"All-on-4" immediate-function concept for completely edentulous maxillae: a clinical report on the medium (3 years) and long-term (5 years) outcomes

Clin Implant Dent Relat Res. 2012 May:14 Suppl 1:e139-50. doi: 10.1111/j.1708-8208.2011.00395.x. Epub 2011 Oct 18.


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.

Purpose: The purpose of this study was to report on the medium- and long-term outcomes of a protocol for immediate function of four implants (All-on-4, Nobel Biocare AB, Göteborg, Sweden) supporting a fixed prosthesis in the completely edentulous maxilla.

Materials and methods: This retrospective clinical study included 242 patients with 968 immediately loaded implants (Brånemark System TiUnite, Nobelspeedy, 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 months, 1 year, and thereafter every 6 months. Radiographic assessment of the marginal bone level was performed after 3 and 5 years in function. Survival was estimated at patient level and implant level using the Kaplan-Meier product limit estimation with 95% confidence intervals.

Results: Nineteen immediately loaded implants were lost in seventeen patients, giving a 5-year survival rate estimation of 93% and 98% at patient and implant level, respectively. The survival rate of the prosthesis was 100%. The marginal bone level was, on average, 1.52 mm (standard deviation [SD] 0.3 mm) and 1.95 mm (SD 0.4 mm) from the implant/abutment junction after 3 and 5 years, respectively.

Conclusion: The high survival rates at patient and implant level indicates that the immediate-function concept for completely edentulous maxillae using the present protocol is viable in the medium- and long-term outcomes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acrylic Resins / chemistry
  • Adult
  • Aged
  • Aged, 80 and over
  • Alveolar Process / diagnostic imaging
  • Dental Implant-Abutment Design
  • Dental Implants*
  • Dental Materials / chemistry
  • Dental Restoration Failure
  • Denture Design
  • Denture Retention
  • Denture, Complete, Upper
  • Female
  • Follow-Up Studies
  • Humans
  • Immediate Dental Implant Loading* / instrumentation
  • Immediate Dental Implant Loading* / methods
  • Jaw, Edentulous / surgery*
  • Longitudinal Studies
  • Male
  • Maxilla / diagnostic imaging
  • Maxilla / surgery*
  • Middle Aged
  • Osseointegration / physiology
  • Radiography
  • Retrospective Studies
  • Surface Properties
  • Survival Analysis
  • Titanium / chemistry
  • Treatment Outcome


  • Acrylic Resins
  • Dental Implants
  • Dental Materials
  • Titanium