title: Immediately loaded mandibular fixed implant prostheses using the all-on-four protocol: a report of 183 consecutively treated patients with 1 year of function in definitive prostheses.
abstract: OBJECTIVE
  The purpose of this study was to evaluate a specific protocol using four implants to support immediately loaded fixed prostheses to restore edentulous and partially edentulous mandibles and report on the outcome after 1 year of function with the definitive prostheses.
  
  
  METHODS
  A retrospective study was conducted of all patients who were treated between June 2008 and December 2010 with fixed prostheses that were loaded immediately after placement of implants. The provisional prostheses were later replaced with computer-aided design/computer-assisted manufacture titanium frames supporting acrylic resin and denture teeth in the definitive prosthesis. All patients were followed for a minimum of 12 months and were assessed for implant survival and prosthetic performance, with descriptive statistics utilized to demonstrate results.
  
  
  RESULTS
  One hundred eighty-three consecutive patients received immediately loaded axial and tilted implants according to the defined protocol. One implant failed, resulting in a 99.86% implant success rate. There were two catastrophic prosthetic failures (fracture of the titanium framework), for a 98.9% prosthetic success rate. Three patients (1.6%) presented with fracture of a prosthetic mandibular incisor tooth. No prosthetic screw loosening or fractures were seen. Radiographic evaluation revealed no major bone loss around dental implants.
  
  
  CONCLUSIONS
  Based on this retrospective study, the following conclusions can be drawn: (1) this technique appears to provide a highly predictable implant performance; (2) it is necessary to critically evaluate framework design, especially around the connectors for cantilever extensions around the most distal implants; and (3) minor complications related to acrylic resin tooth fracture may be anticipated during the early phases of prosthetic treatment.
authors.affiliation: Private Practice Limited to Prosthodontics, Phoenix, AZ, USA. galindoprosthodontics@gmail.com
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Galindo
authors.forename: Caesar C
authors.initials: CC
authors.lastname: Butura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017076:Computer-Aided Design; D003758:Dental Implantation, Endosseous; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003794:Dental Restoration, Temporary; D003826:Denture, Complete, Lower; D003830:Denture, Partial, Fixed; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D057893:Immediate Dental Implant Loading; D007575:Jaw, Edentulous / Q000534:rehabilitation; D008297:Male; D008334:Mandible / Q000601:surgery*; D063168:Mandibular Osteotomy; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult