title: The influence of non-matching implant and abutment diameters on radiographic crestal bone levels in dogs.
abstract: BACKGROUND
  It has been shown that different implant designs and different vertical implant positions have an influence on crestal bone levels. The aim of the present study was to evaluate radiographic crestal bone changes around experimental dental implants with non-matching implant-abutment diameters placed submucosally or transmucosally at three different levels relative to the alveolar crest.
  
  
  METHODS
  Sixty two-piece dental implants with non-matching implant-abutment diameters were placed in edentulous spaces bilaterally in five foxhounds. The implants were placed submucosally or transmucosally in the left or the right side of the mandible. Within each side, six implants were randomly placed at three distinct levels relative to the alveolar crest. After 12 weeks, 60 crowns were cemented. Radiographs were obtained from all implant sites following implant placement, after crown insertion, and monthly for 6 months after loading.
  
  
  RESULTS
  Radiographic analysis revealed very little bone loss and a slight increase in bone level for implants placed at the level of the crest or 1 mm above. The greatest bone loss occurred at implants placed 1 mm below the bone crest. No clinically significant differences regarding marginal bone loss and the level of the bone-to-implant contact were detected between implants with a submucosal or a transmucosal healing.
  
  
  CONCLUSIONS
  Implants with non-matching implant-abutment diameters demonstrated some bone loss; however, it was a small amount. There was no clinically significant difference between submucosal and transmucosal approaches.
authors.affiliation: Department of Fixed and Removable Prosthodontics and Dental Material Science, Dental School, University of Zurich, Zurich, Switzerland. jung@zzmk.unizh.ch
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Jung
authors.forename: Archie A
authors.initials: AA
authors.lastname: Jones
authors.forename: Frank L
authors.initials: FL
authors.lastname: Higginbottom
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Wilson
authors.forename: John
authors.initials: J
authors.lastname: Schoolfield
authors.forename: Daniel
authors.initials: D
authors.lastname: Buser
authors.forename: Christoph H F
authors.initials: CH
authors.lastname: Hämmerle
authors.forename: David L
authors.initials: DL
authors.lastname: Cochran
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology*; D000704:Analysis of Variance; D000818:Animals; D003442:Crowns; D000044:Dental Abutments; D003758:Dental Implantation, Endosseous / Q000009:adverse effects* / Q000379:methods; D015921:Dental Implants; D017267:Dental Prosthesis Design / Q000009:adverse effects*; D019094:Dental Prosthesis, Implant-Supported; D004285:Dogs; D020007:Implants, Experimental; D008297:Male; D009061:Mouth Mucosa; D016348:Osseointegration; D011859:Radiography
chemical_list: D015921:Dental Implants