Abstract:
The present invention is a powered instrument for removing excess bonding material from the surfaces of orthodontic brackets while they are attached to a patient&#39;s teeth. The instrument is particularly effective in removing bonding material from the inner surfaces of orthodontic bracket tie wings.

Description:
FIELD OF INVENTION  
         [0001]    The present invention is directed to a devise for removing excess bonding material and cement from orthodontic brackets which are attached to a patient&#39;s teeth.  
         BACKGROUND OF THE INVENTION  
         [0002]    Orthodontic procedures for straightening teeth involve attaching orthodontic brackets to a patent&#39;s teeth. In the past, the bracket was attached to an orthodontic band which was in turn cemented to the patient&#39;s tooth. Modernly, the orthodontic bracket has a mesh backing and is bonded adhesively directly to the patient&#39;s tooth. Orthodontic movement of the patient&#39;s teeth is accomplished by an orthodontic arch wire which is attached or ligated to the orthodontic bracket which transmits the force to the patient&#39;s teeth. The orthodontic bracket has a slot which receives the arch wire and bracket wings which allow the litigation of the wire to the bracket. The wings are basically hooks which extend toward surface of the teeth. During the bonding process the bonding material will occasionally lodge in the orthodontic bracket wing. The material must be removed in order to allow ligation of the arch wire to the bracket.  
           [0003]    The removal of the bonding material has been attempted with dental instruments such as hand and power dental scalers and rotary dental drills. The difficulty is that the bonding material is difficult to visually see as it is on the tooth side of the orthodontic bracket wing and the gingival wing is often immediately adjacent to the patient&#39;s gingival tissue which further obstructed the view. Dental hand instruments are not particularly effective in removing the bonding material due to the strength and tenaciousness of the bonding material. A power dental drill could remove the material if it had access. The drill would have to be placed parallel to the surface of the tooth which the size and shape of the dental drill head prevents. When all fails the bracket has to be removed replaced, which is very time-consuming along with the difficulty of replacing the new bracket in the same position as the old bracket  
         SUMMARY OF THE INVENTION  
         [0004]    In order to better understand the invention dental terminology should be explained. An orthodontic appliance consists of a series of orthodontic brackets attached to the patient&#39;s teeth. The following dental terminology is used: buccal is towards the patient&#39;s cheek; lingual is towards the tongue; gingival is towards the gums; anterior is towards a front of the mouth; posterior is towards the back of the mouth; incisors are the front teeth; molars and bicuspids are the back teeth; maxilla is the upper jaw; mandible is the lower jaw; and intermaxillary is between the jaws. A bracket has a central slot which receives an arch wire. The arch wire is the force Which actually aligns the teeth. The bracket has gingival and occiusal wings which are used to tie the arch wire to the bracket.  
           [0005]    The present invention is directed to a device which removes excess bonding material from orthodontic brackets, more specifically the bracket tie wings. The orthodontic bracket cleaner comprises a U-shaped wire attached to a power means which moves the U-shaped wire in a single plane back and forth In the direction of the base of the U. The size requirement of the U-shaped wire is the wire must fully engage the inner hook areas of the occiusal and gingival tie wings. As the base portion is moved back and forth the bonding material is removed from the inner hook area allowing the bracket to be ligated. In a preferred embodiment the U-shaped wire is coated with diamond chips equivalent to a dental diamond drill, preferably graded to the coarse or extra coarse as used for dental drills. The back and forth motion of the U-shaped wire must be sufficiently rapid to quickly remove the bonding material. In another preferred embodiment the U-shaped wire  15  may be a spiral saw blade.  
           [0006]    In another preferred embodiment the U-shaped wire may be a flat toothed saw blade where the cutting portion Is angled towards the inner part of the bracket wings.  
           [0007]    The U-shaped wire, in its preferred embodiment, Is 0.018 in. to 0.020 in. in diameter and 6 mm. wide at its base. The diameter fits the inner hook surface of the tie wings and the width is enough to fit the width of brackets and narrow enough to not hit the adjacent teeth brackets when the U-shaped wire is in back and forth motion. The U-shaped wire is Integrated into a female base which is removably attached to a male fitting which is attached to the means which converts to power means to a back and forth motion in a single plane. U.S. Pat. No. 3,978,852 to Annoni teaches a pivot arrangement in which a rotary power force is converted with a pivot arrangement to a single plane force. Another conversion of a rotary force to a back and forth single plane force is shown in No. 4 of the Dremel model 6000 contour sander internal schematic.  
