Oral composition

Abstract

The present application provides an oral composition having an excellent acid resistance improving effect, a persistent hypersensitive symptom suppressing effect, and a feeling of use. A composition for oral use, which contains (A) sodium fluoride, (B) a water-soluble calcium salt, (C) at least one substance selected from the group consisting of pyrophosphoric acid and alkali metal salts thereof, and (D) at least one substance selected from the group consisting of water-soluble aluminum salts and water-soluble potassium salts (however, the pyrophosphate is additionally provided).

Description

Technical Field

[0001] The present invention relates to an oral composition. Background Art

[0002] Dentin on the root surface exposed by gum recession has lower acid resistance than enamel, so caries tend to progress faster. In addition, in teeth with exposed root surfaces, there are many cases where hyperesthesia-like symptoms are manifested.

[0003] Conventionally, fluorides such as sodium fluoride have been widely used as an effective ingredient for preventing dental caries. In addition, Patent Document 1 proposes a dentifrice composition comprising one or more selected from tripolyphosphates and pyrophosphates, a water-soluble calcium salt, sodium fluoride, and cationized cellulose.

[0004] On the other hand, water-soluble aluminum salts or water-soluble potassium salts have been used for hyperesthesia-like symptoms. In addition, Patent Document 2 proposes an oral composition containing potassium nitrate, a linear water-soluble polyphosphate, and a polyol. [Prior art literature] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2021-95380 [Patent Document 2] Japanese Patent Application Publication No. 2006-96696 Summary of the invention [Problems to be solved by the invention]

[0006] However, conventional techniques have not been able to improve the acid resistance of dentin sufficiently. In recent years, with the increase in the number of remaining teeth in the elderly due to aging, the number of root caries occurring on the root surface of gums has increased, and further improvement of the acid resistance improvement effect is required. Regarding hyperesthesia-like symptoms, conventional techniques have not been able to provide a sufficient duration of the suppressive effect on hyperesthesia-like symptoms. Furthermore, oral compositions have also been problematic in terms of feel, such as a peculiar smell, irritation, and insufficient release of the fragrance of the fragrance.

[0007] An object of the present invention is to provide an oral composition having excellent acid resistance improvement effect, durability of hyperesthesia-like symptom suppressive effect, and feeling during use.

Methods to solve the problem

[0008] The present inventors have conducted intensive studies and found that the acid resistance-enhancing effect is synergistically improved by combining sodium fluoride, a water-soluble calcium salt, pyrophosphate or an alkali metal salt thereof, and a water-soluble aluminum salt or a water-soluble potassium salt, and the duration of the hyperesthesia-like symptom suppressing effect and the feeling during use are also excellent. The present invention is based on the above-mentioned findings and has the following forms.

[0009] <1> An oral composition comprising: Component (A): sodium fluoride; Component (B): a water-soluble calcium salt; Component (C): at least 1 selected from pyrophosphoric acid and its alkali metal salts; and Component (D): at least 1 selected from water-soluble aluminum salts and water-soluble potassium salts (excluding pyrophosphates). <2> The oral composition according to <1>, wherein the component (B) is at least 1 selected from calcium chloride, calcium glycerophosphate, calcium gluconate, calcium lactate, and calcium pantothenate. <3> The oral composition according to <1> or <2>, wherein the component (C) is at least 1 selected from pyrophosphoric acid, sodium pyrophosphate, and potassium pyrophosphate. <4> The oral composition according to any one of <1> to <3>, wherein the component (D) is at least 1 selected from aluminum lactate and potassium nitrate. <5> The oral composition according to any one of <1> to <4>, wherein the molar ratio of the component (B) to the component (D) is 0.001 to 15.0. <6> The oral composition according to any one of <1> to <5>, wherein the total amount of aluminum ions and potassium ions in the oral composition is 0.01 to 5% by mass based on the total mass of the oral composition. <7> The oral composition according to any one of <1> to <6>, wherein the oral composition is toothpaste.

