CERAMIC ORTHODONTIC APPLIANCE

摘要

CERAMIC ORTHODONTIC APPLIANCE 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.