Abstract:
There are provided a device and a method for cleaning teeth. The device comprises a brush, a shaft connected to the brush, a neck surrounding the shaft along a substantial portion of the length of the shaft, and a controller coupled to the shaft at the end of the shaft opposite the brush, the controller being mounted at the base of the neck so as to be movable between a first position that extends the brush away from the neck, and a second position that retracts the brush towards the neck. The method comprises inserting, between adjacent teeth, a device having a brush, a controller and a handle, the controller for effecting movement of the brush in a direction generally perpendicular to the handle, and keeping the handle generally stationary while moving the controller up and down to move the brush along front-to-back and back-to-front paths between the adjacent teeth. Moving the controller may occur via pressure from a user&#39;s finger, or via force from a motor in the device. In some cases, the method includes vibrating the brush while it is moved along the front-to-back and back-to-front paths between the adjacent teeth.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates an appliance for cleaning teeth, and more particularly, is directed to a brush suited for cleaning the interproximal areas of teeth. 
         [0002]    Keeping one&#39;s teeth clean is important not only for dental health, but also for cardiovascular health. Known toothbrushes are aggressive in plaque removal on the easily accessed buccal (cheek) and lingual (tongue) surfaces, but are less effective, or wholly ineffective, on interproximal (between adjacent teeth) surfaces. Aggressive cleaning on one or two surfaces of teeth may be of marginal benefit if the remaining surfaces receive less effective cleaning, since the plaque remains in the mouth to inflict periodontal disease (gumdisease and dental caries (cavities). 
         [0003]    Various devices have been proposed for improved interproximal cleaning. U.S. Pat. No. 4,780,923 (Schultheiss) discloses a handle with a bristle brush at a small angle to the handle. The device is used by inserting the bristles between the teeth and moving the handle towards and away from the teeth to cause the bristles to dislodge plaque from the interproximal surfaces. U.S. Patent Application Publication No. 2005/0037316 (Sholder) (abandoned) discloses a molded tip inserted into an arm adapted to be coupled to a base that generates sonic energy. The molded tip is of generally conical shape and includes elastomeric flat-faced flanges extending perpendicularly outwards from the base to the tip in a staggered pattern. 
         [0004]    With known devices, often the brush bends when fitted in between the teeth. In addition, since interproximal embrasures (the spaces between teeth) vary from 0.1 to 6 mm or larger, a successful interproximal device must be able to work in a range of aperture sizes. 
         [0005]    Accordingly, there is room for an improved interproximal cleaning device. 
       SUMMARY OF THE INVENTION 
       [0006]    In accordance with an aspect of this invention, there are provided a device and a method for cleaning teeth. 
         [0007]    The device comprises a brush, a shaft connected to the brush, a neck surrounding the shaft along a substantial portion of the length of the shaft, and a controller coupled to the shaft at the end of the shaft opposite the brush, the controller being mounted at the base of the neck so as to be movable between a first position that extends the brush away from the neck, and a second position that retracts the brush towards the neck. 
         [0008]    In some cases, the brush has nylon bristles attached to a shaft. The shaft is preferably formed of a material that returns to its original shape after being deformed, such as nickel-titanium. The controller may have at least one surface for manual operation thereof. A tip may be attached to the neck, to surround and guide the brush when the brush is extended. An elbow having an adjustable curvature may be connected between the tip and the neck. 
         [0009]    In some cases, the device also has a motor for moving the shaft so that the brush extends and retracts, or a motor for vibrating the shaft and brush bristles. 
         [0010]    The method comprises inserting, between adjacent teeth, a device having a brush, a controller and a handle, the controller for effecting movement of the brush in a direction generally perpendicular to the handle, and keeping the handle generally stationary while moving the controller up and down to move the brush along front-to-back and back-to-front paths between the adjacent teeth. Moving the controller may occur via pressure from a user&#39;s finger, or via force from a motor in the device. In some cases, the method includes vibrating the brush while it is moved along the front-to-back and back-to-front paths between the adjacent teeth. 
