US4828117A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porcelain dental restoration having a plurality of uniform, color-matched layers
Assignee: Dentsply Sirona Inc
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Filing: 1984-07-18
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Granted: 1989-05-09
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Expires: 2004-07-18
Abstract
Abstract A porcelain dental restoration having a plurality of layers including a translucent porcelain layer overlying a more opaque ceramic layer, wherein the color of each of the said two layers is uniform and wherein the colors of the said two layers match.
Inventors
- 👤 Carlino Panzera
- 👤 Robert De Luca
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:35
CPC Classifications
A; A61; A61C; A61C19/00; A61C19/10; A61C5/00; A61C5/70; A61C5/73; A61C5/77; A61K; A61K6/00; A61K6/80; A61K6/802
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
129 words
A kit for the preparation of porcelain dental restorations having a layer of translucent porcelain overlying a more opaque ceramic layer, said kit comprising at least one labeled container of colored translucent porcelain powder and at least one labeled container of ceramic material for said more opaque layer, wherein when the correspondingly labeled translucent porcelain powder and ceramic material for said more opaque layer are fired, the colors of said translucent porcelain and said more opaque ceramic layer match spectrophotometrically such that the chromaticity difference between the two colors is not greater than 1.5, and the color value difference between the two colors is not greater than 1, calculated by the FMC-2 equations from the CIE tristimulus values of the two colors for standard daylight, incandescent, and fluorescent illumination.
Claim 2
Dependent Claim
129 words
A kit for the preparation of porcelain dental restorations having a layer of translucent porcelain overlying a more opaque ceramic layer, said kit comprising at least one labeled container of colored translucent porcelain powder and at least one labeled container of ceramic material for said more opaque layer, wherein when the correspondingly labeled translucent porcelain powder and ceramic material for said more opaque layer are fired, the colors of said translucent porcelain and said more opaque ceramic layer match spectrophotometrically such that the chromaticity difference between the two colors is not greater than 1.5, and the color value difference between the two colors is not greater than 1, calculated by the FMC-2 equations from the CIE tristimulus values of the two colors for standard daylight, incandescent, and fluorescent illumination.
Claim 3
Dependent Claim
29 words
The kit of claim 1 including a plurality of pairs of containers of labeled translucent porcelain powder and correspondingly labeled containers of ceramic material for said more opaque layer.
Claim 4
Dependent Claim
48 words
The kit of claim 1 wherein the said colored translucent porcelain powder is a body porcelain powder that, when fired, has a reflectance of about 35 to 45 per cent, measured by a densitometer using a sample about three and one-half millimeters thick backed by a black material.
Claim 5
Dependent Claim
23 words
The kit of claim 3 wherein said ceramic material for said more opaque layer is a ceramic powder that, when fired, is opaque.
Claim 6
Dependent Claim
50 words
The kit of claim 3 wherein said ceramic material for said more opaque layer is a dentino porcelain powder that, when fired, has a reflectance of about 70 to 80 per cent, measured by a densitometer using a sample about three and one-half millimeters thick backed by a black material.
Claim 7
Dependent Claim
27 words
The kit of claim 3 wherein said ceramic material for said more opaque layer comprises powder from which to make a ceramic core for a dental restoration.
Claim 8
Dependent Claim
19 words
The kit of claim 6 wherein said ceramic material for said more opaque layer additionally includes a porcelain stain.
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) | 1992-05-08 | 1992-11-07 | 1993-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-08 | 1996-11-07 | 1997-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-08 | 2000-11-07 | 2001-05-09 | $7700.00 | Window Closed / Lapsed |