Novel dentifrice compositions and uses

Abstract

The invention relates to dentifrice compositions with occluding properties. The dentifrice compositions can be used in the treatment of dentine hypersensitivity.

Description

[0001] Novel Dentifrice Compositions and uses.

[0002] Field of invention

[0003] The present invention relates to dentifrice compositions. In particular the invention relates to dentifrice compositions with desensitisation properties for consumers with sensitive teeth.

[0004] Background to the invention

[0005] Tooth sensitivity is an exaggerated response to stimuli such as hot, cold, sweet or acidic foods and drinks, exposure to cold air and even brushing your teeth.

[0006] Sensitive teeth are typically the result of worn tooth enamel or exposed tooth roots. (Sometimes, however, tooth discomfort is caused by other factors, such as a cavity, a cracked or chipped tooth, a worn filling, or gum disease.) This exposes the soft dentin layer of the tooth to the environment.

[0007] Dentin hypersensitivity has been defined as the pain arising from exposed dentin, typically in response to chemical, thermal, tactile or osmotic stimuli that cannot be explained as arising from any other form of dental defect or pathology.

[0008] There are many dentifrice (mainly toothpaste) products that seek to help the user reduce the pain and discomfort associated with sensitive teeth.

[0009] There are different approaches and different active components that are used to prepare commercial dentifrices that can counteract the problem of sensitive teeth.

[0010] Some common actives included in dentifrices to treat sensitivity include:

[0011] Potassium nitrate, this soothes the nerves inside your teeth. This ingredient stops the nerves in your teeth from sending pain signals when you encounter triggers (like hot or cold beverages)

[0012] Stannous fluoride, this protects dentin, the soft exposed part of your tooth. The goal of stannous fluoride is to keep triggers from ever reaching the nerves, therefore avoiding pain signals altogether.

[0013] Other ingredients that also attempt the occlusion route (blocking access to the tooth) nerves, include biolglasses like Novamin® It would be desirable to find improved and / or alternative dentifrice formulations to help treat sensitive teeth. In particular to treat dentine hypersensitivity.

[0014] Summary of invention

[0015] In a first aspect the invention describes an oral care dentifrice composition comprising at least 1.5 % by weight polyvinyl methyl ether / maleic anhydride (PVM / MA) copolymer for use as a medicament for reducing tooth sensitivity (in particular dentine hypersensitivity).

[0016] In a further embodiment, the dentifrice composition for use as a medicament for reducing tooth sensitivity (in particular dentine hypersensitivity), comprises at least 2.0 % by weight polyvinyl methyl ether / maleic anhydride copolymer.

[0017] In a further embodiment, the dentifrice composition for use as a medicament for reducing tooth sensitivity (in particular dentine hypersensitivity) comprises at least 3.0 % by weight polyvinyl methyl ether / maleic anhydride copolymer.

[0018] In a further embodiment, the dentifrice composition for use as a medicament for reducing tooth sensitivity (in particular dentine hypersensitivity), comprises an additional tooth sensitivity active compound.

[0019] In a further embodiment, the dentifrice composition for use as a medicament for reducing tooth sensitivity comprises an additional tooth sensitivity active compound, wherein the tooth sensitivity active compound comprises potassium nitrate.

[0020] In a further embodiment, the dentifrice composition for use as a medicament for reducing tooth sensitivity comprises potassium nitrate at about 5 % by weight.

[0021] In a further embodiment, the dentifrice composition for use as a medicament for reducing tooth sensitivity comprises PVM / MA copolymer that is in a powered form prior to addition to the dentifrice composition.

[0022] In a further embodiment, the dentifrice composition for use as a medicament for reducing tooth sensitivity, the composition comprises water.

[0023] In a further embodiment, the dentifrice composition for use as a medicament for reducing tooth sensitivity, the composition comprises water, wherein the water comprises at least 20% by weight of the dentifrice composition.

[0024] In a second aspect, the invention comprises a dentifrice composition comprising at least 1.5 % of polyvinyl methyl ether / maleic anhydride (PVM / MA) copolymer. In a further embodiment the dentifrice composition comprises at least about 3.0 % by weight of PVM / MA copolymer.

[0025] In a further embodiment the dentifrice composition also comprises an additional tooth desensitizing agent.

[0026] In a further embodiment the tooth desensitizing agent is potassium nitrate.

[0027] In a further embodiment the potassium nitrate comprises about 5 % by weight of the dentifrice composition.

