5,891,453
`[11] Patent Number:
`[19]
`United States Patent
`
`Sagel et al.
`[45] Date of Patent:
`Apr. 6, 1999
`
`U8005891453A
`
`[54] DELIVERY SYSTEM FOR A TOOTH
`WHITENER USING A STRIP OF MATERIAL
`HAVING LOW FLEXURAL STIFFNESS
`
`[75]
`
`.
`.
`Inventors. gilgllglfiEkssfilggl’Cfi/ilslgg’atliQObert
`Frederick James’Rohman, li/laineville,
`an of Ohio
`
`.
`.
`[73] ASSlgnee' The .Pmcler 8? Gamble company,
`Cmcmnalh Ohm
`
`[21] Appl. NO’: 40’000
`[22]
`Filed:
`Mar. 17, 1998
`
`_
`_
`Related U.S. Appllcatlon Data
`
`[63] Continual“Il'ill'Part Of Ser- No- 870,330, JUIL 6, 1997-
`[51]
`Int. Cl.5 ............................... A61K 6/02; A61K 7/16;
`A61K 7/20; A61K 33/40
`.............................. 424/401; 424/49; 424/53;
`[52] US. Cl.
`424/613
`,
`.
`.
`[58] Fleld 0f Search “““““““““““““““ 433’215;2442/:/94051é
`_
`
`[56]
`
`References Cited
`US. PATENT DOCUMENTS
`e1 zman ...................................
`5/1976 W 't
`32/14
`2/1979 Weitzman .....
`32/14
`
`4/1982 Arcan etal.
`..
`.. 433/71
`3/1988 Golub ............
`433/215
`
`.. 128/71
`5/1988 Englebert et al.
`
`11/1988 Morais ..........
`,. 433/60
`1/1989 Golub ...................
`433/215
`
`2/1990 Yanagibashi ct al.
`.................. 424/448
`
`,
`,
`3955281
`4,138,814
`4,324,547
`4,728,291
`4,741,941
`4,786,253
`4,799,888
`4,900,554
`
`............................ 524/37
`11/1992 Kuroya et a].
`5,166,233
`. 424/616
`5/1994 Curtis et a1.
`5,310,563
`
`..... 433/215
`7/1994 Gaglio et al.
`5,326,685
`.. 433/1681
`8/1994 Tarius ..........
`5,340,314
`
`.. 132/329
`10/1996 Pieczenik
`5,560,379
`
`.
`6/1997 Curtis et a1.
`5,639,445
`404/49
`2/1998 Yarborough ............................. 433/215
`5,713,738
`FOREIGN PATENT DOCUMENTS
`
`3/1988
`Sho 63—54318
`Japan ............................... A61K 9/70
`1/1998
`Hei 10— 17448
`Japan .............
`A61K 7/16
`
`2 108841A 5/1983 United Kingdom ............. A61K 9/24
`7/1997 WIPO .............................. A61K 7/22
`WO 97/25968
`
`Primary Examiner—Shep K. Rose
`Attorney, Agent, or Firm~Angela Marie Stone; Betty J. Zea
`[57]
`ABSTRACT
`
`A system for delivering a tooth whitening substance to a
`plurality of adjacent teeth, the delivery system comprising a
`Strip 0f fleXible material haVing a SUfliCien‘ fleXibfli‘Y ‘0
`form a curved shape on a plurality of adjacent teeth and a
`mm Whitening subsmnce' The Strip 0f material is readily
`conformable to the teeth surfaces and to interstitial tooth
`spaces without permanent deformation when the delivery
`system is placed thereagainst. The tooth whitening sub-
`stance is applied to the strip of material such that when the
`delivery system is placed on the surface of the teeth, the
`substance contacts the surface providing an active onto the
`surface. The substance also provides adhesive attachment
`between the strip of material and the surface to hold the
`delivery system in place for a sufficient amount of time to
`allow the active to act upon the surface. The method of
`delivery includes pre-coating the strip of material or having
`the wearer apply substance to the strip of material and then
`applying the delivery system to the teeth surfaces.
