Kuraray Noritake Dental Inc.

Other

Noritake Co., Ltd.

Japan Nus Co., Ltd.

Cusp Dental Supply Co., Ltd.

Kiyoko Ban

Toshio Sakakibara

Yoshihisa Ito

Kazuhiro Yamada

Yoshihisa Yamada

Hiroshi Inada

Yuta Tajima

Satoshi Nishimuro

Takeo Hori

The present invention provides a dental product comprising a base material formed of a zirconia sintered body, and having high aesthetic quality with enhanced fracture toughness and with reduced chipping and cracking in the porcelain layer. The present invention also provides a method for manufacturing such a dental product. The present invention relates to a dental product comprising: a base material formed of a zirconia sintered body, and a porcelain layer, wherein the porcelain of the porcelain layer has a suitable firing temperature of 900&#xb0; C. or more, and the porcelain layer has a fracture toughness value of 1.20 MPa&#xb7;mor more.

Dental product with enhanced toughness

The present invention provides a silicate glass that can reduce a color change in base material zirconia even when simultaneously fired with an unsintered zirconia. The present invention also provides a dental product using same. The present invention relates to a silicate glass comprising: 65.0 to 90.0 mol % SiO, 4.0 to 15.0 mol % AlO, 1.0 to 10.0 mol % KO, 0.1 to 7.0 mol % NaO, and 0.01 to 15.0 mol % CaO, the silicate glass being essentially free of BO, and satisfying the relation {(number of moles of AlO)/(total number of moles of RO+RO)}&#x2265;0.70, wherein R in the metal oxide represented by RO represents a metallic element in group 2 or 12 of the periodic table, and R in the metal oxide represented by RO represents a metallic element in group 1 of the periodic table. The present invention also relates to a composite comprising the silicate glass and a base material formed of a ceramic; a sintered body as a fired product of the composite; and a dental product comprising the sintered body.

Silicate glass and dental product

Provided is a high-strength zirconia sintered body in which the progression of low-temperature degradation is inhibited. The zirconia sintered body contains partially-stabilized zirconia as a matrix phase and contains at least one element from among phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi). The content of the abovementioned element(s) in the zirconia sintered body ranges from 4&#xd7;10mol to 4&#xd7;10mol with respect to 1 mol of zirconium(IV) oxide. Preferably, the zirconia sintered body further contains 0.03% to 3% by mass of silicon dioxide.

Zirconia sintered body, and mixture, pre-sintered compact and pre-sintered calcined body for sintering zirconia sintered body

Disclosed is an electrode for electrical discharge used for diesinking, comprising an electrode member produced by subjecting a base and binder of gypsum hemihydrate powder and a filler of conductive metal powder to modeling and/or molding and setting into a desired form of electrode, and followed by plating the electrode member with a conductive metal; and a process for manufacturing the same, wherein a gypsum hemihydrate powder, a gypsum dihydrate powder in an amount of 1% by weight of the gypsum hemihydrate powder and a conductive metal powder are kneaded in vacuo, and water is added thereto to continue further kneading in vacuo, followed by casting into a mold having a predetermined shape transferred thereon to carry out hydration, molding and setting to provide an electrode member; after the electrode member is dried, it is plated with a conductive metal to enhance mutual continuity in the conductivity of the former conductive metal powder and also to form a thin metal layer on the surface of the electrode member. Since the present electrode for electrical discharge machining is based on a gypsum, even one having a subtle and complicated shape can easily be produced using an easy-to-make mold made of a silicone rubber and the like with high accuracy at low cost, so that it is particularly suitable for producing dental crown and bridge one by one. Further, the strength of the electrode is enhanced synergistically by the base of gypsum hemihydrate and the conductive metal layer formed on the surface of the electrode member, allowing precise electrical discharge machining of hard materials such as titanium at the desired speed which was impossible by use of the conventional electrode impregnated with a conductive solution containing a graphite and the like dispersed therein instead of the plating treatment.

Electrode for electrical discharge machining and process for

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Aichi, Japan

Kiyoko Ban