Abstract:
The invention relates to a method for bleaching and cleaning teeth for whitening purposes that involves the substantially simultaneous mixing of peroxide and an abrasive cleaning agent and application of the mixture to a patient&#39;s teeth, and burnishing the mixture onto the enamel of the teeth.

Description:
REFERENCE TO PRIOR APPLICATIONS  
       [0001]    This application is a utility application based on and claims priority from U.S. Provisional Patent Application Serial No. 60/177,538 filed on Jan. 21, 2000. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    There are many prior art tooth bleaching/whitening systems that utilize various peroxides to whiten teeth. Peroxide bleaches through an oxidation-reduction reaction. Peroxide bleaches teeth with which it comes into contact with, the compounds on the teeth serving as the oxidized reactant and the peroxide serving as the oxidizing agent in the reaction. Peroxide may be applied to teeth using various methods and in various concentrations and mixed with various other ingredients. This process serves to whiten the teeth. Having whiter teeth is considered by many to be an aesthetically desirable trait.  
           [0003]    Using a simple tooth whitening method, peroxide, usually carbamide (urea peroxide), is placed upon a patient&#39;s teeth, the carbamide rapidly releases oxygen in an oxidation-reduction reaction and bleaches the enamel of the teeth. A popular use of this method is to place a carbamide-bearing compound in a dental tray and apply the tray about the patient&#39;s teeth for a length of time ranging from seconds to minutes or even overnight and, if necessary, repeat the process either immediately thereafter or at some later time.  
           [0004]    This method has several drawbacks. First, carbamide is an irritant. When used in a dental tray, as described above, the carbamide comes into prolonged contact with the patient&#39;s gums, causing discomfort ranging from mild irritation to severe pain, depending upon the individual patient and the concentration of the carbamide. There is also speculation within the dental profession that prolonged exposure to carbamide may have detrimental effects upon gum and dental tissues. Second, the mere placement of a dental tray about the patient&#39;s teeth does not facilitate the opening of the enamel rods of the teeth. Under normal conditions, the enamel rods of the teeth are closed. If they are open, the enamel rods can uptake carbamide significantly faster and in larger quantity than when they are closed. Opening the enamel rods facilitates a faster, more thorough whitening effect from the carbamide. Tooth bleaching using only carbamide in a dental tray will likely require several applications to achieve a desired level of whitening due to closed rods. This method is even less effective when used by home consumers rather than by dental professionals because carbamide for home use is generally available only in very small concentrations and thus lacks even the limited whitening capabilities of higher concentration, professional use carbamide.  
           [0005]    Another method of peroxide tooth whitening uses a dental laser. Carbamide gel is applied directly to the teeth. A beam from a dental laser is then directed onto the gel and the resulting interaction between the two rapidly activates the oxygen in the gel and thus starts a whitening process.  
           [0006]    The laser method has the first disadvantage of requiring a laser. Lasers are expensive devices that are not possessed or easily attained by all dental professionals. Lasers are also dangerous instruments which may only be properly used by dental professionals and thus are not available to the home consumer. A second disadvantage of the laser method is that it has multiple, time-consuming steps. First, the gel must be applied to the teeth. Then, the laser beam must be directed onto each tooth. Also, since the lasering of all the teeth takes time, the gel setting on portions of teeth not being lasered will already begin reducing, resulting in uneven whitening among some of the teeth.  
           [0007]    Many methods of opening the enamel rods, and thereby assisting in the uptake of carbamide, are known in the prior art. All of these methods suffer from a variety of disadvantages. One method of facilitating the opening the enamel rods during bleaching is acid etching. An acid of sufficient concentration is applied to the teeth and the chemical action of the acid serves to open the enamel rods of the teeth. After the acid application, carbamide is then applied to the teeth. The disadvantages of acid etching are numerous. Acid of concentration sufficient to open enamel rods is somewhat dangerous. In other words, acid etching can only be applied by a dental professional and not a home consumer. Acid etching increases the sensitivity of teeth, making the patient more susceptible to discomfort during and after the process. Also, the application of acid to the teeth can cause severe irritation to the patient&#39;s gums and possible damage to the gum and dental tissues. Further, the acid etching, if not closely monitored, can ultimately cause the destruction of the tooth enamel. Acid etching also has multiple, time-consuming steps. Acid etching is tedious process that requires extreme attention to detail to minimize its potentially dangerous side effects.  
