A measure for quantifying the radiopacity of restorative resins

作者：Sur Jaideep; Endo Atsushi; Matsuda Yukiko; Itoh Kazuo; Katoh Tsuguhisa; Araki Kazuyuki; Okano Tomohiro^*

来源：Oral Radiology, 2011, 27(1): 22-27.

DOI：10.1007/s11282-010-0055-4

• Restorative resins
• Radiopacity
• Attenuation coefficients

To evaluate the utility of the X-ray attenuation coefficient as a measure for quantifying the radiopacity of restorative resins at different exposure times and film speeds.
Five restorative resins were made into disks, measuring 10 mm in diameter with thicknesses of 0.5, 1.0, 1.5, 2.0, and 2.5 mm. These resin disks, an aluminum step wedge, and a lead disk were placed on size 4 Ultraspeed(A (R)) D and Insight(A (R)) E/F films. X-ray parameters were 65 kVp, 10 mA, and 30-cm focus-to-film distance. Exposure times were 0.3, 0.15, and 0.10 s for the D-speed films and 0.15, 0.10, and 0.05 s for the E/F-speed films. At each exposure setting, three D- and E/F-speed films were exposed and processed immediately with an automatic processor. The optical density was measured with a transmission densitometer. The net optical density (D) was used to calculate the linear attenuation coefficients (mu) using lnD = -mu x + lnD (0), where D and D (0) denote the optical density of the specimen and background, respectively.
The linear attenuation coefficients (mm(-1)) of the five restorative resins were 0.24-0.27 for Sorare(A (R)), 0.30-0.34 for Estelite(A (R)), 0.36-0.39 for Gradia(A (R)), 0.51-0.54 for Clearfil AP-X(A (R)), and 0.52-0.56 for Beautifil(A (R)). These were all higher than that of dentin (0.15-0.19). There was no significant difference in the attenuation coefficients at different exposure times or film speeds.
Attenuation coefficients can be used instead of aluminum wedges of equivalent thickness to quantify the radiopacity of restorative resins.

• 出版日期2011-6