Advantages of the Invention

[0010] According to the present invention, an oral composition having excellent acid resistance improvement effect, persistence of dentinal hypersensitivity-like symptom inhibitory effect, and usability can be provided. Detailed Description

[0011] In this specification, "oral composition" refers to a composition mainly for use in the oral cavity. "Water-soluble" means a solubility of 1 g / 100 g or more with respect to water at 20°C. The "~" indicating a numerical range means including the values described before and after it as the lower limit value and the upper limit value.

[0012] 〔Oral Composition〕 The oral composition of the present invention contains component (A), component (B), component (C) and component (D).

[0013] <Component (A)> Component (A) is sodium fluoride (NaF). Since the oral composition contains component (A), fluoride ions are supplied into the oral cavity, and the acid resistance improvement effect of the dentin on the root surface is exhibited. Commercially available products can be used as component (A).

[0014] <Component (B)> Component (B) is a water-soluble calcium salt. Since the oral composition contains component (B), calcium ions are supplied into the oral cavity, and the acid resistance improvement effect of the dentin is enhanced. In addition, the feeling in use also becomes good.

[0015] Examples of component (B) include calcium chloride, calcium nitrate, calcium acetate, calcium citrate, calcium glycerophosphate, calcium gluconate, calcium benzoate, calcium formate, calcium fumarate, calcium lactate, calcium butyrate, calcium isobutyrate, calcium malate, calcium maleate, calcium propionate, calcium valerate, calcium pantothenate, etc. As component (B), at least one selected from calcium chloride, calcium glycerophosphate, calcium gluconate, calcium lactate and calcium pantothenate is preferred, and at least one selected from calcium chloride, calcium glycerophosphate and calcium lactate is particularly preferred. Component (B) can be a single kind or a combination of two or more kinds. Commercially available products can be used as component (B).

[0016] <Component (C)> Component (C) is at least one selected from pyrophosphoric acid and its alkali metal salts. Since the oral composition contains component (C), the acid resistance improvement effect of the dentin and the persistent effect of suppressing dentinal hypersensitivity-like symptoms are continuously enhanced.

[0017] Examples of the alkali metal salt include sodium salt, potassium salt, etc. As component (C), from the viewpoint of acid resistance, at least one selected from pyrophosphoric acid, sodium pyrophosphate and potassium pyrophosphate is preferred, and at least one selected from potassium pyrophosphate and sodium pyrophosphate is particularly preferred. Component (C) can be a single kind or a combination of two or more kinds. Commercially available products can be used as component (C).

[0018] <Component (D)> Component (D) is at least one selected from water-soluble aluminum salts and water-soluble potassium salts (excluding pyrophosphates). Since the oral composition contains the component (D), aluminum ions and / or potassium ions are supplied into the oral cavity, and an inhibitory effect on dentin hypersensitivity-like symptoms is exhibited. In addition, the effect of improving the acid resistance of dentin is enhanced.

[0019] Examples of the water-soluble aluminum salts include inorganic aluminum salts such as aluminum chloride, aluminum sulfate, and potassium alum; and organic aluminum salts such as aluminum lactate, aluminum tartrate, aluminum citrate, aluminum gluconate, aluminum glycolate, aluminum malonate, aluminum glutarate, and aluminum malate. Among them, aluminum lactate is preferred.

[0020] Examples of the water-soluble potassium salts include inorganic potassium salts such as potassium nitrate, potassium chloride, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium hydroxide, potassium carbonate, potassium bicarbonate, potassium alum, and potassium sulfate; and organic potassium salts such as potassium lactate, potassium sorbate, potassium citrate (monopotassium citrate, tripotassium citrate, etc.), potassium oxalate, potassium hydrogen tartrate, potassium sodium tartrate, potassium gluconate, potassium glutamate, potassium succinate, potassium malate, and acesulfame potassium. Among them, potassium nitrate, potassium chloride, potassium hydroxide, potassium sulfate, and potassium citrate are preferred.

[0021] As the component (D), at least one selected from aluminum lactate, potassium nitrate, potassium chloride, potassium hydroxide, potassium sulfate, and potassium citrate is preferred, and at least one selected from aluminum lactate and potassium nitrate is particularly preferred. (D) component may be a single kind or a combination of two or more kinds. (D) component can use commercially available products.

