Patent ID: 7098259

Claim:
A process for the preparation of a polymerizable dental material, the process comprising: (a) preparing a filler from individual components by a melting process at a temperature of at least 1550° C.; (b) grinding the filler obtained in (a) to a particle size of 0.1–15μm; (c) surface-treating the filler obtained in (b); and (d) incorporating the surface-treated filler in a matrix comprising: (i) cationically curable monomers; and (ii) initiators, retarders, accelerators, auxiliary agents, or combinations thereof; wherein the filler is an X-ray opaque filler comprising at least 65 weight % of SiO 2 , and wherein the surface-treated filler has a refractive index of n D =1.49–1.54.