Scientists have developed a technique that can guide a body's stem cells to regenerate teeth, according to an article in the May issue of Journal of Dental Research.
The results of an animal-model study conducted in the Tissue Engineering and Regenerative Medicine Laboratory Columbia University Medical Center in New York City has shown that by guiding stem cells to a scaffold made of natural materials and integrated in surrounding tissue, practitioners do not need to use harvested stem cell lines or create an environment outside of the body (for example, in a petri dish) to grow the tooth and then implant the tooth once it has matured. Instead, the tooth can be grown “orthotopically,” or in the socket, where the tooth can integrate with surrounding tissue in ways that are not possible with hard metals or other materials.
Study researchers made three-dimensional anatomically shaped human molar scaffolds and rat incisor scaffolds. In each of 22 rats, they implanted an incisor scaffold orthotopically in mandibular incisor extraction pockets and a human molar scaffold ectopically in the dorsum. They then infused the scaffolds' microchannels with two growth factors. They also implanted growth-factor–free control scaffolds.
After nine weeks, they found that periodontal ligament–like fibrous tissue and new bone regenerated where the rat incisor scaffolds interfaced with native alveolar bone. The human molar scaffolds showed integration and tissue ingrowth. Researchers also found that the growth factors recruited significantly more endogenous cells and led to greater angiogenesis than did the growth-factor–free control scaffolds.
“These findings represent the first report of regeneration of anatomically shaped tooth-like structures in vivo, and by cell homing without cell delivery,” wrote corresponding author Dr. Jeremy Mao, the Edward V. Zegarelli Professor of Dental Medicine at Columbia University Medical Center, and his colleagues.
The study was supported by National Institutes of Health grant from the National Institute of Dental and Craniofacial Research.
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