WO2025249519A1 - Powder for polishing teeth - Google Patents

Abstract

With this powder for polishing teeth, which demonstrates a solubility of 20 mass% or less in water at 20°C, dirt on the tooth surface can be removed even with a smaller powder particle diameter.

Description

Tooth polishing powder

The present disclosure relates to powders for polishing teeth.

To remove stains from teeth (e.g., tooth surfaces), teeth may be cleaned by spraying a mixture containing powder and water onto the teeth.

Special Publication No. 2017-531690 Special Publication No. 2010-215621

When using conventional particles to remove stains from tooth surfaces, increasing the particle size increases the abrasive power, but also increases the invasiveness, making the tooth surface more susceptible to damage. On the other hand, decreasing the particle size and abrasive power reduces the invasiveness, but makes it more difficult to remove stains from the tooth surface.

The present disclosure aims to provide a powder for polishing teeth that can remove stains from tooth surfaces even when the powder particle size is small.

The present disclosure includes the following aspects:
[Section 1]
A powder for polishing teeth, which has a solubility in water at 20°C of 20% by mass or less.
[Section 2]
Item 1. The powder according to item 1, having a density of 2.0 g/ ^cm3 or less.
[Section 3]
Item 3. The powder according to Item 1 or 2, having an average particle size of 5 μm to 80 μm.
[Section 4]
Item 4. The powder according to any one of Items 1 to 3, which is a compound containing an amino group and a sulfur atom in the molecule.
[Section 5]
Item 5. The powder according to Item 4, which is a compound containing no carboxyl group in the molecule.
[Section 6]
Item 6. The powder according to any one of Items 1 to 5, which is a compound having one or less hydroxyl groups in the molecule.
[Section 7]
The following formula:
R ^S (-R ^C -R ^N ) _n
[In the formula,
R ^N is -N(R ^N1 ) ₂ ,
R ^N1 each independently represents a hydrogen atom, a hydrocarbon group having 1 to 3 carbon atoms which may have a substituent, or a halogen atom;
n is an integer of 1 or 2,
R and ^C each independently represent a divalent hydrocarbon group having 1 to 5 carbon atoms which may have a substituent;
^RS is
When n is 1, it is —SO ₂ R ^S1 or —SOR ^S1 ;
R ^S1 each independently represents a hydrogen atom, a hydrocarbon group having 1 to 3 carbon atoms which may have a substituent, —OH, or —SH;
When n is 2, it is -S-.]
Item 7. The powder according to any one of Items 1 to 6, wherein the compound is represented by the formula:
[Section 8]
n is 1,
R ^N1 each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms,
R ^C is an alkylene group having 1 to 3 carbon atoms;
8. The powder of claim 7, wherein R 1 ^S is --SO ₃ H or --SO ₂ H.
[Section 9]
Item 9. The powder according to any one of Items 1 to 8, which is aminoethylsulfonic acid.
[Section 10]
Item 10. A powder composition for polishing teeth, comprising 1% by weight or more of the powder according to any one of Items 1 to 9.
[Section 11]
Item 11. The powder composition according to Item 10, further comprising at least one selected from the group consisting of sugars, sugar alcohols, amino acids, phosphate compounds, carbonate compounds, calcium compounds, anti-caking agents, bactericides, bioactive glass, and fragrances.
[Section 12]
Item 12. The powder composition according to Item 11, wherein the saccharide is at least one selected from the group consisting of tagatose, trehalose, palatinose, and rhamnose.
[Section 13]
Item 13. The powder composition according to Item 11 or 12, wherein the sugar alcohol is at least one selected from the group consisting of xylitol, erythritol, sorbitol, mannitol, and reduced palatinose.
[Section 14]
Item 14. The powder composition according to any one of Items 11 to 13, wherein the anti-caking agent is at least one selected from the group consisting of silicon dioxide, calcium carbonate, aluminum silicate, magnesium silicate hydrate, and/or aluminum hydroxide.
[Section 15]
Item 15. The powder composition according to item 14, wherein the silicon dioxide is surface-treated fine particle silica having a primary particle size of 1 to 100 nm.

The tooth polishing powder disclosed herein is capable of removing stains from tooth surfaces even with a smaller particle size than conventional powders.

<Definition of terms>
As used herein, the term "n-valent group" refers to a group having n bonds, i.e., a group that forms n bonds.

As used herein, the term "hydrocarbon group" refers to a group containing carbon and hydrogen, resulting from the removal of a hydrogen atom from a hydrocarbon. Examples of such hydrocarbon groups include, but are not limited to, aliphatic hydrocarbon groups. Aliphatic hydrocarbon groups may be linear, branched, or cyclic, and may be saturated or unsaturated. Furthermore, hydrocarbon groups may contain one or more ring structures. Where explicitly stated, hydrocarbon groups may be substituted with one or more substituents.

In this specification, regardless of whether "each independently" or similar expressions are explicitly stated, unless otherwise stated, when a term (symbol) that may appear multiple times in a chemical structure is defined, that definition applies independently to each occurrence.

The chemical structures described herein should be understood not to include chemical structures that would be recognized by those skilled in the art as chemically impossible or extremely unstable.

<Tooth polishing powder>
The powder for polishing teeth of the present disclosure (hereinafter also referred to as the powder of the present disclosure) has a solubility in water at 20°C of 20 mass % or less.

Polishing teeth means brushing and/or filing the teeth. "Tooth" refers to, for example, the tooth surface. Examples of areas of teeth that can be polished include the supragingival or subgingival tooth surfaces.

Polishing your teeth can remove plaque, biofilm, pigmentation, stains, tartar, and other buildup that has accumulated on your teeth.

In addition to tooth polishing, the powders of the present disclosure can also be used for other abrasive and/or polishing applications within the oral cavity. For example, the powders of the present disclosure can be used to prepare cavities, treat fissures when sealing, remove adhesive residues, remove residual cement, roughen adhesive surfaces, and the like. For these applications, the powders of the present disclosure can function as abrasives and/or grinding materials for tooth surfaces.

The powder of the present disclosure may be sprayed into the gingival sulcus and periodontal pocket using a powder spray device. The powder spray device may be a powder spray device commonly used by those skilled in the art, or a commercially available product. For example, the powder spray device may be a device in which the powder is mixed with air in a powder/air mixing chamber, and then air pressure is applied to the mixture, allowing it to be sprayed toward the target.

