Oral composition

Abstract

To provide oral compositions with simple composition that can prevent caries just by contacting the tooth surface for a short time.SOLUTION: Provided is an oral composition containing a silicate compound and / or silicon oxide and having a pH of 3.5 to 6.5. In the volume-based particle size distribution of the silicate compound and / or silicon oxide, the particle diameter (D90) at the 90% position measured from the smaller diameter side is preferably 1 μm or less. The content of the silicate compound and / or silicon oxide can be 0.0005 to 50 wt.% relative to the total weight of the composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an oral composition capable of preventing dental caries. [Background technology]

[0002] Currently, the mainstream of caries prevention in home care is the use of fluorides such as sodium fluoride, stannous fluoride, and sodium monofluorophosphate. Fluoride is incorporated into toothpaste, mouthwash, and topical dental treatments, with most toothpastes containing fluoride. The addition of fluoride to tap water, while not yet in widespread use, has also been reported to be an excellent method (Report from the Japan Dental Association in response to an inquiry issued by the Japanese Dental Society on February 10, 2006, No. 57). In addition, in dental treatment, it has been reported that root caries can be cured by using toothpaste and mouthwash containing fluoride, and treatment with fluoride is recommended (Caries Treatment Guidelines, 3rd Edition, February 10, 2020, edited by the Japanese Society of Conservative Dentistry).

[0003] However, for fluoride to be effective on the tooth surface, it must remain on the tooth surface for as long as possible. Therefore, after applying fluoride to the tooth surface, it is recommended not to gargle and not to eat or drink for approximately 30 minutes. A toothbrushing method known as the Gothenburg technique has been proposed as a way to apply fluoride. This method requires brushing for two minutes, maintaining foam with a humectant, rinsing the mouth with as little water as possible after brushing, gargling for one minute, and spitting out the solution before gargling and not eating or drinking for two hours (Caries Res., 29, 435-441, 1995). Thus, to prevent caries with fluoride, it is necessary not to rinse the formulation off for a long time after use and to restrict eating and drinking. For this reason, fluoride-containing preparations must have a taste that allows them to be kept in the mouth for a long time, and properties that allow fluoride to remain on the tooth surface for a long time, which limits their composition. Furthermore, people often do not gargle or eat or drink for a while after applying the preparation to the tooth surface, so caries is not always effectively prevented. Therefore, there is a need for a preparation that can prevent caries by simply contacting the tooth surface for a short time.

[0004] As an example of an oral cavity composition that prevents dental caries using ingredients other than fluoride, Patent Document 1 discloses a composition that contains 0.05 to 1.2 mass % of a potassium salt of a saturated fatty acid having 12 to 22 carbon atoms and a palmitic acid content of 70 mass % or more, calculated as fatty acid, 5 to 40 mass % of sorbitol, and water, and has a potassium / saturated fatty acid ratio of more than 1 and not more than 3, and a pH of 7 or more and less than 9 at 25°C. The composition enhances the adhesion of the saturated fatty acid potassium salt to the tooth surface while maintaining a good flavor, and confers excellent acid resistance, thereby preventing dental caries. However, the oral composition of Patent Document 1 has many limitations on its composition, limiting the freedom of formulation design. Therefore, there is a demand for an oral composition with a simple composition that can prevent dental caries by simply contacting it with the tooth surface for a short period of time. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2019-48897 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide an oral composition with a simple composition that can prevent dental caries by simply contacting it with the tooth surface for a short period of time. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above problems and have found that an oral composition containing a silicate compound and / or an oxide of silicon and having a pH of 3.5 to 6.5 can impart acid resistance to the tooth surface, inhibit demineralization caused by acid, and promote remineralization when used in a manner that involves repeated short-term contact with the tooth surface, such as during daily tooth brushing or gargling.

[0008] The present invention has been completed based on the above findings, and provides the following oral compositions. [1] An oral composition containing a silicate compound and / or an oxide of silicon and having a pH of 3.5 to 6.5. [2] The oral composition according to [1], wherein the silicate compound and / or silicon oxide is insoluble in water, and the particle size (D90) at the 90% position measured from the small diameter side in the volume-based particle size distribution of the silicate compound and / or silicon oxide is 1 μm or less. [3] The oral composition according to [1] or [2], wherein the content of the silicate compound and / or oxide of silicon is 0.0005 to 50% by weight based on the total amount of the composition. [4] The oral composition according to any one of [1] to [3], which contains sorbitol. [5] The oral composition according to any one of [1] to [4], which is used for imparting acid resistance to tooth surfaces, preventing demineralization of tooth tissue, promoting remineralization of tooth tissue, or preventing or improving dental caries. [Effects of the Invention]

