Evaluation of three calcium hydroxide pastes’ optical density

Abstract

Radiopacity is one of the physical properties requested by the different materials of endodontic use, which evaluate the filling of the pulp canal system. The aim of this study was to evaluate the radiopacity of three calcium hydroxide pastes: calcium hydroxide pro-analysis (biodynamics) + Propilenoglicol 400 (pharmacy pure extract), Calen (SS white) and UltraCal XS (Ultra Dent), associated to a tissue simulator. Fifteen samples were manufactured using a polyethylene tube, originating three experimental groups, with five tubes filled with each one of the pastes evaluated. In order to find out the interference of the tube in the radiopacity, another two groups were included: one composed just by the tooth and other with an empty tube inserted in the root canal. Using the Visuallix system, 25 standardized digital images were obtained (5 of each group). The images were exported to Adobe Photoshop v. 7.0 software, in order to obtain the mean values and standard deviation of gray levels in a standardized area of the image, corresponding to the tube position. The mean values of optic density were, in decreasing order, UltraCal XS (236,25 + 2,96), Calen (230,32 + 3,49) and pro-analyis + propilenoglicol (210,95 + 3,29). The Visualix system was able to identify different patterns of the radiopacity in the tested materials, which were more radiopaque than the empty root canal and significantly different in terms of radiopacity.