Patent ID: 8053490

Claim:
A pre-treated dental filler comprising a reaction product of an acid-reactive filler and a pre-treatment chemical, wherein the pre-treatment chemical is a polymerizable monomer or oligomer comprising: at least one acid group selected from the group consisting of a carboxylic acid, a sulfonic acid, a sulfinic acid, a phosphoric acid, and a phosphonic acid, or at least one acid-precursor functional group selected from the group consisting of a carboxylic acid anhydride, an acyl halide, a sulfonic anhydride, a sulfonyl halide, a sulfinic anhydride, a sulfinyl halide, a phosphoric acid derivative, and a phosphonic acid derivative; at least one polymerizable unsaturated carbon-carbon bond; and a molecular weight of about 1,000 grams per mole or less, with the proviso that where the at least one acid group is the carboxylic acid or the at least one acid-precursor functional group is the carboxylic acid anhydride, the pre-treatment chemical is selected from the group consisting of biphenyl dimethacrylate, 4-methacryloxyethyl trimellitic anhydride, 4-methacryloxyethyl trimellitic acid, adduct reaction product of pyromellitic di-anhydride with 2-hydroxyethylmethacrylate, adduct reaction product of pyromellitic di-anhydride with glycerol dimethacrylate, and adduct reaction product of benzenetetracarboxylic acid di-anhydride with 2-(6-hydroxy-1-oxo-hexyloxy)ethyl methacrylate, and with the proviso that where the at least one acid group is the phosphoric acid, the pre-treatment chemical is an ethylenically unsaturated phosphoric acid ester having the general formula: (CH 2 ═C(CH 3 )CO 2 —R—O) n P(O)(OH) 3-n , wherein R is a substituted or unsubstituted alkyl or aryl group having about 1 to about 36 carbon atoms and n equals 1 or 2.