[0022] <Content of each component> The content of the component (A) is preferably 0.09 to 1.3% by mass, more preferably 0.10 to 1.1% by mass, based on the total mass of the oral composition. When the content of the component (A) is not less than the above lower limit value, the effect of improving acid resistance is more excellent. When the content of the component (A) is not more than the above upper limit value, the feel in use is more excellent.

[0023] The content of the component (B) is preferably 0.02 to 5.0% by mass, more preferably 0.03 to 3.0% by mass, based on the total mass of the oral composition. When the content of the component (B) is not less than the above lower limit value, the effect of improving acid resistance and the feel in use are more excellent. When the content of the component (B) is not more than the above upper limit value, the persistence of the dentin hypersensitivity inhibitory effect is more excellent.

[0024] The content of the component (C) is preferably 0.02 to 3.0% by mass, more preferably 0.03 to 1.3% by mass, based on the total mass of the oral composition. When the content of the component (C) is not less than the above lower limit value, the effect of improving acid resistance and the persistence of the dentin hypersensitivity inhibitory effect are more excellent. When the content of the component (C) is not more than the above upper limit value, the feel in use is more excellent.

[0025] When the (D) component contains a water-soluble aluminum salt, the content of the water-soluble aluminum salt, in terms of aluminum ions converted, is preferably 0.01 to 1% by mass, more preferably 0.05 to 0.5% by mass, relative to the total mass of the oral composition. When the (D) component contains a water-soluble potassium salt, the content of the water-soluble potassium salt, in terms of potassium ions converted, is preferably 0.05 to 4% by mass, more preferably 0.5 to 3% by mass, relative to the total mass of the oral composition. The content of the (D) component, that is, the total content of the water-soluble aluminum salt and the water-soluble potassium salt, is preferably an amount such that the total amount of aluminum ions and potassium ions in the oral composition is within the following preferred ranges.

[0026] The total amount of aluminum ions and potassium ions in the oral composition is preferably 0.01 to 5% by mass, more preferably 0.05 to 4% by mass, relative to the total mass of the oral composition. When the total amount of aluminum ions and potassium ions is above the above lower limit value, the acid resistance improvement effect and the persistence of the dentin hypersensitivity-like symptom inhibition effect are more excellent. When the total amount of aluminum ions and potassium ions is below the above upper limit value, the usability is more excellent. In addition, the total amount of aluminum ions and potassium ions in the oral composition may also include an amount not derived from the (D) component. For example, when the (C) component contains potassium pyrophosphate, the potassium ions derived from potassium pyrophosphate are also included in the above total amount.

[0027] The molar ratio of the (B) component to the (C) component (hereinafter also referred to as "(B) / (C)") is, for example, preferably 0.07 to 150, more preferably 0.1 to 85. When (B) / (C) is above the above lower limit value, the usability is more excellent. When (B) / (C) is below the above upper limit value, the persistence of the dentin hypersensitivity-like symptom inhibition effect is more excellent.

[0028] The molar ratio of the (B) component to the (D) component (hereinafter also referred to as "(B) / (D)") is, for example, preferably 0.001 to 15.0, more preferably 0.005 to 2.0. When (B) / (D) is above the above lower limit value, the acid resistance improvement effect and the usability are more excellent. When (B) / (D) is below the above upper limit value, the acid resistance improvement effect and the persistence of the dentin hypersensitivity-like symptom inhibition effect are more excellent.

[0029] <Other components> Within the range that does not hinder the effects of the present invention, the oral composition of the present invention may further contain other components other than the (A) component, the (B) component, the (C) component, and the (D) component as needed. Other components can be appropriately selected from known components in consideration of the dosage form of the oral composition, method of use, etc. Examples of other components include water, abrasive, binder, thickener, surfactant, colorant, sweetener, preservative, fragrance, active ingredient, pH regulator.

