US4783429A
Expired / Lapsed
US
⏱️ 0.0 years remaining
No alkali containing biocompatible glass ceramic with apatite, wollastonite and diopside crystals mixed
Assignee: Nippon Electric Glass Co Ltd
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Filing: 1987-04-02
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Granted: 1988-11-08
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Expires: 2007-04-02
Abstract
Abstract A biocompatible glass ceramic comprises, by weight, 7-16% MgO, 20-45% CaO, 41-50% SiO 2 , 8-30% P 2 O 5 , 0-5% B 2 O 3 , 0-5% F 2 , and 0-10% Al 2 O 3 , and has a crystal structure where a number of fine crystals of apatite, wollastonite, and diopside are densely dispersed and interlace with one another in a glass phase. The glass ceramic is non-porous and has an increased mechanical strength of 2,000 Kg f/cm 2 without degradation of the chemical bonding with the bone of the living body. The glass ceramic contains no alkali and is chemically stable in the living body. The glass ceramic is useful for replacement materials of tooth roots and crowns as well as bones.
Inventors
- 👤 Takehiro Shibuya
- 👤 Yoshinori Morita
- 👤 Akira Matsui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:26
CPC Classifications
C; C03; C03C; C03C4/00; C03C4/0007; A; A61; A61K; A61K6/00; A61K6/15; A61K6/17; A61K6/50; A61K6/58; A61K6/70; A61K6/71; A61K6/74; A61K6/75; A61K6/80; A61K6/802; A61K6/807; A61K6/831; A61K6/833; A61L; A61L27/00; A61L27/02; A61L27/12; C03C10/00; C03C10/0009; C03C10/0036; C03C10/0045; C03C10/16; C03C3/00; C03C3/04; C03C3/076; C03C3/097; C03C3/11; C03C3/112; A61F; A61F2310/00; A61F2310/00005; A61F2310/00179; A61F2310/00293
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
119 words
A high-strength biocompatible glass ceramic substantially free of alkali having a composition consisting essentially, by weight, of 7.2-16% MgO, 20-45% CaO, 41.5-50% SiO 2 , 8-30% P 2 O 5 , 0-5% B 2 O 3 , 0-5% F 2 , and 0-10% Al 2 O 3 , a total content of MgO, CaO, SiO 2 , and P 2 O 5 being 90% or more, said glass ceramic being substantially non-porous and having a mechanical strength of 2,000 Kg·f/cm 2 or more and a crystal structure where a number of fine crystals are densely dispersed in a glass phase, said fine crystals comprising apatite, wollastonite, and diopside crystals extending to interlace with one another in a complicated form.
Claim 2
Dependent Claim
119 words
A high-strength biocompatible glass ceramic substantially free of alkali having a composition consisting essentially, by weight, of 7.2-16% MgO, 20-45% CaO, 41.5-50% SiO 2 , 8-30% P 2 O 5 , 0-5% B 2 O 3 , 0-5% F 2 , and 0-10% Al 2 O 3 , a total content of MgO, CaO, SiO 2 , and P 2 O 5 being 90% or more, said glass ceramic being substantially non-porous and having a mechanical strength of 2,000 Kg·f/cm 2 or more and a crystal structure where a number of fine crystals are densely dispersed in a glass phase, said fine crystals comprising apatite, wollastonite, and diopside crystals extending to interlace with one another in a complicated form.
Claim 3
Dependent Claim
49 words
A biocompatible glass ceramic as claimed in claim 1, having a composition which consists essentially, by weight, of 7.2-14% MgO, 25-38% CaO, 41.5-50% SiO 2 , 8.2-25% P 2 O 5 , 0-4% B 2 O 3 , 0-3% F 2 , and 0-6% Al 2 O 3 .
Claim 4
Dependent Claim
23 words
A biocompatible glass ceramic as claimed in claim 1, wherein a total content of B 2 O 3 and F 2 is 0.05-5%.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-08 | 1992-05-09 | 1992-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-08 | 1996-05-09 | 1996-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-08 | 2000-05-09 | 2000-11-08 | $7700.00 | Window Closed / Lapsed |