MXPA01007327A - Dual component dentinal desensitizing dentifrice - Google Patents

Abstract

A two component dental composition is disclosed which eliminates or substantially reduces the discomfort and pain associated with dentinal hypersensitivity which composition comprises a first dentifrice component having an alkaline pH, a second dentifrice component having an acid pH and at least one of the components containing a potassium ion releasable compound, the first and second components being maintained separate from each other until dispensed and combined for application to teeth requiring relief from dentine hypersensitivity, whereby heightened desensitization is experienced by the user.

Description

DENTÍFRICO DESIGNIBILIEANTE DENTINAL DUAL COMPONENT BACKGROUND OF THE INVENTION 1. Field of the invention The present invention relates to a composition of a desensitizing toothpaste which eliminates reduces the discomfort and pain associated with dentinal hypersensitivity and more particularly with a two component desensitizing dental composition containing desensitizing agents of potassium salts. 2. Previous Art Dentinal hypersensitivity is defined as localized, acute tooth pain in response to physical stimulation of the dentine surface as by the combination of tactile, thermal osmotic (hot or cold) tactile and osmotic, thermal stimulation of the dentine. exposed Dentin exposure, which is usually due to receding gums, or loss of enamel, often leads to hypersensitivity. The art determined that the tubules of the dentine open to the surface have a high correlation with the dentin hypersensitivity, Abs, J. of Clin. Peridontal. 14, 280-4 (1987). The dentinal tubules lead from the pulp to the cementum. When the cementum surface of the tooth root is eroded the dentinal tubules are exposed to the external environment. The exposed dentinal tubules provide a path for the transmission of fluid flow to the pulpal nerves, transmission induced by changes in temperature, pressure and ionic gradients.

It is known in the art that potassium salts are effective in the treatment of hypersensitivity. For example, U.S. Patent No. 3,863,006 discloses that toothpastes containing potassium salts such as potassium nitrate desensitize the teeth after brushing the teeth for several weeks. It is believed by those with skill in the art that a rise in extracellular potassium concentration in the vicinity of the sensitive dentine underlying the pulpal nerves is responsible for the therapeutic desensitizing effect of topically applied orale products which contain potassium nitrate. Upon passive diffusion of the potassium ion into and out of the open dentine tubules, repeated application of active ingredient is necessary to increase the necessary concentration in the vicinity of the pulpal nerves.

It is believed that the improved pain relief i obtained by the use of potassium salts in combination with the gradual mineralization on the surface of the dentin which can be either partially or completely occluded dentine tubules. Total occlusion can dramatically reduce fluid flow within the tubules which stimulate pain. Partial occlusion of the dentine tubules is thought to increase the supply of the potassium ion within the dient because inward diffuse flow is less dependent on tubule radius than inward fluid flow (due to positive pulp pressures) (See DH Pashley and W Mathews, Archs. Oral Biol. (1993) 38, 577 to 582). Therefore, this increased supply of potassium should increase relief.

Although potassium salts such as potassium nitrate d are highly effective in the treatment of dentine hypersensitivity, the art continually seeks ways to improve the efficacy of such treatment.

SYNTHESIS OF THE INVENTION The present invention is based on the discovery that when a dual-component toothpaste comprising separately packaged dentifrice components of alkaline and acidic p at least one component containing a potassium salt is combined before being used, the combined composition exhibits a unexpected improved effectiveness when applied to the teeth in sealed dentinal tubules with concomitant desensitization of the teeth as compared to the compositions of the simple components of neutral pH.

According to the present invention, it provides a method for the treatment of dentinal hypersensitivity using a multi-component dentifrice composed of two semisolid, separately packed aqueous components. The first component contains a fluoride salt as the fluoride ion source, an orally acceptable carrier having an alkaline pH of at least about 8.0 preferably about 9.0 to about 10.5, and the second component contains an acid to provide an acidic acid from about 1.0 to about 6. preferably about 1.0. up to about 3.0 in an orally acceptable vehicle, at least one component contains a fluoride ion release compound such as a water-soluble potassium ion release compound where the combination and mixture of the components , a mixture having a pH of from about 6.5 to about 9.0 preferably around and 7.0 to about 8.5, and formed where repeated application of the mixture to the teeth increases the relief of dentinal hypersensitivity that is experienced by the user.

In the Drawings Figure 1 is a scanning electron photomicrograph (SEM) (2,000 x 'magnification) of a dentine disk surface treated with a phosphate buffer solution.

Figure 2 is a photomicrograph of scanning electron (2,000 x magnification) of a dentin disc surface treated in a single-component dentifrice containing both NaMFP (0.76% by weight) and potassium nitrate (5 per weight), the pH of the toothpaste is 6.1.

Figure 3 is a photomicrograph of scanning electron (2,000 x magnification) of a disc surface dentin treated with a dual component combinad containing both NaF (0.243% by weight) and KN03 (5% by weight), and The Naf pH of the dentifrice is 1.3 and the pH of the KN03 of toothpaste is 9.9.

DESCRIPTION OF PREFERRED INCORPORATIONS In use, the components of the component dentifrice of the present invention comprise a first component of alkaline dentifrice, and a second component d acidic dentifrice. The two components are preferably combined in approximately equal weight proportions, so that about one-half the concentration of any particular ingredient within any component may be present when the components are combined and applied to the teeth, such as by brushing. Both components are preferably formulated to have similar physical characteristics, so that the two components can be simultaneously supplied in the predetermined amounts desired by extrusion when they are separately packaged in a pump device or in a multi-compartment tube.

To prepare the alkaline toothpaste component of the present invention, an alkaline agent is generally incorporated in the toothpaste component which typically includes a vehicle which contains water, surfactant humectant and an abrasive. The pH of such toothpaste is in the alkaline range of about 8.0 to 11.0 and preferably about 9.0 to about 10.5. The acidic dentifrice component is prepared using a similar vehicle, the p of such a dentifrice is in the acid range of about 1. to about 6.0 and preferably about 1.0 about 3.0.

The humectant is used in the preparation of the components of the dentifrice is generally a mixture d humectants, such as glycerol, sorbitol, and a polyethylene glycol d of molecular weight in the range of 200 to 1000, per other mixtures of humectants and humectants simple can also be used. The humectant content is in the range of about 10% to about 80% by weight preferably about 20 to about 50% by weight of the dentifrice component. The water content is in the range of about 10 to about 40% by weight, preferably about 20 to about 30% by weight.

The thickeners include organic inorganic thickeners. Inorganic thickeners which may be included in the dentifrice components include amorphous silica such as Zeodent 165 available from Hube Corporation, and Sylox 15 from W.R. Grace Organic and synthetic natural colloid and rubber thickeners can also be used to prepare the dentifrice components of the present invention. Examples of such thickeners are carrageenan (Irish moss), xanthan gum, sodium carboxymethyl cellulose, starch, polyvinyl pyrrolidone, hydroxyethylpropyl cellulose, methyl hydroxybutyl cellulose, methyl hydroxypropyl cellulose, and cellulose. hydroxyethyl.

The inorganic thickener can be incorporated into the dentifrice components of the present invention in a concentration of about 0.5 to about 5% by weight and preferably about 1 to about 3% by weight. The organic thickener can be incorporated into the compositions of the present invention in a concentration of about 0. to about 3% by weight and preferably about 0. to about 1.5% by weight. The active surface agents can be incorporated in dentifrices to provide foam properties. The active surface material is preferably anionic or non-ionic in nature. Suitable examples of the anionic surfactants are higher alkyl sulfates such as potassium or sodium lauryl sulfate which is preferred, the monosulfates of higher fatty acid monoglycerides, such as the monosulphated monoglyceride salt of the fatty acids of fatty acid. hydrogenated coconut, alkyl aryl sulfonates such as benzene dodecyl sodium sulfonate, higher fatty sulphoacetates, higher fatty acid esters of hydroxyl propane 1,2-sulfonate.

The active surface agent is generally present in the dentifrice component compositions of the present invention at a concentration of about 0.5 about 10.0% by weight and preferably about 1. about 5.0% by weight.

The abrasives can be incorporated into the components of the dentifrice of the present invention and the preferred abrasives are siliceous materials, such as silica. A preferred silica is a precipitated amorphous hydrated silica, such as Sorbosil AC-35, marketed by Crosfield Chemicals, or Zeodent 115 of Huber Company but other abrasives may also be employed, including hydroxyapatite, sodium metaphosphate, metaphosphate potassium d, tricalcium phosphate, calcium phosphate dihydrate, anhydrous dicalcium phosphate, calcium pyrophosphate d, magnesium orthophosphate, trimagnesium phosphate, calcium carbonate, sodium bicarbonate, aluminum trihydrate d , aluminum silicate, bentonite and calcined aluminum.

