Patents by Inventor Hironobu Akizumi
Hironobu Akizumi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20200069534Abstract: Provided is a photocurable composition that contains a polymerizable monomer (A), a spherical filler (B) having an average particle size within the range of 230-1000 nm, and a polymerization initiator (C), the photocurable composition being such that: 90% or more of the individual particles that constitute the spherical filler (B) are within a range of ±5% of the average particle size; the polymerizable monomer (A) and the spherical filler (B) satisfy condition (X1) represented by formula (1): nP<nF (where nP represents the refractive index at 25° C. of a polymer obtained by polymerizing the polymerizable monomer (A) and nF represents the refractive index at 25° C. of the spherical filler (B)); and the polymerization initiator (C) includes a photosensitizing compound (C1), a tertiary amine compound (C2), and a photoacid generator (C3).Type: ApplicationFiled: March 5, 2018Publication date: March 5, 2020Applicant: TOKUYAMA DENTAL CORPORATIONInventors: Koji Furuhashi, Hironobu Akizumi
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Publication number: 20190292278Abstract: Provided is a curable composition containing a polymerizable monomer (A), an organic-inorganic composite filler (B), and a polymerization initiator (C), wherein the organic-inorganic composite filler (B) includes an organic resin matrix (b1) and a spherical inorganic filler (b2) having an average primary particle size of 230-1000 nm, 90% or more of the number of individual particles constituting the spherical inorganic filler (b2) are present in a range of 5% greater or less than the average primary particle size, and the curable composition satisfies the following formulas (1) and (2): nP<nFb2??(formula 1) and nMb1<nFb2??(formula 2) In the formulas, nP represents the refractive index of the polymer of the polymerizable monomer (A) at 25° C., nFb2 represents the refractive index of the spherical inorganic filler (b2) at 25° C., and nMb1 represents the refractive index of the organic resin matrix (b1) at 25° C.Type: ApplicationFiled: November 28, 2017Publication date: September 26, 2019Applicant: TOKUYAMA DENTAL CORPORATIONInventors: Hironobu Akizumi, Takuma Matsuo
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Publication number: 20190192386Abstract: A photocurable composition is provided, which is characterized by comprising a polymerizable monomer component (A), an inorganic filler component (B) having an average particle diameter of 0.07 ?m or more, an organic-inorganic composite filler component (C) comprising an inorganic filler component (C1) and an organic polymer component (C2) and having an average particle diameter of 0.5 ?m or more, and a photopolymerization initiator (D), wherein the inorganic filler component (B) and the organic-inorganic composite filler component (C) are contained in a total amount of 100 to 1500 parts by mass relative to 100 parts by mass of the polymerizable monomer component (A), and the polymerizable monomer component (A), 90 parts by mass or more of the inorganic filler component (B) and 90 parts by mass or more of the organic-inorganic composite filler component (C) are selected in such a manner that specific requirements can be satisfied.Type: ApplicationFiled: August 30, 2017Publication date: June 27, 2019Applicant: TOKUYAMA DENTAL CORPORATIONInventors: Keishi FUKUDOME, Hironobu AKIZUMI
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Publication number: 20180303721Abstract: Provided is a curable composition including a polymerizable monomer component (A), a spherical filler (B) having an average particle size within the range of 230-1000 nm, and a polymerization initiator (C), wherein the curable composition is characterized by having a value (V) of less than 5 and a chroma (C) of 0.05 or higher in colorimetric values according to the Munsell Color System in colored light on a black background, and a value (V) of 6 or higher and a chroma (C) of less than 2 in colorimetric values according to the Munsell Color System in colored light on a white background, each of the values (V) and chroma (C) being measured using a color difference meter in a state in which a 1-mm-thick cured article has been formed.Type: ApplicationFiled: October 21, 2016Publication date: October 25, 2018Applicant: TOKUYAMA DENTAL CORPORATIONInventors: Hironobu Akizumi, Chika Toriyabe
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Publication number: 20180273766Abstract: Disclosed is an organic/inorganic composite filler that contains: inorganic agglomerated particles comprising agglomerations of inorganic primary particles having a mean diameter between 10 and 1000 nm; an organic resin phase that covers the surface of each inorganic primary particle and binds the inorganic primary particles to each other; and intra-agglomerate voids, formed between the organic resin phase covering the surface of each inorganic primary particle, with a pore volume (here, “pore” refers to holes with diameters between 1 and 500 nm) between 0.01 and 0.30 cm3/g as measured by mercury intrusion porosimetry. Also disclosed is a method for manufacturing the above organic/inorganic composite filler.Type: ApplicationFiled: May 29, 2018Publication date: September 27, 2018Inventors: Tatsuya Yamazaki, Hironobu AKIZUMI
