Patents by Inventor Norikazu Nakagaki

Norikazu Nakagaki 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).

  • Patent number: 6221931
    Abstract: A dental restorative composition is disclosed, comprising: (a) a methacrylate or acrylate monomer, (b) an organic-inorganic composite filler prepared by curing a mixture of a particulate filler having a mean particle size of 20 nm or less with a methacrylate or acrylate monomer having a viscosity of 60 cP or more and pulverizing the cured mixture, (c) a particulate filler having a mean particle size of 20 nm or less, and (d) a polymerization initiator, and further, if desired, (e) a glass powder having a maximum particle size of 5 &mgr;m or less and having a mean particle size of from 0.5 to 2 &mgr;m. The dental restorative composition according to the invention gives restorations having surface smoothness and transparency similar to natural teeth, having superior esthetics and superior physical properties such as bending strength and bending strain energy characteristics, and being provided with easy polishing.
    Type: Grant
    Filed: August 17, 1999
    Date of Patent: April 24, 2001
    Assignee: GC Corporation
    Inventors: Tetsuro Sakuma, Makoto Katsu, Takayuki Ueno, Norikazu Nakagaki, Tomohiro Kumagai