title: Photogrammetry--an alternative to conventional impressions in implant dentistry? A clinical pilot study.
abstract: OBJECTIVE
  The purpose of this clinical pilot study was to describe a photogrammetric technique to determine implant positions in the oral cavity, and to test and compare this technique to conventional impression/master cast procedures for fabrication of titanium frameworks with a computer numeric-controlled (CNC) milling technique.
  
  
  METHODS
  Implant positions were recorded by means of conventional impressions/master casts as well as intraoral 3-dimensional photogrammetric measurements in 2 patients who were provided with 5 Brånemark implants each in the edentulous mandible. For each patient 2 titanium frameworks were made by means of a CNC milling technique (All-in-One). Both frameworks had an identical design, but the orientations of the framework cylinder fit surfaces were machined either from measurements from the master casts or from the intraoral photogrammetric measurements. The frameworks were tried for fit in the oral cavity and on the master casts.
  
  
  RESULTS
  Both cases showed different precision of fit when comparing the 2 frameworks on the master casts. One of the 2 photogrammetric frameworks was not considered acceptable when tried on the models. In the oral cavity, however, all 4 frameworks presented comparable fit, and all were accepted for clinical use.
  
  
  CONCLUSIONS
  The clinical experiences with try-in of the 4 different frameworks indicated that the photogrammetric technique could be a valid option for conventional impressions when using CNC milling fabrication in implant dentistry. The different results from the model and oral examinations also imply the difficulties of assessing clinical fit when testing fit at the master cast level only.
authors.affiliation: Brånemark Clinic, Dental Health Care, Göteborg, Sweden. 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; D003758:Dental Implantation, Endosseous; D003761:Dental Impression Technique; D017267:Dental Prosthesis Design / Q000379:methods*; D019094:Dental Prosthesis, Implant-Supported; D006801:Humans; D007575:Jaw, Edentulous / Q000534:rehabilitation; D008334:Mandible; D003765:Models, Dental; D010780:Photogrammetry; D010865:Pilot Projects; D017755:Prosthesis Fitting