`
`22 Claims, 3 Drawing Sheets
`
`CLIO USA
`EXHIBIT 1001
`PAGE 000001
`
`PAGE 000001
`
`CLIO USA
`
`EXHIBIT 1001
`
`

`

`US. Patent
`
`Apr. 6,1999
`
`Sheet 1 0f3
`
`5,891,453
`
`
`
`PAGE 000002
`
`PAGE 000002
`
`

`

`US. Patent
`
`Apr. 6, 1999
`
`Sheet 2 0f 3
`
`5,891,453
`
`Fig. 5
`
`PAGE 000003
`
`PAGE 000003
`
`
`
`

`

`US. Patent
`
`Apr. 6,1999
`
`Sheet 3 0f3
`
`5,891,453
`
`Fig. 10
`
`PAGE 000004
`
`PAGE 000004
`
`

`

`5,891,453
`
`1
`DELIVERY SYSTEM FOR A TOOTH
`WHITENER USING A STRIP OF MATERIAL
`HAVING LOW FLEXURAL STIFFNESS
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This is a continuation-in-part of application Ser. No.
`08/870,330, filed on Jun. 6, 1997.
`
`FIELD OF THE INVENTION
`
`The present invention relates to a system for the delivery
`of a tooth Whitening substance to a plurality of adjacent teeth
`and more particularly to such delivery system wherein the
`substance is protected from erosion and interaction With
`saliva Within the mouth for a time sufficient to enable an
`
`active provided by the substance to cause tooth Whitening.
`The delivery system comprises a strip of material and tooth
`Whitening substance. Even more particularly, the present
`invention relates to disposable delivery systems that are
`inexpensive and unobtrusive. The present invention also
`relates to a method of delivering a tooth Whitening substance
`to a plurality of adjacent teeth.
`
`BACKGROUND OF THE INVENTION
`
`The most common implement for dental hygiene is the
`toothbrush. The mechanical action of the toothbrush bristles
`
`aids in the removal of food particles, plaque, and the like.
`The toothbrush is normally used with a toothpaste. Prior to
`about 1955, a typical toothpaste consisted of a surfactant and
`an abrasive material. These products were simply intended
`to augment the mechanical action of the brushing.
`In 1955, CREST. toothpaste With fluoride, a Trademark
`of The Procter & Gamble Company of Cincinnati, Ohio, was
`introduced and the toothbrush and fluoride toothpaste com-
`bination proved to be a suitable means to deliver a fluoride
`treatment to the teeth surfaces. Subsequently, other active
`ingredients, such as tartar control agents, have been added to
`toothpaste to provide further dental hygiene benefits. Con—
`sumers have also turned their attention to the cosmetic
`
`aspects of dental care, such as teeth straightening and
`Whitening.
`Given the success of delivering chemicals which provide
`therapeutic benefits for oral care, it is reasonable to expect
`similar success in accomplishing the cosmetic benefit Via
`routine brushing. However, people who are serious about
`Whitening their teeth and who have been disappointed by the
`results of Whitening dentifrices, often resort to professional
`help for Whitening their teeth.
`Professional teeth Whitening programs provided by den-
`tists generally fall into two categories: an in—office bleaching
`procedure and an outside-the-oflice bleaching procedure.
`The in-office procedure involves several visits, each of
`which begins With the fabrication of a specially fitted rubber
`dam Within the mouth to prevent the bleaching chemicals,
`typically hydrogen peroxide, from contacting the soft oral
`tissue. The strength of the peroxide bleach mandates the use
`of the dam.
`
`The outside-the-oflice bleaching program differs in that
`the patient applies the bleaching agent to his or her own teeth
`using a lower strength chemical over an extended period of
`time, typically several hours a day for several weeks. The
`outside-the-ofllce program typically requires an initial fitting
`in the dentist’s oflice for an appliance Which is specific to the
`particular patient. The appliance is a device that is fabricated
`to fit precisely onto the patient’s teeth and is used to deliver
`
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`2
`to the patient’s teeth a bleaching gel. The patient is respon-
`sible for measuring and applying the bleaching agent to the
`surfaces of the teeth using the appliance as the means for
`delivery and containment.
