Dental filler and methods
View Patent ↗A dental filler is disclosed. The filler is produced by admixing a metal oxide sol and a water-soluble organic binder; drying said mixed sol into a dried product; and calcining said dried product; wherein said filler is a substantially amorphous cluster. The filler can be mixed into a hardenable resin to provide radiopaque dental materials having desirable strength and aesthetic character.
1. A method of making a filler for dental material comprising:
a) admixing a non-heavy metal oxide sol, a heavy metal oxide-containing material, and a thermally fugitive water-soluble organic binder to form a mixed sol;
b) drying said mixed sol into a dried product;
c) heating the dried product in an oxygen-containing environment at a temperature sufficient to remove substantially all of the thermally fugitive water-soluble organic binder, to form a friable powder; and
d) calcining the friable powder to form the filler as a powder;
wherein said filler comprises a substantially amorphous cluster of non-heavy metal oxide particles and a heavy metal oxide.
2. The method of making a filler of claim 1 , wherein the ratio of organic binder to heavy metal oxide-containing material is 0.25 to 2.
3. The method of making a filler of claim 1 , wherein the ratio of organic binder to heavy metal oxide-containing material is 0.75 to 1.
4. The method of making a filler of claim 1 , wherein the water-soluble organic binder comprises a sugar.
5. The method of making a filler of claim 1 , wherein the water-soluble organic binder comprises a disaccharide.
6. The method of making a filler of claim 1 , wherein the water-soluble organic binder comprises a trisaccharide.
7. The method of making a filler of claim 1 , wherein the water-soluble organic binder comprises sucrose.
8. The method of making a filler of claim 1 , wherein the water-soluble organic binder comprises polyethylene glycol.
9. The method of making a filler of claim 1 , wherein the water-soluble organic binder comprises poly(vinyl alcohol).
10. The method of making a filler of claim 8 , wherein upon the drying of said mixed sol into a dried product, the mixed sol becomes a foam wherein the foam expands by at least 10 percent.
11. The method according to claim 1 , further comprising the step of surface modifying the filler.
12. The method according to claim 1 , further comprising the step of admixing the filler with a hardenable resin.