title: Marginal bone-level alterations at implants installed in block versus particulate onlay bone grafts mixed with platelet-rich plasma in atrophic maxilla. a prospective 5-year follow-up study of 15 patients.
abstract: BACKGROUND
  Extensive atrophy of the alveolar process may require a bone-grafting procedure prior to implant treatment. Autogenous bone grafts from the iliac crest, used as onlay block and particulate bone, have been used together with sinus-lift procedure in order to rehabilitate patients with extremely resorbed maxillae. However, there are to our knowledge no 5-year follow-up studies evaluating the extent of bone-level change in patients treated with respectively block and particulate autogenous bone grafts.
  
  
  OBJECTIVE
  The purpose of this prospective clinical study was to conduct a 5-year follow-up analysis with focus on bone-level alteration in block versus particulate onlay bone grafts.
  
  
  METHODS
  Fifteen out of originally 19 patients who were treated with iliac bone grafts and oral implants in the maxilla have been followed through the first 5 postoperative years. In a first study conducted on 19 patients, the role of platelet-rich plasma in conjunction with autogenous bone was evaluated. In this 5-year follow-up study, the marginal bone alterations have been documented at base line, 1 year and 5 years of loading to the nearest 0,1 mm at mesial and distal surfaces of the implants. Two implants were installed on each side of the midline in either block or particulate bone grafts giving test and control sides in each patient. Additionally, two implants on each side were installed in residual bone/grafted sinus floor.
  
  
  RESULTS
  Marginal bone alteration in the anterior maxilla appeared larger at the side augmented by block bone at baseline, and after 1 and 5 years of loading, but the change was not statistically significant. Moreover, there was a significantly higher degree of marginal alteration during the first year of loading, compared with the examinations after 5 years.
  
  
  CONCLUSIONS
  The present follow-up study showed that there is no significant difference in the extension of resorption between block- and particulate autogenous bone grafts over a 5-year period. Most of the resorption occurred during the first year in function.
authors.affiliation: Research fellow, Department of Oral & Maxillofacial Surgery, The Sahlgrenska Academy, University of Gothenburg, Sweden; resident, The Maxillofacial Unit, Söder Hospital, Stockholm, Sweden.
authors.forename: Amir
authors.initials: A
authors.lastname: Dasmah
authors.affiliation: associate professor, Department of Surgical Sciences, Oral & Maxillofacial Surgery, Uppsala University Hospital, Uppsala, Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Thor
authors.affiliation: associate professor, Department of Oral & Maxillofacial Radiology, Institute of Odontology, The Sahlgrenska Academy, University of Gothenburg, Sweden.
authors.forename: Annika
authors.initials: A
authors.lastname: Ekestubbe
authors.affiliation: professor, Department of Oral & Maxillofacial Surgery, The Sahlgrenska Academy, University of Gothenburg, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Sennerby
authors.affiliation: professor, head, Department of Oral & Maxillofacial Surgery, The Sahlgrenska Academy, University of Gothenburg, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Rasmusson
mesh_terms: D000328:Adult; D000368:Aged; D064728:Alveolar Bone Grafting / Q000379:methods*; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology*; D001861:Bone Regeneration; D015921:Dental Implants / Q000009:adverse effects*; D017268:Dental Prosthesis Retention; D019094:Dental Prosthesis, Implant-Supported; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008437:Maxilla / Q000601:surgery*; D008875:Middle Aged; D053657:Platelet-Rich Plasma; D011446:Prospective Studies; D011859:Radiography; D018709:Statistics, Nonparametric; D014732:Vibration
chemical_list: D015921:Dental Implants