`Because the appliance is reused, it must be sufficiently
`robust
`to endure repeat handling, cleaning,
`filling,
`installation, and wearing. Such appliances are relatively
`rigid in order to maintain fit during repeat use. Typically, a
`patient uses the device in time periods When social contact
`can be avoided.
`
`There are now non-professional programs available to
`persons interested in Whitening their teeth using commercial
`products available at drug stores. The commercial products
`provide a kit which includes a generic appliance and a
`container of bleaching gel. The obvious appeal is the lower
`cost of the program. A major disadvantage of this “one size
`fits all” appliance is the greater void between the interior
`walls of the appliance and the teeth versus the professionally
`fitted appliance. Hence, in order to insure intimate contact of
`the bleaching gel and the teeth surfaces, more bleaching gel
`is required. Furthermore, the poorer fit means a greater loss
`of bleaching gel onto the gums, into the oral cavity, and
`eventual ingestion. The commercial kits, like the outside-
`the-oflice professionally administered program, require the
`user to clean and to reuse the appliance. Since generic
`appliances are not fitted to the individual user, they are even
`more bulky in the mouth than the fitted appliances and thus
`they restrict social discourse to a greater degree.
`One attempt to remedy some of the problems of the
`commercial kits is disclosed in US. Pat. No. 5,575,654,
`issued to Fontenot on Nov. 19, 1996. Fontenot discloses a
`prepackaged moldable dental appliance, adapted to fit a
`Wide range of variously sized dental arches, which contains
`a premeasured amount of medicinal or bleaching agent. In
`use, the dental appliance is removed from the packaging,
`aligned in a parallel fashion to the edges of the teeth and
`pushed over the teeth in the direction of the periodontal
`tissue until it covers the teeth surfaces.
`
`Another solution is disclosed in US. Pat. No. 5,310,563,
`issued to Curtis et al. on May 10, 1994. Curtis et a1. disclose
`a putty-like material Which is formed by pressing against the
`teeth. It is held in place by mechanical engagement with
`undercut surfaces and by friction. The composition encap-
`sulates the active.
`
`Other methods are disclosed in US. Pat. No. 5,425,953,
`issued to Sintov et al. on Jun. 20, 1995. Sintov et al.
`discloses a liquid polymer composition for bleaching of the
`teeth. The liquid polymer composition forms a film after
`applied to the teeth. Other references which disclose using
`a film in the oral cavity include US. Pat. No. 4,713,243
`issued to Schiraldi et al. on Dec. 15, 1987, and US. Pat. No.
`2,835,628, issued to Saflir on May 20, 1958.
`What is needed is a low cost commercial delivery system,
`Which has a customized fit for a minimal volume of a tooth
`Whitening substance, and which is in conformable contact
`With the appropriate tooth surfaces and interstitial tooth
`spaces for rapid delivery of an active in such substance. In
`addition a delivery system is needed which does not require
`extensive user placement manipulation to be certain of good
`contact. Furthermore, what is needed is a non-bulky active
`containment means that Will permit the wearer to use the
`system during social discourse Without interfering With the
`wearer’s speech or appearance. Also needed is a contain-
`ment means that will protect the tooth Whitening substance
`from erosion from contact With inner mouth surfaces and
`saliva.
