Autologous Dental Pulp Stem Cells in Regeneration of Defect Created in Canine Periodontal Tissue
This study aimed to investigate effects of dental pulp stem cells (DPSCs) on regeneration of a defect experimentally created in the periodontium of a canine model. Surgically created mesial 3-walled periodontal defects with ligature-induced periodontitis were produced bilaterally in the first lower premolar teeth of 10 mongrel dogs. Simultaneously, DPSCs were derived from the maxillary premolar teeth of the same dogs. Four weeks after creation of the periodontitis model, autologous passaged-3 DPSCs combined with Bio-Oss were implanted on one side as the test group. On the other side, only Bio-Oss was implanted as a control. Eight weeks after surgery, regeneration of the periodontal defects was evaluated histologically and histomorphometrically in terms of bone, periodontal ligament (PDL), and cement formation. Histologically, in all test specimens (10 defects), regeneration of cementum, bone, and PDL was observed. In the control groups, although we observed the regeneration of bone in all defects, the formation of cementum was seen in 9 defects and PDL was seen in 8 defects. Histomorphometric analyses showed that the amount of regenerated cementum and PDL in the test groups (3.83 ± 1.32 mm and 3.30 ± 1.12 mm, respectively) was significantly higher than that of the control groups (2.42 ± 1.40 mm and 1.77±1.27 mm, respectively; P < .05). A biocomplex consisting of DPSCs and Bio-Oss would be promising in regeneration of periodontal tissues.
Creation of periodontitis and implantation of biomaterial. (a) Photograph of surgical defect in the mesial portion of the dog's lower premolar. (b) Ligature around the cervical portion of the tooth for the creation of periodontitis. (c) Second phase of surgery: Implantation of biomaterial was performed 4 weeks after creation of the model. (d) Suturing with 3-0 nylon thread.
Pulp-derived cell culture. (a) A large colony formed at the primary culture, day 5. Bar = 200 μm; original magnification, ×30. (b) Confluent culture of pulp-derived cell culture. Bar = 200 μm; original magnification, ×50 (c–g) Flow cytometric analysis of passaged-3 canine pulp-derived stem cells. Most of the cells expressed CD90 and CD44 surface antigens, and CD146, SSEA-4, and anti-macrophage were expressed on a small percentage of the cells.
Multilineage differentiation potential of canine pulp-derived stem cells. Passaged-3 cells tended to differentiate along bone (a–b, bar = 50 μm), adipose (c–d, bar = 50 μm), and cartilage (e–f, bar = 200 μm) cell lineages.
Photomicrograph of section prepared from decalcified Bio-Oss loaded with dental pulp stem cells (DPSCs). The inset indicates the rectangular area at a higher magnification. Bio-Oss internal pores loaded with DPSCs. Bar = 250 μm; original magnification, ×10.
Histologic section from the repair tissue. (a) In some sections from the control, a connective tissue capsule (c) was seen around the bone graft particle (b). Bar = 50 μm; original magnification, ×50. (b) Test group: In most sections, Bio-Oss particles were surrounded by woven bone (w). Bar = 50 μm; original magnification, ×50. (c) Test group: epithelium migration stopped at the coronal portion of the coronal notch. Bar = 100 μm; original magnification, ×10. (d) Control group: Down growth of epithelium was seen in the apical portion of the coronal notch. Bar = 100 μm; original magnification, ×10. (e) A sample of control group containing granulation tissue (g) without any formation of bone, cementum, and periodontal ligament (PDL). Bar = 100 μm; original magnification, ×10. (f) A sample of test group showing perpendicular fibers of PDL (p) that formed between bone (b) and cementum (c). Bar = 100 μm; original magnification, ×25.
Histomorphometric data for amount of new bone, cementum, and periodontal ligament formation in the test and control groups.
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