Dispenser and method for applying a tooth whitening composition

Abstract

A method for applying a composition to teeth and a dispenser for dispensing a composition. The method of the present invention is directed to the storage and dispensing of a composition. During storage and subsequent use the composition in the storage chamber must be maintained segregated from the applicator surface. This is accomplished by delivering the composition from the storage chamber through a delivery channel having a length and a cross-sectional diameter sufficient to preclude the migration of moisture and the enzyme catalase from the application surface to the storage chamber. The composition is applied to teeth by means of bristles, a sponge surface or fibrillated surface. This applicator can be used with both aqueous and non-aqueous compositions.

What is claimed is: 
     
         1 . A method of applying a peroxide containing tooth whitening composition comprising:
 a. providing said tooth whitening composition in a housing sealed at one end and having an application means at another end, the application means comprising an applicator surface having an aperture therein at an end of a channel, said aperture having a cross-sectional area and said channel a length in combination sufficient to prevent the migration of substances from the application means into the housing between applications;   b. dispensing the tooth whitening composition through said channel and said aperture and to the applicator surface; and   c. applying the tooth whitening composition from the applicator surface directly onto at least one tooth.   
     
     
         2 . The method according to  claim 1  wherein the channel has a cross-sectional area of less than about 5 mm 2 . 
     
     
         3 . The method according to  claim 1  wherein said tooth whitening composition has a moisture content of less than about 1 percent by weight. 
     
     
         4 . The method according to  claim 1  wherein the tooth whitening composition has a peroxide content of about 1% to about 35% by weight. 
     
     
         5 . The method according to  claim 1  wherein said application means further comprises a plurality of bristles surrounding said aperture. 
     
     
         6 . The method according to  claim 1  wherein said channel has a diameter of less than about 4 mm. 
     
     
         7 . The method according to  claim 1  wherein the application means comprises a fibrillated surface. 
     
     
         8 . A dispenser for a composition comprising:
 a housing comprising a reservoir having a channel, a composition stored in the reservoir;   an applicator comprising an applicator surface having an aperture therein provided at an end of the channel; and   a drive mechanism disposed within the housing, the drive mechanism comprising:
 a moveable piston attached to a threaded piston rod; 
 a stationary unit; and 
 a rotary unit comprising rotation limiting cams that directly engage and interact with a cooperating cam surface on said stationary unit; and 
   wherein interaction between the rotation limiting cams of the rotary unit and the cooperating cam surface of the stationary unit limits rotation of the threaded piston rod to only one direction that moves the movable piston towards the applicator to dispense the composition through the channel and the aperture to the applicator surface.   
     
     
         9 . The dispenser according to  claim 8  wherein the aperture has a cross-sectional area of less than about 2 mm 2 . 
     
     
         10 . The dispenser according to  claim 8  wherein the channel has a length of more than about 10 mm. 
     
     
         11 . The dispenser according to  claim 8  wherein the channel has a diameter of less than about 4 mm. 
     
     
         12 . The dispenser according to  claim 8  wherein the applicator comprises a plurality of bristles surrounding the aperture. 
     
     
         13 . The dispenser according to  claim 8  wherein the aperture comprises a plurality of apertures having a combined surface area of less than about 10 mm 2 . 
     
     
         14 . The dispenser according to  claim 8  wherein the composition is a peroxide containing tooth whitening composition for application onto at least one tooth. 
     
     
         15 . The dispenser according to  claim 8  wherein the housing is elongated along a longitudinal axis, and wherein the applicator surface of the applicator is a planar surface that is oriented oblique to the longitudinal axis. 
     
     
         16 . The dispenser according to  claim 15  further comprising a plurality of protrusions extending from the applicator surface. 
     
     
         17 . The dispenser according to  claim 16  wherein each of the protrusions extends up to about 3 mm in length. 
     
     
         18 . The dispenser according to  claim 8  wherein the threaded piston rod extends through the stationary unit and the rotary unit. 
     
     
         19 . A dispenser for a composition comprising:
 a housing extending along a longitudinal axis and comprising a reservoir that stores a composition;   an applicator provided at an end of the housing, the applicator having a planar applicator surface having an aperture therein, the planar applicator surface being oriented oblique to the longitudinal axis of the housing; and   a drive mechanism disposed within the housing and comprising a piston that moves in only one direction towards the applicator to dispense the composition from the reservoir to the applicator surface.   
     
     
         20 . The dispenser according to  claim 19  further comprising a plurality of protrusions extending from the applicator surface a distance less than 3 mm.