[0009] Dental caries begins when cariogenic bacteria adsorbed to healthy tooth surfaces produce acid from carbohydrates derived from food, lowering the pH of dental plaque, which dissolves minerals such as phosphorus and calcium from the enamel on the tooth surface, causing the tooth to become demineralized. In the oral cavity, remineralization by saliva occurs along with demineralization. If remineralization progresses faster, early caries will improve, but if demineralization progresses faster, caries will progress.

[0010] The oral composition of the present invention contains a silicate compound and / or an oxide of silicon and has a pH of 3.5 to 6.5, thereby improving the acid resistance of tooth surfaces and effectively inhibiting acid-induced demineralization. It also promotes remineralization. Therefore, it can prevent dental caries and improve early caries. Furthermore, the oral composition of the present invention can improve the acid resistance of tooth surfaces simply by repeatedly (i.e., multiple times) contacting the tooth surface for a short period of time. Since it can be washed away with gargling or other methods, there is no need to restrict eating or drinking after use. Therefore, anyone can easily prevent and improve dental caries. Furthermore, it can be used not only as a mouthwash, but also as a toothpaste-like formulation that is usually rinsed off immediately after use, making it versatile. Furthermore, the oral composition of the present invention does not require the incorporation of any special ingredients, and can be obtained simply by incorporating silicate compounds and / or silicon oxides, which are commonly incorporated into oral compositions as abrasives or thickeners, and, if necessary, adjusting the pH with a general-purpose pH adjuster, thereby allowing for a high degree of freedom in formulation design. [Brief explanation of the drawings]

[0011] [Figure 1] This is a field emission scanning electron microscope (FE-SEM) photograph of the tooth surface, which serves as a criterion for evaluating acid resistance. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in detail below. The oral composition of the present invention contains a silicate compound and / or an oxide of silicon and has a pH of 3.5 to 6.5.

[0013] silicate compounds Examples of silicate compounds include silicates such as sodium silicate, potassium silicate, potassium silicate, sodium metasilicate nonahydrate, calcium silicate, magnesium silicate, aluminum silicate, sodium aluminosilicate, potassium aluminosilicate, and calcium aluminosilicate, and the silicates may be hydrates.

[0014] Silicon oxide (silica) The silica may be either crystalline silica or amorphous silica. One or more silicate compounds and / or oxides of silicon can be used.

[0015] When using water-insoluble silicate compounds and / or silicon oxides such as calcium silicate, magnesium silicate, aluminum silicate, calcium aluminosilicate, and silica, it is preferable to control the maximum particle size. Specifically, the particle size (D90) at the 90% position measured from the smallest diameter side in the volume-based particle size distribution is preferably 1 μm or less, more preferably 0.5 μm or less, and even more preferably 0.2 μm or less. Within this range, acid resistance can be sufficiently improved. The lower limit can be about 0.005 μm. In the present invention, the particle size (including D90) of the water-insoluble silicate compound and / or oxide of silicon is a value measured by a laser diffraction scattering method.

[0016] A low concentration of the silicate compound and / or silicon oxide is sufficient, being 0.0005 wt. % or more relative to the total amount of the composition. It can also be 0.001 wt. %, 0.01 wt. %, 0.1 wt. %, or 1 wt. % or more. Within this range, a composition with a pH of 3.5 to 6.5 will contain enough silicate ions to sufficiently improve acid resistance. While there is no upper limit to the concentration of the silicate compound and / or silicon oxide in improving acid resistance, if the composition is to be liquid (including viscous), too high a concentration is undesirable due to precipitation and aggregation. Therefore, the concentration of the silicate compound and / or silicon oxide should be 50 wt. % or less relative to the total amount of the composition, preferably 10 wt. % or less, and more preferably 5 wt. % or less. It can also be 2 wt. Within this range, a stable formulation can be obtained with minimal precipitation and aggregation.

[0017] Furthermore, the concentration of the silicate compound and / or silicon oxide is preferably such that the silicate ion concentration is 1 ppm or more, more preferably 3 ppm or more, and even more preferably 5 ppm or more, relative to the total amount of the composition. This range can sufficiently improve acid resistance. Furthermore, the silicate ion concentration is preferably 1000 ppm or less, more preferably 500 ppm or less, and even more preferably 100 ppm or less, relative to the total amount of the composition. This range minimizes the effects of precipitation and aggregation, allowing for a stable formulation.