         [0011]    It is not intended that the invention be summarized here in its entirety. Rather, further features, aspects and advantages of the invention are set forth in or are apparent from the following description and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a three-dimensional view of interproximal cleaning device  100 ; 
           [0013]      FIG. 2  is a break-apart view of interproximal cleaning device  100 ; 
           [0014]      FIG. 3  is a partially cut-away side view of interproximal cleaning device  100 ; 
           [0015]      FIG. 4  is a three-dimensional view of interproximal cleaning device  200 ; and 
           [0016]      FIG. 5  is a three-dimensional view of interproximal cleaning device  300 . 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Generally, one of the most difficult areas in the mouth to clean is the interproximal area of the posterior (back) teeth. As used herein and in the claims, cleaning refers to removing food and/or plaque from the surface of at least one tooth. The difficulty is due to the narrowing of the mouth opening towards the throat, and reduced room to maneuver a device inserted in the mouth. The present interproximal device mitigates the maneuvering difficulty by translating movement along its handle to movement of the generally perpendicular brush on its tip. Thus, the interproximal area can be brushed by extending and retracting the brush; the thumb/finger action for moving the retractor often being an easier movement to accomplish than moving the brush directly. Further, the present configuration makes it easier to effect cleaning on both the front-to-back and back-to-front paths of the brush; in contrast, prior art devices generally effect the majority of their cleaning on the front-to-back path. These advantages are also present when using the device on the anterior (front) teeth. 
         [0018]    Other difficult areas to clean are under a dental implant bridge, under a tooth bridge, and around orthodontic braces; the present device is also effective in these areas. 
         [0019]    Additionally, some types of manual disabilities make it difficult for the disabled person to use conventional interproximal cleaners; the present device configuration is easier for these disabled persons to use due to control of the spring loaded interproximal tip or motorized control switch located on the handle. 
         [0020]    Referring now to the drawings, and in particular to  FIG. 1 , there is illustrated interproximal device  100  having brush  150 , tip  140 , elbow  155 , coupler  157 , neck  110 , controller  130  having surfaces  130 A and  130 B, and handle  120 . The apparatus illustrated in  FIG. 1  is adapted for retracting and extending brush  150  by moving controller  130 , thereby enabling improved interproximal cleaning. 
         [0021]      FIG. 2  shows a break-apart view of device  100 , including the aforementioned parts and shaft  152 , membrane  158 , spring or coil  160 , cavity  165 , U-shaped groove  122 , slot  124 , prong  131 A, prong receiver  131 B, landing pad  132 , and base  162 . 
         [0022]    The housing of device  100  comprises tip  140  connected, such as by being screwed, to the outer edge of elbow  155  which is screwed into coupler  157  that in turn is connected to neck  110  that is adjacent to handle  120 . In some embodiments, device  100  is disposable and/or proportionally smaller to be in a “travel size” configuration. 
         [0023]    For consumer use, the housing of device  100  is cleaned by placing device  100  under running water. For consumer use, tip  140  and brush  150  are replaceable. For consumer use, the bottom of neck  110  may be glued to the top of handle  120 . 
         [0024]    For professional use, device  100  is sterilized in an autoclave between uses. For professional embodiments, elbow  155 , coupler  157  and neck  110  have small ventilation holes (not shown) that facilitate penetration of steam from the autoclave (steam sterilizer) or other suitable sterilizer. For professional use, tip  140 , brush  150 , shaft  152  and coil  160  are replaceable or disposable. For professional use, the bottom of neck  110  has flanges (not shown) that enable a removable force-fit into the top of handle  120 . 
         [0025]    Tip  140  is formed of rubber or similar material in a generally conical tapered shape, and is intended to be replaced from time to time as it may wear with use. When brush  150  is retracted, its end is inside tip  140 ; whereas when brush  150  is extended, its end extends beyond tip  140 . As discussed below, the amount of extension is controllable by the user. Tip  140  screws into elbow  155  (the threaded portions of tip  140  and elbow  155  are not shown). In other embodiments, the inner circumference of tip  140  is slightly smaller than the outer circumference of elbow  155 , and tip  140  is pressed into place surrounding the top edge of elbow  155 . In other embodiments where tip  140  is not replaceable, it is glued to elbow  155 , or formed as an extension to elbow  155 . Tip  140  serves to assist in positioning brush  150 , to clean, massage and stimulate the gums of the user which increases blood flow and improves the user&#39;s immune system&#39;s response to bacteria, and to clean brush  150  as brush  150  is retracted due to a squeegee action on the bristles of brush  150 . 
         [0026]    Positioning brush  150  is important. With prior interproximal devices, the brush often quickly bends with use so that it no longer inserts perpendicularly between teeth, making it difficult to use in the mouth, more susceptible to breakage, and reducing the lifetime of the device. Tip  140  and the retractable nature of brush  150  mitigates these problems in device  100 . 
         [0027]    Elbow  155 , coupler  157 , neck  110  and handle  120  are formed of plastic, such as cellulose acetate propionate, nylon, polyethylene, polypropylene, polycarbonate, polyethylene terephthalate or the like. In other embodiments, these parts are formed of metal. In some embodiments, the curvature of elbow  155  can be adjusted by bending elbow  155 , to achieve a more comfortable wrist position for the user. In some embodiments, elbow  155  has small ventilation holes so that the bristles of brush  150  can “breathe” and dry after use; these ventilation holes are also helpful when elbow  155  is intended to be cleaned in an autoclave. 
