X-ray opaque, enamel-matching dental filling composition

In a dental filling composition having a binder resin made of condensation products from the reaction of bisphenol A with glycidyl methacrylate, said binder being in the presence of a diluent and intermixed with a fused glass filler in finely divided particulate form containing 25 to 50 weight percent SiO.sub.2 and a sufficient amount of fluxing agent to bring the fusion temperature below 1350.degree.C, the improvement comprising said glass filler including, at the time of fusing thereof, about 5 to 60 percent by weight of a compound selected from the class consisting of oxides and carbonates of lanthanum, hafnium, strontium and tantalum, to provide a non-toxic, x-ray opaque and optically translucent restorative matrix resistant to oral fluids.