Combinations of sparingly soluble calcium phosphates in slurries and pastes as mineralizers and cements
AssigneeAmerican Dental Association Health Foundation
InventorsWalter E. Brown, Laurence C. Chow
Life of this patent
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Abstract
Dental restorative compositions containing a mixture of Ca.sub.4 (PO.sub.4).sub.2 O and at least one different calcium phosphate.
Claims34
A [dental restorative] slurry [comprising] consisting essentially of an aqueous mixture of Ca.sub.4 (PO.sub.4).sub.2 O and at least one other calcium phosphate selected from the group consisting of CaHPO.sub.4.2H.sub.2 O[,] and CaHPO.sub.4, [Ca.sub.8 H.sub.2 (PO.sub.4).sub.6.5H.sub.2 O, .alpha.--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,] both calcium phosphates being present in the slurry in excess such that hydroxyapatite is substantially continuously precipitated from the slurry at an ambient temperature .
[4. The slurry 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 slurry of claim 1 wherein the other calcium phosphate is .beta.--Ca.sub.3
- (PO.sub.4).sub.2.] 6. The slurry of claim 1 wherein at least one of the calcium phosphates is in crystalline, cryptocrystalline or amorphous form.
- . The slurry of claim 1 further [comprising] including up to approximately 10% by weight of additional calcium or phosphate containing compounds in an amount sufficient to alter the
- pH of the slurry . 8. The slurry of claim 7 wherein the additional calcium containing compounds [comprise] are selected from the group consisting of CaCl.sub.2 [or] and Ca(C.sub.2 H.sub.3 O.sub.2).sub.2. 9. The slurry of claim 7 wherein the additional phosphate containing compounds [comprise] are selected from the group consisting of NaH.sub.2
- PO.sub.4 [or] and (NH.sub.4)H.sub.2 PO.sub.4. 10. The slurry of claim 1 further [comprising] including fluoride containing compounds such that the fluoride content of the slurry is up to approximately 3.8% by weight in an amount sufficient to increase the rate of precipitation of hydroxyapatite from
- the slurry . 11. The slurry of claim 10 wherein the fluoride containing compounds [comprise] are selected from the group consisting of CaF.sub.2, SnF.sub.2, NaF, Na.sub.2 SiF.sub.6
- [or] and NaPO.sub.3 F. 12. The slurry of claim 1 further [comprising] including a gelling agent in
- an amount sufficient to form an aqueous gel . 13. A [dental restorative] paste [comprising] consisting essentially of a nonaqueous mixture of a nontoxic organic solvent, Ca.sub.4 (PO.sub.4).sub.2 O and at least one other calcium phosphate selected from the group consisting of CaHPO.sub.4.2H.sub.2 O[,] and CaHPO.sub.4, [Ca.sub.8 H.sub.2 (PO.sub.4).sub.6.5H.sub.2 O, .alpha.--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] which nonaqueous mixture hardens into a cement upon contact with an aqueous medium at an ambient
- temperature . 14. The paste of claim 13 wherein the other calcium
- phosphate is CaHPO.sub.4.2H.sub.2 O. 15. The paste of claim 13 wherein the other calcium phosphate is CaHPO.sub.4.
[16. The paste of claim 13 wherein the other calcium phosphate is Ca.sub.8 H.sub.2 (PO.sub.4).sub.6.5H.sub.2 O.]