[0018] Sorbitol The oral composition of the present invention preferably contains sorbitol. It has been found that silicate compounds and / or oxides of silicon are unstable in the oral composition of the present invention and are prone to aggregation, precipitation, and turbidity. However, the inclusion of sorbitol inhibits aggregation, precipitation, and turbidity. The concentration of sorbitol depends on the concentration of the silicate compound and / or silicon oxide to be added, and is preferably 50 times or more, more preferably 100 times or more, relative to the concentration of the silicate compound and / or silicon oxide. It can also be 200 times or more. Within this range, aggregation, precipitation, and turbidity can be sufficiently suppressed, and a composition with a moderate sweetness can be obtained. Furthermore, the concentration of sorbitol is preferably 5000 times or less, more preferably 1500 times or less, relative to the concentration of the silicate compound and / or silicon oxide. It can also be 1000 times or less. Within this range, aggregation, precipitation, and turbidity can be sufficiently suppressed.

[0019] pH The oral composition of the present invention has a pH of 3.5 or higher, and can also be 4 or higher, 4.5 or higher, or 5 or higher. The pH is 6.5 or lower, and within this range, sufficient acid resistance can be imparted. The pH can also be 6 or lower, or 5.5 or lower.

[0020] Formulation and properties The oral composition of the present invention may be in the form of a toothpaste, tooth powder, dentifrice such as liquid toothpaste, mouthwash (mouthwash, mouth rinse, etc.), oral freshener, gargle, mouth spray, tooth surface application agent, varnish, food (chewing gum, gummy, film, lozenge, etc.), etc. Liquid (including mucous) preparations are preferred, but solid preparations may also be used as long as the pH can be adjusted by adding water. The oral composition of the present invention can be in the form of a liquid, emulsion (milky lotion, cream), suspension, gel, paste, gum, etc. It can also be made into a cloth impregnated with a liquid, emulsion, suspension, etc.

[0021] Optional ingredients The oral composition of the present invention may contain various base materials, carriers, and additives depending on the formulation, as long as the effects of the present invention are not impaired. One or more types of base materials, carriers, and additives may be blended.

[0022] The oral composition of the present invention contains water as a base or carrier in an amount sufficient to adjust the pH. The concentration of water can be adjusted appropriately depending on the form of the preparation and the solubility of the base or carrier other than water.

[0023] Examples of base materials or carriers other than water include polyhydric alcohols such as propylene glycol, polyethylene glycol, polypropylene glycol, and glycerin, and monohydric alcohols such as ethanol and isopropyl alcohol.

[0024] Examples of additives include pH adjusters, abrasives other than silicon compounds, binders or thickeners other than silicon compounds, surfactants, sweeteners, sterilizing ingredients, preservatives, humectants, and fragrances.

[0025] Examples of pH adjusters include organic acids and salts thereof such as lactic acid, citric acid, malic acid, gluconic acid, maleic acid, tartaric acid, succinic acid, glutamic acid, and acetic acid; inorganic acids and salts thereof such as phosphoric acid, hydrochloric acid, nitric acid, and carbonic acid; sodium hydroxide; and potassium hydroxide.

[0026] Examples of abrasives other than silicate compounds and / or oxides of silicon include sodium chloride, calcium carbonate, alumina, aluminum hydroxide, magnesium acetate, calcium pyrophosphate, magnesium phosphate, and calcium phosphate.

[0027] Examples of binders or thickeners other than silicate compounds and / or oxides of silicon include cellulose-based binders such as carboxymethyl cellulose, sodium carboxymethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, hydroxyethyl cellulose, hydroxymethyl cellulose, and methyl cellulose; polysaccharides and derivatives thereof such as carrageenan, xanthan gum, pectin, tragacanth gum, gum arabic, guar gum, locust bean gum, sodium alginate, and propylene glycol alginate; and synthetic polymers such as sodium polyacrylate, carboxyvinyl polymers, polyvinyl alcohol, and polyvinylpyrrolidone.

