title: A prospective clinical trial of single Astra Tech 4.0 or 5.0 diameter implants used to support two-unit cantilever bridges: results after 3 years.
abstract: OBJECTIVE
  To evaluate the use of a single Astra Tech implant to support a two-unit cantilever fixed dental prosthesis.
  
  
  METHODS
  Twenty-nine subjects with an edentulous space (at least equivalent to two bicuspid units) in the premolar/molar segments of the maxilla or mandible with opposing natural teeth or a fixed/removable prosthesis were treated. They were provided with either a 4 or 5.0 mm diameter fixture MT OsseoSpeed. Prostheses were constructed using a cast-to abutment as a one-piece unit with porcelain fused to precious metal to allow direct screw retention.
  
  
  RESULTS
  Subjects expressed a high satisfaction with treatment, including appearance and function. The most important complication was abutment screw loosening. It occurred as a single episode in four subjects and in another six subjects the loosening was recurrent. Bone levels were stable and there were no significant differences in radiographic bone height between cantilever and non-cantilever sides of the implant at any time point.
  
  
  CONCLUSIONS
  Single implants can be successfully used to support two-unit cantilever FDPs in the premolar region. A common factor could not be identified in relation to abutment screw loosening.
authors: Department of Restorative Dentistry, King's College London Dental Institute, London, UK. richard.m.palmer@kcl.ac.uk
authors: Richard M
authors: RM
authors: Palmer
authors: Leslie C
authors: LC
authors: Howe
authors: Paul J
authors: PJ
authors: Palmer
authors: Ron
authors: R
authors: Wilson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D000044:Dental Abutments; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D003830:Denture, Partial, Fixed; D005260:Female; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D018709:Statistics, Nonparametric; D016896:Treatment Outcome
chemical_list: D015921:Dental Implants