Self ligating orthodontic bracket

Abstract

A self-ligating orthodontic bracket comprised of a ligating member containing a coil spring segment for extending the ligating member over an archwire or retainer wire and over one or more tie wings to secure the archwire or retainer wire in the bottom of a slot in the bracket. The ligating member containing the coil spring may have ends that are engaged in opposing mesially-distally extending bores in one side of the bracket body, with the ligating member being engaged with one or more tie wings on an opposite side of the bracket body. Alternatively, the ligating member may form a closed loop with the ligating member engaged under both occlusally-projecting and gingivally-projecting tie wings or engaged under one or more tie wings on one side of the bracket body and passing through a mesially-distally extending bore on the opposite side of the bracket body.

Having described the invention, what is claimed is:  
     
         1 . An orthodontic bracket comprising: 
 a bracket body having a mesially-distally extending slot for receiving an orthodontic wire, and at least one tie wing; and    a ligating member for ligating an orthodontic wire in said slot, said ligating member engaged with said bracket body and comprised of a length of wire containing at least one coil spring segment.    
     
     
         2 . A bracket according to  claim 1  wherein said slot is an archwire slot and said ligating member is adapted to ligate an archwire in said archwire slot.  
     
     
         3 . A bracket according to  claim 1  wherein said bracket is a lingual bracket.  
     
     
         4 . A bracket according to  claim 1  wherein said bracket is a labial bracket.  
     
     
         5 . A bracket according to  claim 4  wherein said at least one tie wing is selected from the group consisting of gingivally-projecting and occlusally-projecting tie wings.  
     
     
         6 . A bracket according to  claim 1  wherein said bracket body includes a hook.  
     
     
         7 . A bracket according to  claim 1  wherein said bracket body includes two tie wings.  
     
     
         8 . A bracket according to  claim 1  wherein said ligating member defines a closed loop.  
     
     
         9 . A bracket according to  claim 8  wherein said bracket body has a mesially-distally extending bore therethrough and said ligating member passes through said bore.  
     
     
         10 . A bracket according to  claim 9  wherein said ligating member is engageable with said at least one tie wing to ligate an orthodontic wire in said slot.  
     
     
         11 . A bracket according to  claim 1  wherein said ligating member contains Ti.  
     
     
         12 . A bracket according to  claim 1  wherein the elastic recovery stress of said ligating member is in the range of about 100-1000 grams.  
     
     
         13 . A bracket according to  claim 1  wherein said ligating member is made of a material selected from the group consisting of super elastic and shape memory alloys.  
     
     
         14 . A bracket according to  claim 13  wherein said ligating member is made of a Ni/Ti-based alloy.  
     
     
         15 . A bracket according to  claim 13  wherein said ligating member is made of a Ni—Ti—Nb alloy.  
     
     
         16 . A bracket according to  claim 13  wherein said ligating member is comprised of a multiple stranded wire.  
     
     
         17 . A bracket according to  claim 16  wherein said multiple stranded wire includes about 2-7 strands.  
     
     
         18 . A bracket according to  claim 16  wherein said multiple stranded wire has an outer diameter less than about 0.015 inch.  
     
     
         19 . A bracket according to  claim 16  wherein said multiple stranded wire includes strands of wire each having a diameter of about 0.0005 inch to about 0.007 inch.  
     
     
         20 . A bracket according to  claim 1  wherein said at least one coil spring segment includes two coil portions wound in opposite directions from an intermediate point.  
     
     
         21 . A bracket according to  claim 20  wherein said ligating member includes a length of wire containing said coil spring segment intermediate two straight leg portions, wherein said straight leg portions engage said bracket body in the same plane of space.  
     
     
         22 . A bracket according to  claim 20  wherein said two coil portions are each intermediate a first and second straight leg portion and said first straight leg portions are attached at said intermediate point and said second straight leg portions engage said bracket body in the same plane of space.  
     
     
         23 . A bracket according to  claim 20  wherein said ligating member is a multiple stranded wire.  
     
     
         24 . A bracket according to  claim 23  wherein said multiple stranded wire includes about 2-7 strands.  
     
     
         25 . A bracket according to  claim 23  wherein said multiple stranded wire has an outer diameter less than about 0.015 inch.  
     
     
         26 . A bracket according to  claim 23  wherein said multiple stranded wire includes strands of wire each having a diameter of about 0.0005 inch to about 0.007 inch.  
     
     
         27 . A bracket according to  claim 1  wherein said ligating member includes a length of wire containing a coil spring segment and two straight leg portions attached at opposing ends of said coil spring segment such that said straight leg portions engage said bracket body in the same plane of space.  
     
     
         28 . A bracket according to  claim 27  wherein said straight leg portions are welded to opposing ends of said coil spring segment.  
     
     
         29 . A bracket according to  claim 27  wherein said ligating member is a multiple stranded wire.  
     
     
         30 . A bracket according to  claim 29  wherein said multiple stranded wire includes about 2-7 strands.  
     