[17. The paste of claim 13 wherein the
- other calcium phosphate is .beta.--Ca.sub.3 (PO.sub.4).sub.2.] 18. The paste of claim 13 wherein at least one of the calcium phosphates is in
- crystalline, cryptocrystalline or amorphous form. 19. The paste of claim 13 further [comprising] including up to approximately 10% by weight of additional calcium or phosphate containing compounds in an amount sufficient to alter the pH of the paste . 20. The paste of claim 19 wherein the additional calcium containing compounds [comprise] are selected from the group consisting of CaCl.sub.2 [or] and Ca(C.sub.2 H.sub.3
- O.sub.2).sub.2. 21. The paste of claim 19 wherein the additional phosphate containing compounds [comprise] are selected from the group consisting of NaH.sub.2 PO.sub.4 [or] and (NH.sub.4)H.sub.2 PO.sub.4. 22. The paste of claim 13 further [comprising] including fluoride containing compounds such that the fluoride content of the [slurry] paste is up to approximately 3.8% by weight in an amount sufficient to increase the rate of precipitation of hydroxyapatite from the
- paste . 23. The paste of claim 22 wherein the fluoride containing compounds [comprise] are selected from the group consisting of CaF.sub.2, SnF.sub.2, NaF, Na.sub.2 SiF.sub.6 [or] and NaPO.sub.3 F. 24. The paste of claim 13 further [comprising] including a seed crystal compound selected from the group consisting of hydroxyapatite and fluorapatite in an amount
- sufficient to reduce the setting time of the cement . 25. The paste of claim 13 wherein the aqueous medium is humid air or a dilute
- aqueous solvent. 26. A [dental restorative] powder [comprising] consisting essentially of a mixture of Ca.sub.4 (PO.sub.4).sub.2 O and at least one other calcium phosphate selected from the group consisting of CaHPO.sub.4.2H.sub.2 O[,] and CaHPO.sub.4, [Ca.sub.8 H.sub.2 (PO.sub.4).sub.6.5H.sub.2 O, .alpha.--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 powder [being capable of] forming [a] slurry of claim 1 upon contact with an appropriate aqueous solvent[, the slurry being capable of substantially continuously precipitating hydroxyapatite] at an ambient
- temperature . 27. The powder of claim 26 wherein the solvent is
- water or saliva. 28. A [dental restorative] powder [comprising] consisting essentially of a mixture of Ca.sub.4 (PO.sub.4).sub.2 O and at least one other calcium phosphate selected from the group consisting of CaHPO.sub.4.2H.sub.2 O[,] and CaHPO.sub.4, [Ca.sub.8 H.sub.2 (PO.sub.4).sub.6.5H.sub.2 O, .alpha.--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 powder [being capable of forming a hardenable] hardening into a cement upon contact with an appropriate aqueous solvent at an ambient
- temperature . 29. The powder of claim 28 wherein the solvent is
- water or saliva.
The paste of claim 24 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.
The paste of claim 13 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.
The paste of claim 13 additionally including .beta.--Ca.sub.3 (PO.sub.4).sub.2 in an amount sufficient to achieve setting expansion of the cement.
The paste of claim 13 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.
The paste of claim 13 additionally including Ca.sub.5 (PO.sub.4).sub.2 SiO.sub.4 or silicocarnotite in an amount sufficient to improve the setting properties of the cement.
The paste of claim 13 wherein the nontoxic organic solvent is selected from the group consisting of glycerin, ethanol and glycol.
The paste of claim 13 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.
The powder of claim 28 wherein the other calcium phosphate is CaHPO.sub.4.2H.sub.2 O.
The powder of claim 28 wherein the other calcium phosphate is CaHPO.sub.4.
The powder of claim 28 wherein at least one of the calcium phosphates is in crystalline, cryptocrystalline or amorphous form.
The powder of claim 28 further including up to approximately 10% by weight of additional calcium or phosphate containing compounds in an amount sufficient to alter the pH of the accent.
The powder of claim 28 further including fluoride containing compounds such that the fluoride content is up to approximately 3.8% by weight in an amount sufficient to increase the rate of precipitation of hydroxyapatite from the cement.
The powder of claim 28 further including a seed crystal compound selected from the group consisting of hydroxyapatite and fluorapatite in an amount sufficient to reduce the setting time of the cement.
The powder of claim 28 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.
The powder of claim 28 additionally including .beta.-Ca.sub.3 (PO.sub.4).sub.2 in an amount sufficient to achieve setting expansion of the cement.
The powder of claim 13 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.
The powder of claim 28 additionally including Ca.sub.5 (PO.sub.4).sub.2 SiO.sub.4 or silicocarnotite in an amount sufficient to improve the setting properties of the cement.
The powder of claim 28 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.
Dependencies are inferred from the claim text.