`
`PAGE 000005
`
`PAGE 000005
`
`

`

`5,891,453
`
`3
`SUMMARY OF THE INVENTION
`
`In practicing the present invention, a strip of material is
`applied by the wearer to a plurality of adjacent teeth. The
`side of the strip of material facing the tooth is coated with
`a tooth whitening substance. The substance is preferably in
`a viscous state, such as a gel, so that it provides not only the
`active but also tackiness between the teeth surfaces and the
`strip of material to hold the strip of material in place. The
`conformable strip of material is preferably of a size that
`individually fits the front 6—8 teeth of the upper or lower
`rows of teeth when positioned against the teeth. As a soft,
`conformable material, the strip may come into contact with
`the wearer’s gums without causing physical irritation. The
`strip of material readily conforms to the teeth by lightly
`pressing it thereagainst and/or by the wearer gently sucking
`through the gaps between teeth. The strip of material is
`readily conformable without permanent deformation to the
`shape of the teeth when the delivery system is placed
`thereagainst. The strip of material is easily removed by the
`wearer after use by peeling it off. Preferably, each successive
`treatment uses a fresh strip of material.
`By being a relatively thin coating, the tooth whitening
`substance is low in volume compared to the substance
`contained by rigid trays fitted or unfitted. Therefore, sub-
`stance is not wasted, and little of it is accidentally ingested
`or otherwise available for irritation of oral cavity surfaces
`for which it is not intended. Preferably, the strip of material
`and substance are substantially transparent so as to be almost
`unnoticeable when worn.
`
`The delivery system also includes the tooth whitening
`substance applied to the strip of material. When the delivery
`system is placed on the surface of the teeth, the substance
`contacts the surface providing an active onto the surface.
`The substance also provides adhesive attachment between
`the strip of material and the surface to hold the delivery
`system in place for a sufficient time to allow the active to act
`upon the surface. Preferably, the substance is in the form of
`a gel, which is a substantially uniform continuous coating on
`the strip of material.
`In another aspect of the present invention, a method of
`delivering a tooth whitening substance to the surface of the
`teeth includes the step of applying the substance onto a
`conformable strip of material. This is followed by applying
`the conformable strip of material to the surface of the teeth
`without permanent deformation of the strip of material. The
`substance provides an active onto the surfaces and also
`provides adhesive attachment between the strip of material
`and the surface to hold the delivery system in place for a
`sufficient time to allow the active to act upon the surface.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`While the specification concludes with claims which
`particularly point out and distinctly claim the present
`invention, it is believed that the present invention will be
`better understood from the following description of pre-
`ferred embodiments, taken in conjunction with the accom-
`panying drawings, in which like reference numerals identify
`identical elements and wherein:
`
`FIG. 1 is a perspective view of a substantially flat strip of
`material having rounded corners;
`FIG. 2 is a perspective view of an embodiment of the
`present invention, disclosing the flat strip of FIG. 1 coated
`with a tooth whitening substance;
`taken along
`FIG. 3 is a cross-sectional View thereof,
`section line 3—3 of FIG. 2, disclosing an example of the flat
`strip having a thickness less than that of the substance coated
`thereon;
`
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`60
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`65
`
`4
`FIG. 4 is a cross-sectional View showing an alternative
`embodiment of the present
`invention, showing shallow
`pockets in the strip of material, which act as reservoirs for
`additional substance coated on the strip;
`FIG. 5 is a cross-sectional View showing adjacent teeth
`having the strip of material of the present invention con-
`forming thereto and adhesively attached to the teeth by
`means of a substance located between the teeth and the strip
`of material;
`FIG. 6 is a cross-sectional elevation view of a tooth and
`adjoining soft tissue, taken along section line 6—6 of FIG.
`5, disclosing the strip of the present invention conforming to
`and adhesively attached to the tooth by means of the
`substance located between the tooth and the strip of mate-
`rial,
`FIG. 7 is a cross-sectional View, similar to FIG. 5,
`showing a strip of material of the present invention con-
`forming to the teeth and the adjoining soft
`tissue and
`adhesively attached to both sides of the teeth by means of the
`substance located between the teeth and the strip of material;
`FIG. 8 is a cross-sectional elevation view, taken along
`section line 8—8 of FIG. 7, showing the strip of material of
`the present invention conforming to both the tooth and the
`adjoining soft tissue and adhesively attached to both sides of
`the tooth by means of the substance located between the
`tooth and the strip of material;
`FIG. 9 is a perspective view of an alternative embodiment
`of the present invention, disclosing the flat strip coated with
`a tooth whitening substance of FIG. 2 with a release liner;
`and
`FIG. 10 is a cross-section view of an alternative embodi-
`
`taken along section line
`ment of the present invention,
`10—10 of FIG. 9, showing a release liner attached to the
`strip of material by the substance on the strip of material.