[0030] As the abrasive, for example, silica-based abrasives such as anhydrous silicic acid, precipitated silica, silica gel, aluminosilicate, zirconium silicate, dicalcium hydrogen phosphate dihydrate or anhydrate, calcium dihydrogen phosphate, calcium phosphate, quaternary calcium phosphate, calcium carbonate, calcium hydroxide, aluminum hydroxide, insoluble sodium metaphosphate, trimagnesium phosphate, magnesium carbonate can be cited. From the aspect of the manifestation of the effects of the present invention, silica-based abrasives are particularly preferred. The content of the abrasive is preferably 0 to 60% by mass, more preferably 0 to 30% by mass, and may also be 25% by mass or less, based on the total mass of the oral composition. A content of 0% by mass of the abrasive means that no abrasive is contained.

[0031] As the binder, for example, organic binders such as water-soluble polymer substances selected from cellulose derivatives such as sodium carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, gums such as xanthan gum, tragacanth gum, karaya gum, gum arabic, and polyacrylates such as sodium polyacrylate can be cited; inorganic binders such as thickening silica, thickening aluminum silica, magnesium aluminum silicate (veegum), laponite. The content of the binder is preferably 0.05 to 13.0% by mass, based on the total mass of the oral composition. When the binder contains an organic binder, the mixing amount of the organic binder is more preferably 0.1 to 3% by mass, and further preferably 0.5 to 2.5% by mass, based on the total mass of the oral composition. When the binder contains an inorganic binder, from the aspect of the adsorption of fluoride ions to the tooth surface, the content of the inorganic binder is more preferably 0 to 10.0% by mass, and further preferably 0 to 8.0% by mass, based on the total mass of the oral composition.

[0032] As the thickener, for example, sugar alcohols such as sorbitol, xylitol, erythritol, maltitol, and polyhydric alcohols such as glycerin, propylene glycol, and polyethylene glycol having an average molecular weight of 160 to 400 (average molecular weight described in the Standards for Quasi-drug Raw Materials 2006) can be cited. The content of the thickener is preferably 20 to 70% by mass, more preferably 25 to 65% by mass, based on the total mass of the oral composition.

[0033] As surfactants, for example, nonionic surfactants, anionic surfactants, and amphoteric surfactants can be mentioned. As nonionic surfactants, for example, glycerol fatty acid esters such as decaglycerol laurate, polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate (the average number of moles of ethylene oxide added (hereinafter, simply referred to as "E.O.") is 20), alkyl glycosides with 12 to 16 carbon atoms in the alkyl group, sorbitan fatty acid esters such as sorbitan tristearate, sucrose fatty acid esters such as sucrose laurate, and polyoxyethylene alkyl ethers such as polyoxyethylene stearyl ether (E.O. 6) can be mentioned. As anionic surfactants, for example, alkyl sulfates such as sodium dodecyl sulfate and sodium tetradecyl sulfate, acyl sarcosinates such as sodium lauroyl sarcosinate, acyl amino acid salts such as sodium acyl glutamate, sodium acyl taurine, sodium dodecylbenzenesulfonate, sodium lauryl sulfoacetate, and sodium α-olefin sulfonate can be mentioned. As amphoteric surfactants, for example, coconut fatty acid amide propyl betaine, lauryl dimethylaminoacetic acid betaine, and N-coconut fatty acid acyl-N-carboxymethyl-N-hydroxyethyl ethylenediamine can be mentioned. The content of the surfactant is preferably 0.05 to 10.0% by mass, more preferably 0.1 to 8.0% by mass, based on the total mass of the oral composition.

[0034] As colorants, for example, Red No. 2, Red No. 3, Red No. 225, Red No. 226, Yellow No. 4, Yellow No. 5, Yellow No. 205, Blue No. 1, Blue No. 2, Blue No. 201, Blue No. 204, Green No. 3, mica titanium, and titanium oxide can be mentioned. As sweeteners, for example, sodium saccharin, aspartame, stevioside, stevia extract, p-methoxycinnamaldehyde, neohesperidin dihydrochalcone, and perillartine can be mentioned. As preservatives, for example, p-hydroxybenzoates such as methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, and butyl p-hydroxybenzoate, and benzoic acid or its salts such as sodium benzoate can be mentioned.