In this regard, the powder disclosed herein may be a powder intended to be sprayed onto supragingival or subgingival tooth surfaces, or into the gingival sulcus and periodontal pockets, using a powder spraying device.

The powder injection device may be a device that mixes powder with air and water and injects it, a device capable of so-called air polishing. In such powder injection devices, the powder is injected from the nozzle tip together with water that flows out from a separate path, so that the powder is mixed with water on the tooth surface.

The powder of the present disclosure has a solubility in water of 20% by mass or less at 20°C, which prevents the powder from dissolving excessively in water when sprayed. The powder of the present disclosure is more likely to maintain its particle properties, such as hardness, particle shape, and particle size, even in water. Therefore, all of the powder particles come into efficient contact with the tooth surface, making it easier to remove stains from the tooth surface. Efficient contact of all of the powder particles with the tooth surface makes it easier to remove stains from the tooth surface, which makes it easier to reduce the amount of powder consumed. If the powder does not dissolve at all in water, there is a possibility that the powder will remain in the periodontal pockets and the oral cavity, so it is preferable that the powder of the present disclosure is water-soluble.

Because the powder disclosed herein is not prone to excessive dissolution in water, even powders with relatively small particle sizes are likely to remain in water and maintain their abrasive and/or grinding power. For this reason, powders disclosed herein can remove stains from tooth surfaces even when the particle size is small. Powders with small particle sizes are less invasive to tooth surfaces and tend to reduce the surface roughness of the tooth surface after stain removal. For example, powders with small particle sizes may be suitable for removing adhered stains while minimizing damage to the tooth surface of dentin, which is softer than enamel. They may be particularly suitable for cleaning subgingival dentin.

Increasing the particle size of the powder disclosed herein improves its abrasive and/or grinding power, making it easier to remove tooth stains. For example, it makes it easier to remove stubborn stains that have adhered to tooth enamel. In this regard, by adjusting the particle size while keeping the same components, the powder disclosed herein can have abrasive and/or grinding power appropriate for the location on the tooth surface (e.g., supragingival or subgingival).

Conventionally, powders with relatively high solubility, for example, powders with a solubility of more than 20% by mass, have been used for tooth polishing. Because highly soluble powders dissolve easily in water, when such powders are sprayed onto tooth surfaces using a powder spraying device, the powder softens, becomes smaller, or disappears upon dissolution in water, which can make it difficult to achieve the desired polishing and/or grinding power. Making the particle size excessively large to accommodate water solubility makes it easier to maintain polishing and/or grinding power even in water, but it also increases the invasiveness and is more likely to cause damage to the teeth. Furthermore, making the particle size excessively large can have adverse effects such as clogging inside the powder spraying device.

[Solubility]
In the present disclosure, solubility in water at 20°C means solubility in water at a temperature of 20°C and a pH of 7. For example, the solubility of a powder for polishing teeth in water at 20°C of "20% by mass or less" means that 20 g or less of the powder dissolves in 100 ml of water at a temperature of 20°C and a pH of 7. "n% by mass or less" may be rephrased as "ng/100 ml or less."

The solubility in water at 20° C. can be obtained as follows:
50 g of water is added to five times the expected amount of powder, and the container is sealed and mixed using a shaker at a test temperature of 20° C. for 24 hours. The mixed test solution is centrifuged to recover the supernatant, and the weight of the powder contained in the supernatant is measured by the dry weight method to obtain the solubility in water at 20° C.

The solubility of the tooth polishing powder in water at 20°C may be 20% by mass or less, 18% by mass or less, 16% by mass or less, 14% by mass or less, 12% by mass or less, or 10% by mass or less, or may be 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 2% by mass or more, 3% by mass or more, 4% by mass or more, 5% by mass or more, 6% by mass or more, or 7% by mass or more, for example, 1% by mass or more to 20% by mass or less, preferably 3% by mass or more to 15% by mass or less, and more preferably 5% by mass or more to 12% by mass or less. The solubility in water at 20°C may be adjusted from the perspective of better removing stains from the tooth surface and/or making the powder less likely to agglomerate.

[density]
In one embodiment, the density of the powder of the present disclosure may be 2.0 g/cm ^or less, 1.9 g/cm ^or less, 1.8 g/cm ^or less, or 1.7 g/cm ^{or less} , or 1.0 g/cm ^or more, 1.2 g/cm ^or more, 1.3 g/cm ^or more, 1.4 g/cm ^or more, 1.5 g/cm or more, or 1.6 g/cm ^{or more} . Within these density ranges, cleaning power (abrasive power) can be easily maintained while reducing invasiveness to tooth structure. Note that if the density is greater than 2.0 g/cm, the impact force on the tooth surface may be increased, potentially resulting in increased invasiveness to tooth structure. If the density is ^less than 1.0 g/cm, the impact force on the tooth surface may be reduced, potentially resulting in insufficient cleaning power (abrasive power).

[Particle size]
(Average particle size (D50))
In one embodiment, the powders of the present disclosure may have an average particle size (D50) of 5 μm to 80 μm. For example, the powders of the present disclosure may have an average particle size (D50) of 5 μm or more, 6 μm or more, 8 μm or more, 10 μm or more, 12 μm or more, 15 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, 35 μm or more, 40 μm or more, 50 μm or more, or 60 μm or more, or 80 μm or less, 75 μm or less, 70 μm or less, 65 μm or less, 60 μm or less, 55 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, 17 μm or less, 15 μm or less, or 14 μm or less.

The average particle size (D50) may be adjusted appropriately depending on the part of the tooth surface to be cleaned. For example, when the powder of the present disclosure is sprayed onto a subgingival tooth surface, gingival sulcus, or gingival pocket, the average particle size (D50) may be 5 μm or more and 40 μm or less, preferably 10 μm or more and 30 μm or less, and more preferably 15 μm or more and 20 μm or less. For example, when the powder of the present disclosure is sprayed onto a supragingival tooth surface, the average particle size (D50) may be 40 μm or more and 80 μm or less, preferably 50 μm or more and 75 μm or less, and more preferably 60 μm or more and 70 μm or less.

The average particle size (D50) of the powder can be measured using a laser diffraction/scattering method. In other words, the average particle size (D50) is the cumulative value of the 50% smaller particle size in the particle size distribution obtained using the laser diffraction/scattering method. The average particle size (D50) of the powders disclosed herein may also be determined using a dry particle size measurement method.

