title: All-on-4 immediate-function concept with Brånemark System implants for completely edentulous maxillae: a 1-year retrospective clinical study.
abstract: BACKGROUND
  Immediate implant function has become an accepted treatment modality for fixed restorations in totally edentulous mandibles, whereas experience from immediate function in the edentulous maxilla is limited.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate a protocol for immediate function (within 3 hours) of four implants (All-on-4, Nobel Biocare AB, Göteborg, Sweden) supporting a fixed prosthesis in the completely edentulous maxilla.
  
  
  METHODS
  This retrospective clinical study included 32 patients with 128 immediately loaded implants (Brånemark System TiUnite, Nobel Biocare AB) supporting fixed complete-arch maxillary all-acrylic prostheses. A specially designed surgical guide was used to facilitate implant positioning and tilting of the posterior implants to achieve good bone anchorage and large interimplant distance for good prosthetic support. Follow-up examinations were performed at 6 and 12 months. Radiographic assessment of the marginal bone level was performed after 1 year in function.
  
  
  RESULTS
  Three immediately loaded implants were lost in three patients, giving a 1-year cumulative survival rate of 97.6%. The marginal bone level was, on average, 0.9 mm (SD 1.0 mm) from the implant/abutment junction after 1 year.
  
  
  CONCLUSIONS
  The high cumulative implant survival rate indicates that the immediate function concept for completely edentulous maxillae may be a viable concept.
authors.affiliation: Department of Surgery and Prosthodontics, Clinica Maló, Lisbon, Portugal. clin.res.dep@clinicamalo.pt
authors.forename: Paulo
authors.initials: P
authors.lastname: Maló
authors.forename: Bo
authors.initials: B
authors.lastname: Rangert
authors.forename: Miguel
authors.initials: M
authors.lastname: Nobre
mesh_terms: D000180:Acrylic Resins; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003794:Dental Restoration, Temporary; D003799:Dental Stress Analysis; D003825:Denture, Complete, Immediate; D003827:Denture, Complete, Upper; D005260:Female; D006801:Humans; D007575:Jaw, Edentulous / Q000534:rehabilitation / Q000601:surgery*; D008297:Male; D008437:Maxilla / Q000601:surgery*; D008875:Middle Aged; D008953:Models, Anatomic; D011859:Radiography; D012189:Retrospective Studies
chemical_list: D000180:Acrylic Resins; D015921:Dental Implants