title: [Constructing 3-dimensional colorized digital dental model assisted by digital photography].
abstract: OBJECTIVE
  To explore a method of constructing universal 3-dimensional (3D) colorized digital dental model which can be displayed and edited in common 3D software (such as Geomagic series), in order to improve the visual effect of digital dental model in 3D software.
  
  
  METHODS
  The morphological data of teeth and gingivae were obtained by intra-oral scanning system (3Shape TRIOS), constructing 3D digital dental models. The 3D digital dental models were exported as STL files. Meanwhile, referring to the accredited photography guide of American Academy of Cosmetic Dentistry (AACD), five selected digital photographs of patients'teeth and gingivae were taken by digital single lens reflex camera (DSLR) with the same exposure parameters (except occlusal views) to capture the color data. In Geomagic Studio 2013, after STL file of 3D digital dental model being imported, digital photographs were projected on 3D digital dental model with corresponding position and angle. The junctions of different photos were carefully trimmed to get continuous and natural color transitions. Then the 3D colorized digital dental model was constructed, which was exported as OBJ file or WRP file which was a special file for software of Geomagic series. For the purpose of evaluating the visual effect of the 3D colorized digital model, a rating scale on color simulation effect in views of patients'evaluation was used. Sixteen patients were recruited and their scores on colored and non-colored digital dental models were recorded. The data were analyzed using McNemar-Bowker test in SPSS 20.
  
  
  RESULTS
  Universal 3D colorized digital dental model with better color simulation was constructed based on intra-oral scanning and digital photography. For clinical application, the 3D colorized digital dental models, combined with 3D face images, were introduced into 3D smile design of aesthetic rehabilitation, which could improve the patients' cognition for the esthetic digital design and virtual prosthetic effect.
  
  
  CONCLUSIONS
  Universal 3D colorized digital dental model with better color simulation can be constructed assisted by 3D dental scanning system and digital photography. In clinical practice, the communication between dentist and patients could be improved assisted by the better visual perception since the colorized 3D digital dental models with better color simulation effect.
authors.affiliation: Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Hong-qiang
authors.initials: HQ
authors.lastname: Ye
authors.affiliation: Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Yu-shu
authors.initials: YS
authors.lastname: Liu
authors.affiliation: Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Yun-song
authors.initials: YS
authors.lastname: Liu
authors.affiliation: Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Ning
authors.affiliation: Center of Digital Dentistry, Peking University School and Hospital of Stomatology; Research Center of Engineering and Technology for Digital Dentistry, the National Health and Family Planning Commission, Beijing 100081, China; National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing 100081, China.
authors.forename: Yi-jiao
authors.initials: YJ
authors.lastname: Zhao
authors.affiliation: Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China; National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing 100081, China.
authors.forename: Yong-sheng
authors.initials: YS
authors.lastname: Zhou
mesh_terms: D003116:Color; D004955:Esthetics, Dental; D005145:Face; D006801:Humans; D021621:Imaging, Three-Dimensional; D003765:Models, Dental; D010781:Photography; D012984:Software; D014070:Tooth