Patents Assigned to Kuraray Noritake Dental Inc.
  • Patent number: 10758326
    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 1100 MPa. The test sample is formed by preparing a plurality of zirconia powders, each containing zirconia and 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.
    Type: Grant
    Filed: May 8, 2014
    Date of Patent: September 1, 2020
    Assignee: KURARAY NORITAKE DENTAL INC.
    Inventors: Yoshihisa Yamada, Atsushi Matsumoto, Yoshihisa Ito
  • Publication number: 20200237487
    Abstract: The present invention provides a dental mill blank having reduced cracks and that excels in mechanical strength and aesthetic quality. The present invention relates to a dental mill blank comprising an inorganic filler and a polymer, and having a porosity of 25 to 35 volume % after 2-hour ashing at 600° C. In the dental mill blank, the inorganic filler preferably comprises an inorganic filler (A) and an inorganic filler (B), and the dental mill blank preferably satisfies the following formulae (I) and (II), 0.12?a?0.70??(I) 3?b/a??(II), where a is an average primary particle diameter of the inorganic filler (A) in micrometers, and b is an average primary particle diameter of the inorganic filler (B) in micrometers. Preferably, the inorganic filler (A) and the inorganic filler (B) have a volume-to-volume content ratio (A)/(B) of 5/95 to 50/50.
    Type: Application
    Filed: September 26, 2018
    Publication date: July 30, 2020
    Applicant: KURARAY NORITAKE DENTAL INC.
    Inventors: Masashi INOUE, Makoto IKEDA, Hiroshige ISHINO
  • Patent number: 10703076
    Abstract: A zirconia composition, a zirconia semi-sintered body, a zirconia sintered body, and a dental product are provided. The zirconia sintered body contains 4 mol % to 7 mol % of yttria as stabilizer, and a shielding material. The zirconia sintered body comprises first region and second region having a higher content ratio of the shielding material than the first region. Difference between content ratio of yttria in the first region and that of yttria in the second region is 1 mol % or less.
    Type: Grant
    Filed: December 25, 2015
    Date of Patent: July 7, 2020
    Assignee: KURARAY NORITAKE DENTAL INC.
    Inventors: Yoshihisa Ito, Yasutaka Kudo
  • Publication number: 20200206091
    Abstract: The present invention provides a non-solvent dental adhesive composition exhibiting high initial bond strength and high bond durability to a tooth structure (wet matter) and a high dentin cohesive failure rate on a tooth structure (wet matter) and being substantially free of water and an organic solvent. The present invention relates to a non-solvent dental adhesive composition comprising: an acid group-containing polymerizable monomer (A); a hydrophobic polymerizable monomer (B) having no acid group; and a water-soluble photopolymerization initiator (C) having a solubility of 10 g/L or more in water at 25° C.
    Type: Application
    Filed: August 28, 2018
    Publication date: July 2, 2020
    Applicant: KURARAY NORITAKE DENTAL INC.
    Inventors: Yamato NOJIRI, Mitsunobu KAWASHIMA, Ryo MATSUURA, Ryota MURAYAMA
  • Publication number: 20200207019
    Abstract: The present invention provides a container used in a stereolithography apparatus and having excellent transparency, shape accuracy, and durability. The present invention relates to a container for holding a photocurable composition (3), the container being used in a stereolithography apparatus comprising a container (2), an active energy beam irradiation apparatus (5), and an actuator (8), wherein the container (2) comprises a bottom (2?) and a wall, the bottom (2?) comprises a first layer (X) comprising a hard resin, a second layer (Y) comprising a soft resin, and a third layer (Z) comprising a fluorine resin, the second layer (Y) is laminated on the first layer (X) and the third layer (Z) is laminated on the second layer (Y), the pencil hardness measured according to JIS K 5600-5-4:1999 for the first layer (X) is 3 B or harder, the hardness measured for the second layer (Y) using a type A durometer compliant with JIS K 6253-3:2012 is 10 to 90, and the third layer (Z) has a thickness of 0.1 to 5.0 mm.
    Type: Application
    Filed: June 14, 2018
    Publication date: July 2, 2020
    Applicant: KURARAY NORITAKE DENTAL INC.
