Abstract:
An orthodontic bracket assembly and method of assembling an orthodontic bracket assembly. The bracket assembly may generally include a base defining an archwire slot and having a lingual surface attachable to a tooth, the base defining a recess extending from the lingual surface, an insert positionable in the recess, a slot being at least partially defined by the insert, and a locking member including a lingual portion receivable in the slot to support the locking member on the base, the lingual portion being movable in the slot between an open position, in which the locking member permits access to the archwire slot, and a closed position, in which the locking member inhibits access to the archwire slot.

Description:
RELATED APPLICATIONS  
       [0001]     This patent application claims priority to prior-filed, co-pending U.S. Provisional Patent Application Ser. Nos. 60/594,092, filed Mar. 10, 2005; and 60/729,916, filed Oct. 25, 2005; the entire contents of both of which are hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to the field of orthodontics and, more specifically, to the field of self-ligating orthodontic brackets.  
       BACKGROUND  
       [0003]     According to established orthodontic techniques, it is well known to attach an orthodontic bracket to a patient&#39;s tooth. The bracket provides a location for attaching an arch wire and other orthodontic devices to facilitate movement of the tooth. According to established orthodontic techniques, it is well known to ligate an arch wire to the orthodontic bracket utilizing an elastic or metal ligature. In conventional orthodontic brackets, the ligature is wrapped around respective gingival and occlusal tie wings so as to overlay the arch wire at mesial and distal ends of the orthodontic bracket.  
         [0004]     Typically, orthodontic brackets are made of a metallic material, such as stainless steel. These materials are commonly used because they are strong, non-staining, and relatively inexpensive. However, metallic materials can be cosmetically undesirable because they do not match the color of the patient&#39;s teeth, and thus the resulting brackets are very noticeable. To overcome the cosmetic difficulties noted above, manufacturers have developed brackets made from ceramic materials, such as monocrystalline or polycrystalline alumina. These materials can be developed to closely match or refract the color of the patient&#39;s teeth, thus resulting in a bracket that is less noticeable than common metal brackets.  
         [0005]     Recently, designers have created self-ligating brackets that do not require a separate ligature for attachment of the arch wire to the bracket. One type of self-ligating bracket is supplied with a locking member that is movable between an open position, permitting access to the arch wire slot, and a closed position, inhibiting access to the arch wire slot. Self-ligating brackets substantially decrease the time involved in performing ligation procedures.  
       SUMMARY  
       [0006]     The present invention provides a self-ligating orthodontic bracket assembly having a base and a locking member movable relative to the base. The base generally includes an opening (e.g., a gingival-occlusal opening extending all the way through the base on the lingual aspect), and the locking member includes a slide portion positioned in the opening and slidable relative to the base. The opening is formed at least partially by a slot in the lingual surface of the base.  
         [0007]     In one embodiment, an insert may be positioned in the slot to define at least a portion of the opening. The insert can be a longitudinal member having a closed cross section (e.g., oval, rectangular, circular, etc.) or an open cross section (e.g., straight, L-shaped, C-shaped, etc.). When using an insert having a C-shaped cross section, the open side of the insert can be positioned to face the lingual surface of the base so that, when secured in place, the insert and base collectively define the opening extending through the base.  
         [0008]     Independent features and independent advantages of the present invention will become apparent to those skilled in the art upon review of the following detailed description and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is an exploded labial perspective view of an orthodontic bracket assembly embodying aspects of the present invention.  
         [0010]      FIG. 2  illustrates an exploded lingual perspective view of the orthodontic bracket of  FIG. 1 .  
         [0011]      FIG. 3  is an enlarged view of a lingual surface of an insert of  FIG. 2 .  
         [0012]      FIG. 4  illustrates a lingual perspective view of the bracket of  FIG. 1  fully assembled.  
         [0013]      FIG. 5  illustrates the insert of  FIG. 1 .  
         [0014]      FIG. 6  illustrates an alternative insert that can be used to practice the present invention.  
         [0015]      FIG. 7  illustrates a gingival view or an end view of the bracket of  FIG. 2 .  
         [0016]      FIG. 8  illustrates a gingival view or an end view of the bracket of  FIG. 4  in the assembled condition.  
