Patent US4794774A successfully refreshed from Google Patents.
US4794774A
Expired / Lapsed
US
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Method of preparing a dental restoration
Assignee: TANAKA DENTAL ENTERPRISES 5135 GOLF ROAD SKOKIE ILLINOIS 60076 A CORP OF
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Filing: 1987-07-29
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Granted: 1989-01-03
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Expires: 2007-07-29
Abstract
Abstract A method is provided for uniformly fitting a foil to a die in the manufacture of a porcelain-metal dental restoration, the method including the application isostatic pressure to a foil covered die. The inventive method is more economical and not as laborious as prior art methods, and provides a superior fit of the foil to the die, resulting in a better quality restoration.
Inventors
- 👤 Danny R. Clark
- 👤 Asami Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:48
CPC Classifications
A; A61; A61C; A61C13/00; A61C13/0003
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
71 words
A method of preparing an improved metal porcelain dental restoration comprising preparing a die of the tooth on which the restoratioin will be fitted, covering the die with a metal foil, subjecting the foil covered die to isostatic pressure to uniformly press the foil onto the die, applying dental porcelain to the pressed foil on the die, and baking the porcelain on the foil to fuse the porcelain onto the foil.
Claim 2
Independent Claim
71 words
A method of preparing an improved metal porcelain dental restoration comprising preparing a die of the tooth on which the restoratioin will be fitted, covering the die with a metal foil, subjecting the foil covered die to isostatic pressure to uniformly press the foil onto the die, applying dental porcelain to the pressed foil on the die, and baking the porcelain on the foil to fuse the porcelain onto the foil.
Claim 3
Dependent Claim
78 words
The method of claim 1 wherein the step of subjecting the foil covered die to hydraulic isostatic pressure includes the steps of placing the foil covered die in a flexible, fluid impermeable sack; placing the sack in an isostatic press which is filled with a fluid; and placing the fluid under isostatic pressure, whereby the pressure is transmitted isostatically from the fluid through the sack to the foil covered die to uniformly press the foil against the die.
Claim 4
Dependent Claim
15 words
The method of claim 2 wherein said pressure is in the range of 1000-2500 psi.
Claim 5
Independent Claim
80 words
A method of fitting a foil against a die for purposes of preparing a dental restoration comprising providing an isostatic press, covering said die with said foil, placing said foil covered die in a flexible fluid impermeable sack, placing said sack in said isostatic press, and applying isostatic pressure on said sack, whereby said isostatic pressure is transmitted through said sack to isostatically press the foil against the die to obtain a superior fit of the foil to the die.
Claim 6
Independent Claim
80 words
A method of fitting a foil against a die for purposes of preparing a dental restoration comprising providing an isostatic press, covering said die with said foil, placing said foil covered die in a flexible fluid impermeable sack, placing said sack in said isostatic press, and applying isostatic pressure on said sack, whereby said isostatic pressure is transmitted through said sack to isostatically press the foil against the die to obtain a superior fit of the foil to the die.
Claim 7
Dependent Claim
15 words
The method of claim 4 wherein said pressure is in the range of 1000-2500 psi.
Claim 8
Independent Claim
85 words
A method of preparing a mold of a die comprising providing an isostatic press having a chamber containing fluid; covering said die with a heat reformable material; placing said covered die in a flexible fluid-impermeable sack; placing said sack in said chamber of said isostatic press; applying pressure to said fluid; and applying heat to said fluid, whereby said heat and pressure are transmitted through said sack to said heat reformable material to isostatically press said material against said die to make a mold thereof.
Claim 9
Independent Claim
85 words
A method of preparing a mold of a die comprising providing an isostatic press having a chamber containing fluid; covering said die with a heat reformable material; placing said covered die in a flexible fluid-impermeable sack; placing said sack in said chamber of said isostatic press; applying pressure to said fluid; and applying heat to said fluid, whereby said heat and pressure are transmitted through said sack to said heat reformable material to isostatically press said material against said die to make a mold thereof.
Claim 10
Dependent Claim
21 words
The method of claim 6 wherein said heat reformable material is wax and said fluid is heated at about 70° C.
Claim 11
Dependent Claim
13 words
The method of claim 7 wherein said applied pressure is about 10-30 psi.
Claim 12
Dependent Claim
24 words
The method of claim 6 wherein said heat reformable material is a low melting plastic and said fluid is heated to about 100° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-01-03 | 1992-07-04 | 1993-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-03 | 1996-07-04 | 1997-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-03 | 2000-07-04 | 2001-01-03 | $7700.00 | Window Closed / Lapsed |