           [0008]    Another method of facilitating the opening of the enamel rods during bleaching involves the use of a pre-mixed carbamide and dental abrasive agent mixture. Such a mixture is applied to the teeth and is then burnished onto the teeth using either a powered dental cleaning cup or brush, or scrubbed on with a more prosaic toothbrush. The dental abrasive agent in the mixture of prophy paste, serves to abrade the teeth, which does three things, 1) it opens the enamel rods to facilitate their uptake of the carbamide, 2) it removes stains in the tooth enamel through mechanical scrubbing action, and 3) it polishes the tooth enamel through mechanical buffing action. Fluoride can be included in the dental abrasive agent. In such a mixture, fluoride decreases tooth sensitivity, thus making the whitening process more comfortable to the patient. This method has the disadvantage of delivering weakened carbamide to the teeth, resulting is less effective whitening. Most readily and economically available carbamides are highly unstable oxidizing agents which lose much of their oxygen (reduce) when exposed to air and when mixed with other ingredients such as prophy paste for an extended period of time. Without oxygen, carbamides can no longer act as oxidizing agents and therefore cannot bleach. Pre-mixing carbamide with prophy paste causes the carbamide to reduce via its mixture with prophy paste if it is not used within a short time thereafter. Thus, the effectiveness of pre-mixed peroxide as a tooth whitener is limited.  
         OBJECTS AND SUMMARY OF THE INVENTION  
         [0009]    It is an object of this invention is to provide a safe, effective and rapid tooth whitening system.  
           [0010]    It is another object of this invention is to provide a tooth whitening system that minimizes patient irritation and injury.  
           [0011]    It is a further object of this invention is to provide an easy to use tooth whitening system.  
           [0012]    It is still another object of this invention is to provide a tooth whitening system that effectively whitens, as well as cleans and polishes.  
           [0013]    It is yet a further object of this invention to provide even whitening among the various teeth being whitened at a given time.  
           [0014]    Briefly, in accordance with the present invention, these and other objects are attained by providing an improvement in the abrading technique, a method for bleaching and cleaning teeth which comprises providing quantities of peroxide and an abrasive cleaning agent, mixing the two together to form a mixture and, substantially immediately after mixing, applying the mixture to the teeth to be bleached. Applying the mixture can include placing the mixture into a holding container, removing the mixture from the holding container with a powered dental cleaning cup and applying the mixture to the teeth to be bleached using the same cup.  
           [0015]    An apparatus for practicing this method is a two barrel (container) applicator device, similar in configuration to a caulking gun. The applicator contains peroxide and an abrasive cleaning agent in separate barrels. The barrels are sealed to prevent exposure of the peroxide to both the abrasive cleaning agent and air, both of which serve to reduce the oxygen content of the peroxide and its ability to act as an oxidizing or bleaching agent. The applicator also has a mixing applicator tip, which is connected to an end of each barrel, that mixes the peroxide and abrasive cleaning agent as they are being extruded onto the patient&#39;s teeth. Keeping the peroxide and abrasive cleaning agent apart from each other and from exposure to air until ready to use creates an ideal situation.  
           [0016]    The peroxide is mixed with the abrasive cleaning agent in the mixing applicator tip, exposed to air only as it is extruded from the mixing applicator tip into a holding container. From the container, the mixture can be applied to the teeth, preferably immediately after extrusion or at most shortly thereafter. This allows the peroxide to retain most of its oxygen, and thereby its bleaching strength, until it is actually placed on the teeth to be bleached. Alternately, the peroxide is completely mixed with the abrasive cleaning agent such that the peroxide and the abrasive cleaning agent are evenly distributed throughout the mixture. This insures that the mixture is consistent, resulting in even cleaning and whitening of the various teeth.  
           [0017]    The abrasive cleaning agent cleans and opens the enamel rods while the carbamide is also applied to the rods at the same time that they are being opened. This allows maximum peroxide uptake before the rods begin to close. Upon application to the teeth, the mixture is burnished into the tooth using the powered dental cleaning cup. This process, like the normal application of prophy paste, spreads very little excess mixture so that it cannot come into contact with the gums and cause irritation.  
           [0018]    The abrasive cleaning agent, through mechanical abrasion, causes the immediate opening of the enamel rods in the teeth. Simultaneously, the open enamel rods rapidly and voluminously uptake the highly-oxygenated carbamide and fast, effective bleaching results. The burnishing of the mixture&#39;s abrasive cleaning agent also results in scrubbing stains from and polishing the enamel of the teeth, further enhancing both the health and appearance of the teeth. The apparatus is operated by a hand-actuated mechanism which incrementally forces dual plungers into the barrels containing the peroxide and the abrasive cleaning agent and incrementally causes their mixing and extrusion of the mixture. The amount of mixture extruded can be easily controlled by the operator (dental professional).  
           [0019]    The method and apparatus of the invention may also be practiced by the home consumer. A paste similar to toothpaste but containing an abrasive can be used in place of a professional abrasive cleaning agent, such as prophy paste. A firm bristle toothbrush, electric toothbrush or home dental cleaning/polishing cup can be used in place of a powered dental cleaning cup. The peroxide used may be of lower concentration than professional-grade peroxide and the paste may be less abrasive than prophy paste to satisfy pharmaceutical standards or other safety concerns. This alternate home method, by virtue of its potentially lower concentration of peroxide, its less abrasive paste and its less vigorous brushing mechanism, may be less effective than the preferred embodiment of the method. However, it is still a very effective method of whitening teeth when used as a part of a dental hygiene regimen.  
