Events of wound healing/regeneration in the canine supraalveolar periodontal defect model

• Published in: Journal of clinical periodontology Vol. 40; no. 5; pp. 527 - 541
• Main Authors: Dickinson, Douglas P., Coleman, Brandon G., Batrice, Nathan, Lee, Jaebum, Koli, Komal, Pennington, Cathy, Susin, Cristiano, Wikesjö, Ulf M. E.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.05.2013
• Subjects: Alveolar Process - pathology; Animals; Blood; Blood Coagulation - physiology; Bone Matrix - pathology; Cell Differentiation - physiology; Cell Movement - physiology; Cell Proliferation; Cementogenesis - physiology; cementum; Collagen; Coloring Agents; Connective Tissue - pathology; Connective Tissue - physiopathology; critical-size defect; Dental Cementum - pathology; Dentistry; Disease Models, Animal; Dogs; Erythrocytes - pathology; Fibrin; Fibroblasts - pathology; Gingiva - pathology; Gingiva - physiopathology; Immunohistochemistry; Osteoblasts - pathology; Osteogenesis - physiology; osteoid; Periodontal Diseases - pathology; Periodontal Diseases - physiopathology; periodontal ligament; Periodontal Ligament - pathology; periodontal regeneration; Regeneration - physiology; reparative tissue; Time Factors; wound healing; Wound Healing - physiology
• ISSN: 0303-6979; 1600-051X
• DOI: 10.1111/jcpe.12055

Aim 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. Conclusion 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.