    Inventors: Kenji SUZUKI, Hiroyuki SAKAMOTO
  • Publication number: 20200179237
    Abstract: The present invention provides a self-adhesive dental composite resin maintaining mechanical strength, showing excellent storage stability, undergoing little change in transparency and properties of the paste during long-term storage, and having a small solidification risk during long-term storage. The present invention relates to a self-adhesive dental composite resin comprising: an acid group-containing (meth)acrylic polymerizable monomer (a); a polyfunctional (meth)acrylic polymerizable monomer (b) containing no acid group; a photopolymerization initiator (c); and a filler (d), wherein the filler (d) is treated with a surface treatment agent and has an average particle diameter of 0.01 to 50.0 ?m, the surface treatment agent comprises a silane coupling agent (A) represented by the following general formula (1): CH2?C(R1)—COO—(CH2)p—Si—R2qR3(3-q)??(1), and an organosilazane (B) represented by the following general formula (2): R4R5R6—Si—NH—Si—R7R8R9??(2).
    Type: Application
    Filed: October 20, 2017
    Publication date: June 11, 2020
    Applicant: KURARAY NORITAKE DENTAL INC.
    Inventors: Shumei ISHIHARA, Yamato NOJIRI, Mitsuru TAKEI, Kenji HATANAKA
  • Publication number: 20200155421
    Abstract: The present invention provides a two-paste dental curable composition achieving clinically acceptable bond durability to dental adherends including dental glass ceramic restorations (particularly lithium disilicate-containing glass ceramic restorations) without using conventionally used primers. The present invention relates to a two-paste dental curable composition comprising: a first agent comprising a polymerizable monomer (a) having an acid group, a polymerizable monomer (b) having no acid group, a polymerization initiator (c), and a filler (d); and a second agent comprising a polymerizable monomer (b) having no acid group, at least one filler (e) selected from the group consisting of a basic glass filler and alumina, a polymerization accelerator (f), and a silane coupling agent (g) represented by the following general formula [I]: (The definitions of the symbols are omitted.
    Type: Application
    Filed: June 28, 2018
    Publication date: May 21, 2020
    Applicant: KURARAY NORITAKE DENTAL INC.
    Inventors: Mariko KAWANA, Kenji HATANAKA, Momoe ABE
  • Patent number: 10603250
    Abstract: The present invention provides a dentinal tubule occlusion material excellent in terms of initial degree of dentinal tubule occlusion, resistance of dentinal tubule occlusion to acids, handling properties, and storage stability. The present invention relates to an one-pack type dentinal tubule occlusion material comprising fluorapatite particles (A) having an average particle diameter of 0.6 to 10 ?m, inorganic particles (B) having an average particle diameter of 0.6 to 10 ?m and reactive with water to form apatite, and a non-aqueous dispersant (C).
    Type: Grant
    Filed: October 29, 2015
    Date of Patent: March 31, 2020
    Assignee: KURARAY NORITAKE DENTAL INC.
    Inventors: Kenji Hatanaka, Shumei Ishihara
  • Patent number: 10512527
    Abstract: A zirconia sintered body having gradation is provided. A method for preparing a zirconia composition comprises preparing a plurality of powders for lamination; the lamination powders containing zirconia, a stabilizer(s) suppressing phase transition of zirconia and a pigment(s) at respective different pigment content ratios, and laminating the lamination powders in a mold. In the laminating step, the mold is vibrated after at least two lamination powders are charged into the mold.
    Type: Grant
    Filed: January 28, 2019
    Date of Patent: December 24, 2019
    Assignee: KURARAY NORITAKE DENTAL INC.
    Inventors: Yoshihisa Yamada, Atsushi Matsumoto, Yoshihisa Ito
  • Patent number: 10478385
    Abstract: The present invention provides a dental adhesive material kit excellent in storage stability of the materials and exhibiting excellent bond durability to dentin by photopolymerization. The present invention is a dental adhesive material kit comprising a dental aqueous adhesive composition (A) and a dental curable composition (B), wherein: the dental aqueous adhesive composition (A) comprises a (meth)acrylic polymerizable monomer (a) containing an acid group, a vanadium compound (b), water (c), a (meth)acrylic polymerizable monomer (d) containing an amino group, and a polymerization inhibitor (i); the content of the polymerization inhibitor (i) is 25 to 1000 parts by weight per 100 parts by weight of the vanadium compound (b); and the dental curable composition (B) comprises a (meth)acrylic polymerizable monomer (e) containing no acid group, a hydroperoxide (f), a photopolymerization initiator (g), and a filler (h) and does not comprise a thiourea compound.