[0035] As the fragrance, for example, natural fragrances such as peppermint oil, spearmint oil, anise oil, eucalyptus oil, wintergreen oil, cinnamon oil, clove oil, thyme oil, sage oil, lemon oil, orange oil, mint oil, cardamom oil, coriander oil, orange peel oil, pearberry oil, lavender oil, rosemary oil, bayberry fruit oil, chamomile oil, caraway oil, marjoram oil, bay leaf oil, lemongrass oil, oregano oil, pine needle oil, neroli oil, rose oil, jasmine oil, grapefruit oil, pomelo oil, shaddock oil, iris essential oil, peppermint absolute, rose absolute, neroli absolute, etc., or fragrances obtained by processing and treating these natural fragrances (such as removing the front fraction, removing the rear fraction, fractional distillation, liquid-liquid extraction, rectification, powder fragrance formation, etc.), menthol, carvone, anethole, eucalyptol, methyl salicylate, cinnamaldehyde, eugenol, 3-l-methoxy-1,2-propanediol, thymol, linalool, linalyl acetate, limonene, menthone, menthyl acetate, N-substituted-p-menthane-3-carboxamide, pinene, octanal, citral, piperitone, diethylene glycol monoethyl ether acetate, anisaldehyde, ethyl acetate, ethyl butyrate, allyl cyclohexanepropionate, methyl anthranilate, ethyl methylphenylglycidate, vanillin, undecanolide, hexanal, butanol, isoamyl alcohol, hexenol, dimethyl sulfide, methylcyclopentenolone, furfural, trimethylpyrazine, ethyl lactate, ethyl thioacetate and other single-component fragrances, strawberry flavor, apple flavor, banana flavor, pineapple flavor, grape flavor, mango flavor, butter flavor, milk flavor, mixed fruit flavor, tropical fruit flavor and other blended flavors. For use in an oral composition, known fragrance raw materials can be used in combination. The content of the fragrance is not particularly limited. The content of the above-mentioned fragrance raw materials is preferably 0.000001 to 1% by mass based on the total mass of the oral composition. The content of the fragrance for flavoring using the above-mentioned fragrance raw materials is preferably 0.05 to 2% by mass based on the total mass of the oral composition.

[0036] As the active ingredient, for example, bactericides such as isopropylmethylphenol and cetylpyridinium chloride, water-soluble phosphoric acid compounds such as potassium salts and sodium salts of orthophosphoric acid (excluding component (C)), enzymes such as dextranase, mutanase, amylase, protease, tranexamic acid, ε-aminocaproic acid, triclosan, lysozyme chloride, allantoin aluminum chloride hydroxide, hinokitiol, ascorbic acid, tocopheryl acetate, dihydrocholesterol, α-bisabolol, chlorhexidine salts, azulene or water-soluble copper compounds such as sodium copper chlorophyllin, chlorophyll, copper gluconate, strontium chloride, berberine, hydroxamic acid or its derivatives, glycyrrhizic acid or its salts, glycyrrhetinic acid or its derivatives, tartar calculus preventives. An effective amount of the above-mentioned active ingredients can be mixed within the range that does not interfere with the effects of the present invention.

[0037] As a pH regulator, for example, citric acid, tartaric acid, malic acid or their salts such as sodium salts, and sodium hydroxide can be cited.

[0038] <Form, dosage form> The oral composition can be prepared in various forms such as liquid, paste, solid, etc. The dosage form of the oral composition is not particularly limited. The dosage form of the oral composition is typically an oral preparation that is discharged from the oral cavity after use. As the oral preparation, for example, dentifrices (liquid dentifrices, liquid dentifrices, toothpastes, wet powder dentifrices, powder dentifrices, etc.), oral cleansers, mouthwashes, coating agents, mouth sprays, patches, tablets, sustained-release agents in the oral cavity, chewing agents, solubilizers in the oral cavity, disintegrants in the oral cavity, tongue care agents, oral cooling agents, denture care agents, etc. can be cited. Among the above, the oral composition of the present invention is preferably used as a dentifrice, and particularly preferably as a toothpaste.

