Introduction. Optimal canal filling in the apical region poses a challenge for the dentist and determines therapeutic success. The choice of an appropriate material whose physico-chemical properties enable X-ray visualization of the quality of the filling is of great importance. The higher the density of the material, the better the contrast and thus the possibility of correct assessment of the filling. Aim. This study was undertaken to assess radiopacity of materials currently used in endodontics for sealing root canals with a wide apical gap. Material and methods. MTA+ (Cerkamed), Biodentine (Septodont), and gutta-percha with AH Plus paste were used for sealing 27 single-root human teeth. The canals were cleaned with K files to achieve ISO size 40. Next, Gates-Glidden drills size 2 were inserted up to their full working length to enlarge the apex. Each material was used to seal nine canals. X-ray images were taken with the X-Mind DC (Satelec) generator and were recorded, scanned, and analyzed with the Digora digital radiography system. Radiopacity of the image was evaluated on the basis of color change using the 256 levels grayscale. Radiographs of the same roots with a glass plate imitating cheek tissues with a bone fragment were obtained for comparison. Results. The lowest optical density was found for Biodentine. This material demonstrated the smallest X-ray contrast as compared with dentin. The best radiographic visibility was found for gutta-percha with AH Plus paste. In spite of the slightly greater optical density values of MTA+ in comparison with Biodentine, the contrast and radiographic visibility of both materials was poor. Optical density of the materials was reduced in the presence of the glass plate imitating cheek tissues with a bone fragment. Conclusions. MTA+ and Biodentine are characterized by lower optical densities than gutta-percha with AH Plus paste.

Key words: MTA+, Biodentine, radiopacity, X-ray images.