[0028] Examples of surfactants include anionic surfactants such as alkyl sulfates such as sodium lauryl sulfate and potassium lauryl sulfate, alkyl ether sulfates, fatty acid amide sulfonates, phosphate esters and their salts, alkylbenzene sulfonates, fatty acid ester sulfates, α-olefin sulfonates, N-acylsulfonates, fatty acid ester sulfonates, and glycerin fatty acid ester sulfates; Nonionic surfactants such as POE-alkyl ethers, sorbitan fatty acid esters, POE-sorbitan fatty acid esters, POE-glycerin fatty acid esters, POE-castor oil, POE-hydrogenated castor oil fatty acid esters, glycerin alkyl ethers, sucrose fatty acid esters, polyethylene glycol fatty acid esters, and polyglycerin fatty acid esters; Examples of such surfactants include amphoteric surfactants such as alkyl betaine surfactants, amine oxide surfactants, and imidazolinium betaine surfactants.

[0029] Sweeteners include saccharin sodium, stevioside, neohesperidin hydrochalcone, glycyrrhizin, perillartine, p-methoxycinnamic aldehyde, thaumatin, palatinose, maltitol, xylitol, trehalose, and arabitol. Sorbitol is also classified as a sweetener.

[0030] Examples of the disinfectant include quaternary ammonium salt disinfectants such as benzalkonium chloride and benzethonium chloride, cetylpyridinium chloride, chlorhexidine gluconate, chlorhexidine hydrochloride, isopropylmethylphenol, and hinokitiol.

[0031] Examples of preservatives include parahydroxybenzoates such as methylparaben, ethylparaben, and butylparaben, sodium benzoate, and ethylenediaminetetraacetate.

[0032] Humectants include sugar alcohols such as maltitol and lactitol, and polyhydric alcohols such as glycerin, ethylene glycol, and polyethylene glycol. The sugar alcohol sorbitol is also classified as a humectant.

[0033] The flavorings include various essential oils, essential oil components such as menthol, and compound flavors.

[0034] Purpose The oral composition of the present invention can be used to prevent demineralization and promote remineralization by repeatedly (i.e., multiple times) contacting the tooth surface for a short period of time, as in daily tooth brushing or gargling. Therefore, the oral composition of the present invention can be used to prevent caries and improve early caries. Although the oral composition of the present invention is effective even when it is only in contact with the tooth surface, in order to ensure that it is distributed throughout the oral cavity, it is effective to use it in a manner that allows for a single contact time of 5 seconds or more, and preferably 10 seconds or more. There is no upper limit to the contact time, but it may be about 3 minutes, the usual time for brushing teeth. [Example]

[0035] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. (1) Preparation of oral composition Liquid dentifrice compositions having the compositions shown in Tables 1 to 3 were prepared by mixing the components. [Table 1] [Table 2] [Table 3]

[0036] (2) Evaluation of acid resistance Test 1 (surface observation with FE-SEM) The specimens were the crowns of frozen bovine central incisors. The specimen surfaces were polished with #1000 waterproof abrasive paper. The specimens were immersed in each dentifrice composition for 10 seconds, followed by immersion in purified water for 30 minutes. This cycle of immersion in each dentifrice composition and then in purified water was repeated 30 times. The specimens were then immersed in 50 mL of decalcification solution (2.2 mM CaCl, 50 mM acetic acid, 2.2 mM NaHPO, pH 4.5) at 37°C for 2 hours, followed by rinsing with purified water for 10 seconds. The surface of the sample after cleaning was observed with a field emission scanning electron microscope (FE-SEM), and the appearance was evaluated according to the following criteria.

[0037] <Verdict> A (good): Compared to the demineralized enamel surface, the enamel surface to which the dentifrice composition was applied was smooth and no enamel rods were exposed. B (normal): Compared to the demineralized enamel surface, the enamel surface to which the toothpaste composition was applied was smooth, but gaps were formed in the enamel rods. C (Poor): No difference was observed between the demineralized enamel surface and the enamel surface to which the dentifrice composition was applied, and the enamel rods were also exposed. Figure 1 shows FE-SEM photographs of the enamel surface, which serve as the criteria for judging A, B, and C.