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Patent number: 10004667Abstract: An organic-inorganic composite filler contains: inorganic aggregate particles formed by aggregation of inorganic primary particles with an average particle diameter of 10 to 1000 nm; an organic resin phase including a cured polymer of a polymerizable monomer covering surfaces of the inorganic primary particles and bonding the inorganic primary particles to each other, and a water absorbing resin; and aggregation gaps with a volume of micropores formed between parts of the organic resin phase of 0.01 to 0.30 cm3/g in pore volume measurement within a pore diameter range of 1 to 500 nm, as measured by a mercury intrusion technique. In a cross section passing through the centers of the inorganic aggregate particles, based on 100 measured inorganic particles, there are 10 or less inorganic aggregate particles having a macro void with a maximum width of at least 1 ?m.Type: GrantFiled: September 13, 2012Date of Patent: June 26, 2018Assignee: TOKUYAMA DENTAL CORPORATIONInventors: Tatsuya Yamazaki, Hironobu Akizumi
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Patent number: 10005910Abstract: Disclosed is an organic/inorganic composite filler that contains: inorganic agglomerated particles comprising agglomerations of inorganic primary particles having a mean diameter between 10 and 1000 nm; an organic resin phase that covers the surface of each inorganic primary particle and binds the inorganic primary particles to each other; and intra-agglomerate voids, formed between the organic resin phase covering the surface of each inorganic primary particle, with a pore volume (here, “pore” refers to holes with diameters between 1 and 500 nm) between 0.01 and 0.30 cm3/g as measured by mercury intrusion porosimetry. Also disclosed is a method for manufacturing the above organic/inorganic composite filler.Type: GrantFiled: March 11, 2011Date of Patent: June 26, 2018Assignee: TOKUYAMA DENTAL CORPORATIONInventors: Tatsuya Yamazaki, Hironobu Akizumi
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Patent number: 9687421Abstract: Provided is a dental filling and restorative material kit, including: a polymerizable composition (A) for a dentin restorative material for restoring a dentin portion; and a polymerizable composition (B) for an enamel restorative material to be layered on the dentin restorative material, in which the polymerizable composition (A) for a dentin restorative material and the polymerizable composition (B) for an enamel restorative material have different color tones, and in which a difference (nDa?nDb) between a refractive index nDa of a polymer of a polymerizable monomer (a) in the polymerizable composition (A) for a dentin restorative material and a refractive index nDb of a polymer of a polymerizable monomer (b) in the polymerizable composition (B) for an enamel restorative material is 0.005 or more.Type: GrantFiled: March 10, 2014Date of Patent: June 27, 2017Assignee: TOKUYAMA DENTAL CORPORATIONInventors: Chika Toriyabe, Hironobu Akizumi
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Publication number: 20160008232Abstract: Provided is a dental filling and restorative material kit, including: a polymerizable composition (A) for a dentin restorative material for restoring a dentin portion; and a polymerizable composition (B) for an enamel restorative material to be layered on the dentin restorative material, in which the polymerizable composition (A) for a dentin restorative material and the polymerizable composition (B) for an enamel restorative material have different color tones, and in which a difference (nDa-nDb) between a refractive index nDa of a polymer of a polymerizable monomer (a) in the polymerizable composition (A) for a dentin restorative material and a refractive index nDb of a polymer of a polymerizable monomer (b) in the polymerizable composition (B) for an enamel restorative material is 0.005 or more.Type: ApplicationFiled: March 10, 2014Publication date: January 14, 2016Applicant: TOKUYAMA DENTAL CORPORATIONInventors: Chika TORIYABE, Hironobu AKIZUMI
