title: Precision of CNC-milled titanium frameworks for implant treatment in the edentulous jaw.
abstract: OBJECTIVE
  The purpose of this report was to describe a new technique to fabricate one-piece, implant-supported titanium frameworks by means of a computer numeric-controlled (CNC) milling technique, and to compare the fit of these frameworks with conventional cast prostheses.
  
  
  METHODS
  The study comprised 20 patients who were provided with 5 standard Brånemark implants each in the edentulous mandible. The fit of the first 10 prostheses with CNC-milled frameworks was measured by means of a 3-dimensional photogrammetric technique. The distortion of the center point of the framework cylinders was measured in relation to the master cast replicas. These measurements were compared with 10 randomly selected routine prostheses with cast frameworks.
  
  
  RESULTS
  No significant differences were found between the 2 groups. The 3-dimensional distortion of the cylinders in the completed prostheses ranged from 3 to 80 microns; no passive framework was observed. More distortion was observed in the horizontal plane (x and y axes) as compared to the distortion in the vertical direction (z axis).
  
  
  CONCLUSIONS
  The precision of fit of the first CNC-milled prostheses presented a comparable fit to the conventional cast frameworks. Consequently, this new technique could be a valid option for the routine fabrication of frameworks for implant prostheses.
authors.affiliation: Prosthodontic Division, Brånemark Clinic, Dental Health Care, Göteborg, Sweden. torsten.jemt@odontologi.gu.se
authors.forename: T
authors.initials: T
authors.lastname: Jemt
authors.forename: T
authors.initials: T
authors.lastname: Bäck
authors.forename: A
authors.initials: A
authors.lastname: Petersson
mesh_terms: D017076:Computer-Aided Design; D003775:Dental Polishing; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D006801:Humans; D007575:Jaw, Edentulous / Q000534:rehabilitation; D008334:Mandible; D017063:Outcome Assessment, Health Care; D010780:Photogrammetry; D017755:Prosthesis Fitting; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D014025:Titanium
chemical_list: D014025:Titanium