           [0008]    In a preferred embodiment the power means is a battery powered magnetic drive system as in U.S. Pat. No. 5,189,751. One significant advantage of this magnetic drive system is that the drive unit may be physically separate from the U-shaped wire and force conversion portion; therefore, power loss due to mechanical linkages can be avoided. This power saving is very important in the charge life of a rechargeable battery powered unit. Power may also be provided from a 120 volt wall source.  
           [0009]    In another preferred embodiment the power means may be a rotational armature driven motor, powered by a rechargeable battery or a 120 volt wall source.  
           [0010]    In another preferred embodiment the power means may be a dental handpiece. The handpiece may be electrical or air driven. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a perspective view of the removable longitudinal base wire-male base combination;  
         [0012]    [0012]FIG. 2 is a cross section view of an orthodontic bracket mounted to a tooth;  
         [0013]    [0013]FIG. 3 is a perspective view of an orthodontic bracket mounted to a tooth;  
         [0014]    [0014]FIG. 4 is a view of the longitudinal base wire engaged in the inner surface of a bracket wing;  
         [0015]    [0015]FIG. 5 is an internal view of a preferred embodiment of the orthodontic bracket cleaner;  
         [0016]    [0016]FIG. 6 is an internal view of another preferred embodiment of the orthodontic bracket cleaner;  
         [0017]    [0017]FIG. 7 is a view of the directional corrector;  
         [0018]    [0018]FIG. 8 is a view of the directional corrector as used with the electromagnetic power source;  
         [0019]    [0019]FIG. 9 is a view of a preferred embodiment of the orthodontic bracket cleaner adapted to a dental right angle handpiece;  
         [0020]    [0020]FIG. 10 is a view of the locking collar engaging the dental handpiece; and  
         [0021]    [0021]FIG. 11 is a cross section view of the handpiece embodiment. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]    Referring to FIG. 5 the orthodontic bracket cleaner has a longitudinal cylindrical body  39  with first  35  and second ends  36 , an exterior  37  and an interior  38 . In FIG. 6 a straight longitudinal base  1  extends beyond the first end  35  of the longitudinal cylindrical body  39 . In FIG. 1 the longitudinal base  1  has a first  7  and second  8  end and a front  9 A and back  9 B side. In FIG. 1 a longitudinal side wire  2  extends from each end  7  and  8  of the longitudinal base wire  1  and away from the back side  9 B of the horizontal base  1  and are parallel to each other. The two longitudinal side wires  2  are embedded into the solid first end  6  of a female base  3 . The female base  3  has a first solid end  6  and a second open female end  5 . The wire longitudinal base  1  can have a diameter of 0.016-0.020 in. The preferred embodiment is 0.018-0.020 in. in diameter. This is thick enough to give the base rigidity and allow for a shape which conforms with the shape of the orthodontic bracket allowing the removal of the composite resins and cements from the surfaces of orthodontic brackets. The two longitudinal side wires  2  are continuous with the horizontal base  1  and comprising the same material as the base wire  1 . In FIG. 5 a male fitting  33  is longitudinal in shape with a first end  35   a  and second end  35 B, the first end  35 B having a male fitting  33 A. The male fitting  33  inserts into the female cavity  6 , fitted tightly enough to prevent dislodging during use of the orthodontic bracket cleaner tool, but removable to allow replacement of the longitudinal wire base  1 .  
         [0023]    The female base  1  and the male fitting  33 , in a preferred embodiment, are plastic in composition, such as, polyurethane, polypropylene or polyvinylchloride. A hard rubber-based composition may also be used. FIGS.  5 , 6 , 9  and  10 .  
         [0024]    In FIGS. 5 and 6 a power means  31  and  41  supplies a motion force to the male fitting  33  which is translated to movement of the longitudinal wire base  1 . Intermediate between the power source  31  and  41  and its delivery to the male fitting  6  is a directional corrector  30  which translates the motion force into a horizontal force which moves the base wire  1  back and forth FIGS. 2 and 4 in the direction of its longitudinal axis when engaged in the wings  10 B of the orthodontic bracket  10 . Ideally the back and forth motion would be 2-3 mm In a straight line.  