         [0028]    Neck  110  serves to support shaft  152 . Neck  110  has guides to create a channel for shaft  152 . In other embodiments, neck  110  has a thin channel for shaft  152 . The top of neck  110  serves as a stop point for brush  150 . The length of neck  110  is selected so as to conveniently place brush  150  at the back of the mouth and avoid the need to put the user&#39;s hand in his or her mouth. 
         [0029]    In some embodiments, membrane  158  is located in coupler  157 , or at or near the top of neck  110  to prevent liquid leaking into the shaft channel. Membrane  158  is a flexible toroidal surface that enables shaft  152  to move up and down through its center. 
         [0030]    In other embodiments, the bottom of brush  150  has a dish-shaped portion (not shown) that abuts the top of neck  110 . When retracted, the dish-shaped portion fits snugly in the channel for brush  150  and prevents leakage into the channel. 
         [0031]    Handle  120  provides a comfortable area for a user&#39;s hand to wrap around. The top of handle  120  is formed into cavity  165 . Cavity  165  has opposing slots  124 , discussed below. On the outside of handle  120 , slots  124  are formed in respective U-shaped grooves  122 . The bottom of handle  120  is connected to base  162 . Base  162 , at the bottom of handle  120 , generally rests in the user&#39;s palm, and so has a comfortable rounded shape lacking sharp edges that would cause discomfort to a user. 
         [0032]    Brush  150  comprises nylon bristles attached to shaft  152 . The length of the bristles may depend on the use, i.e., for teeth or implants and the size of the interproximal space. Generally, the bristle diameter is 1.5-8.5 mm, while shaft  152  has a diameter of 0.4-1.3 mm; the bristles have a length of 11-22 mm. When brush  150  is completely retracted or completely extended, it has a linear shape; at intermediate retraction points, brush  150  may be curved. In  FIG. 2 , brush  150  has a cylindrical shape with uniform cross-section. In other embodiments, brush  150  is tapered at its point to better fit into small interproximal embrasures. In still other embodiments, brush  150  is of generally conical shape and includes elastomeric flat-faced flanges extending perpendicularly outwards from the base to the tip in a staggered pattern. Other brush shapes and compositions will be apparent to those of ordinary skill. 
         [0033]    Shaft  152  is formed of flexible material that returns to its original shape after being deformed, such as nickel-titanium. In some embodiments, the top part of shaft  152  is coated with plastic or silicone or brush  150  and shaft  152  are made out flexible plastic with plastic bristles to ensure that it does not scratch tooth surfaces or implant posts. The top part of shaft  152  is formed of twisted wire that restrains bristles; in other embodiments, the top of shaft  152  is otherwise suitably connected to brush  150 . Shaft  152  is enclosed along most of its length by elbow  155 , coupler  157  and neck  110 , which together have an internal channel (not shown) formed by guide pieces or a hollowing. The bottom of shaft  152  is enclosed by coil  160 . In the embodiment of  FIG. 2 , the bottom of shaft  152  is connected to the bottom of coil  160 . In other embodiments, the bottom of shaft  152  is connected to a circular plate having a diameter larger than the diameter of coil  160 . In some embodiments, the bottom of shaft  152  is connected to the top of coil  160 . 
         [0034]    Coil  160  is a spiral of metal formed into a spring. In other embodiments, coil  160  is formed of plastic. In other embodiments, coil  160  is omitted. Coil  160  serves to exert pressure against the bottom of shaft  152  and facilitate retraction of shaft  152 . The top of coil  160  fits into the underside of neck  110 . In some embodiments, neck  110  has a cavity at its base for accommodating the top of coil  160 . The bottom of coil  160  fits into cavity  165  at the top of handle  120 . 
         [0035]    Controller  130  is formed by snapping together surfaces  130 A and  130 B, each of which is formed of plastic or metal and preferably has ridges to increase traction with respect to the user&#39;s thumb. The underside of surface  130 A has prong  131 A projecting perpendicularly therefrom, while the underside of surface  130 B has prong receiver  131 B projecting perpendicularly therefrom. Prong  131 A snaps into prong receiver  131 B. The top of surfaces  130 A,  130 B move along landing pads  132  formed on opposite sides in the base of neck  110  (only one landing pad  132  is visible in  FIG. 2 ). The bottom of surfaces  130 A,  130 B move along U-shaped grooves  122  formed on opposite sides in the top of handle  120  (only one U-shaped groove  122  is visible in  FIG. 2 ). U-shaped groove  122  has slots  124  for accommodating prong  131 A and prong receiver  131 B. 