Abrasive concentration in the dentifrice component compositions of the present invention may usually be in the range of from about 2 to about 40% by weight and preferably from 5 to 25% by weight.

Alkaline agents such as alkali metal compounds including sodium hydroxide, potassium hydroxide, sodium bicarbonate, sodium carbonate are included in the alkaline dentifrice component of the present invention in amounts ranging from about 0.5 to 15 by weight, preferably about 1.0 to about 8% by weight and more preferably at about 1.0 to about 5.0 by weight of the component. Mixtures of the above alkali metal compounds can also be used. Sodium hydroxide is the preferred alkaline agent.

The acidic dentifrice component of the composition of the dentifrice of the present invention, which is kept physically separate from the alkaline dentifrice component from the mixing before use, contains an acid or mixture of acids, to acidify the alkaline dentifrice component, for that when the two components are combined before use, the combined dentifrice is at a pH in the range of about 6.5 to about 9.0, preferably about 7.0 to about 8.5.

The acidic components which may be present in the acidic component include both organic and mineral acids, such as sulfuric acid, hydrochloric acid, malic acid, alginic acid, citric acid, succinic acid, lactic acid, acid tartaric, potassium bitartrate, sodium acid citrate, phosphoric acid, and sodium acid phosphate. The acid phosphates are preferred, which include the phosphoric acid, or the phosphoric acid salts contain an ion P04, such as acids or salts thereof, such as sodium phosphate monobasic, not only provides the necessary acidity, but also provides the phosphate ions, to inhibit any demineralization of tooth enamel which may occur with the application of acidulated toothpaste d two components to the teeth. In addition, the combination of an acid such as a phosphoric acid and an acid salt, such as a sodium phosphate monobasic, provides increased buffering to achieve the desired pH of the mixture of the components of the dentifrice. The preferred acid is the phosphoric acid which is commercially available as a liquid in a concentration of 85%. The acid is added to the dentifrice component in an amount to maintain the pH of the dentifrice at a p of about 1.0 about 6.0 and preferably around 1.0 to about 3.0.

Calcium salt sources such as calcium chloride, calcium acetate and dicalcium phosphate dihydrate can be added to the n-fluoride dentifrice composition additionally dated and increase the potential mineralization of this composition to the combination with component fluoridated dentifrice. The concentration of calcium salts is in the range of about .0.5 to 2 percent depending on the solubility of the salt and the interaction with other ingredients of the toothpaste. The source of the desensitizing potassium ion is generally a water-soluble potassium salt that includes potassium nitrate, potassium citrate, potassium chloride, potassium bicarbonate, and potassium oxalate with nitrate potassium being the preferred . The potassium salt is generally incorporated into one or more of the components of the dentifrice at a concentration of about 0.5 to about 20% by weight, preferably about 3 to about 15% by weight.

Salts that provide salt having anti-caries efficiencies can also be incorporated into the dentifrice of the present invention and are characterized by their ability to release fluoride ions in water. It is preferable to employ a water-soluble fluoride salt provided at about 10,000 pounds per minute of fluoride ion, and preferably about 1,000 to 1,500 pounds per minute of fluoride ion. Among these materials are the water soluble inorganic metal salts, for example, sodium fluoride, potassium fluoride, sodium monofluorophosphate, fluoride stannas and sodium fluorurosilicate. Sodium fluoride, sodium monofluorophosphate and stannous fluoride are the preferred fluoride-supplying salts.

Pyrophosphate salts which efficiently extend ant calculations useful in the practice of the present invention include water soluble salts such as tetraalkyl or dialkyl metal pyrophosphate salts such as Na4P207 (TSPP), K4P207, Na2P207, Na2H2P202 and K2H2P207. The pyrophosphate salts include the water-soluble alkyl metal tripolyphosphates such as sodium tripolyphosphate, potassium tripolyphosphate.

The pyrophosphate salts are incorporated in the composition of the dentifrice of the present invention in a concentration of about 0.5 to about 2.0% by weight, preferably about 1.5 to about 2% by weight of the polyphosphate salts are incorporated in the where the dentifrice of the present invention at a concentration d about 1.0 to about 7.0% by weight.