         [0017]      FIG. 9  is a top perspective view of an orthodontic bracket assembly according to another embodiment of the present invention.  
         [0018]      FIG. 10  is a rear perspective view of the orthodontic bracket assembly of  FIG. 9 .  
         [0019]      FIG. 11  is an exploded view of the orthodontic bracket assembly of  FIG. 9 .  
         [0020]      FIG. 12  is a top view of the orthodontic bracket assembly of  FIG. 9 .  
         [0021]      FIG. 13  is a cross-section view of the orthodontic bracket assembly of  FIG. 9  taken along line  13 - 13 .  
         [0022]      FIG. 14  illustrates a method for assembling a portion of the orthodontic bracket assembly of  FIG. 13 .  
         [0023]      FIG. 15  is a perspective view of an insert for an orthodontic bracket according to a further embodiment of the present invention.  
         [0024]      FIG. 16  is an exploded view of the insert of  FIG. 15 .  
         [0025]      FIG. 17  is a cross-section view of a portion of the insert of  FIG. 15  taken along line  17 - 17  in  FIG. 16 .  
         [0026]      FIG. 18  is a perspective view of an insert for an orthodontic bracket according to another embodiment of the present invention.  
         [0027]      FIG. 19  is an exploded view of the insert of  FIG. 18 .  
         [0028]      FIG. 20  is a cross-section view of a portion of the insert of  FIG. 18  taken along line  20 - 20  in  FIG. 19 .  
         [0029]     Before at least one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.  
         [0030]     Although references are made below to directions, such as left, right, up, down, top, bottom, front, rear, forward, back, etc., in describing the drawings, they are made relative to the drawings (as normally viewed) for convenience. These directions are not intended to be taken literally or limit the present invention in any form. 
     
    
     DETAILED DESCRIPTION  
       [0031]      FIG. 1  illustrates a self-ligating bracket B similar to that disclosed in U.S. Pat. No. 6,368,105, which is incorporated herein in its entirety. More specifically, the bracket B includes a base  10  and a locking member  12  slidable relative to the base  10 . The base  10  includes a series of dove tail undercuts  14  that facilitates bonding of the base  10  to a tooth.  
         [0032]     The base  10  further includes a lingual slot  16  that at least partially defines a gingival-occlusal opening  18  adapted to receive and guide the locking member  12  (as shown in phantom in  FIG. 1 ). The slot  16  is preferably machined into the lingual surface  20  of the base  10  after creation of the base  10 . The slot  16  may be formed by cutting (e.g., by a machine or laser) or by burring. However, as an alternative, the slot  16  may be formed (e.g., molded) during creation of the base  10 .  
         [0033]     An insert  22  is secured to the lingual surface  20  of the base  10  in order to at least partially define the gingival-occlusal opening  18 . In the embodiment illustrated in  FIGS. 5 , the insert  22  is a channel having a C-shaped cross section. The open side of the channel is positioned to face the lingual surface  20  of the base  10  so that the insert  22  and the base  10  will cooperatively define the gingival-occlusal opening  18 .  
         [0034]     The insert  22  can be secured to the base  10  by any appropriate process, such as bonding agent, pressed fit, mechanical interlock, brazing, etc. The insert  22  can be made of metal or a combination of metals (e.g., stainless steel, silver-gold, gold-palladium, gold, silver, etc.) resin, silicate, glass, marble, ceramic, granite, or other suitable material.  
         [0035]      FIG. 6  illustrates and alternative configuration for an insert  30 . In this embodiment, the insert  30  has a closed cross section in the form of a rectangle. In the embodiment of  FIG. 3 , it can be seen that the insert  30  fully defines the gingival-occlusal opening  18 . It should be understood that, in other constructions (not shown), the slot  16  may be provided by the base  14  without a separate insert (such as insert  22  or  30 ).  
         [0036]     In either of the above-referenced embodiments, the insert  22  or  30  may be coated on the lingual surface with a resin in order to achieve a desired color, durability, and adhesion between the tooth enamel and the insert. As a further alternative, silane may be used on the lingual surface of the insert  22  or  30  for additional adhesion to the enamel.  
