title: Evaluation of digital dental models obtained from dental cone-beam computed tomography scan of alginate impressions.
abstract: OBJECTIVE
  To investigate the dimensional accuracy of digital dental models obtained from the dental cone-beam computed tomography (CBCT) scan of alginate impressions according to the time elapse when the impressions are stored under ambient conditions.
  
  
  METHODS
  Alginate impressions were obtained from 20 adults using 3 different alginate materials, 2 traditional alginate materials (Alginoplast and Cavex Impressional) and 1 extended-pour alginate material (Cavex ColorChange). The impressions were stored under ambient conditions, and scanned by CBCT immediately after the impressions were taken, and then at 1 hour intervals for 6 hours. After reconstructing three-dimensional digital dental models, the models were measured and the data were analyzed to determine dimensional changes according to the elapsed time. The changes within the measurement error were regarded as clinically acceptable in this study.
  
  
  RESULTS
  All measurements showed a decreasing tendency with an increase in the elapsed time after the impressions. Although the extended-pour alginate exhibited a less decreasing tendency than the other 2 materials, there were no statistically significant differences between the materials. Changes above the measurement error occurred between the time points of 3 and 4 hours after the impressions.
  
  
  CONCLUSIONS
  The results of this study indicate that digital dental models can be obtained simply from a CBCT scan of alginate impressions without sending them to a remote laboratory. However, when the impressions are not stored under special conditions, they should be scanned immediately, or at least within 2 to 3 hours after the impressions are taken.
authors.affiliation: Department of Orthodontics, School of Dentistry, Chonnam National University, Gwangju, Korea.
authors.forename: Tingting
authors.initials: T
authors.lastname: Jiang
authors.affiliation: Department of Orthodontics, School of Dentistry, Chonnam National University, Gwangju, Korea.
authors.forename: Sang-Mi
authors.initials: SM
authors.lastname: Lee
authors.affiliation: Department of Orthodontics, School of Dentistry, Chonnam National University, Gwangju, Korea.; Department of Orthodontics, Peking University School of Stomatology, Beijing, PR China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Hou
authors.affiliation: Department of Orthodontics, Dalian Medical University, Dalian, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Chang
authors.affiliation: Department of Orthodontics, School of Dentistry, Chonnam National University, Gwangju, Korea.; Dental Science Research Institute, Chonnam National University, Gwangju, Korea.
authors.forename: Hyeon-Shik
authors.initials: HS
authors.lastname: Hwang
keywords: Alginate impression; Dental cone-beam computed tomography; Digital dental model; Dimensional accuracy