title: Accuracy of intraoral and extraoral digital data acquisition for dental restorations.
abstract: The computer-aided design (CAD) and computer-aided manufacturing (CAM) process chain for dental restorations starts with taking an impression of the clinical situation. For this purpose, either extraoral digitization of gypsum models or intraoral digitization can be used. Despite the increasing use of dental digitizing systems, there are only few studies on their accuracy.
  
  
  OBJECTIVE
  This study compared the accuracy of various intraoral and extraoral digitizing systems for dental CAD/CAM technology.
  
  
  METHODS
  An experimental setup for three-dimensional analysis based on 2 prepared ceramic master dies and their corresponding virtual CAD-models was used to assess the accuracy of 10 extraoral and 4 intraoral optical non-contact dental digitizing systems. Depending on the clinical procedure, 10 optical measurements of either 10 duplicate gypsum dies (extraoral digitizing) or directly of the ceramic master dies (intraoral digitizing) were made and compared with the corresponding CAD-models.
  
  
  RESULTS
  The digitizing systems showed differences in accuracy. However, all topical systems were well within the benchmark of ±20 µm. These results apply to single tooth measurements.
  
  
  CONCLUSIONS
  Study results are limited, since only single teeth were used for comparison. The different preparations represent various angles and steep and parallel opposing tooth surfaces (incisors). For most digitizing systems, the latter are generally the most difficult to capture. Using CAD/CAM technologies, the preparation angles should not be too steep to reduce digitizing errors. Older systems might be limited to a certain height or taper of the prepared tooth, whereas newer systems (extraoral as well as intraoral digitization) do not have these limitations.
authors.affiliation: Klinik für Zahnärztliche Prothetik, Zentrum Zahn-, Mund-, und Kieferheilkunde, Universität Ulm, Ulm, Germany.
authors.forename: Heike
authors.initials: H
authors.lastname: Rudolph
authors.affiliation: Klinik für Zahnärztliche Prothetik, Zentrum Zahn-, Mund-, und Kieferheilkunde, Universität Ulm, Ulm, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Salmen
authors.affiliation: Klinik für Zahnärztliche Prothetik, Zentrum Zahn-, Mund-, und Kieferheilkunde, Universität Ulm, Ulm, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Moldan
authors.affiliation: Klinik für Zahnärztliche Prothetik, Zentrum Zahn-, Mund-, und Kieferheilkunde, Universität Ulm, Ulm, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Kuhn
authors.affiliation: Poliklinik für Zahnärztliche Prothetik, Justus-Liebig Universität, Giessen, Germany.
authors.forename: Viktor
authors.initials: V
authors.lastname: Sichwardt
authors.affiliation: Poliklinik für Zahnärztliche Prothetik, Justus-Liebig Universität, Giessen, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Wöstmann
authors.affiliation: Klinik für Zahnärztliche Prothetik, Zentrum Zahn-, Mund-, und Kieferheilkunde, Universität Ulm, Ulm, Germany.
authors.forename: Ralph Gunnar
authors.initials: RG
authors.lastname: Luthardt
mesh_terms: D000704:Analysis of Variance; D002133:Calcium Sulfate; D002516:Ceramics; D017076:Computer-Aided Design; D003760:Dental Impression Materials; D003761:Dental Impression Technique; D017267:Dental Prosthesis Design; D003793:Dental Restoration, Permanent / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D015203:Reproducibility of Results
chemical_list: D003760:Dental Impression Materials; D002133:Calcium Sulfate