         [0037]     In addition, the exterior or lingual surface of the insert  22  may include projecting surface portions, retrusive undercuts, or mesh (e.g., metal mesh) and define associated recessed surface portions to provide a non-smooth configuration. The lingual surface of the insert  22  is preferably scored, micro-abraded ( FIGS. 1 and 4 ), micro-etched (chemically or with laser-etching) or may contain micro-protrusions ( FIGS. 2-3  and  5 - 6 ). These surface treatments of the insert produce micro-undercuts to permit a stronger bonding surface for the bonding resin that is sandwiched between the treated lingual surface of the insert  22  (and ceramic base  10 ) and the enamel of the tooth surface. This maximizes bond strength to prevent debonding of the entire bracket B from the tooth. It should be understood that, in other constructions (not shown), the lingual surface of the insert  22  may be substantially smooth.  
         [0038]     As shown in  FIGS. 4 and 8 , when the insert  22  is secured in the slot  16 , it is desired that the insert  22  will be flush with the lingual surface  20  of the base  10 . If desired, the lingual portion  32  of the insert  22  can be slightly concave (see  FIG. 8 ) to match the contour of the lingual surface  20  of the base  10 . Such a design facilitates bonding the bracket B to a curved surface of a tooth.  
         [0039]      FIG. 9  illustrates a self-ligating bracket B′ similar to the bracket B described above. More specifically, the bracket B′ includes a base  54 . The base  54  includes a series of dove-tail undercuts  58  that facilitate bonding of a lingual surface  62  to a tooth.  
         [0040]     The base  54  further includes a slot  66  (shown in  FIG. 11 ) that is preferably machined into the lingual surface  62  of the base  54  after creation of the base  54 . However, as an alternative, the slot  66  may be formed (e.g., molded) during creation of the base  54 . The slot  66  is open to a cut-out  68  in the base  54 . The slot  66  may be adapted to receive an insert  70 .  
         [0041]     The insert  70  is secured to the lingual surface  62  of the base  54 . In the independent embodiment illustrated in  FIGS. 9-13 , the insert  70  is rectangular with a slot  74  extending through the length of the insert  70 . The insert  70  also includes an aperture  78  (shown in  FIG. 11 ) that faces away from the lingual surface  62  of the base  54 .  
         [0042]     The insert  70  can be secured to the base  54  by any appropriate process, such as bonding, pressed fit, mechanical interlock, welding, etc. The insert  70  can be made of metal or a combination of metals (e.g., stainless steel, silver-gold, gold-palladium, gold, silver, etc.) resin, silicate, glass, marble, ceramic, granite, or other suitable material.  
         [0043]     The insert  70  has a lingual surface  82  that, when inserted in the base  54 , aids in securing the base  54  to the tooth. When the insert  70  of the independent embodiment illustrated in  FIGS. 9-13  is positioned inside of the slot  66  of the base  54 , the slot  74  of the insert  70  is aligned with slot  66  and shares a longitudinal axis. The slot  74  of the insert  70  is aligned inside of the slot  66  of the base  54  to receive a locking member  86  when the insert  70  is secured to the base  54 .  
         [0044]     As shown in  FIG. 13 , the locking member  86  has a rounded portion  90  for receiving a tool to move the locking member  86  from a closed position ( FIG. 13 ) to an open position. A buccal portion  94  of the locking member holds a wire  98  within the base  54 . By inserting a tool (not shown) into the rounded portion  90 , the locking member  86  can be pushed downward within the slot  74  to the open position in which the wire  98  is exposed for removal or insertion of a new wire. The cut-out  68  in the base  54  allows for the tool and rounded portion  90  of the locking member  86  to move partially into the cut-out  62  to disengage the locking member  86  from the insert  70  and allow the locking member  86  to slide downward within the slot  74  of the insert  70 .  
         [0045]     In addition, the exterior or lingual surface  82  of the insert  70  is preferably scored, micro-abraded, micro-etched (chemically or with laser-etching) or may contain micro-protrusions. These surface treatments of the insert  70  produce micro-undercuts to permit a stronger bonding surface for the bonding resin that is sandwiched between the treated lingual surface  82  of the insert  70  (and ceramic base  54 ) and the enamel of the tooth surface. This maximizes bond strength to prevent debonding of the entire bracket B′ from the tooth.  
