title: The structure of periodontal tissues formed following guided tissue regeneration therapy of intra-bony defects in the monkey.
abstract: OBJECTIVE
  To describe the periodontal tissues formed following guided tissue regeneration (GTR) therapy of intra-bony defects (IBD).
  
  
  METHODS
  Eight adult Macaca fascicularis monkeys were used. Proximal IBD were created at the mandibular second pre-molars and second molars. After 3 months, GTR surgery was performed. The animals were euthanized at 6 months and 2 years after surgery. Block biopsies were harvested, and prepared for histological analysis.
  
  
  RESULTS
  At 6 months the defect had healed with new cementum (NC), periodontal ligament (PDL) and bone. The NC seemed to be firmly anchored to the dentin. Supra-crestally, the NC consisted of a 10 microm thick layer of acellular extrinsic fibre cementum (AEFC). Sub-crestally, the NC was considerably thicker and consisted of an inner layer of AEFC and an outer thicker layer of cellular mixed fibre cementum (CMFC). The extrinsic fibre density amounted to about 10 fibres per 100 microm. The PDL was wider than the pristine PDL and widened in coronal direction. After 2 years of healing, the thickness of the NC in the sub-crestal compartment had increased by about 20 microm and the fibre density had increased by about 50%.
  
  
  CONCLUSIONS
  After 2 years of healing the structure of the regenerated tissues resembled that of pristine periodontal tissues.
authors.affiliation: Department of Periodontology, Eastman Dental Institute, University College London, London, UK. flh.laurell@telia.com
authors.forename: Lars
authors.initials: L
authors.lastname: Laurell
authors.forename: Manish
authors.initials: M
authors.lastname: Bose
authors.forename: Filippo
authors.initials: F
authors.lastname: Graziani
authors.forename: Maurizio
authors.initials: M
authors.lastname: Tonetti
authors.forename: Tord
authors.initials: T
authors.lastname: Berglundh
mesh_terms: D016301:Alveolar Bone Loss / Q000473:pathology / Q000601:surgery*; D000539:Alveolar Process / Q000473:pathology; D000818:Animals; D001861:Bone Regeneration / Q000502:physiology; D003094:Collagen; D003238:Connective Tissue / Q000473:pathology; D003739:Dental Cementum / Q000473:pathology; D003804:Dentin / Q000473:pathology; D005347:Fibroblasts / Q000473:pathology; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods*; D008252:Macaca fascicularis; D008334:Mandible / Q000473:pathology / Q000601:surgery; D008567:Membranes, Artificial; D010513:Periodontal Ligament / Q000473:pathology; D010518:Periodontitis / Q000473:pathology / Q000601:surgery; D010519:Periodontium / Q000473:pathology*; D011897:Random Allocation; D013524:Surgical Flaps; D013997:Time Factors; D014945:Wound Healing / Q000502:physiology
chemical_list: D008567:Membranes, Artificial; D003094:Collagen