Dyes such as pigments and dyes can be used in the practice of the present invention. The pigments include the water-insoluble, non-toxic inorganic pigments such as titanium dioxide and green chromium dioxide, ultramarine blue and pink and ferric oxides as well as the water-insoluble dye lakes prepared by spreading the salts of aluminum or calcium d FD &C dyes in alumina such as green lake # 1 FD &C, E blue lake # 2 FD &C, lake # 30 FD &C and yellow lake # 15 FD &C. The pigments have a particle size in the range of 5 1000 microns, preferably 250 to 500 microns, and are present in a concentration of 0.5 to 3% by weight.

The dyes used in the practice of the present invention are generally food color additives currently certified under the Food Cosmetics Drug Act for use in ingested drugs and foods, which include dyes such as red No. 3 FD & C (tetraiodofluorescein sodium salt), yellow No. 5 FD &C (4-p-sulfophenylazo-1-p-sulfophenyl-5 hydroxypyrazole-3 carboxylic acid sodium salt), yellow No.6 FD & C (sodium salt of p-sulphophenylazo-B-naphthol-6-monosulfonate), green No. 3 FD &C (disodium sa from 4-. {[[4- (N-ethyl-p-sulfobenzilamio) -phenyl) ] - (4-hydroxy-2-sulphoniumfyl) -methylene.} - [1- (N-ethyl-Np-sulfobenzyl) -? - 3, 5-cyclohexadienimine], blue No. 1 FD &C (to disodium) cidotrisulf or nic dedibenzildietildiaminotrifenilcarbinol of indigotine) and the mixtures thereof in various proportions.The concentration d dye for the most effective result in the present and invention is present in the composition of toothpaste in a quantity from about 0.0005 percent to about percent of the total weight.

A scratched toothpaste product can be obtained using dual component dentifrice of the present invention, wherein the colored dyes contrast or are incorporated into each of the components of the toothpaste to be supplied; the dyes are pharmacologically physiologically non-toxic when used in the suggested amounts. The colorants used in the practice of the present invention include both the pigments and the dyes described above.

Any suitable sweetening or flavoring material can also be incorporated into the dentifrice composition of the present invention. Examples of suitable flavoring constituents are the flavoring oils, for example, oils of spearmint, peppermint, pyrolle, sassafras, clove, sage, eucalyptus, marjoram, lemon cinnamon, and orange, and methyl salicylate. Suitable sweetening agents include sucrose, galactose, maltose, sorbitol, xylitol, sodium coclamate, perilatin, and sodium saccharin. Suitable flavoring sweetening agents can together comprise from 0.01 to 5% or more of the preparations.

The antibacterial agents are the non-cationic antibacterial agents based on bisphenolic and phenolic compounds, the halogenated defined ethers such as Triclosan, the benzoate esters and the carbanilides as well as the cationic antibacterial agents such as the chlorhexidine digluconat. Such antibacterial agents can be present in amounts of from about 0.03 hast to about 1% by weight of the particular component.

When the non-cationic antibacterial agents and the antibacterial agents are included in any of the components of the dentifrice, there are preferably also included about 0.05 to about 5% of the increasing agent which increases the supply and retention of the agents to, the retention of it on oral surfaces. The increasing agents useful in the present invention are described in U.S. Patent Nos. 5,188.82 and 5,192,531.; and include synthetic anionic polymeric polycarboxylates, such as 1: 4 to 4: 1 copolymers of maleic anhydride or acid with another unsaturated monomer and ethylenically polymerizable monomer, preferably the methyl vinyl ether / maleic anhydride having a molecular weight (MW ) d about 30,000 around 1,000,000, more preferably around 30,000 to about 800,000. These copolymers are available for example as Gantrez for example AN 139 (MW 50 (1,000), AN 119 (MW 250,000) and preferably the S-9 Pharmaceutical Grade (MW 700,000) available from IS Technologies, Inc. Bound Brook, NJ 08850. The increasing agents when present are present in amounts in the range of 0.05 about 3% by weight.

