In U.S. patent application Ser. No. 509,770, filed July 1, 1983, now U.S. Pat. No. 4,500,657, for DENTAL RESTORATIVE COMPOSITIONS HAVING IMPROVED MECHANICAL PROPERTIES AND HYDROLYTIC STABILITY, and assigned to the same assignee as this Application, there is disclosed dental restorative compositions containing a monomer having at least two olefinically unsaturated groups, a polymerization initiator, and a filler. In the invention of said Application, both the monomer and the filler are hydrophobic (as defined therein), and the filler has a critical particle size and constitutes a critical proportion of the formulation. The dental restorative compositions of said application exhibit excellent properties, and are serious contenders to be indicated for use in Class II restorations (that is, restorations on the biting surfaces of molars), a distinction that has, thus far, eluded most, if not all, commercial resinous dental restoratives.
This invention is directed to an improvement in the art of resinous dental restoratives, and is particularly useful in the restoratives described in said Application.