INJECTABLE CEMENT COMPOSITION FOR ORTHOPAEDIC AND DENTAL USE

• US 20100050902A1
• Filed: 11/12/2009
• Published: 03/04/2010
• Est. Priority Date: 03/01/2007
• Status: Abandoned Application

• Current Assignee: Doxa Aktiebolag
• Original Assignee: Doxa Aktiebolag
• Inventors: HERMANSSON, LEIF, Engqvist, Hakan
• Application Number:
  US12/617,100
• Publication Number:
  US 20100050902A1
• Time in Patent Office: Days
• US Class Current: 106/35
• CPC Class Codes: A61K 31/695 Silicon compounds
• CPC Class Codes: C04B 14/043 Alkaline-earth metal silicates, e.g. wollastonite
• CPC Class Codes: C04B 14/062 Microsilica, e.g. colloïdal silica preparing microsilica slurries or suspensions C04B18/148
• CPC Class Codes: C04B 14/306 Zirconium oxide zircon C04B14/046
• CPC Class Codes: C04B 20/008 Micro- or nanosized fillers, e.g. micronised fillers with particle size smaller than that of the hydraulic binder colloidal silica C04B14/062 ; silica fume C04B18/146
• CPC Class Codes: C04B 2103/0008 Li
• CPC Class Codes: C04B 2111/00836 for medical or dental applications
• CPC Class Codes: C04B 22/124 Chlorides of ammonium or of the alkali or alkaline earth metals, e.g. calcium chloride
• CPC Class Codes: C04B 24/2641 Polyacrylates; Polymethacrylates
• CPC Class Codes: C04B 24/383 Cellulose or derivatives thereof
• CPC Class Codes: C04B 28/06 Aluminous cements monolithic refractories or refractory mortars C04B35/66
• CPC Class Codes: C04B 28/18 containing mixtures of the silica-lime type
• CPC Class Codes: C04B 40/065 Two or more component mortars
• CPC Class Codes: C04B 7/32 Aluminous cements

Abstract

The present invention relates to ceramic precursor powder compositions and chemically bonded ceramic (CBC) materials, Ca-aluminate and/or calcium silicate, and a composite biomaterial with prolonged shelf time of the precursor, suitable for orthopaedic applications with improved injectability. The present invention also relates to a method of manufacturing said cured material, bioelements, implants, or drug delivery carrier materials made by said cured material, a kit comprising the ceramic precursor powder and hydration liquid, as well as the use of said ceramic precursor powder and hydration liquid, or said cured material, for orthopaedic and dental applications.

Claims

1. A method of preparing a hydraulic ceramic precursor powder based on calcium aluminate and/or calcium silicate and zirconium and/or an inert filler material for orthopaedic and dental use, which powder comprises:

55-65 wt-% of calcium aluminate;

35-45 wt-% of zirconium oxide and/or an inert filler material, and;

0.5-5 wt-% of micro-silica;

wherein said components are based on the total amount of the precursor powder, calcium aluminate is constituted by more than 70 atomic % of CaOAl₂O₃ and less than 30 atomic % of one or more of the phases (CaO)₁₂(Al₂O₃)₇, (CaO)₃Al₂O₃, CaO(Al₂O₃)₂, CaO(Al₂O₃)₆, and CaO—

Al₂O₃ glass phase, and wherein the precursor powder is kept at a relative humidity of below 60% during manufacturing and packaging thereof.

2. The method claim 1, wherein the powder comprises:

57-63 wt-% of calcium aluminate;

38-42 wt-% of zirconium oxide and/or an inert filler material, and;

0.7-1.3 wt-% of micro-silica.

3. The method of claim 1, wherein the calcium aluminate has a grain size of below 30 μ

m, the zirconium oxide a grain size of below 10 μ

m, and the micro-silica a grain size of below 30 nm.

4. The method of claim 1, wherein the calcium aluminate has a grain size of below 15 μ

m, the zirconium oxide a grain size of below 5 μ

m, and the micro-silica a grain size of below 20 nm.

5. The method of claim 1, wherein the calcium silicate, if present, comprises calcium silicate in the form of C₃S or C₂S, or combinations thereof, in an amount of less than 10 wt-% based on the total amount of the precursor powder.

