Promising Cell-Based Therapy for Bone Regeneration Using Stem Cells from Deciduous Teeth, Dental Pulp, and Bone Marrow

Abstract

We attempted to regenerate bone in a significant osseous defect with various stem cells from deciduous teeth, extracted from puppies, and grafted them into a parent canine mandible as an allograft, parent dental pulp, and bone marrow by tissue engineering and regenerative medicine technology using platelet-rich plasma as an autologous scaffold and signal molecules. Initially, teeth were extracted from a child and parent hybrid canine mandible region and bone marrow (canine mesenchymal stem cells; cMSCs), and parent teeth (canine dental pulp stem cells; cDPSCs), and stem cells were extracted from deciduous teeth (puppy deciduous teeth stem cells; pDTSCs). After 4 weeks, bone defects were prepared on both sides of the mandible with a trephine bar. Graft materials were implanted into these defects: 1) control (defect only), 2) platelet-rich plasma (PRP), 3) cMSCs/PRP, 4) cDPSCs/PRP, and 5) pDTSCs/PRP to investigate the effect of stem cells. The newly formed bones were evaluated by histology and histomorphometric analysis in the defects at 2, 4, and 8 weeks. According to histological observations, the cMSCs/PRP, cDPSCs/PRP, and pDTSCs/PRP groups had well-formed mature bone and neovascularization compared with the control (defect only) and PRP groups at 4 and 8 weeks, respectively, and the mineralized tissues in cMSCs/PRP, cDPSCs/PRP, and pDTSCs/PRP specimens were positive for osteocalcin at 8 weeks. Histometrically, newly formed bone areas were 19.0 ± 2.9% (control), 19.7 ± 6.0% (PRP), 52.8 ± 3.5% (cMSCs/PRP), 61.6 ± 1.3% (cDPSCs/PRP), and 54.7 ± 2.2% (pDTSCs/PRP) at 8 weeks. There were significant differences between cMSCs, cDPSCs, pDTSCs/PRP, and control and PRP groups. These results demonstrate that stem cells from deciduous teeth, dental pulp, and bone marrow with PRP have the ability to form bone, and bone formation with DTSCs might have the potential to generate a graft between a child and parent. This preclinical study could pave the way for stem cell therapy in orthopedics and oral maxillofacial reconstruction for clinical application.