title: Histomorphometric analysis after maxillary sinus floor augmentation using cancellous bone-block allograft.
abstract: BACKGROUND
  Cancellous bone-block allografts may contribute to improved initial implant stability during sinus augmentation in cases with posterior atrophic maxillary ridge height < or =4 mm. The present study histologically and histomorphometrically evaluates the application of cancellous bone-block allografts for maxillary sinus-floor augmentation.
  
  
  METHODS
  Thirty-one consecutive patients, 16 females and 15 males (age range, 25 to 65 years; mean age: 54 +/- 9 years) underwent sinus augmentation with simultaneous implant placement with cancellous bone-block allografts. After 9 months, a second-stage surgery was performed. The previous window location was determined. A cylindrical sample core was collected. All specimens were prepared for histologic and histomorphometric examinations.
  
  
  RESULTS
  Seventy-two of 76 implants were clinically osseointegrated (94.7%). All patients received a fixed implant-supported prosthesis. The mean t values of newly formed bone, residual cancellous bone-block allograft, marrow and connective tissue were 26.1% +/- 15% (range: 10% to 58%); 24.7% +/- 19.4% (range: 0.6% to 71%), and 49.2% +/- 20.4% (range: 14.9% to 78.9%), respectively. No statistically significant histomorphometric differences regarding newly formed bone were found between genders (27.02% in males versus 25.68% in females; P = 0.446), ages (29.82% in subjects < or =40 years old versus 24.43% in subjects >40 years old; P = 0.293), presence of membrane perforations (25.5% in non-perforated sinuses versus 27.3% in perforated sinuses; P = 0.427), and residual alveolar bone height (25.85% for residual alveolar bone height <2 mm versus 26.48% for residual alveolar bone height of 2 to 4 mm; P = 0.473).
  
  
  CONCLUSIONS
  The cancellous bone-block allograft is biocompatible and osteoconductive and permits new bone formation in sinus augmentations with simultaneous implant-placement procedures in extremely atrophic posterior maxillae.
authors.affiliation: Department of Oral and Maxillofacial Surgery, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel. gabi.chaushu@gmail.com
authors.forename: Gavriel
authors.initials: G
authors.lastname: Chaushu
authors.forename: Marilena
authors.initials: M
authors.lastname: Vered
authors.forename: Ofer
authors.initials: O
authors.lastname: Mardinger
authors.forename: Joseph
authors.initials: J
authors.lastname: Nissan
mesh_terms: D000328:Adult; D000368:Aged; D000539:Alveolar Process / Q000473:pathology; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D016025:Bone Transplantation / Q000379:methods*; D003238:Connective Tissue / Q000473:pathology; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D019094:Dental Prosthesis, Implant-Supported; D003830:Denture, Partial, Fixed; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008437:Maxilla / Q000473:pathology / Q000601:surgery*; D008443:Maxillary Sinus / Q000473:pathology / Q000601:surgery*; D016876:Metal Ceramic Alloys; D008875:Middle Aged; D016348:Osseointegration / Q000502:physiology; D010006:Osteoblasts / Q000473:pathology; D010011:Osteocytes / Q000473:pathology; D010012:Osteogenesis / Q000502:physiology; D013524:Surgical Flaps; D014184:Transplantation, Homologous
chemical_list: D015921:Dental Implants; D016876:Metal Ceramic Alloys