To prepare either the dentifrice components of the present invention, generally the humectants eg glycerin ingredients, propylene glycol, polyethylene glycol, are dispersed with any organic, sweetener, pigments such as titanium dioxide and any polyphosphates included as an anticalculus ingredient. The water is then added in this dispersion along with any antibacterial agent such as Triclosana, any antibacterial enhancing agent such as Gantrez and any additional anticalculus agents. In the first component (or both) a source of fluoride ion and an alkaline agent such as sodium hydroxide is added. In the second component an ingredient for lowering the pH to an acid level is added such as the phosphoric acid. These ingredients are mixed until a homogeneous phase is obtained for each component. Then the ingredients inorganic thickener, and silica abrasive, the flavoring and the surfactant are added and the ingredients mixed at high speed under vacuum from about 20 to 100 millimeters of Hg. The resulting product was in this case of each component is a product of extrudable, semi-solid, homogeneous paste. t The multi-component dentifrice composition of the present invention is packaged in an appropriate assortment container in which the components are kept physically separate and from which the separate components can be supplied synchronously as a combined ribbon for application to a brush. teeth. Such containers are known in the art. An example or such container is a two-compartment assortment container, such as a bomb or a tube, having folding side walls, is described in U.S. Patent Nos. 4,487,757 and 4,687,663; wherein, the tube body is formed of a foldable plastic fabric such as polyethylene or polypropylene and is provided with a partition within the container body defining separate compartments in which the physically separated components are stored from which they are supplied through an appropriate supply outlet.

The following example is more illustrative of the present invention, but it is understood that the invention is not limited thereto. All amounts and the amounts referred to herein and the appended claims are by weight, unless otherwise indicated.

Example A two component desensitizing toothpaste (component A and B) of the present invention was prepared, designated dentifrice I, component A stops an alkaline pH and component B has an acidic pH. The ingredients and the pH of components A and B are listed in table 1, below.

Table I Toothpaste I% by Weight Component AB Ingredients Alkaline Paste Acidic Acid Deionized Water 28. .714 32,316 Sodium Fluoride 0.486 Potassium Nitrate 10.000 H3P04 (85%) - 2,880 Glycerin 25, .000 33.704 Glycol Polyethylene 600 3.000 Xantana »0. .600 0. 800 Cellulose Carboxymethyl 0..400 0. 000 Sodium Saccharin 0. .400 0. 400 Titanium Dioxide • 2. .000 0. 000 Pluronic F-127"1.000 2,000 Sodium Hydroxide (50%) 3.000 Blue - / l FD &C (l% solution) - 0. 300 Zeodent 115 15.,000.00 .000 Zeodent 165 3, .000 3,000 Sodium Bicarbonate 5.000 Sodium Lauryl Sulfate 1. .500 1,500 Flavor 0. .900 1. 100 pH (as is) 9. .9 1 .3 In the preparation of Toothpaste I, glycerin, polyethylene glycol and organic thickeners were dispersed in a conventional mixer until the mixture was returned to a slurry, which has a smooth appearance.

The color and the sweetener were dispersed in this paste before the addition of water. In the preparation of component A, potassium nitrate was then dispersed in this past wash. In the preparation of component B, the phosphoric acid was then dispersed in a gel phase. This mixture was mixed for 20 to 30 minutes producing a phase of homogenous ge. The mixture was added to a vacuum blender colored below 105 ° F. The zeodent 115, zeodent 165 and sodium bicarbonate were then added and mixed for 1 to 30 minutes at high speed under a vacuum of about 5 i millimeters Hg, providing a homogenous mixture. Sodium lauryl sulfate and flavor were then added to the individual dentifrice components which was followed by mixing for another 5 to 15 minutes under a vacuum of 50 mm Hg to prepare the resulting component product.

The desensitized efficacy of the two-component composition described above was evaluated using square dentin discs of 4.25 mm x 4.25 mm, 750 μm thick, cut from the extracted human molars. The discs were prepared for treatment by etching with 6% of citric acid for 2 minutes to remove any stain on the surface.

The flow rate of a phosphate buffer (0.2 millimeters of phosphate, 0.2 millimeters of CaCl2 O.lM NaCl at pH = 7) through the disks under a water pressure of 70 millimeters was measured to determine the flow rates d basic line, the disks were divided into groups of three cad one such that the average flow rates between groups fu similar.

The dentin discs * were then treated by brushing for a period of 45 seconds with the combined components of dentifrice I at a d-volume ratio of 1: 1. The pH of the combined components was 7.4 when diluted with deionized water.

For comparison purposes the procedure of the example was repeated with another disc group similarly prepared using a single component of commercially available desensitizing tooth paste designated tooth paste "C" containing both 0.76% by weight of NaMFP and 5% by weight of KN03 As a control, the example procedure was repeated using a phosphate buffer solution with the treatment such treatment was designated "control".

The treated discs were immersed in 10 to 2 milliliters of tap water and agitated with the end of a toothbrush to remove the toothpaste from the surface of the disc. The shots were placed in a phosphate buffer solution between brushes. The shots were treated twelve (12) times each for a period of four days.

