US3926646A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of dental cements
Assignee: Individual
•
Filing: 1974-04-26
•
Granted: 1975-12-16
•
Expires: 1994-04-26
Abstract
Abstract Dental cement with superior crushing strength is made from (1) one or more of zinc oxide, silicon oxide, and aluminum oxide, containing conventional additives, if desired, (2) 0% to 20% of a fluoride such as calcium or sodium fluoride, (3) phosphoric acid, diluted and containing additives, if desired. To impart the superior crushing strength, these ingredients are spatulated while applying an electric field across the mixture, either direct current alone, or preferably, direct current on which is superimposed a high-frequency alternating current. The resulting cement is much stronger, adheres better to teeth, and reduces the development of bacteria.
Inventors
- 👤 Kiyoshi Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:21
CPC Classifications
A; A61; A61K; A61K6/00; A61K6/70; A61K6/71; A61K6/60; A61K6/69; A61K6/80; A61K6/849; A61K6/853; A61K6/864
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
75 words
IN THE METHOD OF MAKING A SETTABLE DENTAL CEMENT IN PASTE FORM WHEREIN FINELY DIVIDED OXIDE MATERIAL IN MIXED WITH A LIQUID CONTAINING PHOSPHORIC ACID AND WATER TO FORM A DENTAL PASTE ADMIXTURE, THE IMPROVEMENT CONSISTING ESSENTIALLY OF PREPARING SUCH ADMIXTURE, INCORPORATIINNG FROM 0 TO 20% FLUORIDE COMPOUND THEREIN, SPATULATING THE RESULTANT ADMIXTURE FOR FROM 0.5 TO 5 MINUTES TO FORM SAID PASTE, AND APPLYING AN ELECTRIC FIELD BY LOW-POWER ELECTRIC ENERGY ACROSS SAID AD-
Claim 2
Dependent Claim
75 words
IN THE METHOD OF MAKING A SETTABLE DENTAL CEMENT IN PASTE FORM WHEREIN FINELY DIVIDED OXIDE MATERIAL IN MIXED WITH A LIQUID CONTAINING PHOSPHORIC ACID AND WATER TO FORM A DENTAL PASTE ADMIXTURE, THE IMPROVEMENT CONSISTING ESSENTIALLY OF PREPARING SUCH ADMIXTURE, INCORPORATIINNG FROM 0 TO 20% FLUORIDE COMPOUND THEREIN, SPATULATING THE RESULTANT ADMIXTURE FOR FROM 0.5 TO 5 MINUTES TO FORM SAID PASTE, AND APPLYING AN ELECTRIC FIELD BY LOW-POWER ELECTRIC ENERGY ACROSS SAID AD-
Claim 3
Dependent Claim
15 words
A method as in claim 1 wherein said current is from 0.1 to 120 microamperes.
Claim 4
Dependent Claim
20 words
A method as in claim 1 wherein there is applied across said admixture an electrical potential of about 5 volts.
Claim 5
Dependent Claim
17 words
A method as in claim 1 wherein said energy is applied as a train of shaped pulses.
Claim 6
Dependent Claim
14 words
A method defined in claim 1 wherein said electric field is a unidirectional field.
Claim 7
Dependent Claim
25 words
A method as in claim 5 wherein said dental cement paste is zinc phosphate cement paste and said current is from 3 to 15 microamperes.
Claim 8
Dependent Claim
25 words
A method as in claim 5 wherein said dental cement paste is conventional silicate cement paste and said current is from 0.1 to 3 microamperes.
Claim 9
Dependent Claim
9 words
The product resulting from the method of claim 1.
Claim 10
Dependent Claim
12 words
A method defined in claim 1 wherein said fluoride is calcium fluoride.
Claim 11
Dependent Claim
13 words
A method defined in claim 1 wherein said fluoride compound is sodium fluoride.
Claim 12
Dependent Claim
21 words
The method of claim 1 having additives chosen from the group consisting of the oxides of magnesium, bismuth, calcium, and sodium.
Claim 13
Dependent Claim
24 words
A method as in claim 1 wherein said oxide material is selected from the group consisting of zinc oxide, silicon oxide and aluminum oxide.
References Cited (Backward Citations)
US1509161A
Cited
US2665218A
Cited
US2500866A
Cited
US2522298A
Cited
US2841856A
Cited
US3365522A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |