title: Evaluation of healing following tooth extraction with ridge preservation using cortical versus cancellous freeze-dried bone allograft.
abstract: BACKGROUND
  The objective of this study is to compare histologic and clinical healing following tooth extraction and ridge preservation with either cortical or cancellous freeze-dried bone allograft (FDBA) in non-molar extraction sockets.
  
  
  METHODS
  Forty patients requiring implant placement were enrolled, with 20 patients randomly assigned to each group (cortical versus cancellous FDBA). All of the allograft materials were obtained from the same donor to control for variability between donors and processing. Patients returned after 17 to 21 weeks (average: 18.2 weeks), and a 2-mm-diameter core biopsy was obtained before implant placement. Histomorphometric analysis was performed to determine percentage of new bone formation, residual graft material, and non-mineralized connective tissue (CT)/other material. Clinical measurements of ridge dimensions were taken at the time of tooth extraction and again at implant placement.
  
  
  RESULTS
  There was no significant difference in new bone formation between the cortical and cancellous FDBA groups (P = 0.857). A significantly greater percentage of residual graft material was detected in the cortical FDBA group compared with the cancellous FDBA group (P = 0.019). A significantly greater percentage of non-mineralized CT/other material was found in the cancellous FDBA group compared with the cortical FDBA group (P = 0.040). The only significant clinical difference between groups was a greater loss of lingual ridge height in the cancellous group.
  
  
  CONCLUSIONS
  This is the first reported study to compare the histologic changes following tooth extraction with ridge preservation in humans using cortical versus cancellous FDBA. There were no differences in the percentage of new bone formation between the groups.
authors.affiliation: Currently, Private Practice, Washington, DC; previously, Department of Periodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Eskow
authors.forename: Brian L
authors.initials: BL
authors.lastname: Mealey
mesh_terms: D020341:Absorbable Implants; D000328:Adult; D000368:Aged; D064591:Allografts / Q000145:classification / Q000473:pathology / Q000637:transplantation*; D000539:Alveolar Process / Q000473:pathology; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D062005:Biopsy, Large-Core Needle / Q000379:methods; D016025:Bone Transplantation / Q000145:classification*; D003094:Collagen; D003238:Connective Tissue / Q000473:pathology; D015925:Cryopreservation / Q000379:methods; D015921:Dental Implants; D005260:Female; D005500:Follow-Up Studies; D005612:Freeze Drying / Q000379:methods; D006801:Humans; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D010011:Osteocytes / Q000473:pathology; D010012:Osteogenesis / Q000502:physiology; D014081:Tooth Extraction; D020390:Tooth Socket / Q000473:pathology / Q000601:surgery*; D014945:Wound Healing / Q000502:physiology
chemical_list: D015921:Dental Implants; D008567:Membranes, Artificial; D003094:Collagen