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`The abbreviation “cm”, as used herein, means centimeter.
`The abbreviation “mm”, as used herein, means millimeter.
`Referring now to the drawings, and more particularly to
`FIGS. 1 and 2, there is shown a first preferred embodiment
`of the present invention, which is generally indicated as 10.
`Embodiment 10 represents a delivery system for a tooth
`whitening substance. Delivery system 10 has a strip of
`material 12, which is initially substantially flat, preferably
`with rounded corners.
`
`Applied or coated onto strip of material 12 is a tooth
`whitening substance 14. Preferably, substance 14 is
`homogeneous, uniformly and continuously coated onto strip
`of material 12, as shown in FIG. 3. However, substance 14
`may alternatively be a laminate or separated layers of
`components, an amorphous mixture of components, separate
`stripes or spots or other patterns of different components, or
`a combination of these structures including a continuous
`coating of oral care substance 14 along a longitudinal axis of
`a portion of strip of material 12.
`As shown in FIG. 4, an alternative embodiment, a strip of
`material 12 may have shallow pockets 18 formed therein.
`When substance 14 is coated on a substance-coated side of
`
`strip of material 12, additional substance 14 fills shallow
`pockets 18 to provide reservoirs of additional substance 14.
`FIGS. 5 and 6 show a delivery system 24 of the present
`invention applied to a plurality of adjacent teeth and the
`surface of a tooth. Embedded in adjacent soft tissue 20 is a
`plurality of adjacent teeth 22. Adjacent soft tissue is herein
`
`PAGE 000006
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`PAGE 000006
`
`

`

`5,891,453
`
`5
`defined as soft tissue surfaces surrounding the tooth struc-
`ture including: papilla, marginal gingiva, gingival sulculus,
`inter dental gingiva, gingival gum structure on lingual and
`buccal surfaces up to and including muco—ginival junction
`and the pallet.
`In both FIGS. 5 and 6, delivery system 24 represents strip
`of material 12 and substance 14, with substance 14 on the
`side of strip of material 12 facing adjacent teeth 22. Sub-
`stance 14 may be pre-applied to strip of material 12 or
`applied to strip of material 12 by the delivery system user.
`In either case, strip of material 12 has a thickness and
`flexural stiffness which enable it to conform to the contoured
`surfaces of adjacent teeth 22 and to adjacent soft tissue 20.
`The strip of flexible material has sufficient flexibility to form
`a curved shape around a plurality of adjacent teeth. The strip
`of material is also readily conformable to tooth surfaces and
`to the interstitial tooth spaces without permanent deforma—
`tion when the delivery system is applied. The delivery
`system is applied without significant pressure.
`FIGS. 7 and 8 show delivery system 24 of the present
`invention applied to both front and rear surfaces of a
`plurality of adjacent teeth 22 as well as to adjacent soft tissue
`20 located by the front surfaces of the teeth. Delivery system
`24 represents strip of material 12 and substance 14, with
`substance 14 on the side of strip of material 12 facing
`adjacent teeth 22.
`FIGS. 9 and 10 shows a optional release liner 27. Release
`liner 27 is attached to strip of material 12 by substance 14.
`Substance 14 is on the side of strip of material 12 facing
`release liner 27. This side is applied to the tooth surface once
`release liner 27 is removed.
`
`Strip of Material
`The strip of material serves as a protective barrier to
`substantially prevent saliva contacting the tooth whitening
`substance and leaching and/or erosion of the tooth whitening
`substance from the surface of the teeth by the wearer’s lips,
`tongue, and other soft tissue. In order for an active in tooth
`whitening substance to act upon the surface of tooth over an
`extended period of time, from several minutes to several
`hours,
`it
`is important
`to minimize such leaching and/or
`erosion. The term “act upon” is herein defined as bringing
`about a desired change. For example, if the substance is a
`tooth whitener,
`it bleaches color bodies to bring about
`whitening.
