Abstract: The present invention provides a zirconia sintered body and a method of production thereof satisfying both high translucency and high strength suitable even for front teeth and canines (particularly, central incisors and lateral incisors). The present invention relates to a zirconia sintered body comprising zirconia, and a stabilizer capable of preventing a phase transformation of zirconia, wherein the zirconia sintered body comprises 20 to 50% of particles having a particle diameter of 0.45 ?m or more and less than 1 ?m in a number-based particle size distribution of its crystal particles, the particle diameter being a diameter passing through the particle's center of gravity.

Abstract: Provided are a workpiece unit in which a holding member is attached to a workpiece body without use of an adhesive, and a method of producing the unit. The workpiece unit comprises a workpiece body, and a holding member which is arranged at at least a part of an outer circumferential portion of the workpiece body and directly contacts with at least a part of the outer circumferential portion.

Abstract: Provided are: a workpiece unit (10) that makes it possible to attach a holding member (1) to a workpiece body (1) at a suitable position and that minimizes displacement of the holding member (2) after attachment thereof; and a method for producing the workpiece unit (10). The workpiece unit (10) is provided with a workpiece body (1) and a holding member (2) arranged on at least a part of the outer circumference (1c) of the workpiece body (1). The workpiece body (1) comprises at least one first positioning section (1d) at a part facing the holding member (2). The holding member (2) comprises a second positioning section (2d) that engages with at least a part of the first positioning section (1d).

Abstract: A zirconia sintered body may excel in translucency, strength, in linear light transmittance, and can be produced by short-time sintering without an HIP device, and be used in zirconia molded bodies and pre-sintered bodies from which such a zirconia sintered body can be obtained. A zirconia molded body with zirconia particles and 2.0 to 9.0 mol % yttria, having an average primary particle diameter less than 60 nm, and a monoclinic crystal system in a fraction of ?55%. The zirconia molded body may have ?1% undissolved yttria. A zirconia pre-sintered body may have such zirconia particles, wherein the zirconia pre-sintered body has ?L*(W?B) of ?5 through a thickness of 1.5 mm. A zirconia sintered body may have a fluorescent agent and 2.0 to 9.0 mol % yttria, and a crystal grain size of ?180 nm.

Abstract: A zirconia sintered body is provided in which the strength between layers of powders is improved. A flexural strength of a test sample of the zirconia sintered body, measured pursuant to JISR1601, is not less than 1000 MPa. The test sample is formed by preparing a plurality of zirconia powders, each containing zirconia and preferably yttria as a stabilizer that suppresses phase transition of zirconia, the zirconia powders differing in a composition, layering the zirconia powders to form a zirconia composition, and sintering the zirconia composition to form a zirconia sintered body. The flexural strength is measured such that a load point is positioned at a boundary of the zirconia powders, the boundary traversing the test sample of the sintered body along a direction of load application.

Abstract: A zirconia pre-sintered body suitable for dental milling, grinding and/or cutting can provide a sintered body in which the strength between layers of powders is improved. A flexural strength of a test sample of the zirconia sintered body, measured pursuant to JISR1601, is preferably not less than 1000 or 1100 MPa.

Abstract: A mill blank may have a multilayer structure and desirable aesthetics. Such dental mill blanks may include a mill blank portion having a layered structure of two or more layers, and in which the layered structure includes an enamel layer and a core layer, the core layer comprising a first portion that is substantially a frustum, the frustum having a side face forming a part of an interface between the enamel layer and the core layer.

Abstract: A coloring device for coloring a dental prosthesis by an inkjet method, the dental prosthesis coloring device includes an inkjet head having a nozzle that ejects ink droplets; a holding unit that holds the prosthesis; a drive unit that moves the inkjet head or the holding unit in a predetermined direction in an XYZ orthogonal coordinate system; and a control unit that controls the inkjet head and the drive unit, wherein the control unit is configured to control the inkjet head and the drive unit based on predetermined coloring data and three-dimensional data of the prosthesis.

Abstract: A composition comprises a zirconia powder, in which 55% or more thereof is monoclinic, and a stabilizer capable of suppressing phase transition of zirconia. An average particle diameter of zirconia particles and particles of the stabilizer is 0.06 ?m to 0.17 ?m. At least a portion of the stabilizer does not form a solid solution with zirconia.

