title: Immediate implants supporting single crown restoration: a 4-year prospective study.
abstract: BACKGROUND
  The placement of implants at the time of tooth extraction has several clinical advantages, such as preservation of the alveolar ridge width and height and reduction of the restorative treatment time. The aim of this study was to evaluate the cumulative success rate of dental implants placed in fresh extraction sockets with and without guided bone regeneration (GBR) used to support a single crown restoration. All of the patients were preselected as candidates for implants.
  
  
  METHODS
  Ninety-five patients aged 20 to 68 years with 163 implants were included. All patients were partially edentulous and participated in a personally tailored recall schedule. The follow-up period was 48 months. Patients underwent a clinical and radiographic evaluation annually.
  
  
  RESULTS
  The 4-year cumulative success rate was 97%. Five of the 163 implants failed, two during the initial healing time, which were considered early failures and three a year after prosthetic rehabilitation, which were considered late failures. No failure of prosthetic rehabilitation was observed.
  
  
  CONCLUSIONS
  Implants placed into fresh extraction sockets with or without regenerative procedures and used to support single crown prosthesis showed a very high cumulative success rate (97%) in a 4-year prospective study. Several observations should be made: 1) all the patients were preselected as candidates for implants and were following a strict oral hygiene regimen; 2) all efforts were made to reduce the number of cases requiring GBR procedures; 3) all the implants had an acid etched/sandblasted implant surface; and 4) all the prosthetic restorations were single crowns.
authors.affiliation: Department of Biophysical, Medical and Dental Sciences and Technologies, Medical School, University of Genova, Genova, Italy.
authors.forename: Ugo
authors.initials: U
authors.lastname: Covani
authors.forename: Roberto
authors.initials: R
authors.lastname: Crespi
authors.forename: Roberto
authors.initials: R
authors.lastname: Cornelini
authors.forename: Antonio
authors.initials: A
authors.lastname: Barone
mesh_terms: D000328:Adult; D000368:Aged; D001861:Bone Regeneration; D003758:Dental Implantation, Endosseous / Q000379:methods*; D019250:Dental Implants, Single-Tooth; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D019232:Dental Restoration Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome