title: Horizontal Resorption of Fresh-Frozen Corticocancellous Bone Blocks in the Reconstruction of the Atrophic Maxilla at 5 Months.
abstract: BACKGROUND
  Reliable implant-supported rehabilitation of an alveolar ridge needs sufficient volume of bone. In order to achieve a prosthetic-driven positioning, bone graft techniques may be required.
  
  
  OBJECTIVE
  This prospective cohort study aims to clinically evaluate the amount of resorption of corticocancellous fresh-frozen allografts bone blocks used in the reconstruction of the severe atrophic maxilla.
  
  
  METHODS
  Twenty-two partial and totally edentulous patients underwent bone augmentation procedures with fresh-frozen allogenous blocks from the iliac crest under local anesthesia. Implants were inserted into the grafted sites after a healing period of 5 months. Final fixed prosthesis was delivered ± 4 months later. Ridge width analysis and measurements were performed with a caliper before and after grafting and at implant insertion. Bone biopsies were performed in 16 patients.
  
  
  RESULTS
  A total of 98 onlay block allografts were used in 22 patients with an initial mean alveolar ridge width of 3.41 ± 1.36 mm. Early exposure of blocks was observed in four situations and one of these completely resorbed. Mean horizontal bone gain was 3.63 ± 1.28 mm (p < .01). Mean buccal bone resorption between allograph placement and the reopening stage was 0.49 ± 0.54 mm, meaning approximately 7.1% (95% confidence interval: [5.6%, 8.6%]) of total ridge width loss during the integration period. One hundred thirty dental implants were placed with good primary stability (≥ 30 Ncm). Four implants presented early failure before the prosthetic delivery (96.7% implant survival). All patients were successfully rehabilitated. Histomorphometric analysis revealed 20.9 ± 5.8% of vital bone in close contact to the remaining grafted bone. A positive strong correlation (adjusted R(2)  = 0.44, p = .003) was found between healing time and vital bone percentage.
  
  
  CONCLUSIONS
  Augmentation procedures performed using fresh-frozen allografts from the iliac crest are a suitable alternative in the reconstruction of the atrophic maxilla with low resorption rate at 5 months, allowing proper stability of dental implants followed by fixed prosthetic rehabilitation.
authors.affiliation: Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
authors.forename: Eugénio
authors.initials: E
authors.lastname: Pereira
authors.affiliation: Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Messias
authors.affiliation: Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Dias
authors.affiliation: Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
authors.forename: Fernando
authors.initials: F
authors.lastname: Judas
authors.affiliation: Faculty of Odontology and Medicine, São Leopoldo Mandic, Campinas, Brazil.
authors.forename: Alexander
authors.initials: A
authors.lastname: Salvoni
authors.affiliation: Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
authors.forename: Fernando
authors.initials: F
authors.lastname: Guerra
mesh_terms: D000328:Adult; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000601:surgery*; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D015925:Cryopreservation; D003758:Dental Implantation, Endosseous / Q000379:methods*; D019094:Dental Prosthesis, Implant-Supported / Q000379:methods*; D005260:Female; D006801:Humans; D007085:Ilium / Q000637:transplantation*; D008297:Male; D008437:Maxilla / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D011446:Prospective Studies; D019651:Plastic Surgery Procedures / Q000379:methods*; D014057:Tomography, X-Ray Computed
keywords: allografts; alveolar ridge augmentation; corticocancellous block; fresh-frozen bone; iliac crest