Coating for gold or gold alloy castings for dental bridges and crowns
Abstract
Abstract A powder-liquid system for preparing dispersions useful for coating gold and gold alloy castings for dental bridges and crowns which comprises (1) a gold powder and (2) a liquid vehicle suitable for dispersing said gold powder which comprises a solution of a borate salt and a tin salt in an organic solvent. The gold powder preferably has an average particle size of from between 5 to 16 um, the tin salt is preferably stannous chloride, the borate salt is preferably dilithium tetraborate and the organic solvent is a glycol such as propylene glycol. The gold powder is dispersed in said liquid vehicle at a volume/volume ratio of from 0.5/ 1 to 1.5/ 1 prior to use. The instant invention also relates to a method for treating the surface of a gold or gold alloy casting for a dental bridge or crown to facilitate the bonding thereto of porcelain and to control the shade of such porcelain which comprises coating the surface with the above dispersion, drying to remove the organic solvent, fusing the gold powder to said surface and oxidizing said fused surface to form an oxide layer with a specific morphology thereon.
Inventors
- 👤 John C. Subelka
Bibliographic Details
Claims Analysis
Total Claims: 12References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-07-23 | 1983-01-22 | 1983-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-23 | 1987-01-22 | 1987-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-23 | 1991-01-22 | 1991-07-24 | $7700.00 | Window Closed / Lapsed |