title: Precision for computer-guided implant placement: using 3D planning software and fixed intraoral reference points.
abstract: OBJECTIVE
  The aim of this article is to describe the application of screws as fixed intraoral reference points for stable, precise, and repeatable positioning of diagnostic and surgical templates for implant placement.
  
  
  METHODS
  Currently available software programs in combination with computed tomography data allow 3-dimensional treatment planning in demanding clinical situations prior to implant placement. One drawback of most systems is the lack of stability and support of both radiographic and surgical templates in edentulous patients. The characteristics and application of a new screw system in combination with computer assisted 3-dimensional implant placement are specified.
  
  
  RESULTS
  Implants were placed exactly as projected without impairment of the mandibular nerve despite close proximity of the mental foramen.
  
  
  CONCLUSIONS
  Precision and accuracy of computer-based or -supported implant placement is valuable only if an exact transfer to the intraoral situation is granted. Depending on the clinical patient situation, fixed intraoral reference points can improve precision in an efficient manner.
authors.affiliation: Department of Prosthodontics, Friedrich Alexander University Erlangen-Nuremberg, Erlangen, Germany. sholst@prothetik-erlangen.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Holst
authors.forename: Markus B
authors.initials: MB
authors.lastname: Blatz
authors.forename: Stephan
authors.initials: S
authors.lastname: Eitner
mesh_terms: D000368:Aged; D001863:Bone Screws; D003758:Dental Implantation, Endosseous / Q000295:instrumentation / Q000379:methods*; D019094:Dental Prosthesis, Implant-Supported; D003794:Dental Restoration, Temporary; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007575:Jaw, Edentulous / Q000000981:diagnostic imaging; D008334:Mandible / Q000601:surgery*; D008953:Models, Anatomic; D012984:Software; D025321:Surgery, Computer-Assisted; D014057:Tomography, X-Ray Computed