title: Spontaneous progression of peri-implantitis at different types of implants. An experimental study in dogs. I: clinical and radiographic observations.
abstract: OBJECTIVE
  The aim of the present study was to analyze tissue reactions to plaque formation following ligature removal at commercially available implants exposed to experimental peri-implantitis.
  
  
  METHODS
  Six Labrador dogs about 1 year old were used. All mandibular premolars and the three anterior premolars in both sides of the maxilla were extracted. After 3 months four implants representing four different implant systems with different surface characteristics--implant group A (turned), B (TiOblast), C (sandblasted acid-etched; SLA) and D (TiUnite)--were placed in a randomized order in the right side of the mandible. Three months after implant installation experimental peri-implantitis was initiated by placement of ligatures in a submarginal position and plaque accumulation. At week 12, when about 40-50% of the supporting bone was lost, the ligatures were removed. During the subsequent 24-week period plaque accumulation continued. Radiographic and clinical examinations were performed during the 'active breakdown' period (plaque accumulation and ligatures) and the plaque accumulation period after ligature removal. The experiment was terminated at week 36.
  
  
  RESULTS
  The bone loss that took place during the 'active breakdown' period varied between 3.5 and 4.6 mm. The additional bone loss that occurred during the plaque accumulation period after ligature removal was 1.84 (A), 1.72 (B), 1.55 (C) and 2.78 mm (D).
  
  
  CONCLUSIONS
  Spontaneous progression of experimentally induced peri-implantitis occurred at implants with different geometry and surface characteristics. Progression was most pronounced at implants of type D (TiUnite surface).
authors.affiliation: Department of Periodontology, The Sahlgrenska Academy at Göteborg University, Göteborg, Sweden.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Albouy
authors.forename: Ingemar
authors.initials: I
authors.lastname: Abrahamsson
authors.forename: Leif G
authors.initials: LG
authors.lastname: Persson
authors.forename: Tord
authors.initials: T
authors.lastname: Berglundh
mesh_terms: D000134:Acid Etching, Dental; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology; D000818:Animals; D001641:Bicuspid; D045662:Dental Etching; D015921:Dental Implants / Q000145:classification*; D003764:Dental Materials / Q000737:chemistry; D003773:Dental Plaque / Q000150:complications; D017267:Dental Prosthesis Design; D018450:Disease Progression; D004285:Dogs; D008334:Mandible; D008437:Maxilla; D010518:Periodontitis / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D011859:Radiography; D011897:Random Allocation; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
chemical_list: D015921:Dental Implants; D003764:Dental Materials; C009495:titanium dioxide; D014025:Titanium