Evaluation of the Radiopacity of Resin Cements Using Digital Radiographic

Objectives: The aim of this in vitro study was to evaluate the radiopacity of three different resin cements: GI - CEMENT POST-ÂNGELUS (self- curing/ control group), GII - RelyX™ ARC-3M ESPE (dual curing) and GIII - Variolink II -Ivoclar/Vivadent (photocuring) using digital radiographic images. Methods: The resin cements were prepared according to the manufacturer's instructions. Teflon matrixes were made with an internal cavity with 2 mm of thickness and 8 mm of diameter. Five specimens were prepared for each group; when it was necessary, the cements were photocuried using a convencional quartz tungsten halogen (QTH) (40 seconds – 470 mW/cm² – Optilux 401 Demetron). The samples were stored in a stove at 37°C for 24 hours. After that, radiographs of the specimens were made with a distance of approximately 60 mm of the digital sensor to the cone of the radiograph machine, and an exposure time of 0.06 seconds using an Intra-Oral System of Radiographic Digital (GNATUS DRS) and a Software Cygnus Imaging for Windows. Furthermore, the radiopacity of these radiographs was evaluated by digital image system (fixing gray levels) and then they were analyzed in the Software Image Tool. Results: The results were obtained analyzing the number of pixels in the images. The mean, in black and white percentage (%) respectively, and standard deviation were: GI- 51,06% and 48,94% ± 3,16; GII- 39,78% and 60,22% ± 3,86 and GIII- 30,64% and 69,36% ± 5,32. The data were analyzed by Kruskal-Wallis (p<0,05) and Dunn Tests. Conclusion: The cement of the GIII had the highest value of radiopacity comparing to the others resin cements (GI and GII); and the evaluation of the radiopacity using digital system is a fast, safe and easily executed alternative. Supported by PIBIC / UEPG / CNPq – Brazil.