title: Radiopacity for Contemporary Luting Cements Using Digital Radiography under Various Exposure Conditions.
abstract: OBJECTIVE
  This study examined the radiopacity of contemporary luting cements using direct digital radiography under a range of exposure conditions.
  
  
  METHODS
  Disc specimens (N = 80, n = 10 per group, ø5 mm × 1 mm) were prepared from 8 resin-based luting cements (BisCem Clearfil SA Luting, Duolink, Maxcem Elite Multilink Speed, Panavia F 2.0, RelyX Unicem Clicker, V-link). The specimens were radiographed using a charge-coupled device sensor along with an 11-step aluminum step wedge (1.5-mm incremental steps) and 1-mm-thick tooth cut using five tube voltage/exposure time setups (60 kVp, 0.10/0.08 seconds; 70 kVp, 0.10/0.08/0.06 seconds) at 4 mA and 30 cm. The radiopacity of the specimens was compared with that of the aluminum step wedge and human enamel and dentin using NIH ImageJ software (available at http://rsb.info.nih.gov/ij/). A linear regression model for the aluminum step wedge was constructed, and the data were analyzed by ANOVA and Duncan post hoc test.
  
  
  RESULTS
  Maxcem Elite (5.142 to 5.441) showed the highest radiopacity of all materials, followed in order by Multilink Speed (3.731 to 3.396) and V-link (2.763 to 3.103). The radiopacity of Panavia F 2.0 (2.025 to 2.429), BisCem (1.825 to 2.218), Clearfil SA Luting (1.692 to 2.145), Duolink (1.707 to 1.993), and RelyX Unicem Clicker (1.586 to 1.979) were between enamel (2.117 to 2.330) and dentin (1.302 to 1.685). The radiopacity of 70 kVp conditions was higher than that of the 60 kVp conditions.
  
  
  CONCLUSIONS
  The radiopacities of the tested luting materials were greater than those of dentin or aluminum, satisfying the criteria of the International Organization for Standardization, and they differed significantly from each other in the exposure setups.
authors: Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyungpook National University, Daegu, Korea.
authors: Seo-Young
authors: SY
authors: An
authors: Department of Prosthodontics, School of Dentistry and Advanced Dental Device Development Institute, Kyungpook National University, Daegu, Korea.
authors: Du-Hyeong
authors: DH
authors: Lee
authors: Department of Prosthodontics, School of Dentistry and Advanced Dental Device Development Institute, Kyungpook National University, Daegu, Korea.
authors: Kyu-Bok
authors: KB
authors: Lee
mesh_terms: D003743:Dental Enamel; D003804:Dentin; D006801:Humans; D008422:Materials Testing; D019252:Radiography, Dental, Digital; D019279:Resin Cements
chemical_list: D019279:Resin Cements
keywords: Dental cements; dental; digital; radiography; radiopacity