[0028] In a further embodiment the polyvinyl methyl ether / maleic anhydride (PVM / MA) copolymer comprises at least about 3.0 % by weight and the potassium nitrate comprises about 5 % by weight of the dentifrice composition.

[0029] In a further embodiment the dentifrice is an aqueous composition.

[0030] In a further embodiment the composition comprises; water, between 20 - 40 % w / w, at least one humectant, between 25 - 50 % w / w, at least one thickening silica between 10 -20 % VJ / VJ, at least one abrasive silica between 2 - 10 % w / w and at least one surfactant between 0.5 - 5 % w / w.

[0031] In a further embodiment the composition further comprises a source of fluoride.

[0032] In a further embodiment the dentifrice composition comprises one or more minor ingredients selected from the list of flavourings, tooth whitening agents, colourings, preservatives, fragrances, pH modifiers and mixtures thereof.

[0033] In a further embodiment the dentifrice composition comprises a toothpaste or toothpaste tablet formulation.

[0034] In another aspect of the invention, the dentifrice compositions according to the invention are used in combination with a toothbrush to clean teeth.

[0035] In a further embodiment, the toothbrush is a manual toothbrush.

[0036] In a further embodiment, the toothbrush is an electrically powered toothbrush.

[0037] Detailed description of the invention

[0038] It was surprisingly found that a dentifrice containing polyvinyl methyl ether / maleic anhydride (PVM / MA) copolymer at high levels has strong occluding properties. This property provides for a dentifrice composition comprising the copolymer at at least 1.5% by weight to be an effective treatment for dentine hypersensitivity. This ingredient, usually in liquid form, has been used in dentifrice compositions, in particular toothpaste compositions, at low levels for many years to provide a thickening and stabilising effect to hold the paste formulations together.

[0039] The occluding properties of the copolymer at high levels in the dentifrice composition provide desensitizing properties equivalent to that of known desensitizing active compounds such as bioglasses, stannous fluoride and potassium nitrate.

[0040] Preferably the amount of polyvinyl methyl ether / maleic anhydride (PVM / MA) copolymer is greater than 2.0 % by weight, more preferably at least 2.5% by weight.

[0041] Preferably the amount of polyvinyl methyl ether / maleic anhydride (PVM / MA) copolymer is between about 2.0% and 10% by weight, more preferably between about 2.5% and 8% by weight and most preferably between about 3.0 % and 4.5 % by weight of the dentifrice compositions.

[0042] A particularly preferred source of polyvinyl methyl ether / maleic anhydride ((PVM / MA) copolymer is OraRez™ W-100P, by Boai NKY Pharmaceuticals Ltd. OraRez™ W-100P is a free acid of the cocopolymer of methyl vinyl ether and maleic anhydride In the form of powder.

[0043] The powdered form of the copolymer makes it particularly easy to handle.

[0044] The invention is not limited to dentifrices comprising powdered PVM / MA copolymers nor PVM / MA copolmers from particular suppliers.

[0045] Other sources of PVM / MA copolymers can be used. Non-limiting examples include the Gantrez™ range of products from Ashland and Luviform™ by BASF.

[0046] The dentifrices of the present invention may be prepared as an aqueous or non-aqueous formulation. The dentifrices of the present invention are preferably aqueous based.

[0047] The dentifrices of the present invention are effective desensitizing formulas without further desensitising actives. However the dentifrices of the present invention are particularly effective when the polyvinyl methyl ether / maleic anhydride (PVM / MA) copolymer is used in combination with a second desensitizing active.

[0048] The invention is not limited to particular second actives. Non-limiting examples of further desensitising actives to use in combination with the powdered PVM / MA are bioglasses, in particular Novamin®, stannous fluoride and potassium nitrate.

[0049] These actives have different modes of action. Stannous fluoride and bioglass are occluding desensitising actives, they act to block dentine tubules. Potassium nitrate gains its desensitising properties by acting directly upon the nerves of the teeth.

[0050] The dentifrices of the present invention are particularly effective when the polyvinyl methyl ether / maleic anhydride (PVM / MA) copolymer is combined with potassium nitrate due to the two different modes of action.

[0051] The dentifrices of the present invention are not limited to the amount of potassium nitrate utilised.

[0052] The amount of potassium nitrate contained in the formulas may be from about 1 % and 10 % by weight. The skilled person can adjust the level as required. A particularly effective amount of potassium nitrate is about 5% by weight.

[0053] A preferred dentifrice composition of the present invention comprises from about 3% to about 4.5 % PVM / MA polymer and about 5% potassium nitrate.