(D10)
In one embodiment, in the particle size distribution of the powder of the present disclosure, D10 (μm) may be 0.1 μm or more, 0.5 μm or more, 1 μm or more, 2 μm or more, or 3 μm or more, and may be 10 μm or less, 8 μm or less, 6 μm or less, 5 μm or less, or 4 μm or less.

D10 (μm) is the particle size at which the cumulative particle volume from the small particle size side reaches 10% of the total particle volume in the particle size distribution determined by laser diffraction/scattering. D10 (μm) refers to the specified particle size mentioned above when the cumulative frequency of the particles from the smallest particle size of the powder to the specified particle size is 10%.

(D90)
In one embodiment, the particle size distribution of the powder of the present disclosure may have a D90 (μm) of 20 μm or more, 25 μm or more, 30 μm or more, 33 μm or more, 35 μm or more, 37 μm or more, 39 μm or more, or 41 μm or more, and may be 80 μm or less, 70 μm or less, 60 μm or less, 55 μm or less, 50 μm or less, or 47 μm or less.

D90 (μm) is the particle size at which the cumulative particle volume from the small particle size side reaches 90% of the total particle volume in the particle size distribution determined by laser diffraction/scattering. D90 (μm) refers to the specified particle size mentioned above when the cumulative frequency of the particles from the smallest particle size of the powder to the specified particle size is 90%.

[Compound structure]
The powder of the present disclosure may be a compound containing an amino group and a sulfur atom in the molecule.

(amino group)
The amino group in the molecule means a monovalent functional group obtained by removing one hydrogen atom from ammonia, a primary amine, or a secondary amine. Specifically, the amino group means —NH ₂ , —NHR ¹ , or —NR ¹ R ² , where R ¹ and R ² may each be a hydrocarbon group having 1 to 3 carbon atoms which may have a substituent, or a halogen atom.

The number of amino groups in a molecule is not particularly limited and may be one or more, two or more, or three or more, or may be five or less, four or less, or three or less, with one being preferred.

(sulfur atom)
The sulfur atom in the molecule may be, for example, a group containing a sulfur atom in the molecule. The valence of the sulfur atom in the powder of the present disclosure may be any valence that a sulfur atom can have, for example, divalent, tetravalent, or hexavalent. In other words, the powder of the present disclosure may have at least one sulfur atom selected from the group consisting of divalent sulfur atoms, tetravalent sulfur atoms, and hexavalent sulfur atoms.

The divalent sulfur atom may be a sulfide bond (-S-), a disulfide bond (-S-S-), etc.

The tetravalent sulfur atom may be a sulfine group (-S(=O)-OM, where M is a hydrogen atom or a metal ion such as Na).

The hexavalent sulfur atom may be a sulfo group (-S(=O) ₂ -OM, where M is a hydrogen atom or a metal ion such as Na).

The number of sulfur atoms in the molecule is not particularly limited and may be 1 or more, 2 or more, or 3 or more, or 5 or less, 4 or less, or 3 or less, preferably 1.

(carboxyl group)
In one embodiment, the powder of the present disclosure may be a compound that does not contain a carboxyl group in the molecule. A compound that does not contain a carboxyl group in the molecule means a compound that does not contain —COOH. Not containing a carboxyl group in the molecule makes it easier to achieve a solubility of the powder in water at 20°C of 20% by mass or less.

In one embodiment, the powder of the present disclosure may be a compound other than an amino acid. Note that, in this disclosure, an amino acid refers to a compound having both a carboxyl group and an amino group. A compound having only one of a carboxyl group and an amino group is a compound other than an amino acid.

(Number of hydroxyl groups)
In one embodiment, the powder of the present disclosure may be a compound having one or less hydroxyl groups in the molecule. A compound having one or less hydroxyl groups in the molecule means a compound having one -OH group in the molecule or a compound having no -OH groups. When the number of hydroxyl groups in the molecule is one or less, the hygroscopicity of the powder tends to be low and tooth stains are more easily removed. The powder of the present disclosure may have hydroxyl groups, but from the viewpoint of reducing the hygroscopicity of the powder, it is preferable that the powder does not have hydroxyl groups.

In one embodiment, the powder of the present disclosure may be a compound other than a sugar. For purposes of this disclosure, a sugar is a compound having two or more hydroxyl groups, such as glyceraldehyde, glucose, and mannose. For purposes of this disclosure, a sugar may include a monosaccharide, a disaccharide, a trisaccharide, and a polysaccharide.

In one embodiment, the powder of the present disclosure may be a compound other than a sugar alcohol. The sugar alcohol of the present disclosure is a compound produced by converting the carbonyl group of an aldose or ketose, such as alditol, specifically erythritol, xylitol, and mannitol.

The powders disclosed herein may be compounds having a molecular weight of 80 or more, 90 or more, 100 or more, 110 or more, or 120 or more, and may be compounds having a molecular weight of 300 or less, 250 or less, 200 or less, 170 or less, 150 or less, 140 or less, or 130 or less.

In one embodiment, the powder of the present disclosure comprises:
The following formula:
R ^S (-R ^C -R ^N ) _n
[In the formula,
R ^N is -N(R ^N1 ) ₂ ,
R ^N1 each independently represents a hydrogen atom, a hydrocarbon group having 1 to 3 carbon atoms which may have a substituent, or a halogen atom;
n is an integer of 1 or 2,
R and ^C each independently represent a divalent hydrocarbon group having 1 to 5 carbon atoms which may have a substituent;
^RS is
When n is 1, it is —SO ₂ R ^S1 or —SOR ^S1 ;
R ^S1 each independently represents a hydrogen atom, a hydrocarbon group having 1 to 3 carbon atoms which may have a substituent, —OH, or —SH;
When n is 2, it is -S-.]
The compound may be represented by the formula:

(R ^N )
R ^N is -N(R ^N1 ) ₂ ,
R ^N1 is independently a hydrogen atom, a hydrocarbon group having 1 to 3 carbon atoms which may have a substituent, or a halogen atom. R ^N is a group having a nitrogen atom and may correspond to an amino group.

In R ^N , the number of carbon atoms in the hydrocarbon group having 1 to 3 carbon atoms, which may have a substituent, may be a hydrocarbon group having 1 or 2 carbon atoms, which may have a substituent, preferably a hydrocarbon group having 1 carbon atom (i.e., a methyl group), which may have a substituent.

In R 1 ^N , the hydrocarbon group having 1 to 3 carbon atoms which may have a substituent may be an alkyl group having 1 to 3 carbon atoms which may have a substituent.

