Dental resin materials, method of manufacture, and uses thereof

1. A method of making a hybrid silica filler comprising a crystalline phase, comprising:

adding an amorphous sol comprising about 15 to about 30 weight percent of silica nanoparticles having diameters of about 1 to about 50 nanometers, wherein the nanoparticles are in the form of chains having lengths of about 5 to about 400 nanometers, to a microparticulate filler to form a mixture;

drying the mixture at a temperature and for a time effective to remove liquid therefrom; and

heating the dried mixture to a temperature at or above 800° C. and for a time effective to form at least one crystalline phase.

2. The method of claim 1 , further comprising treating the hybrid silica filler comprising a crystal phase with a silane.

3. The method of claim 2 , wherein the silane comprises gamma-mercaptopropyltrimethoxysilane, gamma-mercaptopropyltriethoxysilane, gamma-aminopropyltriethoxysilane, or a mixture comprising one of the foregoing silanes.

4. The method of claim 1 , wherein the microparticulate filler is selected from the group consisting of zirconia, alumina, and combinations thereof.

5. The method of claim 1 , wherein the microparticulate filler is in the form of an aqueous or organic solution.

6. The method of claim 1 , wherein the solution has a pH of less than about 7.

7. The method of claim 1 , wherein the silica nanoparticles have diameters about 1 to about 30 nanometers.

8. The method of claim 1 , wherein the silica nanoparticles have diameters about 1 to about 20 nanometers.

9. The method of claim 1 , wherein the silica nanoparticles are in the form of chains having lengths of about 10 to about 300 nanometers.

10. The method of claim 1 , wherein the silica particles are in the form of chains having lengths of about 10 to about 200 nanometers.

11. The method of claim 1 , wherein the mixture further comprises an opacifying metal oxide or a calcinable precursor thereof.

12. A method of making a hybrid silica filler comprising a crystalline phase, comprising:

adding a microparticulate filler to a neutral or acidic solution comprising an opacifying oxide or calcinable precursor thereof;

adding an amorphous sol comprising about 15 to about 30 weight percent of silica nanoparticles having diameters of about 1 to about 50 nanometers, wherein the nanoparticles are in the form of chains having lengths of about 5 to about 400 nanometers to the solution of opacifying oxide or calcinable precursor thereof and microparticulate filler to form a mixture;

drying the mixture at a temperature and for a time effective to remove liquid therefrom; and

heating the dried mixture to a temperature at or above 800° and for a time effective to form at least one crystalline phase therein.

13. The method of claim 12 , wherein the microparticulate filler is glass or ceramic.

14. The method of claim 13 , wherein the heating is sufficient to form a material in which nanoparticulate silica is fused onto the microparticulate glass or ceramic surfaces.

15. The method of claim 12 , 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.

16. The method of claim 12 , wherein the sol that is dried comprises the silica nanoparticles as amorphous elongated silica nanoparticles in an aqueous solution.

17. The method of claim 12 , wherein the microparticulate filler is selected from the group consisting of silica, silicate glass, quartz, barium oxide, barium silicate, strontium silicate, barium borosilicate, strontium borosilicate, borosilicate, lithium silicate, lithium alumina silicate, zinc oxide, calcium oxide, tantalum dioxide, amorphous silica, ammoniated or deammoniated calcium phosphate and alumina, zirconia, tin oxide, titania, and mixtures thereof.

18. The method of claim 12 , wherein the filler obtained is a hybrid filler comprising about 40 to about 90 percent by weight of material derived from the sol of silica nanoparticles and about 1 to 20 percent by weight of the microparticulate filler.

19. A method of making a hybrid silica filler comprising a crystalline phase, comprising:

adding a microparticulate filler to a neutral or acidic solution comprising an opacifying oxide or calcinable precursor thereof;

adding an amorphous sol comprising about 15 to about 30 weight percent of silica nanoparticles having diameters of about 1 to about 50 nanometers, wherein the nanoparticles are in the form of chains having lengths of about 5 to about 400 nanometers to the solution of opacifying oxide or calcinable precursor thereof and microparticulate filler to form a mixture;

drying the mixture at a temperature and for a time effective to remove liquid therefrom; and

heating the dried mixture to a temperature above 800° C. and for a time effective to form at least one crystalline phase therein.

20. The method of claim 19 , wherein the opacifying metal oxide is selected from the group consisting of zirconia, zirconia acetate, bismuth acetate, bismuth oxychloride, and combinations thereof.