[0054] A particularly preferred dentifrice composition of the present invention comprises about 3% PVM / MA polymer and about 5% potassium nitrate.

[0055] The dentifrice compositions of the present invention may take any physical form suitable. Particularly preferred forms are toothpastes and toothpaste tablets.

[0056] Optional ingredients The dentifrices of the present invention may comprise a humectant. Any humectant suitable for use in oral care may be used.

[0057] Non limiting examples of suitable humectants include sugar alcohols such as glycerol sorbitol, xylitol and malitol. If used, typically humectants may comprised between 10 and 60 % of the formulations by eight, preferably between 20 and 40% by weight.

[0058] The dentifrices of the present invention may comprise at least one thickener and at least one abrasive to aid the cleaning of the tooth surface. Any thickener or abrasive suitable for use in oral care products may be included. The skilled person is aware of many of these.

[0059] The invention is not limited to any particular abrasive or thickener.

[0060] Examples of suitable dental abrasives and thickeners include silica abrasives / thickeners such as those marketed under the following trade names Zeodent®, Sident®, Sorbosil® or Tixosil® by Huber, Degussa, Ineos and Rhodia respectively.

[0061] The silica thickener, if used, should be present in an amount needed to give the right level of body to the formula.

[0062] The silica abrasive, if included, should be present in an amount sufficient to ensure adequate cleaning of teeth by the dentifrice composition whilst not promoting unnecessary abrasion of the teeth surface.

[0063] The abrasive may be a single component or a mixture of two or more abrasives. The use of different abrasives allows the skilled person to optimise the cleaning power of the dentifrice compositions.

[0064] The total abrasive is generally present in an amount up to 10% by weight of the total dentifrice composition, for example from 1 % to 10 % by weight, and preferably at least 2 % -10%. For example, from 3 % to 7 % by weight and especially 4 % to 6 % by weight of the total composition. Ultimately the level of abrasive in the tablet is determined by the particular abrasive used and the level of abrasivity desired in the final product. The skilled person can adjust the levels required.

[0065] Particularly preferred abrasives include hydrated silicas. And a particularly preferred grade is Zeodent® 124 by Evonik.

[0066] The dentifrices of the present invention may contain surfactants to provide foaming, cleaning and mouthfeel properties. The dentifrice compositions of the present invention may contain at least one surfactant. The dentifrices of the invention may comprise a combination of two or more surfactants.

[0067] The skilled person is aware of the types of surfactants used in oral care compositions. A suitable surfactant for use in the dentifrice compositions according to the invention belongs to the class of compounds known as betaines. Structurally, betaine compounds contain an anionic functional group such as a carboxylate functional group and a cationic functional group such as quaternary nitrogen functional group separated by a methylene moiety. They include n-alkyl betaines such as cetyl betaine and behenyl betaine, and n-alkylamido betaines such as cocoamidopropyl betaine.

[0068] In one embodiment the betaine is cocoamidopropyl betaine, commercially available under the trade name Tego Betain®.

[0069] Suitably the betaine is present in an amount ranging from about 0.1 % to about 10 % by weight of the toothpaste tablet composition, for example from about 0.2 % to about 3.0 % , more preferably between about 0.3 % to about 2.0 % by weight of the dentifrice composition.

[0070] Another surfactant for use in the toothpaste tablet compositions according to the invention is selected from a taurate based surfactant. Taurate surfactants useful in the present invention are salts of fatty acid amides of N-methyl taurine. They conform generally to the structural formula:

[0071] RC(O)N(CH3)CH2CH2SO3l\ / l

[0072] Where RC(O)- represents a fatty acid radical and M represents sodium, potassium, ammonium or triethanolamine. Fatty acids having carbon chain lengths of from 10 to 20, including those derived from coconut, palm and tall oil are used. In one embodiment the fatty acid is derived from coconut. In one embodiment, sodium salts are used.

[0073] In one embodiment the taurate is sodium methyl cocyl taurate. This taurate surfactant is sold under the trademark by Adinol CT® by Croda.

[0074] The taurate surfactant may be present in an amount from about 0.1 to about 10 % of the toothpaste tablet composition. In one embodiment the taurate surfactant is present in an amount from about 0.1 % to about 5 % by weight of the toothpaste tablet composition. In one embodiment the taurate surfactant is present in an amount from about 0.5 % to about 2.0 % by weight of the toothpaste tablet composition.