In R ^N , the hydrocarbon group having 1 to 3 carbon atoms may have a substituent, but is preferably unsubstituted. Examples of the substituent include -OR', -N(R') ₂ , -COOR', and a halogen atom (wherein R' is independently in each occurrence a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms or 1 carbon atom). The substituent may or may not have an active hydrogen. The number of substituents may be 3 or less, 2 or less, 1 or less, or 0.

In R 1 ^N , the halogen atom may be, for example, F, Cl, Br, or I, preferably Cl.

R 1 ^N are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom.

( ^RC )
R ^C is each independently a divalent hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. R ^C is a moiety which can contribute to the hydrophobicity of the powder, and by making the number of carbon atoms 1 to 5, it becomes easier to reduce the hygroscopicity of the powder.

In R ^C , the divalent hydrocarbon group having 1 to 5 carbon atoms which may have a substituent may be a divalent hydrocarbon group having 1 to 3 carbon atoms which may have a substituent, preferably a divalent hydrocarbon group having 1 carbon atom which may have a substituent (i.e., a methylene group).

In R 3 ^C , the divalent hydrocarbon group having 1 to 5 carbon atoms which may have a substituent may be an alkylene group having 1 to 5 carbon atoms which may have a substituent.

In R ^C , the hydrocarbon group having 1 to 5 carbon atoms may have a substituent, but is preferably unsubstituted. Examples of the substituent include -OR', -N(R') ₂ , -COOR', and a halogen atom (wherein R' is independently a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms or 1 carbon atom in each occurrence). The substituent may or may not have an active hydrogen. The number of substituents may be 3 or less, 2 or less, 1 or less, or 0.

(R ^S )
^RS is
When n is 1, it is —SO ₂ R ^S1 or —SOR ^S1 ;
R ^S1 each independently represents a hydrogen atom, a hydrocarbon group having 1 to 3 carbon atoms which may have a substituent, —OH, or —SH;
When n is 2, it is -S-.

n is the number of (-R ^C -R ^N ) bonds to R ^S. n is 1 or 2, and preferably 1.

When n is 1, R 1 ^S is —SO ₂ R ^{1 S1} or —SOR ^{1 S1} . R 1 ^S is preferably —SO ₂ R ^{1 S1} .

In R ^S1 , the hydrocarbon group having 1 to 3 carbon atoms, which may have a substituent, may be a hydrocarbon group having 1 or 2 carbon atoms, which may have a substituent, preferably a hydrocarbon group having 1 carbon atom (i.e., a methyl group), which may have a substituent.

In R ^S1 , the hydrocarbon group having 1 to 3 carbon atoms which may have a substituent may be an alkyl group having 1 to 3 carbon atoms which may have a substituent.

In R ^S1 , the hydrocarbon group having 1 to 3 carbon atoms may have a substituent, but is preferably unsubstituted. Examples of the substituent include -OR', -N(R') ₂ , -COOR', and a halogen atom (wherein R' is independently a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms or 1 carbon atom in each occurrence). The substituent may or may not have an active hydrogen. The number of substituents may be 3 or less, 2 or less, 1 or less, or 0.

R ^S1 is preferably an alkyl group having 1 to 3 carbon atoms which may have a substituent, -OH, or -SH, more preferably -OH or -SH, and even more preferably -OH.

When R ^S1 is —OH, —OH may be —OM, where M is an alkali metal, for example, Na (sodium).

When n is 2, it is -S-. That is, when n is 2, R ^S (-R ^C -R ^N ) _n is
R ^N -R ^C -S-R ^C -R ^N.

When n is 2, each R 1 ^C independently represents an alkylene group having 1 to 3 carbon atoms, or —CHR ^C1 —R ^C2 —
[In the formula,
R ^C1 is an alkylene group having 1 to 3 carbon atoms;
R ^C2 is —COOH.

In one preferred embodiment,
n is 1,
R ^N1 each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms,
R ^C is an alkylene group having 1 to 3 carbon atoms;
R 1 ^S is —SO ₃ H or —SO ₂ H.

In a more preferred embodiment,
Each R ^N1 is independently a hydrogen atom;
R ^C is an ethylene group;
R 1 ^S is —SO ₃ H.

[Specific compounds]
Examples of powders of the present disclosure include taurine (also known as aminoethylsulfonic acid), homotaurine (also known as 3-aminopropiosulfonic acid), hypotaurine (2-aminoethanesulfinic acid), thiotaurine (also known as 2-aminoethanethiosulfonic acid), N-methyltaurine, sodium N-methyltaurate, and taurine chloramine.

From the standpoint of low moisture absorption and ease of removing tooth stains, the powders disclosed herein are preferably taurine, homotaurine, or N-methyltaurine, with taurine being more preferred. Because powders of these compounds have lower moisture absorption, they are less likely to clump. Powders that are less likely to clump are more likely to maintain powder properties such as powder flowability, especially when stored for long periods of time. While introducing clumped powder into the chamber of an injector can cause clogging inside the machine, powders such as taurine are less likely to clump, making such clogging less likely to occur.

Among the specific compounds listed above, taurine, for example, has an amino group but no carboxyl group. Therefore, taurine is a compound that differs from amino acids. Other compounds are also different from amino acids if they do not have both an amino group and a carboxyl group.

The powder disclosed herein may be a powder obtained by extraction from naturally occurring ingredients, or may be a powder obtained through chemical synthesis.

In one embodiment, the taurine may be natural taurine extracted from naturally occurring ingredients or synthetic taurine. Natural taurine may be, for example, an extract from seafood, or may be taurine that complies with food additive regulations. Synthetic taurine may be taurine obtained by chemically reacting a taurine raw material such as methionine.

Another advantage of the powder disclosed herein is that it is less sticky (adhesive). Less sticky powders are less likely to clump, making them less likely to clog inside the powder sprayer. Less sticky powders also make cleaning easier after use, and are expected to reduce discomfort felt by patients after treatment. In particular, compounds such as taurine listed above under [Specific Compounds] tend to be less sticky, making them more likely to exhibit the above advantages.

Powder Composition for Polishing Teeth
The powder composition of the present disclosure includes the powder described above in <Powder for polishing teeth>. The powder composition contains 1% by weight or more of the powder of the present disclosure.

