title: Tolerance within a surgical guide.
abstract: BACKGROUND
  Recently, guided surgery has been introduced and several papers verified its accuracy.
  
  
  OBJECTIVE
  While those studies reported on the accuracy of the entire procedure, this experiment wanted to make clinicians aware of the amount of the deviation that can already occur during the drilling procedure alone, due to the tolerance of the drill in the drill key.
  
  
  METHODS
  Drilling was executed in plexi-glass with a maximal inclination of the drills within the drill keys.
  
  
  RESULTS
  A mean deviation in angulation of 4.7 degrees occurred with a mean horizontal deviation at the implant shoulder of 0.8 mm and 1.8 mm at the apex of 13 mm implant. The deviation was further dependent of the implant length, the distance of the sleeve above the bone and the respective guiding system.
  
  
  CONCLUSIONS
  Increasing the height of the drill key will minimize the inaccuracy.
  
  
  CONCLUSIONS
  The results from this experiment showed the importance of keeping the drill parallel to the guide in a centric position.
authors.affiliation: Department of Periodontology, Catholic University Leuven, Kapucijnenvoer 33, 3000 Leuven, Belgium. nele.vanassche@uz.kuleuven.ac.be
authors.forename: N
authors.initials: N
authors.lastname: Van Assche
authors.forename: M
authors.initials: M
authors.lastname: Quirynen
mesh_terms: D003758:Dental Implantation, Endosseous / Q000295:instrumentation* / Q000379:methods*; D019300:Medical Errors; D008953:Models, Anatomic; D019904:Polymethyl Methacrylate; D025321:Surgery, Computer-Assisted
chemical_list: D019904:Polymethyl Methacrylate