title: The Influence of the Tolerance between Mechanical Components on the Accuracy of Implants Inserted with a Stereolithographic Surgical Guide: A Retrospective Clinical Study.
abstract: BACKGROUND
  The stereolithographic-guided surgery system involves a sequence of diagnostic and therapeutic events, and errors can arise at different stages. In these systems, one of the potentially clinically relevant errors may be the mechanical errors caused by the bur-guide gap due to the presence of a rotational allowance of the drills in the tubes.
  
  
  OBJECTIVE
  The purpose of this retrospective clinical study is to determine if it is possible to reduce the total error by limiting the tolerance among the mechanical components and to evaluate its clinical incidence.
  
  
  METHODS
  Sixty-six implants were inserted using the External Hex Safe® (Materialise Dental, Leuven, Belgium) system (Group A), and 71 implants were inserted using the same system with mechanical components modified to minimize the tolerance (Group B). Regarding only the angular deviation values, the t-test was used to determine the influence of reduced tolerance among the mechanical components on the accuracy values.
  
  
  RESULTS
  t-Test showed that there is a statistically significant better accuracy with the modified system (Group B).
  
  
  CONCLUSIONS
  Limiting the error that originates from mechanical components, total error could be statistically significantly reduced. Mechanical error is one of the most important source of error using External Hex Safe stereolithographic surgical guide.
authors.affiliation: Department of Oral and Maxillofacial Sciences, School of Dentistry, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Cassetta
authors.affiliation: Department of Oral and Maxillofacial Sciences, School of Dentistry, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Di Mambro
authors.affiliation: Department of Oral and Maxillofacial Sciences, School of Dentistry, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Gianni
authors.initials: G
authors.lastname: Di Giorgio
authors.affiliation: Department of Oral and Maxillofacial Sciences, School of Dentistry, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Luigi V
authors.initials: LV
authors.lastname: Stefanelli
authors.affiliation: Department of Oral and Maxillofacial Sciences, School of Dentistry, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Ersilia
authors.initials: E
authors.lastname: Barbato
mesh_terms: D003758:Dental Implantation, Endosseous / Q000295:instrumentation / Q000379:methods*; D015921:Dental Implants; D003762:Dental Instruments; D017267:Dental Prosthesis Design; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery; D008437:Maxilla / Q000000981:diagnostic imaging / Q000601:surgery; D009066:Mouth, Edentulous / Q000534:rehabilitation; D012189:Retrospective Studies; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D015921:Dental Implants
keywords: CAD/CAM technology; accuracy; clinical study; computer-assisted; flapless implant surgery; implant; implantology; retrospective; stereo lithography