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Patent US4515913A successfully refreshed from Google Patents.
US4515913A
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Dental impression composition
Assignee: Laclede Professional Products Inc
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Filing: 1983-11-14
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Granted: 1985-05-07
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Expires: 2003-11-14
Abstract
Abstract Powdered alginate compositions formulated with a polymer comprising polyacrylamide have enhanced smoothness characteristics upon admixing with water to obtain orally settable, dental impression material.
Inventors
- 👤 Michael A. Pellico
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:48
CPC Classifications
C; C08; C08L; C08L5/00; C08L5/04; A; A61; A61K; A61K6/00; A61K6/90
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
126 words
In a powdered alginate, dental impression composition that is adapted to be mixed with water and is orally settable said powdered alginate composition containing: from about 6 to about 10 wt.% of an alkali metal alginate selected from the group consisting of sodium alginate, potassium alginate and mixtures thereof, from about 6 to about 12 wt.% of a calcium sulfate reactant, from about 0.6 to about 1.2 wt.% of a reaction rate retarder selected from the group consisting of phosphate, pyrophosphate and tripolyphosphate salts of sodium, potassium and mixtures thereof, and a filler, the improvement which comprises polyacrylamide in said powdered alginate composition in an amount from about 0.5 to about 6.0 wt.% to thereby effect a smooth admixture of the powdered alginate composition with water.
Claim 2
Dependent Claim
126 words
In a powdered alginate, dental impression composition that is adapted to be mixed with water and is orally settable said powdered alginate composition containing: from about 6 to about 10 wt.% of an alkali metal alginate selected from the group consisting of sodium alginate, potassium alginate and mixtures thereof, from about 6 to about 12 wt.% of a calcium sulfate reactant, from about 0.6 to about 1.2 wt.% of a reaction rate retarder selected from the group consisting of phosphate, pyrophosphate and tripolyphosphate salts of sodium, potassium and mixtures thereof, and a filler, the improvement which comprises polyacrylamide in said powdered alginate composition in an amount from about 0.5 to about 6.0 wt.% to thereby effect a smooth admixture of the powdered alginate composition with water.
Claim 3
Dependent Claim
22 words
The powdered alginate composition of claim 1 wherein the polyacrylamide is present in an amount from about 1.0 to about 3.0 wt.%.
Claim 4
Dependent Claim
21 words
The powdered alginate composition of claim 1 wherein the molecular weight of the polyacrylamide is from about 200,000 to about 6,000,000.
Claim 5
Dependent Claim
25 words
The powdered alginate composition of claim 1 wherein the polyacrylamide is a homopolymer of acrylamide having a molecular weight from about 5,000,000 to about 6,000,000.
Claim 6
Dependent Claim
17 words
The powdered alginate composition of claim 1 wherein the polyacrylamide has a molecular weight of about 200,000.
Claim 7
Dependent Claim
141 words
In a method for preparing an orally settable, dental impression material which comprises admixing from about 2.0 to about 3.0 parts by weight of water with about 1.0 part by weight of a powdered alginate composition containing: from about 6 to about 10 wt.% of an alkali metal alginate selected from the group consisting of sodium alginate, potassium alginate and mixtures thereof, from about 6 to about 12 wt.% of a calcium sulfate reactant, from about 0.6 to about 1.2 wt.% of a reaction rate retarder selected from the group consisting of phosphate, pyrophosphate and tripolyphosphate salts of sodium, potassium and mixtures thereof, and a filler, the improvement which comprises incorporating polyacrylamide into said powdered alginate composition in an amount from about 0.5 to about 6.0 wt.% to thereby effect a smooth admixture of the powdered alginate composition with said water.
Claim 8
Dependent Claim
141 words
In a method for preparing an orally settable, dental impression material which comprises admixing from about 2.0 to about 3.0 parts by weight of water with about 1.0 part by weight of a powdered alginate composition containing: from about 6 to about 10 wt.% of an alkali metal alginate selected from the group consisting of sodium alginate, potassium alginate and mixtures thereof, from about 6 to about 12 wt.% of a calcium sulfate reactant, from about 0.6 to about 1.2 wt.% of a reaction rate retarder selected from the group consisting of phosphate, pyrophosphate and tripolyphosphate salts of sodium, potassium and mixtures thereof, and a filler, the improvement which comprises incorporating polyacrylamide into said powdered alginate composition in an amount from about 0.5 to about 6.0 wt.% to thereby effect a smooth admixture of the powdered alginate composition with said water.
Claim 9
Dependent Claim
29 words
The method of claim 6 wherein from about 2.2 to about 2.8 parts by weight of water is admixed with about 1.0 part by weight of powdered alginate composition.
Claim 10
Dependent Claim
20 words
The method of claim 6 wherein the powdered alginate composition contains from about 1.0 to about 3.0 wt.% of polyacrylamide.
Claim 11
Dependent Claim
19 words
The method of claim 6 wherein the molecular weight of the polyacrylamide is from about 200,000 to about 6,000,000.
Claim 12
Dependent Claim
23 words
The method of claim 6 wherein the polyacrylamide is a homopolymer of acrylamide having a molecular weight from about 5,000,000 to about 6,000,000.
Claim 13
Dependent Claim
15 words
The method of claim 6 wherein the polyacrylamide has a molecular weight of about 200,000.
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) | 1988-05-06 | 1988-11-05 | 1989-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-06 | 1992-11-05 | 1993-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-06 | 1996-11-05 | 1997-05-07 | $7700.00 | Window Closed / Lapsed |