| 摘要 |
A two-phase porcelain composition comprises a leucite crystallite phase dispersed in a feldspathic glass matrix, a maturing temperature of 750-1050 deg C and a coefficient of thermal expansion of 12 x 10-6 - 17.5 x 10-6 / deg C ( room temperature to 450 deg C). The composition comprises ( wt%):SiO2 ( 57-66), Al2O3 (7-15), K2O (7-15), Na2O (7-12), Li2O (0.5-3), CaO (0-3), MgO (0-7), F (0-4) and CeO2 (0-1). The leucite crystallite possesses diameters not exceeding 10 microns and represent 5-65 wt% of the composition. Also claimed are: (1) a dental restoration comprising a high expansion metal alloy or ceramic framework and coating(s) of the porcelain composition; (2) a porcelain-fused-to-metal dental restoration comprising a metallic framework, coating(s) of high expansion ceramic fused to it, and a glaze comprising the porcelain composition at least partially covering the ceramic, fused to it below about 900 deg C; (3) an inlay, onlay or veneer comprising the porcelain composition; (4) a two phase porcelain composition comprising a leucite crystallite phase dispersed in a feldspathic glass matrix, a maturing temperature of 800-1000 deg C and a coefficient of thermal expansion of 12 x 10-6 - 17.5 x 10-6 / deg C ( room temperature to 450 deg C). The composition comprises ( wt%): SiO2 ( 58-65), Al2O3 (8-14), K2O (11-15), Na2O (7.5-11), Li2O (0.7-1.5), CaO (0-1.5), MgO (0-5), F (0-3) and CeO2 (0-0.5). The leucite crystallite possesses diameters not exceeding 10~m and represent 5-50 wt% of the composition; (5) a dental restoration comprising a high expansion metal alloy or ceramic framework and coating(s) of the porcelain composition of (4); (6) a porcelain-fused-to-metal dental restoration comprising a metallic framework, coating(s) of high expansion ceramic fused to it, and a glaze comprising the porcelain composition of (4) at least partially covering the ceramic, fused to it below about 900 deg C;and (7) an inlay, onlay or veneer comprising the porcelain composition of (4). Use - The composition is useful in the preparation and repair of dental restorations such as porcelain-fused-to-metal restorations, all-ceramic restorations, inlays, onlays and veneers. Advantage - The composition can be fused to high expansion alloys and ceramics to provide extremely smooth surfaces upon them. |