         [0046]     As shown in  FIGS. 10 and 12 , when the insert  70  is secured in the slot  66 , it is desired that the insert  70  will be flush with the lingual surface  62  of the base  54 . If desired, the lingual surface  82  of the insert  70  can be slightly concave to match the contour of the lingual surface  62  of the base  54 . Such a design facilitates bonding the bracket B′ to a curved surface of a tooth.  
         [0047]      FIG. 14  illustrates a method for attaching the insert  70  into the body  54 . The insert  70  includes a tab  170  that can be relatively flexible. Because the locking member  86  includes a rounded portion  90  for use with a tool, the flexibility of the tab  170  allows for easier insertion of the locking member  86  with a rounded portion  90  into the slot  74  of the insert  70 .  
         [0048]     The tab  170  helps to prevent bonding substances from entering the lingual slot  74  when the insert  70  is fastened to the base  54 . The tab  170  generally remains on the insert  70  until the locking member  86  is inserted, but can be removed before the locking member  86  is inserted into the slot  74 . After removal of the tab  170 , the insert  70  yields an aperture  78  such that the rounded portion  90  of the locking member  86  can be engaged with a tool to move the locking member  86  to the open position.  
         [0049]     A third embodiment of the invention is illustrated in  FIGS. 15-17 . An insert  230  is shown for use with the base  54  or similar base including a slot  66  and a cut-out  68 . The insert  230 , similar to insert  70  shown in  FIGS. 9-13 , includes a slot  234  and an aperture  238 .  
         [0050]     In the embodiment shown in  FIGS. 15-17 , an aperture cover  274  includes three sides  278 , an open top  282 , a bottom panel  286 , and a fastening portion  290 . The fastening portion  290  extends about the sides  278  and the bottom panel  286 . In other independent embodiments, the aperture cover  274  can have more or less sides, be rounded to form a concave surface about the aperture  238 , or comprise a plurality of different styles. The aperture cover  274  can be integrally molded with the insert  230  or can be fastened to the insert  230  prior to affixing the insert  230  to the base  54 .  
         [0051]     The aperture cover  274  protects the inside of the slot  234  from bonding substances that may enter when the insert  230  is fastened to the base  54 . A locking member (not shown), similar to the locking member  86  shown in  FIGS. 9-13  can be inserted into the slot  234  prior to or after the insert  230  is fastened to the base  54 . The open top  282  of the aperture cover  274  allows the tool to be inserted into a rounded portion similar to the rounded portion  90  (shown in  FIGS. 9-13 ) of the locking member to move the locking member to a second position (e.g., an open position) partially engaged with the base  54 .  
         [0052]     A fourth embodiment of the invention is illustrated in  FIGS. 18-20 . An insert  330  is shown for use with the base  54  or similar base including a slot  66  and a cut-out  68 . The insert  330 , similar to insert  70  shown in  FIGS. 9-13 , includes a slot  334  and an aperture  338 .  
         [0053]     In the embodiment shown in  FIGS. 18-20 , an aperture cover  374  includes three sides  378 , a top panel  382 , a bottom panel  386 , and a fastening portion  390 . The fastening portion  390  extends about the sides  378  and the bottom panel  386 . In other independent embodiments, the aperture cover  374  can have more or less sides, be rounded to form a concave surface about the aperture  338 , or comprise a plurality of different styles. The aperture cover  374  can be integrally molded with the insert  330  or can be fastened to the insert  330  prior to affixing the insert  330  to the base  54 .  
         [0054]     The aperture cover  374  protects the inside of the slot  334  from bonding substances that may enter when the insert  330  is fastened to the base  54 . A locking member (not shown), similar to the locking member  86  shown in  FIGS. 9-13  can be inserted into the slot  334  prior to or after the insert  330  is fastened to the base  54 . The open top of the slot  334  of the insert  330  allows the tool to be inserted into a rounded portion similar to the rounded portion  90  (shown in  FIGS. 9-13 ) of the locking member to move the locking member to a second position (e.g., an open position) partially engaged with the base  54 .  
         [0055]     One or more independent features or independent advantages may be set forth in the following claims: