title: Survival of NobelDirect implants: an analysis of 550 consecutively placed implants at 18 different clinical centers.
abstract: BACKGROUND
  A recently introduced implant, the NobelDirect (Nobel Biocare AB, Göteborg, Sweden), has previously been documented with substantial bone resorption in a large number of operated cases.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the failure rate of NobelDirect implants in a retrospective multicenter survey.
  
  
  METHODS
  A total of 550 NobelDirect implants consecutively placed in over 269 patients at 18 centers were evaluated with regard to failure rate after an average follow-up of about 1 year.
  
  
  RESULTS
  The overall failure percentage was 10.9% (59 failures). The 58 implants not loaded directly showed only one failure (1.7%) versus 58 failures (11.8%) of those implants that were loaded directly. A chemical x-ray photoelectron spectroscopy analysis of an implant from the original batch showed up to 3.5% silicon at parts of the implants. A retrieval analysis of one implant removed at 2 years after placement demonstrated bone resorption down to the level of the fifth thread.
  
  
  CONCLUSIONS
  It is concluded that the NobelDirect implant, if placed with a punch procedure, ground down in situ, and loaded directly, shows an unusually high failure rate at 1 year.
authors.affiliation: Department of Biomaterials, Institute for Clinical Sciences, Sahlgrenska Academy, University of Göteborg, Göteborg, Sweden. tomas.albrektsson@biomaterials.gu.se
authors.forename: Tomas
authors.initials: T
authors.lastname: Albrektsson
authors.forename: Jan
authors.initials: J
authors.lastname: Gottlow
authors.forename: Luiz
authors.initials: L
authors.lastname: Meirelles
authors.forename: Per-Olov
authors.initials: PO
authors.lastname: Ostman
authors.forename: Antonio
authors.initials: A
authors.lastname: Rocci
authors.forename: Lars
authors.initials: L
authors.lastname: Sennerby
mesh_terms: D000368:Aged; D016301:Alveolar Bone Loss / Q000209:etiology; D003238:Connective Tissue / Q000473:pathology; D000044:Dental Abutments / Q000706:statistics & numerical data; D003758:Dental Implantation, Endosseous / Q000706:statistics & numerical data; D015921:Dental Implants / Q000706:statistics & numerical data*; D019232:Dental Restoration Failure; D004577:Electron Probe Microanalysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008336:Mandibular Diseases / Q000209:etiology; D008855:Microscopy, Electron, Scanning; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D012189:Retrospective Studies; D012825:Silicon / Q000032:analysis; D013492:Suppuration; D013499:Surface Properties; D016019:Survival Analysis
chemical_list: D015921:Dental Implants; D010758:Phosphorus; D009584:Nitrogen; D012825:Silicon