Abstract: The present invention provides a pre-sintered body for obtaining a zirconia sintered body that can satisfy both high strength and high translucency, and a method of production of such a pre-sintered body. The present invention relates to a zirconia pre-sintered body comprising a secondary aggregate having an average particle diameter of 275 nm or less, the secondary aggregate comprising zirconia, and a stabilizer capable of preventing a phase transformation of zirconia, the secondary aggregate comprising a larger particle having an average primary particle diameter of 100 nm or more and 200 nm or less, and a smaller particle having an average primary particle diameter of 10 nm or more and less than 60 nm.

Abstract: A composition comprises a zirconia powder, in which 55% or more thereof is monoclinic, and a stabilizer capable of suppressing phase transition of zirconia. An average particle diameter of zirconia particles and particles of the stabilizer is 0.06 ?m to 0.17 ?m. At least a portion of the stabilizer does not form a solid solution with zirconia.

Abstract: The present invention provides a granule and green compact suited for obtaining a high-translucency and high-strength zirconia sintered body, and a high-density and uniform pre-sintered body. The invention also provides methods of production of such a granule and green compact. The present invention relates to a granule comprising zirconia, a stabilizing agent capable of preventing a phase transformation of zirconia, and a binder, the granule having a compression ratio R of 0.46 to 0.53 as calculated by the formula (1) below when tapped and filled into a columnar die in compliance with JIS R 1628:1997, and compressed by uniaxial pressing at a rate of 1 mm/s to 33 MPa, R=(H?D)/H??(1) wherein H represents a height of the granule tapped and filled into the columnar die before applying pressure, and D represents an amount of strain up to 33 MPa.

Abstract: A composition may include granules in which zirconia particles are aggregated. The granules may have an average circularity of 0.81 or greater based on a projected image. The zirconia crystal system of the zirconia particles may be 20% or more monoclinic. An angle of repose of the composition, measured in accordance with JIS R9301-2-2, may be in a range of from 20 degrees to 35 degrees.

Abstract: A composition includes granules in which zirconia particles are aggregated. The granules have an average circularity of 0.81 or greater based on a projected image.

Abstract: A composition comprises a zirconia powder, in which 55% or more thereof is monoclinic, and a stabilizer capable of suppressing phase transition of zirconia. An average particle diameter of zirconia particles and particles of the stabilizer is 0.06 ?m to 0.17 ?m. At least a portion of the stabilizer does not form a solid solution with zirconia.

Abstract: A composition comprises a zirconia powder, in which 55% or more thereof is monoclinic, and a stabilizer capable of suppressing phase transition of zirconia. An average particle diameter of zirconia particles and particles of the stabilizer is 0.06 ?m to 0.17 ?m. At least a portion of the stabilizer does not form a solid solution with zirconia.

Abstract: The present invention provides a zirconia pre-sintered body having excellent machinability and having a low probability of pillar fracture or chipping during milling. A method of production of such a zirconia pre-sintered body is also provided. The present invention relates to a zirconia pre-sintered body comprising zirconia, and a stabilizer capable of reducing a phase transformation of zirconia, the content of the stabilizer being 3 to 8 mol % relative to the total mole of the zirconia and the stabilizer, at least a part of the stabilizer being not dissolved in zirconia as a solid solution, and the zirconia pre-sintered body having a Vickers hardness of 65 to 135 HV 5/30 as measured in compliance with JIS Z 2244:2009.

Abstract: The present invention provides a zirconia pre-sintered body that develops the preferable shade with a short firing time.

Abstract: A method that enables fabrication of a machinable zirconia composite sintered body that is machinable in a sintered state while maintaining properties suited for dental use, in a shorter time than it is possible with conventional methods. A method for producing a machinable zirconia composite sintered body by fabricating a molded body with a raw material composition that includes 78 to 95 mol % of ZrO2 and 2.5 to 10 mol % of Y2O3, and also includes 2 to 8 mol % of Nb2O5 and/or 3 to 10 mol % of Ta2O5, and in which ZrO2 predominantly includes a monoclinic crystal system and sintering the molded body.