US4358549A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dental filling composition utilizing zinc-containing inorganic filler
Assignee: 3M Co
•
Filing: 1981-07-30
•
Granted: 1982-11-09
•
Expires: 2001-07-30
Abstract
Abstract This invention is a dental filling composition for making dental restorations. More particularly, the invention provides a radiopaque dental filling material. Specifically, the dental filling material contains a zinc-containing glass as the component imparting opacity to X-rays.
Inventors
- 👤 Ronald M. Randklev
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:30
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/11; C03C3/112; C03C3/115; C03C3/118; A; A61; A61K; A61K6/00; A61K6/80; A61K6/884; A61K6/887; C03C12/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
103 words
A dental filling composition comprising a polymerizable resin binder and a finely divided inorganic glass filler which is X-ray opaque and single phase, wherein said X-ray opaque inorganic glass filler consists essentially of, in percent by weight: ______________________________________
Zinc oxide 20 to 35%
Silica 45 to 65%
Boric oxide 3 to 15%
Aluminum oxide 0 to 10%
Aluminum fluoride At least 2%
Alkali metal oxide or 0 to 3%
alkaline earth metal
oxide
______________________________________ wherein the combined weight of aluminum oxide and aluminum fluoride is at least about 10%, and wherein said glass exhibits an X-ray absorption characteristic of at least 1/16 inch.
Claim 2
Dependent Claim
103 words
A dental filling composition comprising a polymerizable resin binder and a finely divided inorganic glass filler which is X-ray opaque and single phase, wherein said X-ray opaque inorganic glass filler consists essentially of, in percent by weight: ______________________________________
Zinc oxide 20 to 35%
Silica 45 to 65%
Boric oxide 3 to 15%
Aluminum oxide 0 to 10%
Aluminum fluoride At least 2%
Alkali metal oxide or 0 to 3%
alkaline earth metal
oxide
______________________________________ wherein the combined weight of aluminum oxide and aluminum fluoride is at least about 10%, and wherein said glass exhibits an X-ray absorption characteristic of at least 1/16 inch.
Claim 3
Dependent Claim
15 words
A composition in accordance with claim 1, wherein said binder comprises a free-radically polymerizable resin.
Claim 4
Dependent Claim
14 words
A composition in accordance with claim 2, wherein said polymerizable resin binder comprises BIS-GMA.
Claim 5
Dependent Claim
23 words
A composition in accordance with claim 1, wherein the index of refraction of said glass filler and said resin are substantially the same.
Claim 6
Dependent Claim
46 words
A composition in accordance with claim 1, wherein said composition is in the form of two pastes, the first said paste comprising polymerizable resin binder, inorganic glass filler, and a catalyst, and the second said paste comprising polymerizable resin binder, inorganic glass filler, and an accelerator.
Claim 7
Dependent Claim
21 words
A composition in accordance with claim 5, wherein said filler represents at least about 70% by weight of each said paste.
Claim 8
Dependent Claim
16 words
A composition in accordance with claim 5, wherein said binder in each said paste comprises BIS-GMA.
Claim 9
Dependent Claim
60 words
A composition in accordance with claim 3, wherein said glass filler consists essentially of, in percent by weight: ______________________________________
Zinc oxide 25 to 28%
Silica 46 to 48%
Boric oxide 6 to 9%
Aluminum oxide 1 to 3%
Aluminum fluoride
17 to 19%
______________________________________ wherein the combined weight of aluminum oxide and aluminum fluoride is not greater than about 20%.
References Cited (Backward Citations)
US2523266A
Cited
US3413133A
Cited
US3661601A
Cited
US3911581A
Cited
US3826778A
Cited
US3715331A
Cited
US3728139A
Cited
US3814717A
Cited
US3882080A
Cited
US3801344A
Cited
US3975203A
Cited
US3808170A
Cited
US4028325A
Cited
US3873327A
Cited
US3973972A
Cited
US4017454A
Cited
US4032504A
Cited
US3971754A
Cited
US3959212A
Cited
US4050947A
Cited
US4217264A
Cited
US4215033A
Cited
US4250277A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-08 | 1986-05-10 | 1986-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-08 | 1990-05-10 | 1990-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-08 | 1994-05-10 | 1994-11-09 | $7700.00 | Window Closed / Lapsed |