The present invention relates to metal effect pigments with a high covering power and a thin iron oxide coating, for creating a champagne tone.

A glass-ceramic article comprises a petalite crystalline phase and a lithium silicate crystalline phase. The weight percentage of each of the petalite crystalline phase and the lithium silicate crystalline phase in the glass-ceramic article are greater than each of the weight percentages of other crystalline phases present in the glass-ceramic article. The glass-ceramic article has a transmittance color coordinate in the CIELAB color space of: L*=from 20 to 90; a*=from −20 to 40; and b*=from −60 to 60 for a CIE illuminant F02 under SCI UVC conditions. In some embodiments, the colorant is selected from the group consisting of TiO.sub.2, Fe.sub.2O.sub.3, NiO, Co.sub.3O.sub.4, MnO.sub.2, Cr.sub.2O.sub.3, CuO, Au, Ag, and V.sub.2O.sub.5.

A glass-ceramic article comprises a petalite crystalline phase and a lithium silicate crystalline phase. The weight percentage of each of the petalite crystalline phase and the lithium silicate crystalline phase in the glass-ceramic article are greater than each of the weight percentages of other crystalline phases present in the glass-ceramic article. The glass-ceramic article has a transmittance color coordinate in the CIELAB color space of: L*=from 20 to 90; a*=from −20 to 40; and b*=from −60 to 60 for a CIE illuminant F02 under SCI UVC conditions. In some embodiments, the colorant is selected from the group consisting of TiO.sub.2, Fe.sub.2O.sub.3, NiO, Co.sub.3O.sub.4, MnO.sub.2, Cr.sub.2O.sub.3, CuO, Au, Ag, and V.sub.2O.sub.5.

Modified copper chromite spinel pigments exhibit lower coefficients of thermal expansion than unmodified structures. Three methods exist to modify the pigments: (1) the incorporation of secondary modifiers into the pigment core composition, (2) control of the pigment firing profile, including both the temperature and the soak time, and (3) control of the pigment core composition.

Modified copper chromite spinel pigments exhibit lower coefficients of thermal expansion than unmodified structures. Three methods exist to modify the pigments: (1) the incorporation of secondary modifiers into the pigment core composition, (2) control of the pigment firing profile, including both the temperature and the soak time, and (3) control of the pigment core composition.

The invention relates to a glazing composition for a porous dental zirconia article, the glazing composition comprising liquid, glass particles, fluorescing component(s) comprising europium, optionally hydrophilic silica nano-particles, and optionally hydrophobic silica nano-particles, wherein the fluorescing component(s) can be contained in the glass particles or as separate component. The invention also relates to a process for sintering a porous dental zirconia article with a glazing composition on its surface.

The invention relates to a glazing composition for a porous dental zirconia article, the glazing composition comprising liquid, glass particles, fluorescing component(s) comprising europium, optionally hydrophilic silica nano-particles, and optionally hydrophobic silica nano-particles, wherein the fluorescing component(s) can be contained in the glass particles or as separate component. The invention also relates to a process for sintering a porous dental zirconia article with a glazing composition on its surface.

Masking compositions useful for dental restoration, particularly masking compositions used as a coating to mask the unnatural color of milled lithium-silicate glass-ceramic dental restorations in soft states before crystallization cycle, and method of making same. Some embodiments relate to masking compositions comprising at least one glaze powder, at least one opacifier, and at least one colorant. Some embodiments relate to coating, drying, cooling, characterizing, and firing of dental restorations.

In a process for manufacturing glass, a mixture of solid glass-forming materials may be melted by application of heat from one or more submerged combustion burners to produce a volume of unrefined molten glass comprising, by volume, 20% to 40% gas bubbles. A refining agent may be introduced into the unrefined molten glass to promote gas bubble removal from the molten glass. The unrefined molten glass including the refining agent may be heated at a temperature in the range of 1200° C. to 1500° C. to produce a volume of refined molten glass. The refined molten glass may comprise, by volume, fewer gas bubbles than the unrefined molten glass. A colorant material may be introduced into the refined molten glass to produce a volume of molten glass having a final desired color.

In a process for manufacturing glass, a mixture of solid glass-forming materials may be melted by application of heat from one or more submerged combustion burners to produce a volume of unrefined molten glass comprising, by volume, 20% to 40% gas bubbles. A refining agent may be introduced into the unrefined molten glass to promote gas bubble removal from the molten glass. The unrefined molten glass including the refining agent may be heated at a temperature in the range of 1200° C. to 1500° C. to produce a volume of refined molten glass. The refined molten glass may comprise, by volume, fewer gas bubbles than the unrefined molten glass. A colorant material may be introduced into the refined molten glass to produce a volume of molten glass having a final desired color.