6. The method of claim 5, wherein the calcium silicate has a grain size of below 20 μ

m.

7. An injectable ceramic paste formed by mixing in a powder-to-liquid ratio of 3.75-5 a hydraulic ceramic precursor powder having a water content below 0.08 weight-% measured as loss on ignition, which powder is obtained by means of the method of claim 1, with a hydration liquid comprising:

90-95 wt-% of water;

3-5 wt-% of a compound based on polycarboxylic acid, and having a molecular weight of 10,000-50,000;

1-5 wt-% of methyl cellulose, and;

less than 0.2 wt-% of LiCl;

wherein said amounts are based on the total weight of the hydration liquid.

8. The ceramic paste of claim 7, wherein the hydration liquid from which the paste is formed comprises:

92-94 wt-% water,

3.7-4.3 wt-% of a compound based on polycarboxylic acid, and having a molecular weight of 10,000-50,000;

2.5-3.5 wt-% of methyl cellulose, and,

0.05-0.2 wt-% of LiCl.

9. The ceramic paste according to claim 7, wherein the powder-to-liquid ratio is 4-4.5.

10. The ceramic paste according to claim 7, wherein the paste is injectable through gauge 13 needles or larger.

11. A method of manufacturing a chemically bonded ceramic material, comprising hardening of the paste of claim 7 by hydration thereof.

13. A method of forming a bone replacement in a patient in the need thereof, comprising injecting into the patient the ceramic paste of claim 7.

14. The method of claim 13, wherein the method is used in vertebroplasty.

15. The method of claim 13, wherein the paste is injected through a gauge 13 needle or larger.

16. A method of dental restoration, comprising administering the paste of claim 7.

19. A method of preparing an injectable ceramic paste comprising:

mixing in a powder-to-liquid ratio of 3.75-5, a hydraulic ceramic precursor powder having a water content below 0.08 weight-% measured as loss on ignition, said powder being obtained by the method of claim 1, with a hydration liquid comprising;

90-95 wt-% of water;

3-5 wt-% of a compound based on polycarboxylic acid, and having a molecular weight of 10,000-50,000;

1-5 wt-% of methyl cellulose, and;

less than 0.2 wt-% of LiCl;

wherein said amounts are based on the total weight of the hydration liquid.

12. A method of establishing the workability of a hydraulic ceramic precursor powder based on calcium aluminate and/or calcium silicate and zirconium and/or an inert filler material for orthopaedic and dental use, wherein the water content of the powder is measured as the loss on ignition, and thereafter, the value obtained is compared to a maximum allowable value of 0.08% of water measured as the loss on ignition.

17. A kit for manufacturing a chemically bonded ceramic material, comprising a container containing:

a hydraulic ceramic precursor powder based on calcium aluminate and/or calcium silicate and zirconium and/or an inert filler material for orthopaedic and dental use, which powder comprises;

55-65 wt-% of calcium aluminate;

35-45 wt-% of zirconium oxide and/or an inert filler material, and;

0.5-5 wt-% of micro-silica;

wherein said components are based on the total amount of the precursor powder, calcium aluminate is constituted by more than 70 atomic % of CaOAl₂O₃ and less than 30 atomic % of one or more of the phases (CaO)₁₂(Al₂O₃)₇, (CaO)₃Al₂O₃, CaO(Al₂O₃)₂, CaO(Al₂O₃)₆, and CaO—

Al₂O₃ glass phase, having a water content below 0.08 weight-% measured as loss on ignition; and

a hydration liquid comprising;

90-95 wt-% of water;

3-5 wt-% of a compound based on polycarboxylic acid, and having a molecular weight of 10,000-50,000;

1-5 wt-% of methyl cellulose, and;

less than 0.2 wt-% of LiCl;

wherein said amounts are based on the total weight of the hydration liquid, wherein the hydration liquid and the powder are stored separately, and the part of the container that holds the precursor powder exhibits a relative humidity (RH) of below 60%.

18. The kit of claim 17, wherein the container that holds the precursor powder comprises vacuum and/or inert gas.