`The strip of material may comprise materials such as
`polymers, natural and synthetic wovens, non-wovens, foil,
`paper, rubber, and combinations thereof. The strip of mate-
`rial may be a single layer of material or a laminate of more
`than one layer. Generally, the strip of material is substan-
`tially water impermeable. The material may be any type of
`polymer that meets the required flexural rigidity and is
`compatible with tooth whitening actives, such as peroxide.
`The material may comprise a single polymer or a mixtures
`of polymers. Suitable polymers include, but are not limited
`to, polyethylene, ethylvinylacetate, ethylvinyl alcohol, poly-
`esters such as Mylar® manufactured by DuPont, fluoroplas-
`tics such as Teflon® manufactured by DuPont, and combi—
`nations thereof Preferably, the material is polyethylene. The
`strip of material is generally less than about 1 mm thick,
`preferably less than about 0.05 mm thick, and more prefer-
`ably from about 0.001 to about 0.03 mm thick. A polyeth-
`ylene strip of material is preferably less than about 0.1 mm
`thick and more preferably from about 0.005 to about 0.02
`mm thick.
`Preferably, the shape of the strip of material is any shape
`that has rounded corners. “Rounded corners” is defined as
`
`not having any sharp angles or points. The conformable strip
`
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`of material is preferably of a size that individually fits the
`row of teeth desired to be bleached. Generally, this is the
`front 6—8 teeth of the upper or lower rows of teeth that are
`visible when the wearer is smiling. Optionally, the strip of
`material may fit the entire upper or lower rows of teeth when
`positioned against the teeth. The size of the strip of material
`depends upon many factors, including the number of teeth to
`be bleached, the size of the teeth, and personal preference of
`the wearer. In general, the length of the strip of material is
`from about 2 cm to about 12 cm and preferably from about
`4 cm to about 9 cm. The width of the strip of material will
`also depend upon many factors, including whether or not the
`strip of material wraps around the teeth and covers both
`surfaces of the tooth. In a general application, the width of
`the strip of material is from about 0.5 cm to about 4 cm and
`preferably from about 1 to about 2 cm.
`The strip of material may contain shallow pockets. When
`the substance is coated on a substance-coated side of strip of
`material, additional substance fills shallow pockets to pro-
`vide reservoirs of additional substance. Additionally,
`the
`shallow pockets help to provide a texture to the delivery
`system. The film will preferably have an array of shallow
`pockets. Generally, the shallow pockets are approximately
`0.4 mm across and 0.1 mm deep. When shallow pockets are
`included in the strip of material and substances are applied
`to it in various thicknesses,
`the overall
`thickness of the
`delivery system is generally less than about 1 mm.
`Preferably, the overall thickness is less than about 0.5
`mm.
`
`Flexural stiffness is a material property that is a function
`of a combination of strip thickness, width, and material
`modulus of elasticity. This test is a method for measuring the
`rigidity of polyolefin film and sheeting. It determines the
`resistance to flexure of a sample by using a strain gauge
`affixed to the end of a horizontal beam. The opposite end of
`the beam presses across a strip of the sample to force a
`portion of the strip into a vertical groove in a horizontal
`platform upon which the sample rests. A microammeter,
`wired to the strain gauge is calibrated in grams of deflection
`force. The rigidity of the sample is read directly from the
`microammeter and expressed as grams per centimeter of
`sample strip width. In the present invention, the strip of
`material has a flexural stiflness of less than about 5 grams/
`cm as measured on a Handle-O-Meter, model #211-300,
`available from Thwing-Albert Instrument Co. of
`Philadelphia, Pa., as per test method ASTM D2923-95.
`Preferably, the strip of material has a flexural stiffness less
`than about 4 grams/cm, more preferably less than about 3
`grams/cm, and most preferably from about 0.1 grams/cm to
`about 1 grams/cm. Preferably, the flexural stiffness of the
`strip of material
`is substantially constant and does not
`significantly change during normal use. For example, the
`strip of material does not need to be hydrated for the strip to
`achieve the low flexural stiffness in the above—specified
`ranges.