[0039] The oral composition of the present invention can be prepared by a known method. For example, it can be prepared by mixing component (A), component (B), component (C), component (D) and other components as needed by a conventional method.

[0040] In the oral composition, it is preferable that fluoride ions, calcium ions and phosphate ions form a complex. When the above complex is formed, the retention of fluoride ions in the oral cavity is improved, and thus, the adsorption of fluoride ions to the tooth surface is further improved.

[0041] The formation of the above complex can be confirmed by observing the crystal size based on X-ray crystal structure analysis and the heat generation peak when the crystal water near the phosphate group is detached at around 450 °C based on calorimetry (TG-DTA measurement). That is, when the complex is formed, the crystal size obtained from the diffraction peak attributed to CaF 2 becomes less than 10 nm due to the complexation of the phosphate group. In addition, the peak of the crystal water generation indicates that CaF 2 seen by X-ray crystal structure analysis is not a crystal composed only of calcium and fluoride ions, but a complex in which phosphate groups interact. Specifically, the formation of the complex can be confirmed by confirming that the crystal size is less than 10 nm by the following method (1) and confirming the presence of a heat generation peak at 450 °C by the following method (2). (1) Crystal size The sample was measured using an X-ray structural diffraction apparatus (light source Cu: Kα, 40 kV, 20 mA, divergence slit 1 / 2 deg, scattering slit 1 / 2 deg, receiving slit 0.15 mm, scanning speed 4.000° / min, 2θ = 2.000 to 80.000°). The crystallite size was calculated according to the following formula (Scherrer's formula), and the formation of the complex was evaluated. L = Kλ / (βcosθ) L: crystallite size, K: coefficient 0.9, β: full width at half maximum, λ: θ: diffraction angle (2) TG-DTA measurement (exothermic peak) Heating rate: 5 °C / min, measurement range: 25 °C to 600 °C

[0042] As a method for forming the above complex, there is no particular limitation. When preparing the oral composition, for example, it is preferably any one of the steps of mixing component (B) after mixing components (A) and (C), and mixing component (A) after mixing components (B) and (C). In addition, when components (A) and (B) are mixed simultaneously, a part of calcium fluoride is generated, and the formation efficiency of the complex may deteriorate.

[0043] The oral composition described above contains components (A), (B), (C), and (D), and thus has excellent acid resistance improvement effect, persistence of the effect of suppressing dentin hypersensitivity-like symptoms, and usability.

Examples

[0044] The following examples illustrate the present invention in detail, but the present invention is not limited to the following description. In addition, in the following examples, unless otherwise specified, "%" means "mass %".

[0045] <Raw materials used> Sodium fluoride: manufactured by Stella Chemical Co., Ltd. Also denoted as "NaF" hereinafter. Calcium chloride: manufactured by Tomita Pharmaceutical Co., Ltd. Also denoted as "CaCl" hereinafter. Calcium gluconate: manufactured by Fuso Chemical Industry Co., Ltd. Also denoted as "Ca gluconate" hereinafter. Calcium lactate hydrate: manufactured by Taihei Chemical Industry Co., Ltd., trade name "Calcium lactate". Also denoted as "Ca lactate" hereinafter. Calcium glycerophosphate: manufactured by Iwaki Pharmaceutical Co., Ltd. Also denoted as "Ca glycerophosphate" hereinafter. Calcium pantothenate: manufactured by BASF. Also denoted as "Ca pantothenate" hereinafter. Potassium pyrophosphate: manufactured by Taihei Chemical Industry Co., Ltd. Also denoted as "K pyrophosphate" hereinafter. Sodium pyrophosphate: manufactured by Taihei Chemical Industry Co., Ltd., trade name "Sodium pyrophosphate (anhydrous)". Also referred to as "Na pyrophosphate" hereinafter. Sodium tripolyphosphate: manufactured by Taihei Chemical Industry Co., Ltd. Also referred to as "Na tripolyphosphate" hereinafter. Potassium nitrate: manufactured by Otsuka Chemical Co., Ltd. Aluminum lactate: manufactured by Fujifilm Wako Pure Chemical Corporation. Also referred to as "Al lactate" hereinafter. Water: purified water.

