title: [Precision of digital impressions with TRIOS under simulated intraoral impression taking conditions].
abstract: OBJECTIVE
  To evaluate the precision of digital impressions taken under simulated clinical impression taking conditions with TRIOS and to compare with the precision of extraoral digitalizations.
  
  
  METHODS
  Six #14-#17 epoxy resin dentitions with extracted #16 tooth preparations embedded were made. For each artificial dentition, (1)a silicone rubber impression was taken with individual tray, poured with type IV plaster,and digitalized with 3Shape D700 model scanner for 10 times; (2) fastened to a dental simulator, 10 digital impressions for each were taken with 3Shape TRIOS intraoral scanner. To assess the precision, best-fit algorithm and 3D comparison were conducted between repeated scan models pairwise by Geomagic Qualify 12.0, exported as averaged errors (AE) and color-coded diagrams. Non-parametric analysis was performed to compare the precisions of digital impressions and model images. The color-coded diagrams were used to show the deviations distributions.
  
  
  RESULTS
  The mean of AE for digital impressions was 7.058 281 μm, which was greater than that of 4.092 363 μm for the model images (P<0.05). However, the means and medians of AE for digital impressions were no more than 10 μm, which meant that the consistency between the digital impressions was good. The deviations distribution was uniform in the model images,while nonuniform in the digital impressions with greater deviations lay mainly around the shoulders and interproximal surfaces.
  
  
  CONCLUSIONS
  Digital impressions with TRIOS are of good precision and up to the clinical standard. Shoulders and interproximal surfaces scanning are more difficult.
authors: Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors: Xin
authors: X
authors: Yang
authors: Shenzhen Upcera Co. LTD, Guangdong Shenzhen 518000, China.
authors: Yi-fei
authors: YF
authors: Sun
authors: Shenzhen Upcera Co. LTD, Guangdong Shenzhen 518000, China.
authors: Lei
authors: L
authors: Tian
authors: Department of Material Science and Engineering, Tsinghua University, Beijing 100083, China.
authors: Wen-jie
authors: WJ
authors: Si
authors: Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors: Hai-lan
authors: HL
authors: Feng
authors: Department of General Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China; National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors: Yi-hong
authors: YH
authors: Liu
mesh_terms: D017076:Computer-Aided Design; D003760:Dental Impression Materials; D003761:Dental Impression Technique; D006801:Humans; D021621:Imaging, Three-Dimensional; D003765:Models, Dental
chemical_list: D003760:Dental Impression Materials