ORTHODONTIC BRACKET

摘要

An orthodontic bracket of the type intended for cementing directly to a previously etched surface of the tooth enamel is made by applying to the lingual face thereof that contacts the tooth enamel surface a thin porous layer of sintered metal powder which is arranged to have a porosity such that it has keying characteristics close to that of the etched enamel and thereby facilitates the cementing adhesion of the bracket to the tooth. A particularly suitable metal powder consists of particles of the same alloy as the bracket metal and of size in the range about 10 to about 150 microns (-100 mesh), preferably from about 10 to about 50 microns (-300 mesh) applied in a thickness of about 0.05 to 0.2 mm, by means of a sintering operation that fuses the particles to the lingual face and to one another. The porous layer preferably is pre-filled with a polymer material compatible with the bonding cement, such as the sealant employed with the cement, so as to protect the layer against mechanical damage caused by bending of the bracket by the orthodontist to conform the bracket surface more closely to the tooth surface to which it is to be applied.