초록

A filler for a dental resin composition is disclosed, comprising silica particles derived from a nanoparticulate silica sol, the filler material having at least one crystalline phase. The filler material provides improved wear resistance and other properties.

대표청구항 ▼

What is claimed is: 1. A filler made in accordance with a method comprising: drying a sol comprising individual amorphous silica nanoparticles having diameters of about 1 to about 50 nanometers, wherein the individual amorphous silica nanoparticles are in the form of chains having lengths of about

What is claimed is: 1. A filler made in accordance with a method comprising: drying a sol comprising individual amorphous silica nanoparticles having diameters of about 1 to about 50 nanometers, wherein the individual amorphous silica nanoparticles are in the form of chains having lengths of about 5 to about 400 nanometers, at a temperature and for a time effective to remove liquid therefrom; and heating the dried silica sol to a temperature at about or above about 800° C. and for a time effective to form at least one crystalline phase therein. 2. The filler of claim 1 wherein the heated dried silica sol has at least one crystalline phase that retains nanostructured character. 3. The filler of claim 1, wherein the chains have lengths of about 5 to about 300 nanometers. 4. The filler of claim 1, wherein the silica nanoparticles have diameters of about 1 to about 30 nanometers. 5. The filler of claim 1, wherein the silica nanoparticles have diameters of about 1 to about 20 nanometers. 6. The filler of claim 1, wherein the method further comprises surface treating the heated dried silica sol with a silane. 7. The filler of claim 6, wherein the silane comprises gamma-mercaptopropyltrimethoxysilane, gamma-mercaptopropyltriethoxysilane, gamma-aminopropyltriethoxysilane, or mixtures thereof. 8. The filler of claim 7, further comprising a microparticulate glass filler, a ceramic filler, or a mixture thereof. 9. The filler of claim 1, further comprising an opacifying oxide. 10. The filler of claim 1, wherein an X-ray diffraction pattern of material formed after the drying shows a dominant amorphous curve and no crystalline peaks, and an X-ray diffraction pattern of material formed after the heating exhibits crystalline peaks. 11. The filler of claim 1, wherein the sol that is dried comprises amorphous elongated silica nanoparticles in an aqueous solution. 12. The filler of claim 1, wherein, prior to said drying and heating, the sol comprising silica nanoparticles is mixed with a microparticulate filler. 13. The filler of claim 1, wherein, prior to said drying and heating, the sol comprising the silica nanoparticles is mixed with a microparticulate filler and an opacifying oxide or calcinable precursor thereof. 14. A composition comprising the filler of claim 1 in admixture with a resin material to form a dental composite.