[0075] Another class of surfactants suitable for the present invention are alkyl sulphate surfactants of the following structural formula:

[0076] R1OSO3I\ / I

[0077] R1represents a fatty alcohol moiety and M represents sodium, potassium, ammonium or triethanolamine. Fatty alcohols having carbon chain lengths of from about 10 to about 20, including those derived from coconut, palm oil and tall oil. In one embodiment, the fatty alcohol is lauryl alcohol. In one embodiment, a sodium salt is used.

[0078] In one embodiment the alkyl sulphate is sodium lauryl sulphate (SLS).

[0079] The alkyl sulphate surfactant may be present in an amount from about 0.1 % to about 10 % of the non-aqueous composition. In one embodiment the alkyl sulphate surfactant may be present in an amount from about 0.1 to about 5% by weight of the dentifrice composition.

[0080] In one embodiment the alkyl sulphate surfactant is present in an amount from about 0.5 to about 2.5% by weight of the toothpaste tablet composition.

[0081] The total amount of surfactant in the dentifrice formulation is preferably less than about 10 %, more preferably less than 5 % and most preferably less than 3 % by weight of the formulation.

[0082] The dentifrice compositions of the invention may have a source of fluoride ion.

[0083] The fluoride source may be selected from sodium fluoride, stannous fluoride, sodium monofluorophosphate, potassium fluoride, ammonium fluoride, bis-(hydroxethyl) amino-propyl-N- hydroxyethyloctadecylamine-dihydrofluoride and mixtures thereof.

[0084] A particularly preferred source of fluoride ions forthe present invention is sodium fluoride or stannous fluoride or mixtures thereof.

[0085] The dentifrices of the present invention may have any level of fluoride from lOOppm to lOOOOppm.

[0086] The level of fluoride in most jurisdictions is heavily controlled by state regulation. 450ppm, 1150ppm and 1426ppm levels are typical levels for commercial toothpastes. The present invention works well with these levels but is not limited to these amounts of fluoride.

[0087] The skilled person can readily determine the correct amount of fluoride source to add to get the correct levels.

[0088] The dentifrice compositions of the present invention may be toothpaste or toothpaste tablet formulations.

[0089] The formulations may be aqueous or non-aqueous formulations.

[0090] The use of tablets for toothpaste allows for the controlled use of the correct amounts of actives for a single brushing. The dentifrices of the present invention may contain many other minor ingredients.

[0091] The minor ingredients may be selected from the list of flavourings, whitening agents, colourings, preservatives, fragrances, pH modifiers and mixtures thereof.

[0092] The dentifrice compositions of the present invention may contain a total of 0.1 % -8 % by weight of minor ingredients.

[0093] Minor ingredients may include one or more, flavours, colourants, preservatives, sweeteners or flavour enhancers, pH modifiers, rheology modifiers, or combinations of the these.

[0094] The skilled person would be aware of examples of all of these ingredients that are suitable for oral care use.

[0095] General dentifrice compositions of the present invention

[0096] A non-limiting example of a dentifrice composition of the present invention is shown below on table

[0097] 1. The composition would comprise the following ingredients:

[0098] Table 1

[0099] Table 2 discloses a further preferred non-limiting example of the dentifrice compositions of the present invention. The composition would comprise the following ingredients:

[0100] Table 2

[0101] A preferred non limiting example of the dentifrices of the present invention including a desensitizing active, potassium nitrate is sent out in Table 3. The composition would comprise the following ingredients:

[0102] Table 3

[0103] Table 4 discloses a preferred non-limiting example of the present invention comprising the copolymer and potassium nitrate at highly desired levels.

[0104] Table 4

[0105] Example formulations

[0106] The following toothpaste formulations were prepared to demonstrate the effects of the invention.

[0107] The samples were all subjected to hydraulic conductance testing and the results compared.

[0108] Table 5

[0109] Table 6

[0110] Table 7

[0111]

[0112] Table 8

[0113] Discussion

[0114] Control samples la, 1, 3, and 5 demonstrate the effect of using a known occluding desensitizing agent in a dentifrice formulation (SnFj and Bioglass Novamin™ ) in reducing conductance across a tooth compared with desensitising (potassium nitrate) formulations without occluding agents (Control 2 and 4).

[0115] Hydraulic conductance is reduced by 20-30% with the addition of SnFj (Control 1 and 3 versus control 2 (with non-occluding potassium nitrate) on table 5)

[0116] Table 5 also demonstrates that 1.5 % by weight of the PVM / MA copolymer in a toothpaste formulation has the occlusive properties equivalent to commercial stannous fluoride formulations. (Example 1 versus Controls 1 or 3).