`This relatively low stiffness enables the strip of material
`to drape over the contoured surfaces of teeth with very little
`force being exerted; that is, conformity to the curvature of
`the wearer’s mouth and gaps between adjacent
`teeth is
`maintained because there is little residual force within strip
`of material to cause it to return to its substantially flat shape.
`The flexibility of the strip enables the strip of material to
`contact adjoining soft tissue over an extended period of time
`without physical irritation. The strip of material does not
`require pressure forming it against the teeth.
`The strip of material is held in place on a plurality of
`adjacent
`teeth by adhesive attachment provided by the
`
`PAGE 000007
`
`PAGE 000007
`
`

`

`5,891,453
`
`7
`substance. The viscosity and general tackiness of the sub-
`stance cause the strip of material to be adhesively attached
`to a plurality of adjacent teeth without substantial slippage
`under the potential friction from the lips, tongue, and other
`soft tissue rubbing against the strip of material during mouth
`movements associated with talking, drinking, etc. However,
`this adhesion to the teeth is low enough to allow the delivery
`system to be easily removed by the wearer by peeling off the
`strip of material using one’s finger or fingernail. The deliv-
`ery system is easily removable from the surfaces of the teeth
`without the use of an instrument, a chemical solvent, or
`undue friction. Chemical solvents include any organic sol—
`vents commonly used in oral care products such as alcohol
`and other safe solvents such as water, which could be used
`to dilute the gelling agent. Undue friction is described as any
`type of rubbing with one’s finger or a soft implement, such
`as cotton balls, swabs, or gauze pads.
`Apeel force of from about 1 gram to about 50 grams for
`a 1.5 cm strip width (approximately 17 grams/cm) is all that
`is required. Preferably, the peel force is from about 5 grams
`to about 40 grams and more preferably from about 10 grams
`to about 30 grams. The low peel force is desired for
`consumer handling purposes. The low peel force is possible
`because of the non-aggressive nature of a gel substance.
`Only when the flexural stiffness of the strip is low can the
`adhesion of the substance also be low. The adhesion of a
`
`stiffer strip would have to be greater in proportion to the strip
`stiffness in order to prevent the strip from returning to its flat
`condition and pulling away from the contoured surface of a
`plurality of tccth.
`The strip of material may be formed by several of the film
`making processes known in the art. Preferably, a strip of
`material made of polyethylene is made by a blown process
`or a cast process. Processes, such as extrusion and other
`processes that do not affect the flexural rigidity of the strip
`of material, are also feasible. Additionally, the substance
`may be incorporated onto the strip during the processing of
`the strip. The substance may be a laminate on the strip.
`Tooth Whitening Substance
`a composition,
`The tooth whitening substance is
`compound, or mixture capable of influencing or effecting a
`desired change in appearance and/or structure of the surface
`it contacts. Examples of appearance and structural changes
`include, but are not necessarily limited to, whitening, stain
`bleaching, stain removal, plaque removal, and tartar
`removal. Preferably, the active is for the whitening of the
`tooth surfaces.
`The amount of substance applied to the strip of material
`or teeth will depend upon the size and capacity of the piece
`of material, concentration of the active, and the desired
`benefit. Generally, less than about 1 gram of substance is
`rcquircd. Prcfcrably, from about 0.05 grams to about 0.5
`grams and more preferably from about 0.1 gram to about 0.4
`grams of the substance is used. The amount of substance per
`square cm of material is less than about 0.2 grams/cmz,
`preferably from about 0.005 to about 0.1 grams/cmz, and
`more preferably from about 0.01 grams/cm2 to about 0.04
`grams/cmz.