[Amount of powder for polishing teeth]
In one embodiment, the powder composition may comprise greater than 1 wt. % of the powder of the present disclosure, 2 wt. % or more, 3 wt. % or more, 5 wt. % or more, 7 wt. % or more, 10 wt. % or more, 12 wt. % or more, 15 wt. % or more, 20 wt. % or more, 25 wt. % or more, 30 wt. % or more, 35 wt. % or more, 45 wt. % or more, 50 wt. % or more, 60 wt. % or more, 70 wt. % or more, 80 wt. % or more, 90 wt. % or more, 95 wt. % or more, or 97 wt. % or more, and 99.9 wt. % or less, 99 wt. % or less, 90 wt. % or less, 85 wt. % or less, 80 wt. % or less, 75 wt. % or less, 70 wt. % or less, 65 wt. % or less, 60 wt. % or less, 55 wt. % or less, 50 wt. % or less, 45 wt. % or less, 40 wt. % or less, 35 wt. % or less, 30 wt. % or less, 25 wt. % or less, or 20 wt. % or less.

[Particle size]
In one embodiment, the powder composition of the present disclosure may have an average particle size (D50) of 5 μm to 80 μm. For example, the powder composition of the present disclosure may be 5 μm or more, 6 μm or more, 8 μm or more, 10 μm or more, 12 μm or more, 15 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, 35 μm or more, 40 μm or more, 50 μm or more, or 60 μm or more, or 80 μm or less, 75 μm or less, 70 μm or less, 65 μm or less, 60 μm or less, 55 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, 17 μm or less, 15 μm or less, or 14 μm or less.

If the average particle size (D50) is below the above range, the fluidity of the powder composition according to this embodiment will be poor, and the powder will not be uniformly mixed with the air in the powder/air mixing chamber attached to the powder injection device, which could result in clogging inside the powder/air mixing chamber attached to the powder injection device, at the connecting parts through which the powder flows to the injection nozzle, and in the injection nozzle, and there is a risk of problems such as uneven and unstable injection from the injection nozzle onto the tooth surface.

If the particle size is small, the impact force will be low, making it difficult to achieve satisfactory results in terms of removing tartar and plaque that has hardened on the tooth surface. If the average particle size (D50) exceeds the above range, the impact force will also increase as the particle size becomes larger, which is undesirable as it will damage the tooth surface after removing the hardened tartar and plaque.

In addition to the powder described above in the section <Powder for tooth polishing>, the powder composition of the present disclosure may further contain additional components described below in order to further improve the powder's fluidity, stain removal power, etc.

[Additional Ingredients]
The powder composition according to this embodiment may contain an additional component. The additional component is at least one selected from the group consisting of sugars, sugar alcohols, amino acids, phosphate compounds, carbonate compounds, calcium compounds, anticaking agents, bactericides, bioactive glass, and flavoring agents. The additional component may also be a mixture thereof.

(Sugars)
Any sugar can be used as long as it is in powder form at room temperature, regardless of the powder form. Examples of sugars include monosaccharides, disaccharides, trisaccharides, and polysaccharides, and mixtures thereof can also be used without any restrictions. By including sugars in the powder composition, tooth surface stains can be more easily removed while reducing damage to the tooth surface (especially dentin).

Specific examples of monosaccharides among these sugars include aldoses, which have a single aldehyde group (-CHO) at the end of a chain structure; ketoses, which have a single ketone group (=CO) within a chain structure; and deoxysaccharides, in which one of the hydroxyl groups within the molecule has been reduced and replaced with a hydrogen atom.

Examples of aldoses include, but are not limited to, glyceraldehyde, arabinose, lyxose, allose, altrose, glucose, and mannose.

Ketoses include, but are not limited to, dihydroxyacetone, psicose, fructose, sorbose, and tagatose.

Examples of deoxysugars include, but are not limited to, deoxyribose, fucose, and rhamnose.

Specific examples of disaccharides include, but are not limited to, sucrose, lactose, maltose, trehalose, turanose, cellobiose, and palatinose. Among these, from the perspective of emphasizing the prevention of dental caries, the disaccharides may be, for example, lactose, maltose, trehalose, turanose, cellobiose, and palatinose, with trehalose and palatinose being preferred.

There are no restrictions on trisaccharides or polysaccharides (more specifically, oligosaccharides of trisaccharides or higher), and any oligosaccharide can be used. Note that some of the above sugars have asymmetric carbon atoms within the molecule, resulting in the existence of stereoisomers, and all of these are included in the names shown.

From the perspective of prioritizing cost reduction, the sugar may be, for example, a sugar that occurs abundantly in nature or a sugar that can be industrially produced. From the perspective of prioritizing cost reduction as well as the ability to inhibit the onset of dental caries (anti-caries-inducing properties), the sugar may be, for example, at least one selected from the group consisting of trehalose, tagatose, rhamnose, and palatinose.

(Sugar alcohol)
Any sugar alcohol can be used as long as it is in powder (solid) form, regardless of the powder form. Examples of sugar alcohols include monosaccharides and disaccharides, and mixtures thereof can also be used without any restrictions. By including a sugar alcohol in the powder composition, tooth surface stains can be more easily removed while reducing damage to the tooth surface (especially dentin).

Among these sugar alcohols, monosaccharides include, for example, sugar alcohols produced by reducing the carbonyl group of the monosaccharide aldoses and ketoses described above under sugars. Specific examples of monosaccharide sugar alcohols called alditols (sugar alcohols formed by reducing aldoses, which are sugars with an aldehyde group (-CHO) in the chain molecule, to form a hydromethyl group) include, but are not limited to, erythritol, threitol, ribitol, xylitol, arabinitol, glucitol (sorbitol), and mannitol.

Specific examples of disaccharide sugar alcohols (i.e., sugar alcohols obtained by reducing disaccharide sugars) include, but are not limited to, lactitol, maltitol, and reduced palatinose.

Some of the sugar alcohols listed above have asymmetric carbon atoms in the molecule and exist as stereoisomers, but all of these are included in the names listed.

Among these, from the perspective of cost reduction, the sugar alcohol may be, for example, a sugar alcohol that occurs abundantly in nature or a sugar alcohol that can be industrially produced. From the perspective of cost reduction as well as cariogenicity, for example, erythritol, xylitol, glucitol (sorbitol), mannitol, maltitol, and reduced palatinose may be used, and erythritol, mannitol, and reduced palatinose are preferred.

Among these, the sugar alcohol may more preferably be erythritol, xylitol, sorbitol, mannitol, or reduced palatinose.

