title: Radiopacity of esthetic restorative materials compared with human tooth structure.
abstract: OBJECTIVE
  To compare the radiopacity of 13 restorative materials, (a conventional glass-ionomer cement, three resin-modified glass-ionomer cements, six polyacid-modified resin-based composites, and three resin-based composites) to sound tooth structure.
  
  
  METHODS
  315 specimens were made of the restorative materials (n = 21), of 2 mm height and 4.1 mm diameter. Radiographs were taken of the specimens, together with the tooth structure sample and an aluminum step wedge. The radiopacity values of each specimen were taken using a transmission densitometer.
  
  
  RESULTS
  ANOVA and Tukey's test (95% level of confidence) revealed that, except for a resin-based composite, a polyacid-modified resin-based composite, a resin-modified glass-ionomer cement and the conventional glass-ionomer cement, all the evaluated restorative materials were more radiopaque than the tooth structure.
authors.affiliation: Department of Radiology, School of Dentistry, Piracicaba, University of Campinas (UNICAMP), Brazil.
authors.forename: A T
authors.initials: AT
authors.lastname: Hara
authors.forename: M C
authors.initials: MC
authors.lastname: Serra
authors.forename: F
authors.initials: F
authors.lastname: Haiter-Neto
authors.forename: A L
authors.initials: AL
authors.lastname: Rodrigues
mesh_terms: D015502:Absorptiometry, Photon; D000704:Analysis of Variance; D020770:Compomers; D003188:Composite Resins; D003287:Contrast Media; D003743:Dental Enamel / Q000000981:diagnostic imaging; D003793:Dental Restoration, Permanent; D003804:Dentin / Q000000981:diagnostic imaging; D005899:Glass Ionomer Cements; D006801:Humans; D011861:Radiography, Dental; D018709:Statistics, Nonparametric
chemical_list: D020770:Compomers; D003188:Composite Resins; D003287:Contrast Media; D005899:Glass Ionomer Cements