title: Accuracy of a digital impression system based on active wavefront sampling technology for implants considering operator experience, implant angulation, and depth.
abstract: BACKGROUND
  There is a scarce knowledge on the accuracy of intraoral digital impression systems for dental implants.
  
  
  OBJECTIVE
  The purpose of this study is to evaluate the accuracy of a digital impression system considering clinical parameters.
  
  
  METHODS
  A master model with six implants (27, 25, 22, 12, 15, 17) was fitted with polyether ether ketone scan bodies. Implant no. 25 was placed with 30° mesial angulation in relation to the vertical plane (y axis), and implant no. 15 was positioned with 30° distal angulation. Implant no. 22 was placed 2 mm and no. 12, 4 mm below the gingiva. Experienced (n = 2) and inexperienced operators (n = 2) performed scanning (Lava Chairside Oral Scanner; 3 M ESPE, St Paul, MN, USA) at standard and high accuracy mode. Measurements involved five distances (27-25, 27-22, 27-12, 27-15, 27-17). Measurements with high accuracy three-dimensional coordinated measuring machine (CMM) of the master model acted as the true values. The data obtained were subtracted from those of the CMM values.
  
  
  RESULTS
  Experience of the operator significantly influenced the results (p = .000). Angulation (p = .195) and depth of implant (p = .399) did not show significant deviation from the true values. The mean difference between standard and high accuracy mode was 90 μm.
  
  
  CONCLUSIONS
  With the active wavefront sampling, technology-based digital impression system training seems to be compulsory. Impressions of angulated implants may diminish the accuracy of the impression, yet the results were not significant.
authors.affiliation: Department of Buccofacial Prosthesis, Faculty of Odontology, University Complutense of Madrid, Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Giménez
authors.forename: Mutlu
authors.initials: M
authors.lastname: Özcan
authors.forename: Francisco
authors.initials: F
authors.lastname: Martínez-Rus
authors.forename: Guillermo
authors.initials: G
authors.lastname: Pradíes
mesh_terms: D017076:Computer-Aided Design; D003757:Dental Implantation / Q000379:methods*; D015921:Dental Implants; D003760:Dental Impression Materials; D003761:Dental Impression Technique; D061827:Dimensional Measurement Accuracy; D006801:Humans; D003765:Models, Dental
chemical_list: D015921:Dental Implants; D003760:Dental Impression Materials
keywords: accuracy; dental implant; digital impression; implant angulation; implant depth; intraoral scanner