    Type: Grant
    Filed: December 12, 2016
    Date of Patent: November 19, 2019
    Assignee: KURARAY NORITAKE DENTAL INC.
    Inventor: Kenji Suzuki
  • Patent number: 10456333
    Abstract: Provided herein is a self-etching dental adhesive that exhibits excellent adhesiveness not only to dentin untreated by phosphoric acid etching, but to dentin treated by phosphoric acid etching. The present invention relates to a dental adhesive containing a (meth)acrylamide compound (a), an asymmetric acrylamide-methacrylic acid ester compound (b), and an acid group-containing (meth)acrylic polymerizable monomer (c). The (meth)acrylamide compound (a) is at least one selected from the group consisting of compounds represented by general formula (1), and compounds represented by general formula (2). The asymmetric acrylamide-methacrylic acid ester compound (b) is a compound represented by general formula (3). (In the formulae, the meanings of the symbols are omitted.
    Type: Grant
    Filed: December 6, 2016
    Date of Patent: October 29, 2019
    Assignee: KURARAY NORITAKE DENTAL INC.
    Inventors: Yamato Nojiri, Mitsuru Takei
  • Publication number: 20190315970
    Abstract: The present invention provides a method that enables production of a surface-treated colored inorganic particle with which the desired color tone can be consistently reproduced as intended with no variation occurring in the color tone of the compositions produced with the particle, within each production and over multiple production runs. The invention relates to a method for producing a surface-treated colored inorganic particle, comprising spray drying a mixture of a dispersion [I] and a solution [II], wherein the dispersion [I] is a dispersion of inorganic particles having an average particle diameter of 0.005 to 5 ?m dispersed in a solvent with a pigment, and the solution [II] is a solution of a surface treatment agent hydrolyzed in the presence of a hydrolysis aid.
    Type: Application
    Filed: December 18, 2017
    Publication date: October 17, 2019
    Applicant: KURARAY NORITAKE DENTAL INC.
    Inventors: Takehiro KAMEYA, Shogo HIRAMATSU, Masashi INOUE
  • Patent number: 10426712
    Abstract: The present invention provides a dental polymerizable composition that requires less discharging force, is easily formable, has low polymerization shrinkage stress during curing, and exhibits high stain resistance and surface gloss when cured. The present invention relates to a dental polymerizable composition including a (meth)acrylic block copolymer (A), a polymerizable monomer (B), and a polymerization initiator (C). The (meth)acrylic block copolymer (A) consists of a (meth)acrylic polymer block (a) having a curable functional group and a (meth)acrylic polymer block (b) having no curable functional group.
    Type: Grant
    Filed: September 16, 2015
    Date of Patent: October 1, 2019
    Assignee: KURARAY NORITAKE DENTAL INC.
    Inventors: Hirotsugu Ida, Kenji Suzuki, Seiya Shimizu, Kenji Shachi, Kazuhiko Maekawa
  • Publication number: 20190262240
    Abstract: The present invention provides a dental cement showing excellent storage stability, undergoing little change in paste properties during long-term storage, and having a small solidification risk during long-term storage. The present invention relates to a multi-part dental cement comprising: a first paste comprising an acid group-containing (meth)acrylic polymerizable monomer (a), a polyfunctional (meth)acrylic polymerizable monomer (b) containing no acid group, an oxidizing agent (c-1) of a chemical polymerization initiator, and a filler (d); and a second paste comprising a polyfunctional (meth)acrylic polymerizable monomer (b) containing no acid group, a reducing agent (c-2) of a chemical polymerization initiator, and a filler (e), wherein the filler (d) is treated with a surface treatment agent and has an average particle diameter of 0.01 to 50.
    Type: Application
    Filed: October 20, 2017
    Publication date: August 29, 2019
    Applicant: KURARAY NORITAKE DENTAL INC.