[0038] Test 2 (Quantification of minerals by TMR analysis) The specimens were the crowns or roots of cryopreserved bovine central incisors. The specimen surfaces were polished with #2000 waterproof abrasive paper. The specimens were immersed in each dentifrice composition for 30 seconds, then drained without rinsing, and then immersed in a remineralization solution (0.02 M HEPES, 3.0 mM CaCl2, 1.8 mM KH2PO4, pH 7.0) for 30 minutes. After draining without rinsing, the specimens were immersed in a demineralization solution (1.5 mM CaCl2, 50 mM acetic acid, 0.9 mM KH2PO4, 0.1 ppm F, pH 5.0). This cycle of immersion in each dentifrice composition, remineralization solution, and demineralization solution was repeated twice daily for five days (a total of 10 times). The prepared specimens were rinsed with deionized water, dehydrated sequentially through an ethanol series from 70 to 99.5%, and then embedded in 100% propylene oxide and embedding resin (Spurr Low-Viscosity Embedding Kit, Polisciences, USA). After polymerization, three 300 μm-thick sections were cut from each block perpendicular to the tooth axis using a diamond wire precision cutting machine (Well 3242, Walter Ebner, Germany). Each section was then subjected to TMR imaging (tube voltage 35 kV, tube current 15 mA, exposure time 15 min) using a high-resolution X-ray glass plate (Konica Minolta) with a Cu source and Ni filter. After development, the images obtained through the optical microscope were transferred to a Windows computer, and mineral profiles were created and lesion depths (LDs) were measured using analysis software (TMR2006, 2012, Inspektor Research Systems, The Netherlands). Significance tests for these parameters within each group were performed using one-way ANOVA and Tukey's test at a significance level of 5%.

[0039] <Verdict> Good: LD value is 95% or less of the LD value of the control sample Poor: LD value is >95% of the LD value of the control sample The control sample was a sample that underwent the same procedure except that no dentifrice composition was used.

[0040] In Test 1, the tooth sample was repeatedly immersed in the dentifrice composition and demineralizing solution, and thus acid resistance was evaluated. On the other hand, in Test 2, the tooth sample was repeatedly immersed in the dentifrice composition, remineralization, and demineralizing solution, and thus not only the acid resistance but also the remineralization ability of the dentifrice composition could be evaluated.

[0041] Test 3 (quantification of demineralization depth using a color laser microscope) The samples were the crown (enamel) and root (dentin) of cryopreserved bovine central incisors. The sample surfaces were polished with #2000 waterproof abrasive paper, and a 2 mm x 3 mm window was defined using nail varnish. The following decalcification test was performed. The test was performed on the crown (enamel) in Examples 1 and 8 and Comparative Example 1, and on the root (dentin) in Examples 10, 12 and Comparative Example 2. The specimens were immersed in each dentifrice composition for 10 seconds, then immersed in a remineralization solution (0.02 M HEPES, 3.0 mM CaCl2, 1.8 mM KH2PO4, pH 7.0) for 30 minutes, drained without rinsing, and then immersed in 30 mL of a demineralization solution (1.5 mM CaCl2, 0.9 mM KH2PO4, 50 mM acetic acid, 0.1 ppm F, pH 5.0) for 30 minutes. The series of immersion in each dentifrice composition, purified water, and demineralizing solution was repeated 30 times. After immersion in the demineralizing solution at 37°C for 24 hours, the nail varnish was removed and the nails were washed with purified water for 10 seconds. The sample surface after cleaning was observed with a color laser microscope, and the step between the window and the sample surface that had been covered with nail varnish was quantified.

[0042] <Verdict> Good: Value less than 100 μm Poor: Value is 100 μm or more

[0043] (3) Evaluation of stability (suppression of aggregation, precipitation, and turbidity) To disperse the silicate compound and / or silicon oxide, sorbitol was added in an amount of 0 times (Example 14), 105 times (Example 10), 210 times (Example 13), or 1050 times (Examples 1 and 15) the concentration of the silicate compound and / or silicon oxide, and the mixture was stored at 60°C for 2 weeks. The mixture was visually inspected for changes in properties such as aggregation, precipitation, and turbidity due to storage.

[0044] (4) Results The evaluation results are shown in Tables 1 to 3. As a result of Test 1, the compositions of Examples 1 to 15, which had a pH in the range of 3.5 to 6.5, had good acid resistance. In contrast, the compositions of Comparative Examples 3 to 6, which had a pH below 3.5 or above 6.5, had poor acid resistance. Specifically, Example 1 (pH = 4.2), Example 10 (pH = 5.0), Comparative Example 3 (pH = 2.5), and Comparative Example 4 (pH = 7.0) had the same composition except for the pH, but Examples 1 and 10 had good acid resistance, while Comparative Examples 3 and 4 had poor acid resistance. Furthermore, Example 11 (pH = 3.5), Example 12 (pH = 6.5), Comparative Example 5 (pH = 3.2), and Comparative Example 6 (pH = 7.0) had the same composition except for the pH, but Examples 11 and 12 had good acid resistance, while Comparative Examples 5 and 6 had poor acid resistance. This indicates that excellent acid resistance can be achieved by keeping the pH between 3.5 and 6.5.

