Radiopacity of posterior composite resins, composite resin luting cements, and glass ionomer lining cements.

The radiopacities of seven posterior composite resins, seven composite resin luting cements, and six glass ionomer lining cements were studied. The purpose was to obtain an indication of radiopacity values of different brands within each of these three groups of materials and to show differences in radiopacities of composite resin inlay materials and their accompanying luting cements. On radiographs, the optical densities of standardized samples were determined and radiopacity values of the materials were expressed in millimeter equivalent aluminum. The composite resins observed displayed higher radiopacities than aluminum. A luting cement and a glass ionomer cement were shown to be less radiopaque than aluminum. Generally the radiopacity of composite resins appeared to be higher than their accompanying luting cements. If materials with substantial differences in radiopacity are used in combined applications for the restorative treatment of teeth, lower radiopacity can interfere with the diagnosis of caries and the detection of gaps near the restoration.