Hydraulic cements with optimized grain size distribution, methods, articles and kits
Inventors
ENGQVIST HAAKAN, null • Engqvist, Håkan • AABERG JONAS, null • Åberg, Jonas
Assignees
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Publication Number
US-8591645-B2
Publication Date
2013-11-26
Expiration Date
Abstract
A non-aqueous hydraulic cement composition comprises a non-aqueous mixture of (a) β-tricalcium phosphate powder, (b) monocalcium phosphate powder, and (c) non-aqueous water-miscible liquid, wherein (i) at least about 90% of the monocalcium phosphate powder has a grain size in a range of about 200-600 μm and the powder (weight) to liquid (volume) ratio is about 2.5-5.5, (ii) at least about 90% of the monocalcium phosphate powder has a grain size in a range of about 1-400 μm and the powder (weight) to liquid (volume) ratio is about 2-5, or (iii) at least about 90% of the monocalcium phosphate powder has a grain size in a range of about 1-600 μm and the powder (weight) to liquid (volume) ratio is about 2.5-5.5. Methods, hardened cements, articles of manufacture and kits employ such compositions.
Core Innovation
The invention provides a non-aqueous hydraulic cement composition for in vivo bone and tooth repair that includes a non-aqueous mixture of β-tricalcium phosphate powder, monocalcium phosphate powder, and a non-aqueous water-miscible liquid. The composition is characterized by a defined monocalcium phosphate powder grain-size distribution in which at least about 90% of the monocalcium phosphate powder has a grain size in a range of about 1-600 μm, with grain sizes apportioned into multiple ranges.
A central aspect of the invention is the tailoring of injectable and hardened properties through the selected monocalcium phosphate grain-size distribution together with the powder-to-liquid ratio. The described cement setting is linked to contact with a hydrating liquid or vapor, and the composition is configured to provide a pH less than 6.0.
The disclosed compositions are further framed to include optional additives and formulation elements that influence porosity and mechanical strength, including porogens and porous β-TCP granules. The document also describes delivery and packaging concepts for placing the cement, including syringe/spatula concepts and kits with separately contained hydrating liquid.
Claims Coverage
The independent claim coverage centers on quantitative formulation constraints for a non-aqueous hydraulic cement. Two inventive feature groupings across the two independent claims are identified, each defining component identity, grain-size distribution, powder-to-liquid ratio, pH, and setting phase formation.
Nonaqueous hydraulic cement with β-tricalcium phosphate, monocalcium phosphate grain-size distribution, and specified powder-to-liquid ratio
A non-aqueous hydraulic cement composition comprising a non-aqueous mixture of β-tricalcium phosphate powder, monocalcium phosphate powder, and a non-aqueous water-miscible liquid, wherein at least about 90% of the monocalcium phosphate powder has a grain size in a range of about 1-600 μm, wherein the monocalcium phosphate powder has grain sizes in each of the ranges of <100 μm, 100-200 μm, 200-400 μm, and 400-600 μm, and wherein the powder (weight) to liquid (volume) ratio is about 2.5-5.5.
Nonaqueous hydraulic cement with β-tricalcium phosphate mean particle size, monocalcium monohydrate grain-size distribution, Monetite setting, and specified component ratios
A non-aqueous hydraulic cement composition comprising a non-aqueous mixture of β-tricalcium phosphate powder having a mean particle size of about 1-40 μm, monocalcium phosphate monohydrate powder, wherein at least about 90% of the monocalcium phosphate monohydrate powder has a grain size in a range of about 1-600 μm and the monocalcium phosphate monohydrate powder has grain sizes in each of the ranges of <100 μm, 100-200 μm, 200-400 μm, and 400-600 μm, and non-aqueous water-miscible liquid, wherein the weight ratio of (a) β-tricalcium phosphate powder to (b) monocalcium phosphate powder is from about 2:3 to about 3:1, the powder (weight) to liquid (volume) ratio is about 3.5-5, the pH of the cement composition is less than 6.0, and the cement composition forms Monetite upon setting.
Across the independent claims, the inventive coverage focuses on non-aqueous hydraulic cement formulations defined by β-tricalcium phosphate and monocalcium phosphate components, specified monocalcium powder grain-size distributions, specified powder-to-liquid and component weight ratios, together with a pH less than 6.0 and formation of Monetite upon setting in the second independent claim.
Stated Advantages
The composition is described as providing tailored injectable and hardened properties through the selected monocalcium phosphate grain-size distribution together with the powder-to-liquid ratio.
The document provides example results correlating monocalcium particle size and optional porogen content with injectability, compressive strength, and porosity.
Documented Applications
in vivo bone and tooth repair
percutaneous vertebroplasty
endodontic
CMF defects
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