Reduced palatinose is also known as isomalt, reduced isomaltulose, or palatinit. The precursor, palatinose, has a reducing group on the fructose moiety within the molecule. The α-1,6-glucosidic bond is stable and hydrolysis does not occur under water-added conditions, allowing the reaction to be completed while maintaining the basic molecular structure of the disaccharide. Therefore, the final product of reduced palatinose can be an equimolar mixture of α-D-glucopyranosyl-1,6-mannitol and its stereoisomer, α-D-glucopyranosyl-1,6-sorbitol. Reduced palatinose is the most preferred sugar alcohol because it has properties intermediate between the two.

(amino acid)
Any amino acid can be used as long as it is in powder (solid) form, regardless of the powder form. Examples of amino acids include acidic amino acids having two carboxyl groups in the molecule, basic amino acids having two or more amino groups in the molecule, and neutral amino acids having characteristic groups (more specifically, hydroxyl groups, amide groups, and aromatic groups), moieties (more specifically, alkyl chains, etc.) or atoms (more specifically, sulfur atoms) other than carboxyl groups and amino groups in the molecule, and mixtures thereof can also be used without any restrictions. By including amino acids in the powder composition, tooth surface stains can be more easily removed while reducing damage to the tooth surface (especially dentin).

Examples of amino acids that have two carboxyl groups and exhibit acidic properties include aspartic acid and glutamic acid.

Amino acids that have two or more amino groups and exhibit basic properties include, for example, lysine, arginine, and histidine.

Examples of neutral amino acids that have alkyl chains include glycine, alanine, valine, leucine, and isoleucine.

Amino acids that have a hydroxy group and exhibit neutrality include, for example, serine and threonine.

Amino acids that contain a sulfur atom and exhibit neutrality include, for example, cysteine and methionine.

Examples of amino acids that have an amide group and exhibit neutrality include asparagine and glutamine.

An example of an amino acid that has an imino group and exhibits neutrality is proline.

Amino acids having an aromatic group include, but are not limited to, phenylalanine, tyrosine, and tryptophan.

Some of the above amino acids have asymmetric carbon atoms within the molecule and exist as stereoisomers, but all of these are included in the names shown.

Among these, the amino acid may be, for example, an essential amino acid, which is an amino acid that cannot be synthesized in the body of an animal. Essential amino acids may include histidine, tryptophan, lysine, methionine, phenylalanine, threonine, valine, leucine, isoleucine, and glycine.

(phosphate compounds)
Any phosphate compound can be used as long as it is in powder (solid) form, regardless of its form. Examples of phosphate compounds include tricalcium phosphate, calcium dihydrogen phosphate, calcium monohydrogen phosphate, calcium hydroxide phosphate (synthetic hydroxyapatite), etc., and mixtures thereof can also be used without any problems, but are not limited to these. By including a phosphate compound in the powder composition, it becomes easier to remove stains from the tooth surface while reducing damage to the tooth surface (especially dentin).

Among these, the phosphate compound may be, for example, calcium hydroxide phosphate (synthetic hydroxyapatite), which is composed of the same components as natural hydroxyapatite contained in tooth enamel and dentin.

(carbonate compounds)
Any carbonate compound can be used as long as it is in powder (solid) form. Examples of carbonate compounds include heavy calcium carbonate (natural calcium carbonate), light calcium carbonate (more specifically, synthetic calcium carbonate, precipitated calcium carbonate, etc.), calcium bicarbonate, sodium bicarbonate (baking soda), sodium carbonate, etc., and mixtures thereof can also be used without any restrictions, but are not limited to these. By including a carbonate compound in the powder composition, tooth surface stains can be more easily removed while reducing damage to the tooth surface (especially dentin).

Heavy calcium carbonate may be produced by crushing and/or classifying limestone, which is calcium carbonate. Light calcium carbonate may be produced by precipitating fine crystals in a liquid through a chemical reaction.

The carbonate compound may be, for example, sodium bicarbonate (baking soda), which has a proven track record of being used as a powder raw material in conventional powder sprayers.

(Calcium compounds)
Any calcium compound can be used as long as it is in powder (solid) form, regardless of its form. Examples of calcium compounds include, but are not limited to, calcium oxide, calcium hydroxide (slaked lime), and calcium fluoride. By including a calcium compound in the powder composition, tooth surface stains can be more easily removed while reducing damage to the tooth surface (especially dentin).

Among these, it is preferable to use calcium fluoride, which can strengthen tooth structure by fluoridating the natural hydroxyapatite contained in tooth enamel and dentin.

(Anti-caking agent)
Anti-caking agents are known in the art of spray powders and may be added to inhibit agglomeration of the powder composition and/or to modify the flowability of the powder composition. In this regard, the anti-caking agent may be referred to as a flowability modifier. The addition of an anti-caking agent makes the powder composition less likely to agglomerate and less likely to clog the nozzles of the spray equipment.

The anti-caking agent may be at least one selected from the group consisting of silicon dioxide, calcium carbonate, aluminum silicate, magnesium silicate hydrate, and/or aluminum hydroxide.

The anti-caking agent may be in the form of fine particles to suppress aggregation. The particle size of the anti-caking agent may be 0.01 nm or more, 0.1 nm or more, 1 nm or more, 10 nm or more, 50 nm or more, 100 nm or more, 200 nm or more, 300 nm or more, or 500 nm or more, or may be 1000 nm or less, 900 nm or less, 800 nm or less, 700 nm or less, 500 nm or less, or 300 nm or less.

(fungicide)
As the bactericide, specifically, triclosan; chlorhexidine; copper salts, zinc salts and tin(II) salts, such as zinc citrate, zinc sulfate, zinc glycinate, zinc sodium citrate, tin(II) pyrophosphate, etc.; metronidazole; quaternary ammonium compounds; biguanides, such as chlorhexidine digluconate, etc.; hexetidine; cetylpyridinium chloride; octenidine; alexidine can be used.The bactericide can generally be a substance with antibacterial activity.Also, natural substances or parts thereof, or substances or parts thereof derived from natural substances or microorganisms can be used in the use/composition according to the present invention.For example, Lactobacillus bacteria or fragments thereof can be used, and these can be live bacteria.

(bioactive glass)
Bioactive glass is glass that can interact with biological tissue, and may be glass that can bond with biological tissue such as teeth or bones. There are no particular limitations on the bioactive glass, but any powdered (solid) bioactive glass can be used regardless of its form.

