title: Comparative radiopacity of six flowable resin composites.
abstract: OBJECTIVE
  This study investigated the radiopacity of six commercially available flowable composites by using a digital image analysis method to determine the mean gray values of the materials.
  
  
  METHODS
  The flowable resin composites evaluated in this study were Clearfil Majesty Flow, Estelite Flow Q, Tetric N Flow, Esthet X Flow, Filtek Supreme XT Flow and Gradia Direct LoFlo. Ten sample discs (6 x 1 mm) for each group were prepared and 1-mm thick slices were obtained from freshly-extracted teeth for the control group. The mean gray values (MGVs) of each specimen and aluminum (Al) stepwedge were measured by using the histogram function of a computer graphics program. Analysis of variance (ANOVA) was used to investigate the significance of the differences among the groups. For pairwise comparisons, the Tukey test was applied (alpha=0.05).
  
  
  RESULTS
  The radiopacity values of Gradia Direct LoFlo, dentin and Estelite Flow Q were close to that of 1 mm Al. Tetric N Flow and Cl Majesty Flow were more radiopaque than enamel, whereas Filtek Supreme XT Flow had a similar radiopacity to enamel.
  
  
  CONCLUSIONS
  The radiopacity of flowable composites varies considerably, and care must be taken when selecting an appropriate material to enable secondary caries detection under posterior composite restorations.
authors.affiliation: Restorative Dentistry & Endodontics, Ege University School of Dentistry, Izmir, Turkey. zergucu@yahoo.com
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Ergücü
authors.forename: L Sebnem
authors.initials: LS
authors.lastname: Türkün
authors.forename: Erinç
authors.initials: E
authors.lastname: Onem
authors.forename: Pelin
authors.initials: P
authors.lastname: Güneri
mesh_terms: D015502:Absorptiometry, Photon; D003188:Composite Resins / Q000737:chemistry*; D003196:Computer Graphics; D003287:Contrast Media / Q000737:chemistry*; D003743:Dental Enamel / Q000000981:diagnostic imaging; D003764:Dental Materials / Q000737:chemistry*; D003804:Dentin / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008422:Materials Testing; D014783:Viscosity
chemical_list: D003188:Composite Resins; D003287:Contrast Media; D003764:Dental Materials; C510276:Esthet-X Flow; C474035:Filtek Supreme; C523003:Gradia Direct LoFlo; C541508:clearfil majesty; C527485:estelite flow quick; C111840:flowable hybrid composite; C452226:tetric flow composite resin