title: [Quantitative assessment on artifacts of dental restorative materials in cone beam computed tomography].
abstract: OBJECTIVE
  To quantitatively evaluate the artifacts appearance of eight kinds of common dental restorative materials, such as zirconia.
  
  
  METHODS
  For the full-crown tooth preparation of mandibular first molar, eight kinds of full-crowns, such as zirconia all-ceramic crown, glass ceramic crown, ceramage crown, Au-Pt based porcelain-fused-metal (PFM) crown, Pure Titanium PFM crown, Co-Cr PFM crown, Ni-Cr PFM crown, and Au-Pd metal crown were fabricated. And natural teeth in vitro were used as controls. These full-crown and natural teeth in vitro were mounted an ultraviolet-curable resin fixed plate. High resolution cone beam computed tomography (CBCT) was used to scan all of the crowns and natural teeth in vitro, and their DICOM data were imported into software MIMICS 10.0. Then, the number of stripes and the maximum diameters of artifacts around the full-crowns were evaluated quantitatively in two-dimensional tomography images.
  
  
  RESULTS
  In the two-dimensional tomography images,the artifacts did not appear around the natural teeth in vitro, glass ceramic crown, and ceramage crown. But thr artifacts appeared around the zirconia all-ceramic and metal crown. The number of stripes of artifacts was five to nine per one crown. The maximum diameters of the artifacts were 2.4 to 2.6 cm and 2.2 to 2.7 cm.
  
  
  CONCLUSIONS
  In the two-dimensional tomography images of CBCT, stripe-like and radical artifacts were caused around the zirconia all-ceramic crown and metal based porcelain-fused-metal crowns. These artifacts could lower the imaging quality of the full crown shape greatly. The artifact was not caused around the natural teeth in vitro, glass ceramic crown, and ceramage crown.
authors.affiliation: Center of Digital Dentistry, National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology Beijing 100081, China.
authors.forename: Fu-song
authors.initials: FS
authors.lastname: Yuan
authors.forename: Yu-chun
authors.initials: YC
authors.lastname: Sun
authors.affiliation: Department of Radiology, Peking University School and Hospital of Stomatology Beijing 100081, China.
authors.forename: Xiao-yan
authors.initials: XY
authors.lastname: Xie
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Pei-jun
authors.initials: PJ
authors.lastname: Lv
mesh_terms: D016477:Artifacts; D002516:Ceramics; D003188:Composite Resins; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D003442:Crowns; D003764:Dental Materials; D003776:Dental Porcelain; D016876:Metal Ceramic Alloys; D017640:Silicates; D015040:Zirconium
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D016876:Metal Ceramic Alloys; D017640:Silicates; C574687:ceramage; D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide