Agent for inhibiting tooth staining

Abstract

To inhibit internal staining of teeth.SOLUTION: Using an oral composition containing one or more calcium phosphates having specific physical properties enables inhibition of internal staining of teeth.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to oral compositions and the like. The contents of all documents described in this specification are incorporated herein by reference.

Background Art

[0002] For many years, tooth discoloration due to aging and eating habits has been known as a problem in oral aesthetics. The main cause of discoloration is the attachment of stains to the tooth surface. Patent Document 1 describes tooth surface polishing with a cleaning agent, dissolution of dirt with a surfactant, an acid, or the like.

[0003] However, the main cause of tooth discoloration associated with aging is the deposition of coloring substances in the gaps between enamel rods and dentinal tubules. Since this coloring substance penetrates into the tooth, it cannot be prevented or improved by the conventional aesthetic technique of approaching the tooth surface, and at present, it can only be improved by aesthetic treatment at a dental clinic. Therefore, there has been a demand for the development of a technology based on a different approach that can easily prevent and improve internal tooth coloring.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In order to effectively prevent tooth discoloration, it is necessary not only to remove the coloring on the tooth surface but also to suppress the internal coloring itself.

Means for Solving the Problems

[0006] The inventors of the present invention have conducted studies focusing on preventing internal tooth discoloration. As a result, they have found that by fixing calcium phosphates having specific physical properties to the tooth surface, penetration of coloring substances into the tooth can be suppressed.

[0007] This disclosure includes, for example, the subject matter described in the following items. Item 1. A tooth discoloration inhibitor containing calcium phosphates in which the product of the ratio of the diffraction peak intensity near 2θ = 32° to the diffraction peak intensity near 2θ = 26° in the powder X-ray diffraction pattern measured by CuKα characteristic X-rays and the average particle diameter (50% cumulative diameter; d50) is 8.0 or less. Item 2. A method for preventing tooth discoloration using calcium phosphates in which the product of the ratio of the diffraction peak intensity near 2θ = 32° to the diffraction peak intensity near 2θ = 26° in the powder X-ray diffraction pattern measured by CuKα characteristic X-rays and the average particle diameter is 8.0 or less.

Effects of the Invention

[0008] By suppressing internal tooth discoloration, it becomes possible to prevent tooth yellowing.

Brief Description of the Drawings

[0009]

Figure 1

Modes for Carrying Out the Invention

[0010] Hereinafter, each embodiment of the present invention will be described in more detail.

[0011] The discoloration inhibitor of the present invention contains calcium phosphates having specific physical properties and can be used as a composition for tooth cleaning. In particular, by using the discoloration inhibitor of the present invention, internal tooth discoloration can be effectively suppressed.

[0012] The discoloration inhibitor in the present invention can be preferably used as an oral composition.

[0013] The calcium phosphates of the present invention are selected from one or two types in which the product of the ratio of the diffraction peak intensity near 2θ = 32° to the diffraction peak intensity near 2θ = 26° in the powder X-ray diffraction pattern measured by CuKα characteristic X-rays and the average particle size is 8.0 or less. The type of calcium phosphates is not particularly limited, and examples thereof include hydroxyapatite, fluoroapatite, calcium pyrophosphate, tricalcium phosphate, tetracalcium phosphate, octacalcium phosphate, calcium hydrogen phosphate or its hydrate, calcium dihydrogen phosphate or its hydrate, etc. Calcium phosphates that are poorly soluble in water are preferred, and more preferably hydroxyapatite, fluoroapatite, and tricalcium phosphate.

[0014] In this specification, the average particle size (50% cumulative diameter; d50) is a value measured by a laser diffraction particle size distribution measuring device and is a value measured by wet concentration distribution measurement. As an example of the measurement conditions, the following example can be given. Blank solvent: distilled water, dispersion solvent: distilled water, ultrasonic treatment of the sample: 1 minute before measurement.

[0015] The calcium phosphates of the present invention preferably have an average particle size (50% cumulative diameter; d50) of 1.0 to 10 μm, and most preferably 1.5 to 4.0 μm.

[0016] In this specification, the X-ray diffraction pattern is a powder X-ray diffraction pattern measured by CuKα characteristic X-rays. As an example of the measurement conditions, the following conditions can be given. Target: Cu, tube voltage 40 kV, tube current: 30 mA, sampling width: 0.02°, scan speed: 2.00° / min, divergence slit: 1.0°, scattering slit: 1.0°, receiving slit: 0.3 mm.

[0017] The calcium phosphates of the present invention have a ratio (32° / 26°) of the diffraction peak intensity near 2θ = 32° to the diffraction peak intensity near 2θ = 26° of less than 2.5. The peak intensity ratio is preferably from 0.7 to 2.4, more preferably from 0.8 to 2.4, still more preferably from 0.85 to 2.1, and even more preferably from 1.05 to 1.5.

[0018] The oral composition of the present invention can be produced by conventional methods and can be used, for example, as cosmetics, pharmaceuticals, quasi-drugs, and medical devices. In particular, ordinary oral compositions and quasi-drug oral compositions that consumers can select and use at their own discretion are preferred. Further, the form of the oral composition of the present invention is not particularly limited, but can be made into forms (dosage forms) such as ointments, pastes, pastas, gels, liquids, sprays, liquid dentifrices, chewing dentifrices, coating agents, etc. according to conventional methods. Among them, mouthwash liquids, liquid dentifrices, powder dentifrices, pastes, liquids, sprays, gels, and coating agents are preferred, and powder dentifrices, pastes, and gels are more preferred.

[0019] In the oral composition of the present invention, in addition to the components described in the above claims, optional components that can be incorporated into the oral composition may be further incorporated alone or in combination of two or more, as long as the effects of the present invention are not impaired.

[0020] For example, as the surfactant, a nonionic surfactant, an anionic surfactant, or an amphoteric surfactant can be incorporated. Specifically, examples of the nonionic surfactant include sugar fatty acid esters such as sucrose fatty acid ester, maltose fatty acid ester, and lactose fatty acid ester; fatty acid alkanolamides; sorbitan fatty acid esters; fatty acid monoglycerides; and the like. Examples of the anionic surfactant include Polyoxyethylene alkyl ethers with a polyoxyethylene addition coefficient of 8 to 10 and an alkyl group having 13 to 15 carbon atoms; polyoxyethylene alkyl phenyl ethers with a polyoxyethylene addition coefficient of 10 to 18 and an alkyl group having 9 carbon atoms; diethyl sebacate; polyoxyethylene hydrogenated castor oil; fatty acid polyoxyethylene sorbitan, etc. are exemplified. Examples of anionic surfactants include sulfate esters such as sodium lauryl sulfate and sodium polyoxyethylene lauryl ether sulfate; sulfosuccinates such as sodium lauryl sulfosuccinate and sodium polyoxyethylene lauryl ether sulfosuccinate; acyl amino acid salts such as sodium cocoyl sarcosinate and sodium lauroyl methylalanine; sodium cocoyl methyl taurine, etc. Examples of amphoteric surfactants include betaine-type surfactants such as lauryldimethylaminoacetic acid betaine and coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine; imidazoline-type surfactants such as N-cocoyl-N-carboxymethyl-N-hydroxyethyl ethylenediamine sodium; amino acid-type surfactants such as N-lauryl diaminoethyl glycine, etc. These can be used alone or in combination of two or more. Also, these can be blended in an amount of 0.1 to 5% by mass based on the total amount of the composition.

[0021] In addition, as sweeteners, saccharin sodium, acesulfame potassium, stevioside, neohesperidin dihydrochalcone, perillartine, thaumatin, aspartylphenylalanyl methyl ester, p-methoxycinnamic aldehyde, etc. can be used. These can be used alone or in combination of two or more. Also, these can be blended in an amount of 0.01 to 1% by mass based on the total amount of the composition.

[0022] In addition, as the binder, for example, cellulose derivatives such as sodium carboxymethyl cellulose, carboxymethyl ethyl cellulose salt, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, etc., microbial-produced polymers such as xanthan gum, gellan gum, natural polymers or natural rubbers such as tragacanth gum, karaya gum, gum arabic, carrageenan, dextrin, etc., synthetic polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, etc., thickening silica, inorganic binders such as beegum, cationic binders such as O-[2-hydroxy-3-(trimethylammonio)propyl] hydroxyethyl cellulose chloride, etc. can be used. These can be used alone or in combination of two or more kinds.

[0023] In addition, as the wetting agent, sorbitol, glycerin, propylene glycol, xylitol, maltitol, lactitol, polyoxyethylene glycol, etc. can be used alone or in combination of two or more kinds.

[0024] In addition, as the preservative, parabens such as methylparaben, ethylparaben, propylparaben, butylparaben, etc., sodium benzoate, phenoxyethanol, alkyldiaminoethyl glycine hydrochloride, etc. can be used alone or in combination of two or more kinds.

[0025] In addition, as the pH adjuster, citric acid, phosphoric acid, malic acid, pyrophosphoric acid, lactic acid, tartaric acid, glycerophosphoric acid, acetic acid, nitric acid, or chemically possible salts thereof, sodium hydroxide, etc. may be blended. These can be used alone or in combination of two or more kinds so that the pH of the composition is in the range of 5 to 10, preferably 6 to 8. Also, these can be blended in an amount of 0.01 to 2% by weight based on the total amount of the composition.

[0026] Furthermore, medicinal ingredients may be incorporated. For example, bactericides such as cetylpyridinium chloride, triclosan, chlorhexidine hydrochloride, isopropylmethylphenol, benzalkonium chloride, and benzethonium chloride; fluorides such as sodium monofluorophosphate, sodium fluoride, stannous fluoride, and strontium fluoride; condensed phosphates such as sodium pyrophosphate and sodium polyphosphate; phosphates such as zeolite, sodium hydrogen phosphate, and trisodium phosphate; tranexamic acid, dipotassium glycyrrhizinate, monoammonium glycyrrhizinate, β-glycyrrhetinic acid, ε-aminocaproic acid, ouabain extract, sodium chloride, aluminum lactate, strontium chloride, ascorbic acid, sodium ascorbate, pyridoxine hydrochloride, vitamin agents such as tocopherol acetate; glucanase enzymes such as dextranase and mutanase; degrading enzymes such as protease and lysozyme; inorganic salts such as zinc chloride, zinc citrate, strontium chloride, and potassium nitrate; chelating compounds such as zeolite, chlorophyll, and glycerophosphate; polyethylene glycol that dissolves fats, and the like. These can be incorporated alone or in combination of two or more kinds.

[0027] Furthermore, as the base, for example, alcohols, silicon, apatite, white petrolatum, paraffin, liquid paraffin, microcrystalline wax, squalane, plastic base, etc. can be incorporated alone or in combination of two or more kinds.

[0028] The description of the above optional components is illustrative and does not limit the optional components that can be used.

Examples

[0029] The content of the present disclosure will be specifically described using the following experimental examples and examples. However, the present disclosure is not limited thereto in any way. In the following, unless otherwise specified, the experiments are carried out under atmospheric pressure and normal temperature conditions. Also, unless otherwise specified, “%” means “mass %”. Further, the compounding amount values of each component described in each table also indicate “mass %” unless otherwise specified.

[0030] [Preparation of Pretreatment Solution] Pretreatment solutions of Examples 1 to 4 and Comparative Examples 1 to 3 were prepared according to the compositions and contents (mass %) shown in Table 1 below.

[0031]

Table 1

[0032] [Tooth Cutting Process] Test pieces of Examples 1 to 4 and Comparative Examples 1 to 3 were obtained by cutting bovine teeth into segments as shown by the dotted line in Fig. 1.

[0033] [Embedding Process] Test blocks were obtained by embedding each of the obtained test pieces in an embedding agent. As the embedding agent, a room temperature polymerizing resin (Orthofast, manufactured by GC) was used.

[0034] [Surface Polishing Process] The obtained test blocks were polished with abrasive paper of #250 grit and then with abrasive paper of #600 grit to smooth the enamel on the surface.

[0035] [Protection Process] Surface protection was performed by applying a coating agent to the surface of the test block. As the coating agent, a transparent nail top coat was used.

[0036] [Tooth Surface Treatment Process] Each of the obtained test blocks was immersed in the pretreatment solutions of Examples 1 to 4 and Comparative Examples 1 to 3 for 3 minutes, then immersed in distilled water for 1 minute, and then immersed in artificial saliva (CaCl2: 1.5 mM, KH2PO4: 0.9 mM, KCl: 130 mM, HEPES: 20 mM, pH 7.0 (KOH)) for 4 hours. Thereafter, it was immersed in the pretreatment solutions of Examples 1 to 4 and Comparative Examples 1 to 3 for 3 minutes, then immersed in distilled water for 1 minute, and then immersed in artificial saliva overnight. This treatment was regarded as one set and repeated for 7 days.

[0037] [Coloring Process] Each test block with tooth surface treatment was colored by immersing it in the dye solution for 16 hours. As the dye solution, a 0.05% aqueous solution of Pigment Red 201 was used.

[0038] [Evaluation Specimen Preparation Process] With the opposite side of the colored surface of each test block gripped by a clamp, the test block was cut by a diamond cutter to obtain an evaluation sample. The cross-section of the evaluation sample was obtained as a plane perpendicular to the colored surface. Then, after polishing the cross-section of the evaluation specimen with abrasive paper of grit #800, the cross-section of the evaluation sample was polished with abrasive paper of grit #1200.

[0039] [Evaluation Process] Using a photographing stage with illumination, the evaluation sample was placed on the photographing stage with the cross-section of the evaluation sample facing upward. The cross-section of the test piece in the evaluation sample placed on the photographing stage was photographed from above the evaluation sample. For the image of the cross-section of the test piece photographed, binarization processing was performed using Photoshop Elements (manufactured by Adobe) to quantify the penetration of the colored substance.

[0040] Using the number of pixels of the colored substance that penetrated into the test piece on which the coloring process was performed without performing the tooth surface treatment process and the number of pixels of the colored substance that penetrated into the bovine teeth of Examples 1 to 4 and Comparative Examples 1 to 3, the coloring penetration inhibition rate was calculated from the following calculation formula. The coloring penetration inhibition rate was evaluated as × for 0 to 50%, △ for 51 to 75%, and ○ for 76% or more. The results are shown in Table 2. Coloring Penetration Inhibition Rate (%) = 100 × [1 - (B / B0)] However, B: The number of pixels of the colored substance that penetrated into the test pieces of Examples 1 to 4 and Comparative Examples 1 to 3 B0: The number of pixels of the colored substance that penetrated into the test piece when the coloring process was performed without performing the tooth surface treatment process

[0041]

Table 2

[0042] As shown in Table 2, it was revealed that when any of Examples 1 to 4 was used, coloring inside the teeth could be suppressed.

Claims

1. A tooth coloring inhibitor containing calcium phosphates, wherein the product of the ratio of the diffraction peak intensity near 2θ = 32° to the diffraction peak intensity near 2θ = 26° in the powder X-ray diffraction pattern measured by CuKα characteristic X-rays and the average particle diameter (50% cumulative diameter; d50) is 8.0 or less.

2. A method for preventing tooth coloring using calcium phosphates, wherein the product of the ratio of the diffraction peak intensity near 2θ = 32° to the diffraction peak intensity near 2θ = 26° in the powder X-ray diffraction pattern measured by CuKα characteristic X-rays and the average particle diameter (50% cumulative diameter; d50) is 8.0 or less.

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