from the periodontal ligament of mo­lars extracted from mice, ex­panded them in an incubator, and then seeded them on barren rat molars. The stem cell-treated molars were reinserted into the tooth sockets of rats. After 2 and 4 months, the stem cells aligned and formed new fibrous attachments be­tween the tooth and bone, firmly attaching the replanted tooth into the animal’s mouth, reported Mr. Smit Dan­garia, a bioengineering doctoral candidate who conducted the research. Tis­sue sections showed that the re­planted tooth was surrounded by newly formed, functional periodontal ligament fibers and new cementum, the essential ingredients of a healthy tooth attachment. In contrast, tooth molars that were replanted without new stem/progen­itor cells were either lost or loosely attached and were resorbed, stated Mr. Dangaria.
     Mr. Dangaria continued to explain that the natural surface of the tooth played an essential role in the study. “Our research uncovered the code required to reattach teeth—a combination of natural tooth root surface structure together with periodontal progenitor cells,” he said. To verify that the ligament was formed by the transplanted stem cells and not by the animal’s own cells, stem cells were labeled with green fluorescent protein prior to seeding them on the molars and reinserting the teeth into the animal’s mouth. According to Dr. Tom Diekwisch, director of the Brodie Laboratory, who is senior author on the pa­per, this is the first progenitor cell-based regeneration of a complete periodontal ligament in which a functional tooth was attached. “Our strategy could be used for replanting teeth that were lost due to trauma or as a novel approach for tooth replacement using tooth-shaped replicas,” said Dr. Diekwisch, who is also professor and head of oral bio­logy at the UIC College of Dentistry.
     The study, published in an online issue of Tissue Engineering, was funded by a National Institute of Health grant.