There are disclosed amphoteric nano-sized metal oxide particles functionalized with silyl esters of a phosphonate and composites thereof with an acrylate-based monomer, including liquid crystal monomers photopolymerizable at ambient temperature. Also disclosed are the method making such functionalized particular by reacting a metal oxide with a silyl ester of a phosphonate in the presence of a non-aqueous solvent and in an inert atmosphere and the method of making the composites wherein the functionalized particles are admixed with an acrylate-based matrix monomer, including liquid crystal monomers photopolymerizable at ambient temperature. Further disclosed is the method of dental repair wherein the composites are applied to a tooth and photopolymerized.