title: [Non-invasive detection of metal casting defects using dental X ray machine].
abstract: OBJECTIVE
  The purpose of this in vitro study is to find the best parameters in detecting the casting defects made of titanium, nickel-chromium and chromium-cobalt using dental X ray machine.
  
  
  METHODS
  Casting sheets in different thickness (1.0 mm, 0.6 mm, 0.3 mm)were fabricated using of Ti, Ni-Cr and Cr-Co.Small pores on the surfaces were made with laser welder to simulate the internal porosity of the castings. Parameters of the dental X ray machine were adjusted to take films. The data were analyzed using SPSS12 software package for group t test.
  
  
  RESULTS
  The thickness of Ti had no significant effect on the setting of the parameters of the dental X ray machine in detecting the defects of titanium castings (P>0.05), while the thickness of Ni-Cr and Cr-Co had significant effect on the setting of the parameters (P<0.05).
  
  
  CONCLUSIONS
  Dental X ray machine can be used in detecting the defects of titanium casting sheets.
authors.affiliation: Department of Prosthodontics, School of Stomatology, Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Kan
authors.initials: K
authors.lastname: Xu
authors.forename: Zheng-jie
authors.initials: ZJ
authors.lastname: Dong
authors.forename: Yu-hua
authors.initials: YH
authors.lastname: Wang
authors.forename: Fu-qiang
authors.initials: FQ
authors.lastname: Zhang
mesh_terms: D002858:Chromium Alloys / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry*; D003735:Dental Casting Technique / Q000295:instrumentation*; D066298:In Vitro Techniques; D008422:Materials Testing; D016062:Porosity; D011861:Radiography, Dental; D014025:Titanium / Q000737:chemistry; D014965:X-Rays
chemical_list: D002858:Chromium Alloys; D003722:Dental Alloys; D014025:Titanium