`The substance of the present invention can be in the form
`of a viscous liquid, paste, gel, solution, or other suitable
`form that can provide sufficient adhesion. Preferably, the
`substance is in the form of a gel. The substance will have a
`viscosity of from about 200 to about 1,000,000 at low shear
`rates (less than one 1/seconds). Preferably, the viscosity is
`from about 100,000 to about 800,000 cps and more prefer-
`ably from about 400,000 to about 600,000 cps.
`Actives suitable for whitening include any material safe
`for use in the oral cavity which provides bleaching or stain
`
`10
`
`15
`
`20
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`8
`removal. The actives suitable for whitening are selected
`from the group consisting of the peroxides, metal chlorites,
`perborates, percarbonates, peroxyacids, and combinations
`thereof. Suitable peroxide compounds include hydrogen
`peroxide, calcium peroxide, carbamide peroxide, and mix-
`tures thereof. Most preferred is carbamide peroxide. Suitable
`metal chlorites include calcium chlorite, barium chlorite,
`magnesium chlorite, lithium chlorite, sodium chlorite, and
`potassium chlorite. Additional whitening actives may be
`hypochlorite and chlorine dioxide. The preferred chlorite is
`sodium chlorite.
`The tooth whitening active is present in an amount of
`from about 0.01% to about 40%, by weight of the substance.
`If a peroxide compound is chosen as the active, the peroxide
`compound should provide an amount of hydrogen peroxide
`equivalent of from about 0.1% to about 20%, preferably
`from about 0.5% to about 10%, and most preferably from
`about 1% to about 7%, by weight of the substance. To
`deliver this amount of hydrogen peroxide equivalent, the
`peroxide compound, such as carbamide peroxide, is gener—
`ally present in an amount of from about 0.1% to about 30%
`and preferably from about 3% to about 20%, by weight of
`the substance.
`
`The actives are generally contained in an aqueous gel. The
`gel is a high viscosity matrix formed from gelling agents
`known in the art. These gelling agents are safe for oral use,
`do not readily dissolve in saliva, and do not react with or
`inactivate the oral care compounds incorporated into them.
`Generally,
`the gelling agent
`is a swellable polymer.
`Furthcrmorc,
`thc gcl formcd with these agcnts providcs
`sufficient adhesive attachment of the film material to the
`
`targeted area of the mouth. The level of gelling agent to form
`the gel composition is from about 0.1% to about 15%,
`preferably from about 1% to about 10%, more preferably
`from about 2% to about 8%, and most preferably from about
`4% to about 7%, by weight of the substance.
`Suitable gelling agents useful in the present invention
`include carboxypolymethylene, carboxymethyl cellulose,
`carboxypropyl cellulose, poloxamer, carrageenan, Veegum,
`carboxyvinyl polymers, and natural gums such as gum
`karaya, xanthan gum, Guar gum, gum arabic, gum
`tragacanth, and mixtures thereof. The preferable gelling
`agent
`for use in the present
`invention is
`carboxypolymethylene, obtained from B. F. Goodrich Com-
`pany under the tradename “Carbopol”. Particularly prefer-
`able Carbopols include Carbopol 934, 940, 941, 956 and
`mixtures thereof. Particularly preferred is Carbopol 956.
`Carboxypolymethylene is a slightly acidic vinyl polymer
`with active carboxyl groups. The normal concentration of
`various carboxypolymethylene resins in water, according to
`the manufacturer, is below about 2%. However, it has been
`found that by prcparing supersaturated carboxypolymcthyl-
`ene compositions having an absolute concentration in the
`ranges specified above, suitable high viscosity oral gel
`compositions may be prepared.
`The concentrated carboxypolymethylene gels have a
`number of important characteristics in addition to high
`Viscosity. Enough carboxypolymethylene is added to the
`oral gel compositions beyond that required to provide high
`viscosity such that a significant quantity of saliva or water is
`required to lower the viscosity to the point that the compo-
`sition may be diluted and washed out by saliva. The con-
`centrated carboxypolymethylene composition also has a
`unique tackiness or stickiness which retains and seals the
`strip material against the targeted oral cavity surface it is
`affixed to, particularly teeth. However, care should be taken
`to avoid t