     
         31 . A bracket according to  claim 29  wherein said multiple stranded wire has an outer diameter less than about 0.015 inch.  
     
     
         32 . A bracket according to  claim 29  wherein said multiple stranded wire includes strands of wire each having a diameter of about 0.0005 inch to about 0.007 inch.  
     
     
         33 . A bracket according to  claim 27  wherein said coil spring segment comprises a single strand of wire, and said straight leg portions comprise a multiple stranded wire.  
     
     
         34 . A bracket according to  claim 27  wherein said coil spring segment comprises a multiple stranded wire, and said straight leg portions comprise a single strand of wire.  
     
     
         35 . A bracket according to  claim 1  wherein said at least one coil spring segment includes two individual coils wound in opposite directions and attached at an intermediate point.  
     
     
         36 . A bracket according to  claim 35  wherein said individual coils are welded at the intermediate point.  
     
     
         37 . A bracket according to  claim 35  wherein said individual coils are made from a multiple stranded wire.  
     
     
         38 . A bracket according to  claim 35  wherein said ligating member includes a straight leg portion extending from each individual coil, said straight leg portions engaging said bracket body in the same plane of space.  
     
     
         39 . A bracket, according to  claim 1  wherein: 
 said bracket body has two opposed bores therein along a single mesial-distal axis in a gingival portion or an occlusal portion of said bracket body, each said bore extending into said bracket body to a depth of less than one half the length of the bracket body, and wherein  
 said ligating member is engaged with said bores in said bracket body.  
 
     
     
         40 . A bracket according to  claim 39  wherein said ligating member has two ends, each of which is disposed within one of said opposed bores.  
     
     
         41 . A bracket according to  claim 40 , further comprising means for retaining each end of said ligating member in a respective bore in said bracket body.  
     
     
         42 . A bracket according to  claim 40  wherein each end of said ligating member is retained in a respective bore in said bracket body by a crimp which deforms a portion of said bracket body into each of said bores.  
     
     
         43 . A bracket according to  claim 39  wherein said ligating member includes a length of wire containing said coil spring segment intermediate two straight leg portions, wherein said straight leg portions engage said bracket body within said bores and in the same plane of space.  
     
     
         44 . A bracket according to  claim 39  wherein said ligating member includes a length of wire containing a coil spring segment and two straight leg portions attached at opposing ends of said coil spring segment such that said straight leg portions engage said bracket body within said bores and in the same plane of space.  
     
     
         45 . A bracket according to  claim 39  wherein said at least one coil spring segment includes two individual coils wound in opposite directions and attached at an intermediate point.  
     
     
         46 . A bracket according to  claim 45  wherein said individual coils are made from a multiple stranded wire.  
     
     
         47 . A ligature for an orthodontic bracket comprising a coil spring having a first portion wound in a first direction from an intermediate point and a second portion wound in second direction from said intermediate point opposite said first direction.  
     
     
         48 . A ligature according to  claim 47  wherein said coil spring comprises a multiple stranded wire.  
     
     
         49 . A bracket according to  claim 48  wherein said multiple stranded wire includes about 2-7 strands.  
     
     
         50 . A bracket according to  claim 48  wherein said multiple stranded wire has an outer diameter less than about 0.015 inch.  
     
     
         51 . A bracket according to  claim 48  wherein said multiple stranded wire includes strands of wire each having a diameter of about 0.0005 inch to about 0.007 inch.  
     
     
         52 . A ligature according to  claim 47  wherein said ligating member is a single length of wire.  
     
     
         53 . A ligature according to  claim 47  wherein said ligating member includes two lengths of wire joined at said intermediate point.  
     
     
         54 . A ligature according to  claim 53  wherein a first straight leg portion extends from an end of said first portion of said coil spring opposite said intermediate point, and wherein a second straight leg portion extends from an end of said second portion of said coil spring opposite said intermediate point, and wherein said first and second straight leg portions are engageable with a bracket body in the same plane of space.  
     
     
         55 . A ligature for an orthodontic bracket comprising a coil spring segment intermediate two straight leg portions joined to each end of said coil spring segment such that said straight leg portions are engageable with a bracket body in the same plane of space.  
     
     
         56 . A ligature according to  claim 55  wherein said coil spring segment and said straight leg portions comprise multiple stranded wire.  
     
     
         57 . A bracket according to  claim 55  wherein said coil spring segment comprises a single strand of wire, and said straight leg portions comprise a multiple stranded wire.  
     
     
         58 . A bracket according to  claim 55  wherein said coil spring segment comprises a multiple stranded wire, and said straight leg portions comprise a single strand of wire.  
     
     
         59 . A ligature for an orthodontic bracket comprising a coil spring segment.  
     
     
         60 . An orthodontic bracket comprising: 
 a bracket body having a mesially-distally extending slot for receiving an orthodontic wire, and at least one tie wing; and    a ligating member engaged with said bracket body for ligating an orthodontic wire in said slot, said ligating member comprising a coil spring.