Orthodontic bracket

Abstract

By using titanium, titanium based alloys, or related metals or alloys, an orthodontic bracket can be manufactured which is lighter and stronger than any conventional type of bracket made of stainless steels, plastics and even ceramics. Ti based brackets have shown excellent corrosion resistance and possess good biocompatibility. Surface treatments including nitriding, diamond coating, pre-oxidation or shot-peening on the slot bottom surface of such brackets reduce the friction coefficient against the orthodontic archwire. Furthermore, the bonding strength may be enhanced by shot-peening, ion beam etching or reactive ion etching on the tooth contact surface of the base portion of the bracket.

What is claimed is: 
     
       1. An orthodontic . .bracket.!. .Iadd.appliance not including an archwire, for attachment to a tooth in the oral cavity and cooperable with an archwire, said appliance .Iaddend.having a body portion formulated of at least one of a group comprised of alloys based on elements Ti, Zr, Si, B, Be, Cr, Nb and Co in a composition in which at least one of the elements of this group exists in the body portion in a range of between 40% and greater than 99% by weight.Iadd., and wherein said appliance does not include any nickel or nickel alloy surfaces exposed to the oral cavity when the appliance is attached to a tooth in the oral cavity.Iaddend.. 
     
     
       2. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 1 wherein said . .bracket.!. .Iadd.appliance .Iaddend.is made of a material that has a modulus of elasticity between 2 million and 20 million pounds per square inch. 
     
     
       3. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 1 wherein said . .bracket.!. .Iadd.appliance .Iaddend.is made of a material that has a resilience of at least 50% greater than that of stainless steel. 
     
     
       4. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 1 wherein said . .bracket.!. .Iadd.appliance .Iaddend.is made of a material that contains at least 45% metallic titanium by weight in its composition. 
     
     
       5. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 4 comprising a receptacle for accommodating an arch wire extending from a top side of a base portion and a tooth contact surface on a bottom side of said base portion. 
     
     
       6. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 5 wherein chemical adhesion properties of the tooth contact surface of the base portion to orthodontic adhesives is improved by further chemical treatment of the base portion. 
     
     
       7. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 5 wherein the chemical adhesion of the tooth contact surface of the base portion to orthodontic adhesives is improved further by addition of means for mechanical bonding. 
     
     
       8. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 5 wherein the chemical adhesion of the tooth contact surface of the base portion to orthodontic adhesives is improved further by attachment of particles to the base. 
     
     
       9. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 5 wherein the chemical adhesion of the tooth contact surface of the base portion to orthodontic adhesives is improved further by addition of means of attachment to alloys that are capable of chemically bonding to the adhesives. 
     
     
       10. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 5 wherein the bottom interior of the receptacle is nitrided to form a titanium nitride coating thereon in order to reduce a friction coefficient against the archwire, and also to provide resistance against wear, galling and corrosion. 
     
     
       11. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 5 wherein the bottom interior of the receptacle is diamond coated to reduce the coefficient of friction against the archwire, and also to provide resistance against wear, galling and corrosion. 
     
     
       12. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 5 wherein the bottom interior of the receptacle is pre-oxidized to improve the frictional property and resistances against wear and corrosion. 
     
     
       13. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 5 wherein the receptacle bottom portion is treated by one of the group of treatments of shot-peening, ion beam etching and reactive ion beam etching to reduce the coefficient of friction against the archwire. 
     
     
       14. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 5 wherein the tooth contact surface of the base portion is treated by one of the group of treatments of shot-peening, ion beam etching, or reactive ion beam etching to increase effective surface area in order to enhance bonding strength to dental enamel. 
     
     
       15. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 5 wherein the tooth contact surface of the base of the . .bracket.!. .Iadd.appliance .Iaddend.is machined to provide undercuts for increasing surface area for better bonding to dental enamel. 
     
     
       16. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 5 wherein the tooth contact surface of the base of the . .bracket.!. .Iadd.appliance .Iaddend.is attached to a mesh for better bonding to dental enamel. 
     
     
       17. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 1 wherein said . .bracket.!. .Iadd.appliance .Iaddend.is made of a material that contains at least 80% metallic titanium by weight in its composition. 
     
     
       18. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 17 wherein said . .bracket.!. .Iadd.appliance .Iaddend.is made of an alloy that contains at least 80% titanium by weight in its composition and addition contains at least one element from the group of Al, V, Fe and Nb. 
     
     
       19. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 1 wherein said . .bracket.!. .Iadd.appliance .Iaddend.is made of a material that contains at least 99% metallic titanium by weight in its composition. 
     
     
       20. An orthodontic . .bracket.!. .Iadd.appliance .Iaddend.according to claim 1 wherein said . .bracket.!. .Iadd.appliance .Iaddend.serves as an active appliance.