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Publication number: 20150272833Abstract: A dental restorative material including a photocurable composition that contains a polymerizable monomer component (A), an inorganic filler component (B) having an average particle size of not smaller than 0.07 ?m, and a photo polymerization initiator (C), the inorganic filler component (B) being contained in an amount of 100 to 1500 parts by mass per 100 parts by mass of the polymerizable monomer component (A), and the polymerizable monomer component (A) and the inorganic filler component (B) being so selected as to satisfy a condition (X1) represented by the following formulas (1a) and (1b): nF?0.005<nM<nF+0.005??(1a) nF+0.020<nP<nF+0.040??(1b) wherein, nM is a refractive index of the polymerizable monomer component (A) at 25° C., nP is a refractive index at 25° C. of a polymer obtained by polymerizing the polymerizable monomer component (A), and nF is a refractive index of the inorganic filler component (B) at 25° C.Type: ApplicationFiled: September 17, 2013Publication date: October 1, 2015Inventors: Chika Toriyabe, Hironobu Akizumi
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Patent number: 9132068Abstract: There is provided a dental composite restorative material that has an excellent opalescent effect, no paste stickiness, small polymerization shrinkage during curing and is suitable for the restoration of the incisal edge of a tooth. This dental composite restorative material comprises: (A) a polymerizable monomer, (B) a spherical silica-based particle [I] having an average particle diameter in the range of from 0.1 to 0.5 ?m and a standard deviation of particle diameter distribution within 1.30, preferably a silica-titanium group oxide-composite oxide particle, (C) an organic-inorganic composite filler prepared by dispersing the above-described silica-based particle [I] in an organic resin matrix, and (D) a polymerization initiator.Type: GrantFiled: June 10, 2011Date of Patent: September 15, 2015Assignee: TOKUYAMA DENTAL CORPORATIONInventors: Chika Toriyabe, Hironobu Akizumi
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Patent number: 9114080Abstract: A dental curable composition includes: a radically polymerizable monomer; a polymerization initiator; and a hyperbranched polymer, in which the hyperbranched polymer includes a unit structure represented by the general formula (I) and unit structures represented by the general formula (IIA) and/or the general formula (IIB) (in the general formula (I), A represents a single bond for bonding C and R1, >C?O, —O—, or —COO—, R1 represents a divalent saturated aliphatic hydrocarbon group or a divalent aromatic hydrocarbon group, and R2 represents a hydrogen atom or a methyl group; and in the general formula (IIA) and the general formula (IIB), R3, R4, and R5 each represent a hydrogen atom, an alkyl group, an alkoxycarbonyl group, an aryl group, or a cyano group, and R6 represents an alkylene group).Type: GrantFiled: February 10, 2012Date of Patent: August 25, 2015Assignee: TOKUYAMA DENTAL CORPORATIONInventors: Tomonao Shimizu, Tatsuya Yamazaki, Hideki Kazama, Hironobu Akizumi
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Patent number: 9113981Abstract: [Problems] To fill a container with a material without applying a high pressure to the material that is to be filled. [Means for Solution] An ejection device 1 comprises a filling chamber 24 formed in a cylindrical member for containing a material to be filled, a discharge portion 7 having a discharge nozzle 12 for pouring out the filled material to the exterior, and a piston 4 that pushes the filled material toward the front end side of the filling chamber 24 to discharge the filled material through the discharge nozzle 12. In the ejection device 1, the discharge portion 7 is formed separately from the filling chamber 24 and in a manner to be fitted to an opening on one end side of the cylindrical member 24, the opening serving as a filling port for filling the material to be filled, and after the material to be filled is poured into the filling chamber 24 through the filling port, the discharge portion 7 is coupled to the filling chamber 24.Type: GrantFiled: April 20, 2011Date of Patent: August 25, 2015Assignee: Tokuyama Dental CorporationInventors: Nobutoshi Yamaguchi, Hironobu Akizumi, Yusaku Andoh
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Patent number: 8946318Abstract: The present invention discloses a kit of material for dentin restoration including a combination of a plurality of kinds of curable pastes each having a different hue, wherein each of the curable pastes exhibits L* of 55 to 75 and a fluctuation range of L* of 3 or less in a CIELab color system when the color of a cured body with a thickness of 3.0 mm obtained by curing the pastes is measured against a black background, and a method for producing the kit of material for dentin restoration.Type: GrantFiled: September 16, 2013Date of Patent: February 3, 2015Assignee: Tokuyama Dental CorporationInventors: Hironobu Akizumi, Chika Toriyabe