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0020]    A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily understood by reference to the following detailed description when considered in connection with the accompanying drawings in which:  
         [0021]    [0021]FIG. 1 is a perspective view of an embodiment of apparatus in accordance with the invention utilized in the preferred embodiment of the method of the invention;  
         [0022]    [0022]FIG. 2 is a front elevation, exploded view of the components of the apparatus shown in FIG. 1;  
         [0023]    [0023]FIG. 3 is a perspective view of the apparatus of FIG. 1 illustrating the addition of the container component to the applicator;  
         [0024]    [0024]FIG. 4 is a perspective view of the apparatus of FIG. 1 in use prior to mixing and application of the mixture; and  
         [0025]    [0025]FIG. 5 is a perspective view of the apparatus being utilized during simultaneous mixing and application in accord with the preferred embodiment of the method of the invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0026]    In accordance with the present invention, a method for bleaching, cleaning and teeth whitening comprises the steps of providing a quantity of peroxide, providing a quantity of abrasive cleaning agent, completely mixing a portion of said peroxide with a portion of said abrasive cleaning agent to form a mixture wherein the portion of peroxide and the portion of abrasive cleaning agent are evenly distributed, substantially immediately after the mixture step placing/applying the mixture into a holding container, removing the mixture from the container with a powered dental cleaning cup and using this cup to apply the mixture to at least one tooth. This method provides safe, rapid tooth whitening that also cleans and polishes teeth. The method can be practiced by dental professionals and home consumers while minimizing the potential for patient injury and irritation.  
         [0027]    Referring to FIGS.  1 - 5 , a preferred embodiment of an apparatus for practicing the method of the invention comprises an applicator loaded with a container unit which contains the peroxide, i.e., carbamide, and the abrasive cleaning agent, i.e., prophy paste with fluoride, which is applied using a mixing applicator tip. Container unit  30  comprises a first barrel  15  and a second barrel  25  which are joiningly attached to each other on their respective exteriors for ease of handling. Container unit  30  is removably attachable at a plunging end  35  to dual plunger applicator  100  at ends of a pair of plungers  110  and  120 . Container unit  30  is secured into applicator  100  by locking mechanism  105 . Plungers  110  and  120  are formed as a single plunger unit  130  interconnected by a grip  140  having a plurality of ratchet teeth  145 . Applicator  100  also has a ratcheting mechanism  150  with actuation lever  155 , release  160  and handle  165 . Ratcheting mechanism  150  engages ratchet teeth  145 . Container unit  30  is connected at an orifice end  32  to a mixing applicator tip  40 .  
         [0028]    As shown in FIG. 2, the bleaching and cleaning method for tooth whitening comprises placing carbamide  10  into barrel  15  and fluoridated prophy paste  20  into barrel  25 . This placement preferably takes place under controlled, factory conditions to avoid spillage, contamination and exposure of the carbamide to air. The placement may alternately take place under sanitary conditions in a dentist&#39;s office, wherein the method of the invention is still practiced but without the advantage of avoiding any contact between the carbamide and air. Mixing applicator tip  40  is attached to orifice  32  of container unit  30 .  
         [0029]    Next, as shown in FIGS. 3 and 4, plunger unit  130  is placed in its retracted position A. This is accomplished by pressing release  160  while pulling grip  140  away from mixing applicator tip  40 . The filled container unit  30  is then attached to applicator  100  at plunging end  35  and secured thereto by locking mechanism  105 . As shown in FIG. 4, applicator unit  100  is then gripped around handle  165  and actuation lever  155  by a user&#39;s hand. The applicator unit  100  is then placed in proximity to a dappen dish  200 . As shown in FIG. 5, the user then squeezes the actuation lever  155  and the handle  165  together. This ratchets ratchet teeth  145  and causes plunger unit  130  to move toward mixing applicator tip  40  (extended position B), applying constant, equal and controlled pressure to carbamide  10  and prophy paste  20  in separate barrels  15  and  25  of container unit  30  respectively. The actuation is repeated until the pressure is sufficient to force an amount of carbamide  10  and prophy paste  20  into and through mixing applicator tip  40 , wherein they are completely mixed together.  
         [0030]    The mixture  60  is extruded from mixing applicator tip  40  into dappen dish  200 . A dental cleaning cup is then immediately dipped into dappen dish  200  and mixture  60  is removed therefrom. The mixture is burnished onto the teeth with the dental cleaning cup in the same manner in which prophy paste alone is normally burnished onto teeth for cleaning (not shown).  
         [0031]    In alternate embodiments, the dental cleaning cup may be replaced by a number of other mechanical cleaning implements. These include but are not limited to a firm bristle toothbrush, an electric tooth brush and a home dental cleaning/polishing cup. Also, in alternate embodiments, the applicator may be replaced by a number of other application implements. These include but are not limited to a plunger apparatus similar to those used to mix and apply epoxy.  
         [0032]    Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. Accordingly, it is understood that other embodiments of the invention are possible in the light of the above teachings.