Artificial saliva (pH = 7) has the following composition: 0.2 mM phosphate ion (millimole) CaCl, 6.2 mM NaCl 150.0 mM were milligrams of artificial saliva per second in this pressure such flow rates are recorded in Table I below.

Table II Average Flow Treatment (mg / s) * 1 Toothpaste I 0.443 2 Toothpaste C 1.02 3 Control 1.53 * Average of 3 replicates The flow rates of the artificial saliva solution through the discs of dentin recorded in Table II indicate that the dentifrice I was pronounced effective and glistening the relative flow to the comparative commercial toothpaste, toothpaste C, and the solution of phosphate buffer d control. The reductions in flow are believed to be due to the completion of the dentinal tubules. The occlusive state produced by the dentifrice treatment I is considered by the art to be predictive of the reduction to the hypersensitivity of clinical dentinal (M. Brannstrom and A Astrom, J. Dent. Res. (1964) 43,619,625. i

Claims (19)

R E I V I N D I C A C I O N S

1. A dual-component dental composition which essentially eliminates or reduces the discomfort and pain associated with dentinal hypersensitivity, the composition of which comprises a first component of dentifrice having an alkaline pH, or a second component of dentifrice having an acidic pH and at least one of The components containing a liberated compound of potassium ion, the first and second components are kept separate from each other until they are supplied and combine for the application to the teeth that require relief of dentin hypersensitivity, so that the increased desensitization is experienced by the user.

2. The composition as claimed in clause 1 characterized in that the potassium ion-releasable compound is water-soluble potassium salt.

3. The composition as claimed in Clause 2 characterized in that the potassium salt is potassium nitrate d. •

4. The composition as claimed in clause 2 characterized in that the potassium salt is present in the first dentifrice component.

5. The composition as claimed in clause 4 characterized in that the fluoride salt is present in the composition. '

6. The composition as claimed in clause 1 characterized in that the alkaline dentifrice component is an aqueous dentifrice having a pH of about 8 around 11.

7. The composition as claimed in clause 1 characterized in that pH of the alkaline dentifrice component is adjusted with sodium hydroxide.

8. The composition as claimed in clause 1 characterized in that a silica abrasive is present in the dentifrice component.

9. The composition as claimed in clause 1 characterized in that the acidic dentifrice component is an aqueous dentifrice having a pH of around d 1.0 to about 6.0.

10. The composition as claimed in clause 1 characterized in that the pH of the acidic dentifrice component is adjusted with H3P04.

11. A method for eliminating or reducing the discomfort and pain associated with dentin hypersensitivity which comprises preparing (1) a first dentifrice component having an alkaline pH and (29) a second dentifrice component having an acidic pH, at least one of the components contains a releasable potassium ion sensitizing compound containing separately the first and second components, supplying the first and second components by combining the assorted components for the application to the teeth that require relief of dentine hypersensitivity and then applying the components combined to the teeth so the desensitization is increased by the user.

12. The method as claimed in clause 11 characterized in that the potassium compound is a potassium salt soluble in water.

13. The method as claimed in clause 10 characterized in that the potassium salt is potassium nitrate d.

14. The method as claimed in clause 12 characterized in that the potassium salt is present in the first dentifrice component.

15. The method as claimed in clause 14 characterized in that a fluoride salt is present in the composition. t

16. The method as claimed in clause 11 characterized in that the alkaline dentifrice component is an aqueous dentifrice having a pH of around d 8 to about 11.

17. The method as claimed in clause 11 characterized in that the pH of the alkaline tooth component d is adjusted to an alkaline pH with sodium hydroxide.

18. The method as claimed in clause 11 characterized in that the acrylic dentifrice component is an aqueous dentifrice having a pH of around 1.0 around 6.0.

19. The method as claimed in clause 10 characterized in that the pH of the acidic tooth component d is adjusted with H3P04.SUMMARY A component dental composition which eliminates or substantially reduces the discomfort and pain associated with dentinal hypersensitivity which composition comprises a first component of dentifrice having an alkaline pH, a second component of dentifrice having an acid pH and At least one of the components contains a releasable compound of potassium ion, the first and second components are kept separate from each other until they are supplied and combined for application to the teeth which require relief of the dentine hypersensitivity, so What is a desensitization has increased and is experienced by the user.