Pressable lithium disilicate glass ceramics
US6455451B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1999 |
| Grant date | Sep 24, 2002 |
| Priority date | — |
| Expiry date | Dec 10, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C10/0027
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
This invention is directed to lithium disilicate (Li2Si2O5) based glass-ceramics comprising silica, lithium oxide, alumina, potassium oxide and phosphorus pentoxide. The glass-ceramics are useful in the fabrication of single and multi-unit dental restorations (e.g. anterior bridges) made by heat pressing into refractory investment molds produced using lost wax techniques. The glass-ceramics have good pressability, i.e., the ability to be formed into dental articles by heat-pressing using commercially available equipment. In accordance with one embodiment directed to the process of making the glass-ceramics, the compositions herein are melted at about 1200° to about 1600° C., thereafter quenched (e.g., water quenched or roller quenched) or cast into steel molds, or alternately, cooled to the crystallization temperature. The resulting glass is heat-treated to form a glass-ceramic via a one or two step heat-treatment cycle preferably in the temperature range of about 400° to about 1100° C. The resulting glass ceramics are then pulverized into powder and used to form pressable pellets and/or blanks of desired shapes, sizes and structures which are later pressed into den…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.