Abstract
Compositions that are useful and unique as dental remineralizers and dental cements, as well as methods for their use, are disclosed. The compositions are mixtures of at least two sparingly soluble calcium phosphates that are present in excess and a dilute aqueous solution approximately saturated with
Filing date: May 18, 1987
Issue date: May 22, 1990
Inventors: Walter E. Brown, Laurence C. Chow
Assignee: American Dental Association Health Foundation
Primary Examiner: Linda D. Skaling
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What is claimed is:
1. A .[.dental restorative.]. paste .Iadd.consisting essentially of .Iaddend..[.comprising.]. an aqueous mixture of Ca.sub.4 (PO.sub.4)O and at least one other calcium phosphate selected from the group consisting of CaHPO.sub.4.2H.sub.2 O .[.,.]. .Iadd.and .Iaddend.CaHPO.sub.4, .[.Ca.sub.8 H.sub.2 (PO.sub.4).sub.6.5H.sub.2 O, .beta.-Ca.sub.3 (PO.sub.4).sub.2, .beta.-Ca.sub.3 (PO.sub.4).sub.2, and modified Ca.sub.3 (PO.sub.4).sub.2, the paste being capable of hardening.]. .Iadd.which aqueous mixture hardens .Iaddend.into a cement .Iadd.at an ambient temperature.
2. The paste of claim 1 wherein the other calcium phosphate is CaHPO.sub.4.2H.sub.2 O.
3. The paste of claim 1 wherein the other calcium phosphate is CaHPO.sub.4. .[.4. The paste of claim 1 wherein the other calcium phosphate is Ca.sub.8 H.sub.2 (PO.sub.4).sub.6.5H.sub.2 O..]. .[.5. The paste of claim 1 wherein
the other calcium phosphate is .beta.-Ca.sub.3 (PO.sub.4).sub.2..]. 6. The paste of claim 1 wherein both calcium phosphates are in crystalline,
cryptocrystalline, or amorphous form. 7. The paste of claim 1 further .[.comprising.]. .Iadd.including .Iaddend.up to approximately 10% by weight of additional calcium or phosphate containing compounds .Iadd.in an
amount sufficient to alter the pH of the paste.Iaddend.. 8. The paste of claim 7 wherein the additional calcium containing compounds .[.comprise.]. .Iadd.are selected from the group consisting of .Iaddend.CaCl.sub.2
.[.or.]. .Iadd.and .Iaddend.Ca(C.sub.2 H.sub.3 O.sub.2).sub.2. 9. The paste of claim 7 wherein the additional phosphate containing compounds .[.comprise.]. .Iadd.are selected from the group consisting of .Iaddend.NaH.sub.2 PO.sub.4 .[.or.]. .Iadd.and .Iaddend.(NH.sub.4)H.sub.2
PO.sub.4. 10. The paste of claim 1 further .[.comprising.]. .Iadd.including .Iaddend.fluoride containing compounds such that the fluoride content of the paste is up to approximately 3.8% by weight .Iadd.in an amount sufficient to increase the rate of precipitation of
hydroxyapatite from the paste.Iaddend.. 11. The paste of claim 10 wherein the fluoride containing compounds .[.comprise.]. .Iadd.are selected from the group consisting of .Iaddend.CaF.sub.2, SrF.sub.2, NaF, Na.sub.2
SiF.sub.6 .[.or.]. .Iadd.and .Iaddend.NaPO.sub.3 F. 12. A paste .[.comprising.]. .Iadd.consisting essentially of .Iaddend.CaHPO.sub.4 and Ca.sub.4 (PO.sub.4).sub.2 O having a particle size of approximately 1 .mu.m and a 20mM solution of H.sub.3 PO.sub.4 .Iadd., the paste hardening
into a cement at an ambient temperature.Iaddend.. 13. The paste of claim 1 additionally .[.comprising.]. .Iadd.including .Iaddend.a seed crystal compound selected from the group consisting of hydroxyapatite and fluorapatite .Iadd.in an amount sufficient to reduce the setting time of the cement.Iaddend.. .Iadd.14. The paste of claim 13 wherein the seed crystal compound is hydroxyapatite, the hydroxyapatite being present in an amount up to 43% by weight and in an amount sufficient to reduce the setting time of the cement. .Iaddend. .Iadd.15. The paste of claim 1 additionally including up to approximately 5% by weight of a high molecular weight crystal growth inhibitor selected from the group consisting of proteoglycans, glycoproteins, polylysine and protamine in an amount sufficient to inhibit the growth of hydroxyapatite crystals. .Iaddend. .Iadd.16. The paste of claim 1 additionally including .beta.-Ca.sub.3 (PO.sub.4).sub.2 in an amount sufficient to achieve setting expansion of the cement. .Iaddend. .Iadd.17. The paste of claim 1 additionally including up to 1% by weight of a crystal habit modifier selected from the group consisting of Mg.sup.2+, Sr.sup.2+, citrate, phosphonates, carbonate, polyphosphates, sucrose phosphate, and phosphocitrate in an amount sufficient to achieve setting expansion of the
cement. .Iaddend. .Iadd.18. The paste of claim 1 wherein the paste is slightly acidic. .Iaddend. .Iadd.19. The paste of claim 1 where in the
paste is slightly basic. .Iaddend. .Iadd.20. The paste of claim 1 additionally including granular sugar, the sugar being present in an amount up to 20% by weight and in an amount sufficient to form a porous cement upon removal of the sugar by application of hot water to the cement. .Iaddend.