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US6312472B1
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Biocompatible medical implant element
Assignee: Nobel Biocare Services AG
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Filing: 1998-10-28
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Granted: 2001-11-06
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Expires: 2018-10-28
Abstract
Abstract The object of the invention is to make available implant elements or other medical products made of biological material with optimum mechanical and biological properties for a wide group of materials by introduction of a specially designed surface layer onto a strong core, where the surface layer is densified by means of hot isostatic pressing and dimensioned according to the basic fracture mechanics equation so that the thickness of the surface layer is less than c in the equation K IC =Yσ c ½ , where K lc is the fracture toughness, Y a position and shape factor, c the critical defect size, and σ the permitted stress for the actual material and the chosen design stress.
Inventors
- 👤 Jan Hall
- 👤 Leif Hermansson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:33
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/40; A61L27/02; A61L27/04; A61L27/10; A61L27/28; A61L27/30; A61L27/306; A61L27/32
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
65 words
A biocompatible implant comprising: a core; and at least one surface layer, said surface layer having a thickness less than c, wherein c is defined by the equation K IC =Yσc ½ , wherein K IC is the fracture toughness, Y is a constant related to position and shape factor, σ is the allowed stress for the material, and c is the critical defect size.
Claim 2
Dependent Claim
65 words
A biocompatible implant comprising: a core; and at least one surface layer, said surface layer having a thickness less than c, wherein c is defined by the equation K IC =Yσc ½ , wherein K IC is the fracture toughness, Y is a constant related to position and shape factor, σ is the allowed stress for the material, and c is the critical defect size.
Claim 3
Dependent Claim
19 words
A biocompatible implant, according to claim 1 , wherein said surface layer has a thickness at least 0.005 micrometers.
Claim 4
Dependent Claim
19 words
A biocompatible implant, according to claim 1 , wherein said surface layer has a thickness at least 0.03 micrometers.
Claim 5
Dependent Claim
20 words
A biocompatible implant, according to claim 1 , wherein said surface layer has an average thickness less than 30 micrometers.
Claim 6
Dependent Claim
20 words
A biocompatible implant, according to claim 1 , wherein said surface layer has an average thickness less than 5 micrometers.
Claim 7
Dependent Claim
20 words
A biocompatible implant, according to claim 1 , wherein said surface layer has an average thickness less than 10 micrometers.
Claim 8
Dependent Claim
55 words
A biocompatible implant, according to claim 1 , wherein said surface layer comprises: a metal-ceramic matrix, wherein said ceramic is preferably in the range 30-50% by volume and wherein said ceramic includes apatitic or active glass CaPO; and said metal being selected from the group consisting of Ti, TiO 2 , and other Ti compound.
Claim 9
Dependent Claim
20 words
A biocompatible implant, according to claim 7 , wherein said surface layer has an average thickness less than 10 micrometers.
Claim 10
Dependent Claim
20 words
A biocompatible implant, according to claim 7 , wherein said surface layer has an average thickness less than 2 micrometers.
Claim 11
Dependent Claim
36 words
A biocompatible implant, according to claim 1 , wherein said surface layer comprises: 50-100% of a biocompatible phase comprising calcium phosphate containing material, wherein the thickness of said surface layer is less than about 5 micrometers.
Claim 12
Dependent Claim
21 words
A biocompatible implant, according to claim 1 , wherein the thickness of said surface layer is less than about 1 micrometer.
Claim 13
Dependent Claim
66 words
A biocompatible implant, according to claim 1 , wherein said surface layer comprises: a corrosion-resistant matrix phase, wherein said matrix comprises a metal selected from the group consisting of Ti, TiO 2 , and other Ti compound; and 30-50% of a biocompatible phase wherein said biocompatible phase comprises a calcium phosphate compound selected from the group consisting of apatite, CaP biologically-active glass, and other CaP compound.
Claim 14
Dependent Claim
15 words
A biocompatible implant, according to claim 1 , wherein said surface layer comprises an oxide.
Claim 15
Dependent Claim
25 words
A biocompatible implant, according to claim 13 , wherein said oxide is selected from the group consisting of titanium dioxide, zirconium oxide, and tantalum oxide.
Claim 16
Dependent Claim
15 words
A biocompatible implant, according to claim 1 , wherein said core comprises metal or ceramic.
Claim 17
Dependent Claim
17 words
A biocompatible implant, according to claim 1 , wherein said core comprises titanium, zirconium, or alloys thereof.
Claim 18
Dependent Claim
15 words
A biocompatible implant, according to claim 16 , wherein said alloys comprise Fe or Co.
Claim 19
Dependent Claim
16 words
A biocompatible implant, according to claim 1 , wherein said surface layer is treated by densification.
Claim 20
Dependent Claim
17 words
A biocompatible implant, according to claim 18 , wherein said densification comprises temperatures less than 1000° C.
Claim 21
Dependent Claim
17 words
A biocompatible implant, according to claim 18 , wherein said densification comprises temperatures less than 900° C.
Claim 22
Dependent Claim
34 words
A biocompatible implant, according to claim 18 , wherein said surface layer comprises a plurality of layers wherein for any two adjacent layers, the core-most layer comprises a lower concentration of said biocompatible phase.
Claim 23
Dependent Claim
49 words
A biocompatible implant, according to claim 12 , wherein said biocompatible phase comprises: a plurality of particles embedded in said corrosion-resistant matrix phase, wherein each of said particles comprises: an axis, perpendicular to a surface of said core, wherein the length of said axis is less than 1 micrometer.
Claim 24
Dependent Claim
19 words
A biocompatible implant, according to claim 12 , wherein the length of said axis is less than 0.4 micrometer.
References Cited (Backward Citations)
US4497629A
Cited
US4702930A
Cited
US4846837A
Cited
US4965088A
Cited
US5139424A
Cited
US5211833A
Cited
US5609633A
Cited
US5723038A
Cited
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