    Inventors: Mariko KAWANA, Shumei ISHIHARA, Mitsuru TAKEI, Kengo FUTAMI
  • Publication number: 20190254936
    Abstract: The present invention provides a composition for optical three-dimensional modeling that offers desirable shape accuracy in optical three-dimensional modeling, and that provides desirable transparency and mechanical characteristics upon being cured. The present invention relates to a composition for optical three-dimensional modeling comprising a polymerizable monomer (a), an ultraviolet-absorbing inorganic particle (b), and a photopolymerization initiator (c).
    Type: Application
    Filed: October 13, 2017
    Publication date: August 22, 2019
    Applicant: KURARAY NORITAKE DENTAL INC.
    Inventors: Kenji SUZUKI, Naoki NISHIGAKI
  • Publication number: 20190231651
    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. Additionally, a layered body includes a first layer and a second layer that comprise granules and are adjacent to each other. The granules in the first layer have an average circularity of 0.70 or smaller based on a projected image. The granules in the second layer have an average circularity of 0.92 or greater based on a projected image.
    Type: Application
    Filed: September 20, 2017
    Publication date: August 1, 2019
    Applicant: KURARAY NORITAKE DENTAL INC.
    Inventor: Yoshihisa ITO
  • Publication number: 20190176183
    Abstract: A dispenser can prevent leakage of contents from a nozzle tip when stopping discharging the contents. A dispenser includes: a syringe body that has a filled space of contents, and has a discharge hole at a tip thereof; a plunger that is slid in the syringe body by application of a pushing force, to discharge the contents in the filled space from the discharge hole; and a piston that is formed of an elastic material and located at a tip part of the plunger, wherein a gap is formed between an inner peripheral surface of the syringe body and an outer peripheral surface of the piston, when the plunger is pushed, the piston deforms to narrow the gap, and a back leakage risk (=(gap area/final discharge hole area)) after the deformation of the piston is 0 or more and less than 1.
    Type: Application
    Filed: June 30, 2017
    Publication date: June 13, 2019
    Applicants: KURARAY NORITAKE DENTAL INC., YOSHINO KOGYOSHO CO., LTD.
    Inventors: Hirotaka HORIGUCHI, Kazuhisa YOSHIMURA, Toru TOMA
  • Publication number: 20190151055
    Abstract: A zirconia sintered body having gradation is provided. A method for preparing a zirconia composition comprises preparing a plurality of powders for lamination; the lamination powders containing zirconia, a stabilizer(s) suppressing phase transition of zirconia and a pigment(s) at respective different pigment content ratios, and laminating the lamination powders in a mold. In the laminating step, the mold is vibrated after at least two lamination powders are charged into the mold.
    Type: Application
    Filed: January 28, 2019
    Publication date: May 23, 2019
    Applicant: KURARAY NORITAKE DENTAL INC.
    Inventors: Yoshihisa Yamada, Atsushi Matsumoto, Yoshihisa Ito
  • Patent number: 10285913
    Abstract: A dental polymerizable composition according to the present invention includes a (meth)acrylic acid ester polymer (a), a polymerizable monomer (b) including a (meth)acrylic acid ester and/or a (meth)acrylamide, and a polymerization initiator (c). The (meth)acrylic acid ester polymer (a) includes a (meth)acrylic acid ester homopolymer having a glass transition temperature of 25° C. to 50° C. and/or a random copolymer of a (meth)acrylic acid ester whose homopolymer has a glass transition temperature higher than 37° C. and a (meth)acrylic acid ester whose homopolymer has a glass transition temperature lower than 37° C. The (meth)acrylic acid ester polymer (a) has a glass transition temperature of 25° C. to 50° C., has tan ? at 37° C. of 0.10 or more as determined by dynamic mechanical analysis, and has no melting point.
    Type: Grant
    Filed: February 10, 2015
    Date of Patent: May 14, 2019
    Assignee: KURARAY NORITAKE DENTAL INC.
    Inventor: Kenji Suzuki
  • Patent number: 10280120
    Abstract: Provided is a zirconia sintered body that suppresses discoloration due to porcelain. The zirconia sintered body comprises at least one of a coloring agent A: erbium oxide and a coloring agent B: nickel oxide, and a composite oxide of zirconium and vanadium.
    Type: Grant
    Filed: May 16, 2017
    Date of Patent: May 7, 2019
    Assignee: KURARAY NORITAKE DENTAL INC.
    Inventors: Yoshihisa Ito, Atsushi Matsumoto, Tomohiro Emoto