الفهرس 
The role of stem cells in periodontal regeneration.Only 14 pages are availabe for public view
 |  | from | 155 |  |  |
| | | from | 155 | | |
Abstract
Periodontitis is one of the most widespread chronic inflammatory diseases, and it progressively destroys the tooth-supporting structure. The ideal goal of periodontal therapy is to regenerate these lost tissues to their original form, architecture and function. Numerous approaches have been used to stimulate bone formation, these include root surface conditioning, bone grafts, guided tissue regeneration, and bioactive materials, but all of them show limited values in regeneration. As a consequence, current research trends have been directed towards developing cell-based techniques for periodontal regeneration.
Tissue engineering is an emerging field of science that encompasses the principles of cell biology, developmental biology and biomaterials science to generate new structures required to replace lost or damaged tissues. The most critical component of cell-based tissue engineering is the selection of an appropriate cell population. A combination of dental stem cell and tissue-engineering technology has provided promising evidence for periodontal regeneration.
The aim of this study was to compare the regenerative potential of pulp derived stem cells and gingival derived stem cells in periodontal alveolar defects. Periodontitis model was created in the second and third mandibular premolars of eight healthy beagle dogs. Extraction of the mandibular pre-canine tooth was done in order to obtain the pulp tissue, and gingival tissue was obtained from the interdental papilla of the maxillary canine tooth. After the isolation of DPSCs and GMSCs, they were characterized by their plastic adherence, flow cytometry analysis revealed that both DPSCs and GMSCs positively expressed CD90 and
Summary
49
negative for CD45. Both stem cells were positively differentiated to osteoblast, adipocytes, and chondrocytes when cultured in osteo-inductive, adipo-inductive, and chondro-inductive medium respectively.
DPSCs and GMSCs were then differentiated to osteoblast and seeded in a collagen sponge for their transplantation in the defect site. Probing depth, attachment loss, and defect size has been measured for clinical evaluation prior to implantation of the stem cells. Three groups were used in this study, group 1 (DPSCs with collagen sponge), group 2 (GMSCs with collagen sponge), and group 3 (control group) where collagen sponge was used without stem cells. After four weeks healing period, clinical evaluation was done then dogs were euthanized and serial sections were cut in buccolingual plane and prepared for histological and histomorphometrical analysis.
Clinical evaluation revealed periodontal regeneration in all groups. Clinical attachment gained by DPSCs and GMSCs was significantly higher than that of the control group revealed by decrease in probing depth and attachment loss. Although there was no statistical difference in the defect size in all groups, but the amount of bone formed in DPSCs and GMSCs groups was significantly higher than the control one as evidenced by the histomorphometric analysis. Mature lamellar bone with variable sized osteons that were higher in number in GMSCs group than DPSCs and the control groups was revealed histologically. Histomorphometrical analysis showed that there was no statistical difference in the number of cells in all groups. Optical density analysis of the newly formed bone showed that GMSCs group was significantly higher than the control group, but there was no statistical difference between (GMSCs and DPSCs) groups, and DPSCs and the control one.