The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 04, 1990
Filed:
Sep. 21, 1988
John S Kelly, Temple City, CA (US);
Henrick K Gille, Van Nuys, CA (US);
Unitek Corporation, Monrovia, CA (US);
Ceradyne, Inc., Costa Mesa, CA (US);
Abstract
An orthodontic bracket or similar orthodontic appliance is made of a polycrystalline ceramic having a translucency which minimizes visibility of the appliance when mounted on a tooth. The ceramic is formed by pressing a powder material, such as high purity aluminum oxide, and sintering to yield a single phase appliance having substantially zero porosity and an average grain size preferably in the range of 10 to 30 microns. The substantially color-free ceramic appliance has desirable strength and other mechanical properties combined with a translucency which permits the natural color of the tooth to diffusely show through in a fashion tending to make the appliance blend with and disappear against the tooth.