title: Periodontal ligament cell sheet promotes periodontal regeneration in athymic rats.
abstract: OBJECTIVE
  The primary goal of periodontal treatment is regeneration of the periodontium. Current theories suggest that the periodontal ligament (PDL) cells have the capacity to participate in restoring connective and mineralized tissues, when appropriately triggered. We evaluated whether human PDL cell sheets could reconstruct periodontal tissue.
  
  
  METHODS
  To obtain the cell sheet, human PDL cells were cultured on temperature-responsive culture dishes with or without osteogenic differentiation medium. The cell sheets were transplanted on periodontal fenestration defects of immunodeficient rats. Forty rats were divided in two groups: in one group, cell sheets cultured with control medium were transplanted and in the other, cell sheets cultured with osteogenic differentiation medium were transplanted. The defects were analysed histologically and histomorphologically after healing.
  
  
  RESULTS
  Most of the experimental group exhibited a new cementum-like layer and new attachment of collagen fibres to the layer. Histomorphological analyses indicated significant periodontal regeneration. The control group revealed dense extracellular matrix and fibre formation, but an obvious cementum layer was not observed.
  
  
  CONCLUSIONS
  Transplanted PDL cell sheets cultured with osteogenic differentiation medium induced periodontal regeneration containing an obvious cementum layer and Sharpey's fibres. Thus, the method could be feasible as a new therapeutic approach for periodontal regeneration.
authors.affiliation: Section of Periodontology, Department of Hard Tissue Engineering, Graduate School, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan.
authors.forename: Mara Gomez
authors.initials: MG
authors.lastname: Flores
authors.forename: Reiko
authors.initials: R
authors.lastname: Yashiro
authors.forename: Kaoru
authors.initials: K
authors.lastname: Washio
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamato
authors.forename: Teruo
authors.initials: T
authors.lastname: Okano
authors.forename: Isao
authors.initials: I
authors.lastname: Ishikawa
mesh_terms: D000199:Actins / Q000096:biosynthesis; D000818:Animals; D001205:Ascorbic Acid / Q000031:analogs & derivatives; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D002478:Cells, Cultured; D025021:Cementogenesis; D017077:Culture Media, Conditioned; D003907:Dexamethasone; D005994:Glycerophosphates; D006801:Humans; D058574:Integrin-Binding Sialoprotein; D010006:Osteoblasts / Q000378:metabolism / Q000637:transplantation*; D053495:Osteopontin / Q000096:biosynthesis; D010513:Periodontal Ligament / Q000166:cytology* / Q000502:physiology; D051381:Rats; D011923:Rats, Nude; D012038:Regeneration / Q000502:physiology*; D012795:Sialoglycoproteins / Q000096:biosynthesis; D014092:Tooth Root / Q000601:surgery
chemical_list: D000199:Actins; D017077:Culture Media, Conditioned; D005994:Glycerophosphates; C546871:IBSP protein, human; D058574:Integrin-Binding Sialoprotein; D012795:Sialoglycoproteins; D053495:Osteopontin; C011669:ascorbate-2-phosphate; D003907:Dexamethasone; D001205:Ascorbic Acid; C031463:beta-glycerophosphoric acid