Preliminary study on dental pulp stem cell-mediated pulp regeneration in canine immature permanent teeth.

INTRODUCTION The health of human teeth depends on the integrity of the hard tissue and the activity of the pulp and periodontal tissues, which are responsible for nutritional supply. Without the nourishing of the pulp tissue, the possibility of tooth fracture can increase. In immature permanent teeth, root development may be influenced as well. This study explored the potential of using autologous dental pulp stem cells (DPSCs) to achieve pulp regeneration in a canine pulpless model. METHODS The establishment of the pulpless animal model involved pulp extirpation and root canal preparation of young permanent incisor teeth in beagles. Autologous DPSCs were obtained from extracted first molars and expanded ex vivo to obtain a larger number of cells. The biological characteristics of canine DPSCs (cDPSCs) were analyzed both in vitro and in vivo by using the same method as used in human DPSCs. cDPSCs were transplanted into the pulpless root canal with Gelfoam as the scaffold, and root development was evaluated by radiographic and histologic analyses. RESULTS cDPSCs with rapid proliferation, multiple differentiation capacity, and development potential were successfully isolated and identified both in vitro and in vivo. After they were transplanted into the pulpless root canal with Gelfoam as the scaffold, DPSCs were capable of generating pulp-like tissues containing blood vessels and dentin-like tissue. Thickening of the root canal wall was also observed. CONCLUSIONS This study demonstrates the feasibility of using stem cell-mediated tissue engineering to realize pulp regeneration in immature teeth.