[0045] Furthermore, the results of Test 2 showed that the composition of Example 1 had a high remineralization promoting ability. In contrast, the compositions of Comparative Examples 1, 2, 5, and 6 had a low remineralization promoting ability. The compositions of Example 1 and Comparative Example 1 have the same pH of 4.2, but the composition of Example 1 contains calcium silicate, while the composition of Comparative Example 1 contains neither silicate compounds nor silicon oxides. The composition of Comparative Example 2 has a pH of 5.8, within the range of 3.5 to 6.5, but contains neither silicate compounds nor silicon oxides. This demonstrates that the inclusion of silicate compounds and / or silicon oxides provides excellent remineralization-promoting properties. It is shown that excellent remineralization promoting ability can be obtained by including a silicate compound and / or an oxide of silicon and having a pH of 3.5 to 6.5.

[0046] Furthermore, the composition of Comparative Example 7 contains alumina as an inorganic substance that dissolves in acid like a silicate compound or an oxide of silicon, but the acid resistance was poor in Test 1. It is clear that a silicate compound and / or an oxide of silicon is essential to obtain excellent acid resistance.

[0047] Regarding the stability of the compositions, the compositions of Examples 1, 10, 13, and 15, in which sorbitol was blended in an amount 105 to 1050 times the concentration of the silicate compound and / or silicon oxide, respectively, showed good properties even after storage at 60°C for two weeks, with no aggregation, precipitation, or turbidity of the silicate compound and / or silicon oxide. In contrast, the composition of Example 14, which had the same composition as Example 13 except for not containing sorbitol, showed aggregation after 2 weeks of storage at 60° C. Similarly, aggregation was also observed in Example 16, which contained sorbitol in an amount 10,000 times the concentration of the silicate compound and / or silicon oxide. [Industrial Applicability]

[0048] The oral composition of the present invention can impart acid resistance to tooth surfaces by simply contacting them for a short period of time, and can inhibit the progression of acid-induced calcification and caries. Furthermore, since it is obtained using ingredients commonly blended in oral compositions, it is a highly versatile composition.

Claims

1. An oral composition comprising a silicate compound and / or an oxide of silicon and having a pH of 3.5 to 6.5 (provided that, when used in combination with an inorganic phosphate aqueous solution, the composition comprises 0.01 to 1.5% by weight of xanthan gum, 0.01 to 1.5% by weight of polyacrylic acid, 0.01 to 2.0% by weight of carrageenan gum, and silica and has a pH of 5.5 to 6.5, the composition comprises a stannous compound, a phytic acid compound, and silicic anhydride, and the composition comprises sodium fluoride and silica with a moisture content of less than 11%, % or less by weight of a citrate hydrogen ion source and 7% or less by weight of oxalate, and having a pH of 4 to 7; containing fluoride, hinokitiol or γ-oryzanol, and azulene; containing stannous chloride and silica; containing an aluminum compound, fluoride, and a calcium compound, with a fluorine concentration of 100 to 2000 ppm, and a molar ratio of fluorine to aluminum and calcium of F:Al:Ca=1:0.3-3:0.1-2; and containing silica and citrus essential oil).

2. 2. The oral composition according to claim 1, wherein the silicate compound and / or silicon oxide is insoluble in water, and the particle diameter (D90) at the 90% position measured from the small diameter side in the volume-based particle size distribution of the silicate compound and / or silicon oxide is 1 μm or less.

3. 3. The oral composition according to claim 1, wherein the content of the silicate compound and / or oxide of silicon is 0.0005 to 50% by weight based on the total amount of the composition.

4. The oral composition according to any one of claims 1 to 3, which contains sorbitol.

5. An agent for imparting acid resistance to tooth surfaces, preventing demineralization of tooth tissue, promoting remineralization of tooth tissue, or preventing or ameliorating dental caries, which contains a silicate compound and / or an oxide of silicon and is used in an oral composition having a pH of 3.5 to 6.5 (excluding cases where the composition is used in combination with an inorganic phosphate aqueous solution and where the composition contains 0.01 to 1.5 wt % xanthan gum, 0.01 to 1.5 wt % polyacrylic acid, 0.01 to 2.0 wt % carrageenan gum, and silica and has a pH of 5.5 to 6.5).

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