title: Success and survival of single dental implants placed in sites of previously failed implants.
abstract: BACKGROUND
  The aim of this study was to assess the clinical effectiveness of single dental implants placed in sites of previously failed implants.
  
  
  METHODS
  The study consisted of a consecutive cohort of 1,215 patients who received 1,387 single implants for single-tooth replacement during a 6-year period (1999 to 2005). Inclusion criteria were a single implant replacing a previously failed implant and follow-up data > or =6 months. Data were recorded and analyzed regarding implant survival and location, need for bone augmentation, and implant dimensions.
  
  
  RESULTS
  A total of 75 patients experienced the failure of 96 implants. Of those, 31 implants in 28 patients were replaced by a similar implant placed in the same location. Nine of the replacement implants failed, resulting in an overall survival rate of 71%. Follow-up ranged from 6 to 46 months (mean, 19.4 +/- 11.4 months). Replacement of maxillary and mandibular failed implants was similar. All failures occurred during the first year after implant replacement. On average, implant replacement occurred 5.8 +/- 5.2 months after original implant removal; three implants were placed immediately after implant removal. A third attempt for single implant replacement was made in two patients. However, one failed.
  
  
  CONCLUSIONS
  Replacement of a failed implant presents a challenge to achieve osseointegration in a healed bone site and may result in a decline in the survival rates. Patients and clinicians should be aware of these results before a replacement attempt is considered. The success of replacement may be increased by the use of wider implants or with improved surfaces.
authors.affiliation: Department of Prosthodontics, Oral and Maxillofacial Center, Sheba Medical Center, Tel-Hashomer, Israel.
authors.forename: Yoav
authors.initials: Y
authors.lastname: Grossmann
authors.forename: Liran
authors.initials: L
authors.lastname: Levin
mesh_terms: D000328:Adult; D003758:Dental Implantation, Endosseous; D019250:Dental Implants, Single-Tooth; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D012189:Retrospective Studies