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US 4,752,221 AGranted
Orthodontic bracket
AssigneesAugusta Developments Inc., Ontario Research Foundation
InventorsGustaf H. Hanson, William M. Gibbon
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AssigneesAugusta Developments Inc., Ontario Research Foundation
InventorsGustaf H. Hanson, William M. Gibbon
Estimating the term…
An orthodontic bracket of the type intended for cementing directly to a previously etched surface of the tooth enamel has on 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 micons (-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.
An orthodontic bracket comprising a bracket body having a lingual surface which is applied to an acid-etched surface of a tooth on which the bracket body is to be mounted and bonded by a bonding material, the said lingual surface having thereon so as to be interposed between the said lingual and acid-etched surfaces a thin sintered layer of metal powder of thickness about 0.05 to about 0.2 mm and of particle size about 10 to about 150 microns, the sintered layer being porous to the bonding material and having relatively elongated, tortuous, irregular, random pores extending in random directions from the surface thereof which receives the bonding material so as to provide a three-dimensional interconnecting network of capillaries that will become filled with the bonding material, the surface of the layer thereby corresponding at least approximately to the etched tooth surface to facilitate the bonding of the bracket to the tooth surface.
An orthodontic bracket comprising an attachment base for the adhesion of said bracket to a tooth and having a tooth-engaging surface having an area of about 3.times.4 mm, and a porous coating on said tooth-engaging surface consisting of metal particles joined to each other and to said tooth-engaging surface at their points of contact therewith, said porous coating having a thickness of about 50 to about 200 microns and a porosity exhibiting excellent mechanical keying properties when a cement is applied thereto, said particles having a particle size of about 10 to about 150 microns, and said porous coating, the interface between said porous coating and said tooth-engaging surface, and said tooth-engaging surface having a structural strength of at least 0.5 kg/mm.sup.2.
An orthodontic bracket comprising a bracket body having a lingual surface which is applied to an acid-etched surface of a tooth on which the bracket body is to be mounted and bonded by a bonding material, the said lingual surface having thereon so as to be interposed between the said lingual and acid-etched surfaces a thin sintered layer of metal powder of thickness about 0.05 to about 0.2 mm and of particle size about 10 to about 150 microns, the sintered layer being porous to the bonding material and having pores extending from the surface thereof which receives the bonding material so as to provide a three-dimensional interconnecting network of capillaries that will become filled with the bonding material to exhibit excellent mechanical keying properties, the bracket being adhered to the tooth to an extent that a force of at least 0.5 kg/mm.sup.2 is required to separate the bracket from the tooth.
An orthodontic bracket comprising a bracket body having a lingual surface which is applied to an acid-etched surface of a tooth upon which the bracket body is to be mounted and bonded by a bonding material, said lingual surface having thereon so as to be interposed between the said lingual surface and the said acid-etched tooth surface a thin sintered layer of metal particles having a thickness of about 0.5 to about 0.2 mm and produced from metal particles having a particle size of about 10 to about 150 microns, the sintered layer forming an integral porous layer with excellent mechanical keying properties when the bonding material is applied thereto such as to adhesion of the bracket to the tooth to the extent that the adhere the bracket to the tooth is at least 0.5 kg/mm.sup.2, the sintered layer having pores extending from the surface thereof which receives bonding material so as to provide a 3-dimensional interconnecting network of capillaries which can be filled with the bonding material, the surface of the sintered layer corresponding at least approximately to the etched tooth surface to facilitate the bonding of the bracket to the tooth surface.
Dependencies are inferred from the claim text.