title: Accuracy of computer-aided design/computer-aided manufacturing-generated dental casts based on intraoral scanner data.
abstract: BACKGROUND
  Little is known about the accuracy of physical dental casts that are based on three-dimensional (3D) data from an intraoral scanner (IOS). Thus, the authors conducted a study to evaluate the accuracy of full-arch stereolithographic (SLA) and milled casts obtained from scans of three IOSs.
  
  
  METHODS
  The authors digitized a polyurethane model using a laboratory reference scanner and three IOSs. They sent the scans (n = five scans per IOS) to the manufacturers to produce five physical dental casts and scanned the casts with the reference scanner. Using 3D evaluation software, the authors superimposed the data sets and compared them.
  
  
  RESULTS
  The mean trueness values of Lava Chairside Oral Scanner C.O.S. (3M ESPE, St. Paul, Minn.), CEREC AC with Bluecam (Sirona, Bensheim, Germany) and iTero (Align Technology, San Jose, Calif.) casts were 67.50 micrometers (95 percent confidence interval [CI], 63.43-71.56), 75.80 μm (95 percent CI, 71.74-79.87) and 98.23 μm (95 percent CI, 94.17-102.30), respectively, with a statistically significant difference among all of the scanners (P < .05). The mean precision values were 13.77 μm (95 percent CI, 2.76-24.79), 21.62 μm (95 percent CI, 10.60-32.63) and 48.83 μm (95 percent CI, 37.82-59.85), respectively, with statistically significant differences between CEREC AC with Bluecam and iTero casts, as well as between Lava Chairside Oral Scanner C.O.S. and iTero casts (P < .05).
  
  
  CONCLUSIONS
  All of the casts showed an acceptable level of accuracy; however, the SLA-based casts (CEREC AC with Bluecam and Lava Chairside Oral Scanner C.O.S.) seemed to be more accurate than milled casts (iTero).
  
  
  CONCLUSIONS
  On the basis of the results of this investigation, the authors suggested that SLA technology was superior for the fabrication of dental casts. Nevertheless, all of the investigated casts showed clinically acceptable accuracy. Clinicians should keep in mind that the highest deviations might occur in the distal areas of the casts.
authors.affiliation: Dr. Patzelt is an associate professor, scientific associate and the vice director, postgraduate program, Department of Prosthetic Dentistry, Center for Dental Medicine, Medical Center-University of Freiburg, Baden-Württemberg, Germany. He also is a visiting scholar and a research professor, Department of Periodontics, School of Dentistry, University of Maryland, Baltimore. Address correspondence to Dr. Patzelt at Department of Prosthetic Dentistry, Center for Dental Medicine, Medical Center-University of Freiburg, Huggstetter Strasse 55, 79106 Freiburg, Germany, e-mail sebastian.patzelt@uniklinik-freiburg.de.
authors.forename: Sebastian B M
authors.initials: SB
authors.lastname: Patzelt
authors.affiliation: Dr. Bishti was a doctoral candidate, Department of Prosthetic Dentistry, Center for Dental Medicine, Medical Center-University of Freiburg, Baden-Württemberg, Germany, when this article was written. She now is an assistant professor, Department of Removable Prosthodontics, School of Dentistry, University of Zawia, Libya.
authors.forename: Shaza
authors.initials: S
authors.lastname: Bishti
authors.affiliation: Dr. Stampf is a biostatistician, Clinical Epidemiology, Department of Clinical Research, University Hospital Basel, Switzerland.
authors.forename: Susanne
authors.initials: S
authors.lastname: Stampf
authors.affiliation: Dr. Att is an associate professor and the director, Postgraduate Program, Department of Prosthetic Dentistry, Center for Dental Medicine, Medical Center-University of Freiburg, Baden-Württemberg, Germany.
authors.forename: Wael
authors.initials: W
authors.lastname: Att
mesh_terms: D017076:Computer-Aided Design; D003761:Dental Impression Technique / Q000295:instrumentation*; D061827:Dimensional Measurement Accuracy; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation; D021621:Imaging, Three-Dimensional / Q000295:instrumentation; D003765:Models, Dental; D011140:Polyurethanes; D012984:Software
chemical_list: D011140:Polyurethanes
keywords: Intraoral scanner; accuracy; dental casts; digital impression; milling; precision; stereolithography; trueness