title: Failed dental implants: diagnosis, removal and survival of reimplantations.
abstract: BACKGROUND
  Over time, the percentage of dental implants that fail increases because of biological and technical issues. Inevitably, clinicians will dedicate more time to dealing with ailing and failing dental implants.
  
  
  METHODS
  The authors searched the literature for articles that addressed diagnostic manifestations of failed implants and reasons for their demise, as well as survival rates of dental implant reimplantations.
  
  
  RESULTS
  The authors found that there is no precise cut point (besides 100 percent) with regard to the amount of bone loss in the absence of mobility that indicates an implant has failed. The decision to treat or explant an ailing implant is a judgment call by the treating clinician. Survival rates found in the literature after first and second reimplantations ranged from 71 percent to 100 percent and 50 percent to 100 percent, respectively. The 100 percent findings were based on small groups of implants, and there were scant data addressing implant survival after second reimplantations.
  
  
  CONCLUSIONS
  The decision to remove an implant needs to be based on clinical assessments, radiographic evaluations or both. If the implant is deemed hopeless, there are devices that facilitate their removal. Furthermore, reimplantations can be performed successfully, but their survival rate appears to be lower than that of implants placed at sites from which they were not lost formerly.
  
  
  CONCLUSIONS
  Ailing dental implants should not be condemned prematurely, because patients often respond to treatment of peri-implantitis. Many patients desire reimplantations in sites in which implants have failed. This procedure is valuable, especially if it makes possible the fabrication of an implant-supported fixed or removable prosthesis.
authors.affiliation: Dr. Greenstein is a clinical professor, Department of Periodontology, College of Dental Medicine, Columbia University, New York City, and maintains a private practice in surgical implantology and periodontics in Freehold, N.J. Address correspondence to Dr. Greenstein at 900 W. Main St., Freehold, N.J. 07728, e-mail ggperio@aol.com.
authors.forename: Gary
authors.initials: G
authors.lastname: Greenstein
authors.affiliation: Dr. Cavallaro is a clinical associate professor, Department of Prosthodontics, College of Dental Medicine, Columbia University, New York City, and maintains a private practice in surgical implantology and prosthodontics in Brooklyn, N.Y.
authors.forename: John
authors.initials: J
authors.lastname: Cavallaro
mesh_terms: D015921:Dental Implants; D019232:Dental Restoration Failure; D006801:Humans; D011861:Radiography, Dental; D014090:Tooth Replantation
chemical_list: D015921:Dental Implants
keywords: Dental implants; reimplantations