[0046] <Examples 1 to 31, Comparative Examples 1 to 5> Toothpaste compositions (toothpastes) having the compositions shown in Tables 1 to 4 were prepared by conventional methods. The blank columns in the tables indicate that the component was not mixed. The "balance" of water indicates the amount that makes the total amount of the toothpaste composition 100%. The following evaluations were performed on the obtained toothpaste compositions. The results are shown together in Tables 1 to 4.

[0047] (Evaluation of acid resistance of dentin) The toothpaste composition was diluted 4 times with artificial saliva to prepare a treatment solution. Dentin blocks with a 3 mm × 3 mm window on the surface were prepared from bovine tooth roots. The dentin blocks were immersed in the treatment solution at room temperature for 3 minutes. Then, the dentin blocks were taken out of the treatment solution, gently rinsed with purified water to remove the treatment solution, and then immersed in a demineralization solution containing CaCl 2 : 2.2 mM, KH 2 PO 4 : 2.2 mM, acetic acid: 100 mM at pH 4.5 for 6 hours. Then, the dentin blocks were taken out of the demineralization solution and immersed in the treatment solution at room temperature for 3 minutes again. Then, the dentin blocks were taken out of the treatment solution, gently rinsed with purified water to remove the treatment solution, and then immersed in the centrifuged supernatant of human saliva at 37 °C for 18 hours. These series of treatments were performed once a day and repeated a total of 5 days. After the treatment, the dentin blocks were carefully rinsed with purified water and immersed in the demineralization solution at 37 °C for 6 hours. The calcium ion dissolution amount at this time was measured by atomic absorption spectrometry. A series of experimental operations were performed on each example and comparative example with N = 3, and the average value was calculated and evaluated according to the following evaluation criteria. [Evaluation criteria] ◎: Calcium ion dissolution amount is less than 5 μg. ○: Calcium ion dissolution amount is less than 8 μg and 5 μg or more. △: Calcium ion dissolution amount is less than 13 μg and 8 μg or more. ×: Calcium ion dissolution amount is 13 μg or more.

[0048] (Evaluation of the suppression time of dentin hypersensitivity-like symptoms) Using the dentifrice composition in a conventional manner, evaluate the inhibitory effect on dentin hypersensitivity-like symptoms after use in the oral cavity. Specifically, five subjects with dentin hypersensitivity-like symptoms used the dentifrice composition twice a day for one week by the following method. After a specified time (60 minutes, 120 minutes, 180 minutes) from the last brushing, evaluate the presence or absence of dentin hypersensitivity-like symptoms when holding 10°C water in the mouth using the following four-stage scoring criteria. Calculate the average score of the five people and make a judgment using ◎, ○, △, × according to the following evaluation criteria. [Method of using dentifrice] Place 1 g of the dentifrice composition on a toothbrush, brush teeth for 2 minutes, spit it out, and then rinse the mouth with 50 mL of water. [Scoring criteria] 4 points: There are no dentin hypersensitivity-like symptoms until 180 minutes later. 3 points: There are no dentin hypersensitivity-like symptoms until 120 minutes later. 2 points: There are no dentin hypersensitivity-like symptoms until 60 minutes later. 1 point: Dentin hypersensitivity-like symptoms are felt after 60 minutes. [Evaluation criteria] ◎: The average score is 3.5 or more. ○: The average score is 3.0 or more and less than 3.5. △: The average score is 2.0 or more and less than 3.0. ×: The average score is less than 2.0.