(fragrance)
Examples of fragrances include musk, lemon oil, 1-heptanol, α-methyl ionone, aldehyde C-10, aldehyde C-11, aldehyde C-9, allyl heptanoate, anisaldehyde, benzaldehyde, benzacetate, benzyl acetate, butyl propionate, cedar leaf oil, cedrol, cedryl acetate, cinnamic alcohol, cinnamon leaf, citronella oil, citronellal, glove bud oil, cyclamen aldehyde, ethyl butyrate, ethyl caproate, ethyl isobutyrate, ethyl isovalerate, ethyl propionate, eucalyptus oil, eugenol, farnesol, geraniol, heptadecyl benzoate, benzo ... Cetyl aldehyde, heptyl formate, hexyl acetate, hydrotropic aldehyde, isobornyl acetate, isoamyl formate, limonene, linalool, linalyl acetate, methylheptenone, nonyl aldehyde, organum oil, p-cresyl acetate, p-methylacetophenone, phenylacetaldehyde, propyl propionate, spearmint oil, terpenyl acetate, linalool, tetrahydrolinalool, thymol, isobornyl acetate, alpha-ionone, beta-ionone, acetylcedrene, acetyleugenol, C-10 alcohol, C-11 undecylenic alcohol, C-12 alcohol, C-14 aldehyde , aldehyde C-18, anise alcohol, anisyl acetate, benzyl benzoate, benzyl isovalerate, benzyl salicylate, cinnamyl acetate, citronellol, citronellyl isobutyrate, citronellyloxyacetaldehyde, coumarin, ethyl cinnamate, ethyl vanillin, geranyl isobutyrate, geranyl tiglate, heliotropin, hexyl cinnamic aldehyde, hydroxycitronellal, indole, isoamyl cinnamic aldehyde, isoamyl salicylate, jasmone, methyl anthranilate, methyl cinnamate, muscone, musk ketone, nerolidol, pentalide, phenylacetic acid, lavender oil, menthol, vanillin, etc. These fragrances can be used alone or in combination.

[Particle size]
Additional ingredients can be classified into organic powders and inorganic powders. Organic powders include sugars, sugar alcohols, amino acids, fragrances, disinfectants, etc. Inorganic powders include phosphate compounds, carbonate compounds, calcium compounds, anti-caking agents, disinfectants, etc. Whether an additional ingredient falls into the category of organic powder or inorganic powder may be classified based on the common technical knowledge of a person skilled in the art and the structure, properties, etc. of the additional ingredient.

These classified powders have different hardnesses of material, so even if they have the same particle size, the impact force when removing tartar and plaque that has adhered to the tooth surface will vary, which may in turn affect the removability of tartar and plaque that has adhered to the tooth surface and the damage that may be caused to the tooth surface. Therefore, from the perspective of prioritizing the removability and low abrasiveness of the powder composition, an appropriate particle size can be selected depending on the type of powder.

Organic powders can be softer and less hard than inorganic powders. The average particle size (D50) of the organic powder may be, for example, 0.1 to 200.0 μm, preferably 1.0 to 100.0 μm, more preferably 5.0 to 80.0 μm, even more preferably 10.0 to 50.0 μm, and particularly preferably 12.0 to 35.0 μm.

Inorganic powders can be harder materials with a higher hardness than organic powders. The average particle size (D50) of the inorganic powder may be, for example, 0.1 to 100.0 μm, preferably 1.0 to 80.0 μm, more preferably 5.0 to 70.0 μm, even more preferably 10.0 to 70.0 μm, and particularly preferably 30.0 to 70.0 μm.

[Amount of additional ingredients]
In one embodiment, the powder composition may include more than 1 wt.% of the additional component, 2 wt.% or more, 3 wt.% or more, 5 wt.% or more, 7 wt.% or more, 10 wt.% or more, 12 wt.% or more, 15 wt.% or more, 20 wt.% or more, 25 wt.% or more, 30 wt.% or more, 35 wt.% or more, 45 wt.% or more, 50 wt.% or more, 60 wt.% or more, 70 wt.% or more, 80 wt.% or more, 90 wt.% or more, 95 wt.% or more, or 97 wt.% or more, and 99.9 wt.% or less, 95 wt.% or less, 90 wt.% or less, 85 wt.% or less, 80 wt.% or less, 75 wt.% or less, 70 wt.% or less, 65 wt.% or less, 60 wt.% or less, 55 wt.% or less, 50 wt.% or less, 45 wt.% or less, 40 wt.% or less, 35 wt.% or less, 30 wt.% or less, 25 wt.% or less, or 20 wt.% or less.

(Surface-treated fine particle silica)
The silicon dioxide used as the anti-caking agent described above may be surface-treated fine particle silica. By including surface-treated fine particle silica in the powder composition, the powder properties such as flowability of the powder composition can be improved.

Surface-treated fine particle silica refers to fine particle silica in which the surface of the silica particles has been treated with an organic compound or the like to modify the silica surface with specific organic groups. Such organic groups are not particularly limited, but examples include alkyl groups, methacryl groups, amino groups, mercapto groups, vinyl groups, etc.

The organic compound used to treat the surface of the fine silica particles is not particularly limited, but may be, for example, a silane compound capable of undergoing a condensation reaction with the OH groups on the silica surface. Such a silane compound is a compound having at least one of the organic groups exemplified above.

Organic compounds used for surface treatment of fine silica particles include, for example, silane compounds with alkyl groups such as dimethyldichlorosilane, trimethylchlorosilane, and hexamethyldisilazane; silane compounds with methacryl groups such as 3-methacryloxypropylmethyldimethoxysilane and 3-methacryloxypropyltrimethoxysilane; silane compounds with amino groups such as 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane; silane compounds with mercapto groups such as 3-mercaptopropyltrimethoxysilane; and silane compounds with vinyl groups such as vinyltrimethoxysilane and vinyltriethoxysilane.

Commercially available surface-treated silica particles may be used. Examples of surface-treated silica particles that can be used include Aerosil R812S (manufactured by Nippon Aerosil Co., Ltd.), Aerosil R711 (manufactured by Nippon Aerosil Co., Ltd.), and Aerosil R504 (manufactured by Nippon Aerosil Co., Ltd.).

(Hydrophobicized fine particle silica)
The surface-treated fine particle silica may be hydrophobized fine particle silica from the viewpoint of further suppressing aggregation and/or further improving the flowability.

Hydrophobicized particulate silica inhibits aggregation and/or improves flowability of the powder composition. There are no restrictions on the hydrophobicized particulate silica that can be used, as long as it is made hydrophobic by surface-treating fine silica particles with primary particles of 0.01 to 1000 nm with an organic compound, either in the primary particle state or after processing into aggregated or agglomerated particles.