[0117] Table 6 demonstrates that 3.0% by weight of the PVM / MA copolymer in a toothpaste formulation has the occlusive properties of a commercial bioglass (Novamin®) formulation.

[0118] Table 8 demonstrates a clear dose response in terms of effective occlusion. Increasing the amounts of the copolymer, (Examples 2-4), steadily increases the occlusive effect.

[0119] This is a highly surprising result in the absence of known occluding actives. Hydraulic conductance - Optimised Method Summary:

[0120] Dentine discs were cut from unrestored, caries free, coronal portions of human molars. All cuts were made perpendicular to the longitudinal axis of each tooth, using a diamond wire saw (approximate thickness: 550 pm). Fifty-six discs passing the baseline criteria were used in this study; eight discs per group.

[0121] Each disc was etched with 1% (w / w) citric acid for 2 minutes; rinsed for 30 seconds with deionised water; sonicated for 10 minutes in deionised water; rinsed for 30 seconds with deionised water; and, pat-dried using absorbent tissue. The disc was then secured within a Pashley cell while taking care to eliminate any air bubbles or debris. An Elveflow OBI flow controller (UK01200-203) was used to force the perfusion solution (Earle's Balanced Salt Solution), via an Elveflow FS2 sensor (FLOW-02-46675), through the disc, under a constant pressure of 100 mbar, and the mean flow rate was measured over 5 minutes using the Elveflow software (version 2.6.1). A mean fluid flow rate within the range 3 to 7.6 pL / min was deemed acceptable for a baseline measurement. Each disc passing the baseline flow criteria was randomly assigned to a treatment group and subjected to the following treatment regime. The cell was filled with deionised water and approximately 0.5g of the assigned toothpaste. The exposed dentine was brushed using an artist's brush for 30 seconds, under moderate manual pressure, to incorporate maximum amount of product into the exposed dentinal tubules. The resultant slurry was allowed to settle for a further 30 seconds before being rinsed with deionised water until all visible slurry had been removed. The cell was refilled with deionised water, left for 30 seconds and a 5-minute flow measurement was recorded. This procedure was repeated a further three times for each disc (4 brushings).

[0122] A washout treatment was then performed, which consisted of filling the cell with 10% (w / w) citric acid for 30 seconds after which the 5-minute flow rate was recorded. The disc was then treated with 5% oxalic acid solution for 30 seconds after which the 5-minute flow rate was again recorded, to ensure there were no leaks in the system or fractures in the disc. The data for each disc was accepted if the post-oxalate treatment flow rate was no more than 10% of the baseline flow rate.

[0123] Clinical studies On the basis of the positive hydraulic conductance data, a clinical trial was carried out to determine if desensitizing effects could be proven against dentine hypersensitivity (DH) in normal in vivo conditions.

[0124] This was a proof of principle study to investigate the ability of a 3% methyl vinyl ether / maleic anhydride co-copolymer (PVM / MA) + 5% potassium nitrate (KNO3) combination toothpaste to protect from dentine hypersensitivity across an 8-week treatment period.

[0125] Key study aspects: o Randomised, controlled, examiner blind, 4 treatment arm, parallel design, stratified (by maximum Baseline Schiff sensitivity score of the two selected test teeth) o Study period: 2-4 weeks acclimatisation; 8 weeks product usage o DH to evaporative air (Schiff sensitivity score) and tactile (tactile threshold) stimuli was assessed at Baseline, Day 3, and Weeks 2, 4 and 8 after twice daily brushing o Subjects with good general and oral health with self-reported and examiner confirmed DH

[0126] • Two 'Test Teeth' which met tactile threshold (<20g) & Schiff sensitivity score (>2) criteria @ both screening and baseline visit

[0127] 133 subjects were screened, 120 were randomised, 118 completed the study.

[0128] Four test products:

[0129] 1 - Example 3a - (see table 8 above) - A 3% PVM / MA + 5% KNO3 paste

[0130] 2 - Example 3 - (see table 7 above) - A 3% PVM / MA only paste

[0131] 3 - Desensitizing control - Sensodyne paste (5% KNO3)

[0132] 4 - Negative control - Colgate Cavity Protection, (fluoride only) Results

[0133] Change in Baseline in Schiff Sensitivity Score

[0134] Table 9

[0135] Change from baseline: p-value < 0.05 for all products at all time points.

[0136] Figure 2 shows the results on table 9 in graphical form.

