Included is a step of exposing a glass blank at a temperature lower than the temperature at which crystals of lithium metasilicate are generated, to an atmosphere at a temperature equal to or higher than the temperature at which crystals of lithium disilicate are generated and lower than the melting point of the crystals of lithium disilicate, to heat the glass blank so that the main crystalline phase of the glass blank is of lithium disilicate.

Included is a step of exposing a glass blank at a temperature lower than the temperature at which crystals of lithium metasilicate are generated, to an atmosphere at a temperature equal to or higher than the temperature at which crystals of lithium disilicate are generated and lower than the melting point of the crystals of lithium disilicate, to heat the glass blank so that the main crystalline phase of the glass blank is of lithium disilicate.

A block for dental prostheses is in the form of a column or a board, a main crystalline phase of the block being of lithium disilicate, and when the block is observed in a field of view of a partially enlarged cross section of the block, the proportion of the total area of crystals having a length of at least 0.5 μm, the crystals appearing in the field of view, to an area of the field of view is at most 21%.

Lithium silicate-low quartz glass ceramics are described which are characterized by a combination of very good mechanical and optical properties and can therefore be used in particular as restoration material in dentistry.

Lithium silicate-low quartz glass ceramics are described which are characterized by a combination of very good mechanical and optical properties and can therefore be used in particular as restoration material in dentistry.

An object of the present invention is to provide a dental resin-reinforced glass ionomer cement composition which exhibit high surface curability even under wet conditions, which makes it difficult for the surface to become cloudy even if moisture comes in contact with at the initial stage of curing, exhibits high mechanical properties, low water absorption expansion and excellent coloring resistance in the set product and is also excellent in storage stability. The dental resin-reinforced glass ionomer cement composition consisting of a powder material and a liquid material, wherein the powder material contains (a) acid-reactive glass powder, the liquid material contains (b) water, (c) polymer of acidic group-containing polymerizable monomer, (d) hydroxyl group-containing (meth)acrylate-based polymerizable monomer and (e) tri or more functional (meth)acrylamide-based polymerizable monomer, and at least one of the powder material and the liquid material contains (f) polymerization initiator.

An object of the present invention is to provide a dental resin-reinforced glass ionomer cement composition which exhibit high surface curability even under wet conditions, which makes it difficult for the surface to become cloudy even if moisture comes in contact with at the initial stage of curing, exhibits high mechanical properties, low water absorption expansion and excellent coloring resistance in the set product and is also excellent in storage stability. The dental resin-reinforced glass ionomer cement composition consisting of a powder material and a liquid material, wherein the powder material contains (a) acid-reactive glass powder, the liquid material contains (b) water, (c) polymer of acidic group-containing polymerizable monomer, (d) hydroxyl group-containing (meth)acrylate-based polymerizable monomer and (e) tri or more functional (meth)acrylamide-based polymerizable monomer, and at least one of the powder material and the liquid material contains (f) polymerization initiator.

The invention relates to a process of producing a dental zirconia article, the process comprising the step of sintering a porous dental zirconia article, the sintering comprising a heat-treatment segment A characterized by a heating rate of at least 3 K/sec up to a temperature of at least 1,200° C., the porous dental zirconia article being composed of a zirconia material containing 6.0 to 8.0 wt. % yttria, 0.05 to 0.12 wt. % alumina and comprising a coloring component containing Tb, the porous dental zirconia article being essentially free of Fe components. The invention also relates to a process comprising the additional step of applying a glazing composition to the outer surface of the porous zirconia article before the heat-treatment or sintering is conducted.

The invention relates to a process of producing a dental zirconia article, the process comprising the step of sintering a porous dental zirconia article, the sintering comprising a heat-treatment segment A characterized by a heating rate of at least 3 K/sec up to a temperature of at least 1,200° C., the porous dental zirconia article being composed of a zirconia material containing 6.0 to 8.0 wt. % yttria, 0.05 to 0.12 wt. % alumina and comprising a coloring component containing Tb, the porous dental zirconia article being essentially free of Fe components. The invention also relates to a process comprising the additional step of applying a glazing composition to the outer surface of the porous zirconia article before the heat-treatment or sintering is conducted.

Radically polymerizable dental material which contains at least one compound of Formulae I to III:

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The material preferably additionally contains a radically polymerizable monomer, an initiator for the radical polymerization and filler. It is characterized in particular by a low polymerization contraction stress.