title: Direct loading of Nobel Direct and Nobel Perfect one-piece implants: a 1-year prospective clinical and radiographic study.
abstract: OBJECTIVE
  The aim of this prospective study was to evaluate the Nobel Direct and Nobel Perfect one-piece implants (OPIs) when used for immediate function.
  
  
  METHODS
  Forty-eight patients were provided with 115 OPIs for loading with a provisional crown or a bridge within 24 h and followed for at least 12 months with clinical and radiographic examinations. A group of 97 patients previously treated under identical conditions by the same team with 380 two-piece implants (TPIs) for immediate loading in the mandible and maxilla served as the reference group.
  
  
  RESULTS
  Six (5.2%) OPIs failed during the follow-up due to extensive bone loss. Five (1.3%) implants failed in the reference group. After 1 year, the mean marginal bone loss was 2.1 mm (SD 1.3) for OPIs and 0.8 mm (SD 1) for TPIs. 20% of OPIs showed more than 3 mm of bone loss compared with 0.6% for TPIs. When compensating for vertical placement depth, OPIs still showed a lower marginal bone level and thus more exposed threads than TPIs. Depending on the criteria used, the success rate for OPIs was 46.1% or 72.2% compared with 85% or 91.6% for TPIs.
  
  
  CONCLUSIONS
  The Nobel Direct and Nobel Perfect OPIs show lower success rates and more bone resorption than TPIs after 1 year in function. Factors such as implant design, insertion depth, rough surface towards the mucosa, in situ preparation and immediate loading may have an influence on the clinical outcome.
authors.affiliation: Department of Biomaterials, Institute for Clinical Sciences, Sahlgrenska Academy, Gothenburg University, Sweden. po.ostman@telia.com
authors.forename: Per-Olov
authors.initials: PO
authors.lastname: Ostman
authors.forename: Mats
authors.initials: M
authors.lastname: Hellman
authors.forename: Tomas
authors.initials: T
authors.lastname: Albrektsson
authors.forename: Lars
authors.initials: L
authors.lastname: Sennerby
mesh_terms: D000368:Aged; D016301:Alveolar Bone Loss / Q000209:etiology*; D003758:Dental Implantation, Endosseous; D015921:Dental Implants / Q000009:adverse effects*; D017267:Dental Prosthesis Design / Q000009:adverse effects; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D003831:Denture, Partial, Immediate; D005260:Female; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography
chemical_list: D015921:Dental Implants