US4020557A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite for dental restorations
Assignee: American Hospital Supply Corp
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Filing: 1974-09-18
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Granted: 1977-05-03
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Expires: 1994-09-18
Abstract
Abstract An improved composite material for use as a dental restorative in which the major component consists of a finely-divided reinforcing filler having a hardness no greater than about 5.0 on the Moh's scale. Despite the relative softness of such a filler, in contrast to fillers conventionally used in dental composites, the final restoration has superior resistance to abrasion and wear, can be finished more effectively and more aesthetically, and can be handled with metal dental instruments.
Inventors
- 👤 Thomas J. Rockett
- 👤 John S. Tiffany
- 👤 John J. O'Connell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:22
CPC Classifications
A; A61; A61K; A61K6/00; A61K6/80; A61K6/884; A61K6/887
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
117 words
A method for preparing a dental restoration, comprising the steps of mixing and chemically coupling (a) a non-toxic and substantially water-insoluble inorganic compound having a hardness within the range of 3.0 to about 4.5 Mohs and in the form of a powder having finely-divided particles of an average size less than 15 microns with (b) minor proportion of a methacrylate polymeric resin binder having a refractive index within the range of 1.53 to 1.56 and having a hardness when cured within the range of 2.0 to 4.0 Mohs, said inorganic compound being selected from a group consisting of silicates and phosphates of crystalline and amorphous form, and thereafter applying the mixture to a site requiring dental restoration.
Claim 2
Independent Claim
117 words
A method for preparing a dental restoration, comprising the steps of mixing and chemically coupling (a) a non-toxic and substantially water-insoluble inorganic compound having a hardness within the range of 3.0 to about 4.5 Mohs and in the form of a powder having finely-divided particles of an average size less than 15 microns with (b) minor proportion of a methacrylate polymeric resin binder having a refractive index within the range of 1.53 to 1.56 and having a hardness when cured within the range of 2.0 to 4.0 Mohs, said inorganic compound being selected from a group consisting of silicates and phosphates of crystalline and amorphous form, and thereafter applying the mixture to a site requiring dental restoration.
Claim 3
Dependent Claim
12 words
The method of claim 1 in which said inorganic compound is wollastonite.
Claim 4
Dependent Claim
12 words
The method of claim 1 in which said inorganic compound is whitlockite.
Claim 5
Dependent Claim
12 words
The method of claim 1 in which said inorganic compound is hemimorphite.
Claim 6
Dependent Claim
12 words
The method of claim 1 in which said inorganic compound is clinoenstatite.
Claim 7
Dependent Claim
12 words
The method of claim 1 in which said inorganic compound is fluoroapatite.
Claim 8
Dependent Claim
12 words
The method of claim 1 in which said inorganic compound is apophylite.
Claim 9
Dependent Claim
48 words
The method of claim 1 in which said inorganic compound is pseudowollastonite in crystalline form prepared by first heating precipitated calcium silicate to a temperature in excess of 1150 degrees C. to form pseudowollastonite having non-fibrous crystals and then quenching and grinding said pseudowollastonite to a finely-divided powder.
Claim 10
Independent Claim
75 words
A method for preparing an improved composite material for use as a dental restorative, comprising the steps of heating precipitated calcium silicate to a temperature in excess of 1150° C. to form pseudowollastonite having non-fibrous crystals, then quenching and grinding said pseudowollastonite to a finely-divided powder, and thereafter mixing and coupling said finely-divided powder with a minor proportion of a methacrylate polymeric resin binder having a refractive index within the range of 1.53 to 1.56.
Claim 11
Independent Claim
75 words
A method for preparing an improved composite material for use as a dental restorative, comprising the steps of heating precipitated calcium silicate to a temperature in excess of 1150° C. to form pseudowollastonite having non-fibrous crystals, then quenching and grinding said pseudowollastonite to a finely-divided powder, and thereafter mixing and coupling said finely-divided powder with a minor proportion of a methacrylate polymeric resin binder having a refractive index within the range of 1.53 to 1.56.
References Cited (Backward Citations)
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Cited
US3452437A
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US3442851A
Cited
US3520949A
Cited
US3597389A
Cited
US3625916A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-02 | 1980-11-01 | 1981-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-02 | 1984-11-01 | 1985-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-02 | 1988-11-01 | 1989-05-03 | $7700.00 | Window Closed / Lapsed |