[0137] Change from Baseline in Tactile Threshold

[0138] Table 10

[0139] Change from baseline: p-value < 0.05 for all products at all time points.

[0140] Figure 1 shows the results of table 10 in graphical form. Conclusions

[0141] Primary objective (to characterise the sensitivity protection profile of study products) was met.

[0142] The combination toothpaste containing 3 % of PVM / MA + 5% KNO3, the PVM / MA only (PVM / MA) toothpaste and the KNO3 toothpaste showed a consistent DH protection, as measured by Schiff sensitivity score and Tactile threshold across an 8-week treatment period with twice daily tooth brushing.

[0143] The experimental combination toothpaste containing 3 % of PVM / MA + 5 % KNO3showed better DH protection, as measured by Schiff sensitivity score and tactile threshold, than the KNO3only toothpaste and the negative control toothpaste. The difference was statistically significant at all timepoints.

[0144] The experimental combination toothpaste containing 3 % of PVM / MA + 5 % KNO3showed better DH protection, as measured by Schiff sensitivity score and tactile threshold, than the copolymer only (PVM / MA) toothpaste. The difference was statistically significant at all timepoints except Schiff sensitivity score at Day 3.

[0145] All study products were generally well tolerated.

Claims

Claims1. An oral care dentifrice composition comprising at least about 1.5 % by weight polyvinyl methyl ether / maleic anhydride (PVM / MA) copolymer for use as a medicament for reducing dentine hypersensitivity.

2. The oral care dentifrice composition for use according to claim 1 comprising at least about 2.0 % by weight polyvinyl methyl ether / maleic anhydride copolymer for use as a medicament for reducing dentine hypersensitivity.

3. The oral care dentifrice composition for use according to claim 1 or claim 2 comprising at least about 3.0 % by weight / maleic anhydride copolymer for use as a medicament for reducing dentine hypersensitivity.

4. The oral care dentifrice composition for use according to any of the previous claims wherein the composition further comprises a further tooth desensitising active compound.

5. The oral care dentifrice composition for use according to claim 4 wherein the tooth desensitising active compound comprises potassium nitrate.

6. The oral care dentifrice composition for use according to claim 5 wherein the composition comprises potassium nitrate at about 5 % by weight.

7. The oral care dentifrice composition for use according to any of the previous claims wherein the copolymer is in a powered form prior to addition to the dentifrice composition.

8. The oral care dentifrice composition for use according to any of the previous claims wherein the composition comprises water.

9. The oral care dentifrice composition for use according to any of the previous claims wherein the water comprises at least 20 % by weight of the composition.

10. A dentifrice composition comprising at least about 1.5 % of polyvinyl methyl ether / maleic anhydride (PVM / MA) copolymer.

11. The dentifrice composition according to claim 11 wherein the PVM / MA copolymer powder comprises at least about 3.0 % by weight.

12. The dentifrice composition according to claim 10 or claim 11 wherein the dentifrice also comprises a tooth desensitizing agent.

13. The dentifrice composition according to claim 12 wherein the tooth desensitizing agent is potassium nitrate.

14. The dentifrice composition according to claim 13 wherein the potassium nitrate comprises about 5 % by weight of the dentifrice composition.The dentifrice composition according to claim 13 wherein the polyvinyl methyl ether / maleic anhydride (PVM / MA) copolymer comprises at least about 3.0 % by weight and the potassium nitrate comprises about 5 % by weight. The dentifrice composition according to any of the previous claims wherein the dentifrice is an aqueous composition. The dentifrice composition of any of the preceding claims wherein the composition further comprises; water between 20 - 40 % w / w, at least one humectant, between 25 - 50 % w / w, at least one thickening silica between 10 -20 % VJ / VJ, at least one abrasive silica between 2 - 10 % VJ / VJ and at least one surfactant between 0.5 - 5 % w / w. The dentifrice composition according to any of the previous claims wherein the composition further comprises a source of fluoride. The dentifrice composition according to any of the previous claims wherein the composition further comprises one or more minor ingredients selected from the list of flavourings, tooth whitening agents, colourings, preservatives, fragrances, pH modifiers and mixtures thereof. The dentifrice composition according to any one of claims 10 - 19 wherein the composition comprises a toothpaste or toothpaste tablet formulation. The use of the dentifrice composition according to any one of claims 10 - 19 in combination with a toothbrush to clean teeth. The use according to claim 21 wherein the toothbrush is a manual or an electrically powered toothbrush.

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