         [0036]    As shown in  FIG. 3 , prong  131 A is snapped into prong receiver  131 B to form member  131 C, so that coil  160  rests atop member  131 C. Pushing controller  130  to its topmost position in landing pad  132  compresses coil  160  providing energy thereto, and fully extends brush  150 . Pushing controller  130  to its bottommost position in U-shaped groove  122  enables coil  160  to return to its natural length using its stored energy to pull shaft  152  downwards, and fully retracts brush  150 . In operation, a user&#39;s thumb moves controller  130  up and down, to cause brush  150  to move in front-to-back and back-to-front paths along the interproximal surfaces of adjacent teeth. Thus, device  100  can remain generally stationary while brush  150  is at the back of a user&#39;s mouth and the user&#39;s thumb is controlling the movement of brush  150 . This configuration is convenient. Additionally, for persons with impaired gripping ability, such as those with arthritis, it is substantially easier to hold handle  120  and move controller  130 , than to move a thinner conventional device at the back of the mouth. In some embodiments, there is a structure, such as an internal hook, for fixing controller  130  in its topmost position, thereby causing interproximal device  160  to function with a non-retractable brush. 
         [0037]    Dimensions of the parts of device  100  may be as follows. These dimensions may vary depending on the particular construction of device  100 , and its intended user, such as adult or child. 
         [0038]    Lengths: tip  140 —5 mm; brush  150 —11-22 mm; elbow  155  (including curvature)—10-12 mm; coupler  157 —5 mm; neck  110 —59-61 mm; coil  160 —10 mm; surface  130 A,  130 B—26 mm; and handle  120 —100 mm. The length of landing pad  132  depends on the length of brush  150 , with a longer lading pad length corresponding to a longer brush length. The inner circumference of tip  140  is about 0.5-1.5 mm. 
         [0039]      FIG. 4  is a three-dimensional view of interproximal cleaning device  200  that is similar to interproximal cleaning device  100 ; for brevity, only the differences are discussed. 
         [0040]    U.S. Pat. No. 5,123,841 (Millner), the disclosure of which is hereby incorporated by reference in its entirety, shows an interproximal dental plaque remover having a substantially fixed brush that is vibrated by a motor with an eccentrically mounted cylindrical weight. The vibration splays the bristles of the brush into the furca (below gum line), subgingival pockets at the cemento-enamel junction (CEJ), thereby disrupting adherent plaque colonies and mobilizing bacteria into the subgingival fluids. 
         [0041]    Interproximal cleaning device  200  includes motor  270 , battery cover  280 , battery  290  and activation switch  285 . Motor  270  operates as described in the Millner &#39;841 patent by imparting vibratory motion to shaft  252  so that, in addition to the in-and-out manual movement of brush  250 , there is also small vibratory movement. Battery cover  280  enables access to a chamber for holding battery  290 . Activation switch  285  enables a user to activate and deactivate motor  270 . Accordingly, device  200  can be used in three modes: (a) with motor  270  deactivated, so that device  200  operates exactly as does device  100 , (b) with motor  270  activated and brush  250  maximally extended, so that device  200  operates substantially as described in the Millner &#39;841 patent, or (c) with motor  270  activated and brush  250  being manually moved between extension and retraction. 
         [0042]      FIG. 5  is a three-dimensional view of interproximal cleaning device  300  that is similar to interproximal cleaning device  200 ; for brevity, only the differences are discussed. 
         [0043]    U.S. Pat. No. 4,787,847 (Martin), the disclosure of which is hereby incorporated by reference in its entirety, shows an electric toothbrush wherein the brush is vibrated at subsonic frequencies to assist in subgingival plaque removal. 
         [0044]    Interproximal cleaning device  300  includes motor  370  substantially as described in Martin, except that device  300  is configured so that motor  370  causes brush  350  to extend and retract at generally subsonic frequencies. Device  300  is powered by battery  390  rather than by a connection to a wall outlet. Device  300  lacks the ability for finger-operated manual retraction and extension of brush  350 ; however, manual movement of brush  350  can be accomplished by moving handle  320 . Activation switch  385  is preferably located between neck  310  and handle  320 , i.e., at the bottom of neck  310  and/or the top of handle  320 , so that the user can more easily activate and deactivate motor  370  while using device  300 . Generally, device  300  serves as an interproximal powered tooth brush. 
         [0045]    Although illustrative embodiments of the present invention, and various modifications thereof, have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to these precise embodiments and the described modifications, and that various changes and further modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.