[0049] (Evaluation of the feeling in use) Using the dentifrice composition in a conventional manner, evaluate the presence or absence of abnormal odor and irritation after use in the oral cavity. Specifically, ten subjects used the dentifrice composition by the following method and evaluated the presence or absence of abnormal odor (astringency, bitterness) and irritation in the oral cavity after 10 minutes using the following five-stage scoring criteria. Calculate the average score of the ten people and make a judgment using ◎, ○, △, × according to the following evaluation criteria. [Method of using dentifrice] Place 1 g of the dentifrice composition on a toothbrush, brush teeth for 2 minutes, spit it out, and then rinse the mouth with 50 mL of water. [Scoring criteria] 5 points: There is no abnormal odor or irritation at all. 4 points: There is almost no abnormal odor or irritation. 3 points: Slightly feel abnormal odor or irritation. 2 points: Feel abnormal odor or irritation. 1 point: Strongly feel abnormal odor or irritation. [Evaluation Criteria] ◎: The average score is above 4.5 points. ○: The average score is above 4.0 points and less than 4.5 points. △: The average score is above 3.0 points and less than 4.0 points. ×: The average score is above 1.0 points and less than 3.0 points.

[0050] [Table 1]

[0051] [Table 2]

[0052] [Table 3]

[0053] [Table 4]

[0054] As shown in the above results, among the dentifrice compositions of Examples 1 to 31, the acid resistance of dentin, the suppression time of dentin hypersensitivity-like symptoms, and the usability are excellent. On the other hand, the acid resistance of dentin in the dentifrice compositions of Comparative Examples 1 to 5 that do not contain any of the (A) component, (B) component, (C) component, and (D) component is poor. The usability of Comparative Example 2 that does not contain the (B) component is also poor. The suppression time of dentin hypersensitivity-like symptoms in Comparative Example 3 that does not contain the (C) component and Comparative Example 4 that does not contain the (D) component is also poor.

[0055] Comparing Example 17, Comparative Example 3, and Comparative Example 5, with respect to Comparative Example 3 that does not contain the (C) component and Comparative Example 5 that contains tripolyphosphate instead of the (C) component, the acid resistance of dentin is △, while that of Example 17 is ◎. From this result, the significance of the acid resistance improvement effect based on the (C) component can be confirmed.

[0056] Then, formulation examples are presented. Dentifrice compositions (toothpaste) having the following compositions are prepared by the same method as in the above examples and evaluated. As a result, the acid resistance of dentin, the suppression time of dentin hypersensitivity-like symptoms, and the usability are excellent in any of the formulation examples.

[0057] <Formulation Example 1 Dentifrice>[

[0058] <Formulation Example 2 Dentifrice>[

[0059] <Formulation Example 3 Dentifrice>[

[0060] <Formulation Example 4 Toothpaste>

Claims

1. An oral composition comprising (A) Ingredients: sodium fluoride; (B) ingredient: water-soluble calcium salt; (C) component: at least one selected from pyrophosphoric acid and alkali metal salts thereof; and (D) Component: at least one selected from the group consisting of water-soluble aluminum salts and water-soluble potassium salts, excluding pyrophosphates.

2. The oral composition according to claim 1, wherein The component (B) is at least one selected from the group consisting of calcium chloride, calcium glycerophosphate, calcium gluconate, calcium lactate, and calcium pantothenate.

3. The oral composition according to claim 1, wherein The component (C) is at least one selected from the group consisting of pyrophosphoric acid, sodium pyrophosphate and potassium pyrophosphate.

4. The oral composition according to claim 1, wherein The component (D) is at least one selected from the group consisting of aluminum lactate and potassium nitrate.

5. The oral composition according to claim 1, wherein The molar ratio of the component (B) to the component (D) is 0.001 to 15.

0.

6. The oral composition according to claim 1, wherein The molar ratio of the component (B) to the component (D) is 0.004 to 12.

041.

7. The oral composition according to claim 1, wherein The total amount of aluminum ions and potassium ions in the oral composition is 0.01 to 5% by mass based on the total mass of the oral composition.

8. The oral composition according to claim 1, wherein The total amount of aluminum ions and potassium ions in the oral composition is 0.01 to 4% by mass based on the total mass of the oral composition.

9. The oral composition according to claim 1, wherein The content of the component (A) is 0.09 to 1.3% by mass, the content of the component (B) is 0.02 to 5.0% by mass, and the content of the component (C) is 0.02 to 3.0% by mass based on the total mass of the oral composition.

10. The oral composition according to any one of claims 1 to 9, wherein The oral composition is a toothpaste.

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