A zirconia sintered body for dental use may not require coloring or firing after shaping, and have aesthetic properties. A preform may include a body and a stem. The body has a Vickers hardness of 4 to 20 HV (GPa), and is machinable. The stem has a width of 4 mm or less at a position where it protrudes from a central portion of the body. At this position, the central portion has a cross-sectional geometric shape with an inscribed circle having a diameter of >12 mm, and a circumscribed circle having a diameter of <20 mm. The body shows a color change from an upper to a lower end portion of the body, and unchanging patterns of increase and decrease of the L*a*b* color system values from the upper to the lower end portion. The preform can be shaped into a dental restoration such as a crown.

A zirconia sintered body for dental use may not require coloring or firing after shaping, and have aesthetic properties. A preform may include a body and a stem. The body has a Vickers hardness of 4 to 20 HV (GPa), and is machinable. The stem has a width of 4 mm or less at a position where it protrudes from a central portion of the body. At this position, the central portion has a cross-sectional geometric shape with an inscribed circle having a diameter of >12 mm, and a circumscribed circle having a diameter of <20 mm. The body shows a color change from an upper to a lower end portion of the body, and unchanging patterns of increase and decrease of the L*a*b* color system values from the upper to the lower end portion. The preform can be shaped into a dental restoration such as a crown.

The present invention relates to a method for manufacturing a prefabricated crown by processing and tabulating the type, size, material and color of prefabricated crowns for sub-gingival and supra-gingival, and actual and try-in crowns by a table system (1), and a prefabricated crown manufactured therefrom, and the method includes a first step (S100) of classifying a plurality of prefabricated crowns by type and size by a first module (5) of the table system (1); a second step (S110) of classifying the plurality of prefabricated crowns by color and material by a second module (7) of the table system (1); a third step (S120) of tabulating the type, size, color and material data of the prefabricated crowns classified in the first and second steps (S100, S110) by a third module (9) of the table system (1), and assigning an identification code to each data; a fourth step (S130) of manufacturing the tabulated plurality of prefabricated crowns; and a fifth step (S140) of inputting the measured type, size, color and material data of patient's tooth into a fourth module (11) of the table system (1) to select a prefabricated crown corresponding thereto.

The present invention provides a method for producing a zirconia particle-containing powder that enables easy production of a zirconia sintered body having both high translucency and high strength. The present invention relates to a method for producing a zirconia particle-containing powder, comprising a drying step of spray drying a slurry containing zirconia particles, wherein the zirconia particles have an average primary particle diameter of 30 nm or less, and the slurry comprises a dispersion medium containing a liquid having a surface tension at 25° C. of 50 mN/m or less. Preferably, the zirconia particles comprise 2.0 to 9.0 mol % yttria. Preferably, wherein the content of the liquid in the dispersion medium is 50 mass % or more.

A zirconia sintered body is provided and includes yttria and zirconia, containing yttria by a content ranging from 4.5 mol % or more to 6.5 mol % or less and zirconia as the remainder, the total light transmittance of a 1-mm thick sample measured in compliance with JIS K 7361-1 being 46.5% or higher, the three-point bending strength being 700 MPa or higher, and a ratio of an integrated value for the total light transmittance to an integrated value for the parallel light transmittance of a 1-mm thick sample measured at the measurement wavelength ranging from 400 to 700 nm being 1.3% or less.

A lithium silicate glass ceramic having lithium metasilicate as main crystal phase and having not more than 30 wt.-% of lithium metasilicate crystals and having the following components in the amounts indicated:

TABLE-US-00001 Component Wt.-% SiO.sub.2 71.0 to 82.0 Li.sub.2O 6.0 to 14.0 Me.sup.I.sub.2O 4.0 to 15.0 Al.sub.2O.sub.3 2.0 to 10.0 P.sub.2O.sub.5 0.5 to 7.0,
wherein Me.sup.I.sub.2O is selected from Na.sub.2O, K.sub.2O, Rb.sub.2O, Cs.sub.2O and mixtures thereof, and
wherein the molar ratio of SiO.sub.2 to Li.sub.2O is in the range of 2.5 to 5.0.

A lithium silicate glass ceramic having lithium metasilicate as main crystal phase and having not more than 30 wt.-% of lithium metasilicate crystals and having the following components in the amounts indicated:

TABLE-US-00001 Component Wt.-% SiO.sub.2 71.0 to 82.0 Li.sub.2O 6.0 to 14.0 Me.sup.I.sub.2O 4.0 to 15.0 Al.sub.2O.sub.3 2.0 to 10.0 P.sub.2O.sub.5 0.5 to 7.0,
wherein Me.sup.I.sub.2O is selected from Na.sub.2O, K.sub.2O, Rb.sub.2O, Cs.sub.2O and mixtures thereof, and
wherein the molar ratio of SiO.sub.2 to Li.sub.2O is in the range of 2.5 to 5.0.

The present invention relates to a method for additive manufacturing of a position sensitive colored ceramic article comprising: a) providing at least one flowable ceramic component; b) forming a green body by sequential deposition of the ceramic component provided in step a) and optionally a support material not intended to be part of the final article; c) position sensitive application of a coloring substance in a solvent to at least a part of the surface of the green body formed in step b), wherein the coloring substance is applied simultaneously to the sequential deposition; d) heat treatment or curing of at least a part of the green body surface obtained in step c); wherein the method steps a)-d) are at least performed once; e) optionally removing the support material from the green body; and f) sintering the green body to obtain the ceramic article; wherein the coloring substance is a dyestuff according to ISO 18451-1:2019(E). In addition, the present invention relates to a system adapted to perform the method and a control data set configured, when implemented in an additive manufacturing system, to cause the system to execute the steps of the inventive method.

The present invention relates to a method for additive manufacturing of a position sensitive colored ceramic article comprising: a) providing at least one flowable ceramic component; b) forming a green body by sequential deposition of the ceramic component provided in step a) and optionally a support material not intended to be part of the final article; c) position sensitive application of a coloring substance in a solvent to at least a part of the surface of the green body formed in step b), wherein the coloring substance is applied simultaneously to the sequential deposition; d) heat treatment or curing of at least a part of the green body surface obtained in step c); wherein the method steps a)-d) are at least performed once; e) optionally removing the support material from the green body; and f) sintering the green body to obtain the ceramic article; wherein the coloring substance is a dyestuff according to ISO 18451-1:2019(E). In addition, the present invention relates to a system adapted to perform the method and a control data set configured, when implemented in an additive manufacturing system, to cause the system to execute the steps of the inventive method.

A dental blank for the manufacture of a dental restoration. The dental blank comprises a dental block and an insert with an opening facing toward an outer surface of the dental blank. The insert comprises at least one positioning element for the positioning of an abutment.