Metal Oxide Compositions and Methods: 6,417,244

Metal oxide and metal oxide-silica nanoparticles are disclosed wherein the surfaces thereof are complexed with a polymerizable, biocompatible, heterocyclic base. Polymerizable compositions are prepared by loading such nanoparticles into acrylate based monomer matrices, which compositions can then be photocured into X-ray opaque, transparent or translucent solids. Methods are disclosed for forming such complexed nanoparticles and compositions and for using such compositions as medical or dental restoratives.