title: Events of wound healing/regeneration in the canine supraalveolar periodontal defect model.
abstract: OBJECTIVE
  The objective of this research was to elucidate early events in periodontal wound healing/regeneration using histological and immunohistochemical techniques.
  
  
  METHODS
  Routine critical-size, supraalveolar, periodontal defects including a space-providing titanium mesh device were created in 12 dogs. Six animals received additional autologous blood into the defect prior to wound closure. One animal from each group was killed for analysis at 2, 5, 9, 14 days, and at 4 and 8 weeks.
  
  
  RESULTS
  Both groups behaved similarly. Periodontal wound healing/regeneration progressed through three temporal phases. Early phase (2-5 days): heterogeneous clot consolidation and cell activation in the periodontal ligament (PDL) and trabecular bone was associated with PDL regeneration and formation of a pre-osteoblast population. Intermediate phase (9-14 days): cell proliferation (shown by PCNA immunostaining)/migration led to osteoid/bone, PDL and cementum formation. Late phase (4-8 weeks): primarily characterized by tissue remodelling/maturation. Fibrous connective tissue from the gingival mucosa entered the wound early, competing with regeneration. By day 14, the wound space was largely filled with regenerative and reparative tissues.
  
  
  CONCLUSIONS
  Activation of cellular regenerative events in periodontal wound healing/regeneration is rapid; the general framework for tissue formation is broadly outlined within 14 days. Most bone formation apparently originates from endosteally derived pre-osteoblasts; the PDL possibly acting as a supplementary source, with a primary function likely being regulatory/homeostatic. Blood accumulation at the surgical site warrants exploration; supplementation may be beneficial.
authors: Laboratory for Applied Periodontal & Craniofacial Regeneration, Georgia Regents University College of Dental Medicine, Augusta, GA, USA. dougdickinson4357@gmail.com
authors: Douglas P
authors: DP
authors: Dickinson
authors: Brandon G
authors: BG
authors: Coleman
authors: Nathan
authors: N
authors: Batrice
authors: Jaebum
authors: J
authors: Lee
authors: Komal
authors: K
authors: Koli
authors: Cathy
authors: C
authors: Pennington
authors: Cristiano
authors: C
authors: Susin
authors: Ulf M E
authors: UM
authors: Wikesjö
mesh_terms: D000539:Alveolar Process / Q000473:pathology; D000818:Animals; D001769:Blood; D001777:Blood Coagulation / Q000502:physiology; D001857:Bone Matrix / Q000473:pathology; D002454:Cell Differentiation / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation; D025021:Cementogenesis / Q000502:physiology; D003094:Collagen; D004396:Coloring Agents; D003238:Connective Tissue / Q000473:pathology / Q000503:physiopathology; D003739:Dental Cementum / Q000473:pathology; D004195:Disease Models, Animal; D004285:Dogs; D004912:Erythrocytes / Q000473:pathology; D005337:Fibrin; D005347:Fibroblasts / Q000473:pathology; D005881:Gingiva / Q000473:pathology / Q000503:physiopathology; D007150:Immunohistochemistry; D010006:Osteoblasts / Q000473:pathology; D010012:Osteogenesis / Q000502:physiology; D010510:Periodontal Diseases / Q000473:pathology / Q000503:physiopathology*; D010513:Periodontal Ligament / Q000473:pathology; D012038:Regeneration / Q000502:physiology*; D013997:Time Factors; D014945:Wound Healing / Q000502:physiology*
chemical_list: D004396:Coloring Agents; D005337:Fibrin; D003094:Collagen