         [0025]    The orthodontic bracket cleaner is used intraorally to remove composite resins from orthodontic brackets. An orthodontic bracket FIGS. 2,3 and  4  is comprised of a base  17  bonded to a tooth  15 . The central portion of the bracket  13  contains a bracket archwire slot  12 , usually 0.018 in. or 0.022 in., for receiving an orthodontic archwire. Tie wings  10  extend occlusally and gingivally from the slot  12  with the inner tie areas  15  on the tooth side of the bracket wings  10  which are used to ligate the arch wire to the bracket  10 . The inner part  10 B of the bracket wing  10  is the most difficult area to remove excess material. The wire base  1  is placed in the inner hook area  10 B, as in FIGS. 2 and 4, and is powered with sufficient frequency and torque to remove the material. In a preferred embodiment the width of the base wire  1  is 6 mm. This is enough width to simultaneously clean both wings of a twin bracket as in FIG. 4 and to allow for 2-3 mm of back and forth motion  20  of the wire. The orthodontic bracket cleaning tool in FIG. 5 in a preferred embodiment has as a power means an electrical armature rotary motor  31  powered by a battery  33  power source. The portability of battery power is desirable, but a 120 volt wall power source may also be used. In FIG. 5 the power shaft  81  is connected to a directional corrector  30  which transmits a back and forth motion force  20  to the wire base  1  via the male fitting  33  to female base  3 . In FIG. 7 the direction corrector  30  is shown with an eccentric cam  61  and connected to the male fitting  33 . This direction corrector is found in Dremel® tool model 6000.  
         [0026]    Another preferred embodiment of the power means is shown in FIG. 6. This embodiment is found in U.S. Pat. No. 5,189,751 for a vibrating toothbrush. An electromagnet  41  receives an alternating current driving signal from an oscillating battery section  4 . The frequency of operation is in the range of 150-400 Hz. A pair of permanent magnets  42  are provided at the end of a lever arm  44 . The action of the alternating current in the electromagnet  41  upon the magnets  42  causes the lever arm  44  to move back and forth. The advantage of this power means is its energy efficiency due to the fact there is no mechanical connector between the electromagnetic and the magnets. A wall 120 volt power source may also be used. In FIG. 8 the force produced by the magnets  42  is a back and forth motion on a slight arc  101 . In a preferred embodiment the power source is a battery where energy efficiency lengthens battery charge life  
         [0027]    In another preferred embodiment FIGS. 9, 10 and  11  the power means may be a dental handpiece  83 . The handpiece may be electrical or air driven. The orthodontic bracket cleaner is in FIGS. 9, 10 and  11  wherein the orthodontic bracket cleaner is designed to fit a power means comprising a right angle handpiece  83 , electrical or air driven. Referring to FIG. 11 the wire base  1  is attached to the two sides  2  which are embedded into the female base  3  which in turn connects via the male connector  33  to the directional corrector  30  The directional corrector  30  is the same as shown in FIG. 7. The directional corrector  30  is connected to a shaft  81  which is inserted and locked into the dental handpiece  83  as in FIG. 9. The orthodontic bracket cleaner mechanism is enclosed in a cylindrical housing  80  mounted to the shaft  81 , as in FIG. 11, with a bearing means  85  mounting shaft  81  to the housing  80  wall. In FIGS. 9,10 and  11  a collar  82  is shown at the handpiece end of the cylindrical housing  80  which encircles the head of the handpiece  83  preventing the entire cylindrical housing  80  from rotating during operation. The handpiece mounted orthodontic bracket cleaner FIGS. 9, 10,  11  is also adaptable to a straight dental handpiece.  
         [0028]    The preferred embodiment of the directional corrector  30  used in all the embodiments involving a rotational power source is shown in FIGS. 7 and 8. The shaft  81  from the power source has an eccentric lobe  90  at its end. The lobe  90  as it rotates strikes cams on the Internal moving mount  94  which is mounted on two rings  91  to a pin anchor housing  92 , producing a straight line back and forth horizontal movement which is translated directly to the wire base  1  by way of the male fitting  33 , the female base  3 , and the two sides  2 .