title: Complications with allogeneic, cancellous bone blocks in vertical alveolar ridge augmentation: prospective clinical case study and review of the literature.
abstract: OBJECTIVE
  Vertical bone augmentation in dental implantology is an indication for cancellous allogeneic bone blocks (ABB). However, these materials may lead to adverse reactions, which are known well in orthopedics but rarely published. Therefore, in this study, we performed an evaluation of the use of ABB in vertical bone augmentation in clinical dental implantology.
  
  
  METHODS
  The prospective clinical study included 20 cases with vertical augmentation using ABB and subsequent or simultaneous placement of implants in the lateral maxilla and mandible. Follow-up included panoramic radiography, tissue healing, and peri-implantitis. Because of the limited number of patients, the report was planned to be descriptive only. Loss of ABB or peri-implantitis of more than 30% of the intraosseous implant length was deemed to indicate failure.
  
  
  RESULTS
  The study was cancelled after six cases because of an unexpectedly high number of complications (5 of 6; 83%). The average surveillance time was 1460 days. Three types of unsatisfying outcome were observed: type I, early complete loss of the augmentation with soft tissue defects after 3 to 8 weeks (n = 2); type II, early soft tissue maceration (up to 8 weeks) without loss of coverage and complete early bone healing with later peri-implantitis and bone loss after prosthetic loading (6 months or later; n = 2); and type III, complication-free bone healing with subsequent peri-implantitis after prosthetic loading (6 months or later; n = 1).
  
  
  CONCLUSIONS
  Complications were observed in vertical augmentation with ABB and implant placement. After careful consideration, literature data were found to support these results and also suggest that tissue level implants may be advantageous in vertical bone augmentation with ABB.
authors.affiliation: D Implant Institute, Tal 4, Munich, Germany; Extraordinary Professor for Oral & Maxillofacial Surgery, University of Marburg, Marburg, Germany. Electronic address: draenert@profdraenert.de.
authors.forename: Florian G
authors.initials: FG
authors.lastname: Draenert
authors.affiliation: Clinic for Oral & Maxillofacial Surgery, University of Rostock, Rostock, Germany.
authors.forename: Peer W
authors.initials: PW
authors.lastname: Kämmerer
authors.affiliation: D Implant Institute, Tal 4, Munich, Germany; Extraordinary Professor for Oral & Maxillofacial Surgery, University of Marburg, Marburg, Germany; Department of Prosthodontics, Ludwig Maximilians University of Munich, Munich, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Berthold
authors.affiliation: Clinic for Oral & Maxillofacial Surgery, University of Marburg, Marburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Neff
mesh_terms: D000328:Adult; D000368:Aged; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D018786:Bone Substitutes; D016025:Bone Transplantation / Q000379:methods*; D000071556:Cancellous Bone / Q000637:transplantation*; D003758:Dental Implantation, Endosseous / Q000379:methods; D019232:Dental Restoration Failure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology*; D011446:Prospective Studies; D011862:Radiography, Panoramic; D012307:Risk Factors; D014184:Transplantation, Homologous / Q000009:adverse effects
chemical_list: D018786:Bone Substitutes