Biocompatible ceramic glass
First Claim
1. A biocompatible glass ceramic consisting essentially of a Na2 O, CaO and SiO2 vitreous matrix containing vitreous inclusions in which are dispersed crystals of a compound isomorphous with hydroxyapatite and having the formula Ca.sub.(10-x) Mx Six P.sub.(6-x) O24 F2, where x is 2 to 6 and M is a lanthanide or yttrium, and crystals of Na2 Ca2 Si3 O9 and Ca3 (PO4)2.2Ca2 SiO4 in said matrix, said crystals being present in an effective amount to permit bonding of said glass ceramic to bone, the glass ceramic being prepared from a mixture having the following molar percentage limits:
- SiO2 = 35 to 50Na2 O = 20 to 30CaO = 10 to 30P2 o5 = 2.5 to 10lanthanide or yttrium oxide = 3 to 10alumina = up to 5sodium fluoride = up to 10calcium fluoride = up to 5.
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Abstract
A biocompatible glass ceramic consisting of a vitreous matrix containing vitreous inclusions in which are dispersed crystals of a compound, isomorphous with hydroxyapatite, of at least the following elements: calcium, a lanthanide or yttrium, silicon, phosphorus and oxygen, these inclusions being surrounded by crystals of at least one compound belonging to the group consisting of Na2 Ca2 Si3 O9 and Ca3 (PO4)2.2 Ca2 SiO4, can be used to construct artificial bone segments etc in bone surgery and bonds firmly with the new bone tissue without causing inflammation.
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Citations
5 Claims
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1. A biocompatible glass ceramic consisting essentially of a Na2 O, CaO and SiO2 vitreous matrix containing vitreous inclusions in which are dispersed crystals of a compound isomorphous with hydroxyapatite and having the formula Ca.sub.(10-x) Mx Six P.sub.(6-x) O24 F2, where x is 2 to 6 and M is a lanthanide or yttrium, and crystals of Na2 Ca2 Si3 O9 and Ca3 (PO4)2.2Ca2 SiO4 in said matrix, said crystals being present in an effective amount to permit bonding of said glass ceramic to bone, the glass ceramic being prepared from a mixture having the following molar percentage limits:
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SiO2 = 35 to 50 Na2 O = 20 to 30 CaO = 10 to 30 P2 o5 = 2.5 to 10 lanthanide or yttrium oxide = 3 to 10 alumina = up to 5 sodium fluoride = up to 10 calcium fluoride = up to 5. - View Dependent Claims (2, 3, 4, 5)
- 4. The glass ceramic defined in claim 1 wherein said compound isomorphous with hydroxyapatite is a compound of the formula
- space="preserve" listing-type="equation">Ca.sub.6 La.sub.4 Si.sub.2 P.sub.4 O.sub.24 F.sub.2 .
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5. The glass ceramic defined in claim 1 wherein said crystals isomorphous with hydroxyapatite include said lanthanide or yttrium in a nontoxic quantity but sufficient to permit partial dissolution of the glass ceramic to form holes and allow growth of bone tissue in these holes whereby the lanthanide or yttrium is incorporated in the bone tissue thus grown in the holes whereby epitaxy exists between the hydroxyapatite phase of the bone and crystals of the ceramic glass isomorphous with the hydroxyapatite.
Specification