Invention Grant
- Patent Title: Orthodontic bracket and process for producing the same
- Patent Title (中): 正畸支架和生产过程相同
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Application No.: US11660991Application Date: 2005-08-26
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Publication No.: US08133051B2Publication Date: 2012-03-13
- Inventor: Koji Tsukuma , Toru Tsuyoshi
- Applicant: Koji Tsukuma , Toru Tsuyoshi
- Applicant Address: JP Shunan-shi
- Assignee: Tosoh Corporation
- Current Assignee: Tosoh Corporation
- Current Assignee Address: JP Shunan-shi
- Agency: Oblon, Spivak, McClelland, Maier & Neustadt, L.L.P.
- Priority: JP2004-249225 20040827
- International Application: PCT/JP2005/015566 WO 20050826
- International Announcement: WO2006/022384 WO 20060302
- Main IPC: A61C3/00
- IPC: A61C3/00

Abstract:
An orthodontic bracket is comprised of a translucent ceramic containing at least 99.5 wt % of alumina, and having an absorption/scattering coefficient of at most 2.8 mm−1 for visible light at a wavelength of 550 nm and a bending strength of, at least 700 MPa. This bracket is obtained, for example, by sintering a molded body of highly-pure alumina fine powder at a temperature of from 1,200° C. to 1,300° C. to obtain a sintered body composed of crystals having a relative density of from 96% to 99.5% and an average crystal grain size of at most 1 μm, and thereafter subjecting the sintered body to an HIP treatment at a temperature of from 1,200° C. to 1,350° C. and under a pressure of at least 50 MPa. Such an orthodontic bracket has high strength and high translucency, can be processed into a complicated shape, similar to that of a metal bracket, and maintains excellent translucency.
Public/Granted literature
- US20070259303A1 Orthodontic Bracket and Process for Producing the Same Public/Granted day:2007-11-08
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