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Publication number: 20140213687Abstract: An organic-inorganic composite filler contains: inorganic aggregate particles formed by aggregation of inorganic primary particles with an average particle diameter of 10 to 1000 nm; an organic resin phase including a cured polymer of a polymerizable monomer covering surfaces of the inorganic primary particles and bonding the inorganic primary particles to each other, and a water absorbing resin; and aggregation gaps with a volume of micropores formed between parts of the organic resin phase of 0.01 to 0.30 cm3/g in pore volume measurement within a pore diameter range of 1 to 500 nm, as measured by a mercury intrusion technique. In a cross section passing through the centers of the inorganic aggregate particles, based on 100 measured inorganic particles, there are 10 or less inorganic aggregate particles having a macro void with a maximum width of at least 1 ?m.Type: ApplicationFiled: September 13, 2012Publication date: July 31, 2014Applicant: TOKUYAMA DENTAL CORPORATIONInventors: Tatsuya Yamazaki, Hironobu Akizumi
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Patent number: 8708684Abstract: In dental crown restoration, a dental shade guide which is selected to match patient's teeth comprises a shade-guide portion and a handle. A molding device for molding the dental shade guide comprises a molding plate having a shade-guide molding portion and a handle-holding groove. The molding plate is closed by a cover. While the handle is held in the handle-holding groove of the molding plate, dental composite resin paste is filled in the shade-guide molding portion and the upper surface of the molding plate is tightly pressed by the inner surface of the cover.Type: GrantFiled: August 30, 2011Date of Patent: April 29, 2014Assignee: Tokuyama Dental CorporationInventors: Makoto Oguri, Hironobu Akizumi
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Publication number: 20140017638Abstract: The present invention discloses a kit of material for dentin restoration including a combination of a plurality of kinds of curable pastes each having a different hue, wherein each of the curable pastes exhibits L* of 55 to 75 and a fluctuation range of L* of 3 or less in a CIELab color system when the color of a cured body with a thickness of 3.0 mm obtained by curing the pastes is measured against a black background, and a method for producing the kit of material for dentin restoration.Type: ApplicationFiled: September 16, 2013Publication date: January 16, 2014Applicant: TOKUYAMA DENTAL CORPORATIONInventors: Hironobu AKIZUMI, Chika TORIYABE
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Publication number: 20130324635Abstract: A dental curable composition includes: a radically polymerizable monomer; a polymerization initiator; and a hyperbranched polymer, in which the hyperbranched polymer includes a unit structure represented by the general formula (I) and unit structures represented by the general formula (IIA) and/or the general formula (IIB) (in the general formula (I), A represents a single bond for bonding C and R1, >C?O, —O—, or —COO—, R1 represents a divalent saturated aliphatic hydrocarbon group or a divalent aromatic hydrocarbon group, and R2 represents a hydrogen atom or a methyl group; and in the general formula (IIA) and the general formula (IIB), R3, R4, and R5 each represent a hydrogen atom, an alkyl group, an alkoxycarbonyl group, an aryl group, or a cyano group, and R6 represents an alkylene group).Type: ApplicationFiled: February 10, 2012Publication date: December 5, 2013Applicant: TOKUYAMA DENTAL CORPORATIONInventors: Tomonao Shimizu, Tatsuya Yamazaki, Hideki Kazama, Hironobu Akizumi
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Publication number: 20130096226Abstract: There is provided a dental composite restorative material that has an excellent opalescent effect, no paste stickiness, small polymerization shrinkage during curing and is suitable for the restoration of the incisal edge of a tooth. This dental composite restorative material comprises: (A) a polymerizable monomer, (B) a spherical silica-based particle [I] having an average particle diameter in the range of from 0.1 to 0.5 ?m and a standard deviation of particle diameter distribution within 1.30, preferably a silica-titanium group oxide-composite oxide particle, (C) an organic-inorganic composite filler prepared by dispersing the above-described silica-based particle [I] in an organic resin matrix, and (D) a polymerization initiator.Type: ApplicationFiled: June 10, 2011Publication date: April 18, 2013Inventors: Chika Toriyabe, Hironobu Akizumi
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Patent number: 8394869Abstract: Disclosed are photopolymerizable compositions suitable for uses such as dental composite resins, and that comprise (A) a radical-polymerizable monomer, (B) a photopolymerization initiator that comprises (B1) an ?-diketone compound, (B2) a photoacid generating agent, (B3) an aromatic amine compound, and (C) an organic filler containing a phthalate ester fluorescent agent.Type: GrantFiled: May 20, 2009Date of Patent: March 12, 2013Assignee: Tokuyama Dental CorporationInventors: Hironobu Akizumi, Junichiro Yamagawa