The primary particles of the fine silica particles may be 0.01 nm or more, 0.1 nm or more, 1 nm or more, 10 nm or more, 50 nm or more, 100 nm or more, 200 nm or more, 300 nm or more, or 500 nm or more, or 1000 nm or less, 900 nm or less, 800 nm or less, 700 nm or less, 500 nm or less, or 300 nm or less, for example, 0.01 to 1000 nm, 1 to 100 nm, or 5 to 20 nm.

There are no particular restrictions on the method of producing the fine particle silica, and fine particle silica produced by any method can be used, including the dry method (high-temperature hydrolysis method) which produces dry silica using raw materials such as silicon tetrachloride, the wet method which produces precipitated silica using raw materials such as water glass, and the sol-gel method which produces sol-gel silica using raw materials such as alkoxide compounds. There are also no restrictions on mixed fine particle silica produced by mixing silica produced by different methods.

There are no particular restrictions on the crystallinity of the fine particle silica; it can be crystalline, amorphous, or a mixture of the two. It is preferable to use amorphous fine particle silica produced by a dry method, in which fine silica particles with primary particles of 1 to 100 nm are processed into aggregated or agglomerated particles.

The BET specific surface area of the particulate silica that has been processed into aggregated particles or agglomerated particles may be, for example, 20 to 400 (m ² /g), preferably 50 to 300 (m ² /g), and more preferably 100 to 300 (m ² /g). These particulate silicas can be used alone or in combination.

Fine particle silica may be made hydrophobic by surface treatment with an organic compound. There are no restrictions on the organic compound, and any organic compound can be used as long as it can be made hydrophobic.

By treating the surface of fine silica particles with an organic compound, the hydrophilic surface characteristics of the fine silica particles can be modified to hydrophobicity, but the degree of hydrophobicity varies depending on conditions such as the surface treatment method and the amount of organic compound used for surface treatment.

In this embodiment, hydrophobization is defined as when hydrophobized silica particles float even slightly on the surface of the water when added to water. There are no restrictions on the organic compound that can be used for this hydrophobization treatment, but it is preferable to use a silane compound that can undergo a condensation reaction with the OH groups on the surface of the silica particles.

Examples of hydrophobic treatments include dimethylsilylation, trimethylsilylation, alkylsilylation, trialkylsilylation, dimethylpolysiloxane conversion, aminoalkylsilylation, methacrylsilylation, and methacrylalkylsilylation.

Among these, hydrophobic treatment by dialkylsilylation or trialkylsilylation is preferred, hydrophobic treatment by dimethylsilylation or trimethylsilylation is more preferred, and hydrophobic treatment by trimethylsilylation is even more preferred. Specifically, the particulate silica is preferably dimethylsilylated particulate silica and/or trimethylsilylated particulate silica.

Specific examples of silane compounds that can be used for hydrophobic treatment include dimethyldichlorosilane, trimethylchlorosilane, and hexamethyldisilazane. These hydrophobic fine particle silicas can be used alone or in combination with several types. Furthermore, hydrophobic fine particle silicas that have been further granulated or aggregated to have larger particle sizes can also be used without any restrictions.

Furthermore, fine particle titania, fine particle alumina, other oxide fine particles, or mixtures thereof, which are manufactured by the same manufacturing method as the fine particle silica used in this embodiment and have similar particle sizes and specific surface areas, can also be used in this embodiment by subjecting them to hydrophobic treatment. Furthermore, these fine particle oxides can be mixed with the above-mentioned fine particle silica and subjected to hydrophobic treatment, or the respective hydrophobic treated fine particles can be mixed and used as the powder composition according to this embodiment.

(Amount of surface-treated fine particle silica)
The amount of surface-treated fine particle silica is not particularly limited, and surface-treated fine particle silica can be mixed in any ratio. The content of surface-treated fine particle silica may be 0.001 parts by weight or more, 0.01 parts by weight or more, 0.05 parts by weight or more, 0.1 parts by weight or more, 0.3 parts by weight or more, 0.5 parts by weight or more, 1 part by weight or more, 3 parts by weight or more, 5 parts by weight or more, 7 parts by weight or more, 10 parts by weight or more, or 20 parts by weight or less, 15 parts by weight or less, 10 parts by weight or less, 7 parts by weight or less, 5 parts by weight or less, or 3 parts by weight or less, relative to 100 parts by weight of the powder composition. The content of surface-treated fine particle silica may be, for example, 0.001 parts by weight to 10.0 parts by weight, preferably 0.01 parts by weight to 8.0 parts by weight, and more preferably 0.1 parts by weight to 5.0 parts by weight, relative to 100 parts by weight of the powder composition.

When the content of surface-treated fine particle silica per 100 parts by weight of the powder composition is 0.001 parts by weight or more, the powder composition is less likely to aggregate, and the flowability of the powder composition is improved. In other words, the powder composition is more likely to be uniformly mixed with air in the powder/air mixing chamber attached to the powder injection device, and clogging is less likely to occur inside the powder/air mixing chamber attached to the powder injection device, in the connecting parts through which the powder flows to the injection nozzle, and in the injection nozzle, etc.

On the other hand, if the content of surface-treated fine particle silica per 100 parts by weight of the powder composition is 10.0 parts by weight or less, the effects of the present invention can be maintained while preventing a decrease in workability. Specifically, in such a case, the surface-treated fine particle silica will not be present in excess in the powder composition, so the powder composition is less likely to become bulky, and handling difficulties, such as difficulties in filling the composition when transferring it into a powder/air mixing chamber, are less likely to occur.

Commercially available hydrophobic silica particles may be used. For example, Aerosil R812S (manufactured by Nippon Aerosil Co., Ltd.) can be used as the hydrophobic silica particles.

The silicon dioxide used as the anti-caking agent described above may be hydrophilic fine particle silica. As the hydrophilic fine particle silica, the fine particle silica before being hydrophobized, as described in (Hydrophobized fine particle silica), may also be used.

Commercially available hydrophilic particulate silica may be used. Examples of hydrophilic particulate silica that can be used include Aerosil 200 (manufactured by Nippon Aerosil Co., Ltd.), Aerosil 300 (manufactured by Nippon Aerosil Co., Ltd.), and Aerosil 90 (manufactured by Nippon Aerosil Co., Ltd.). The amount of hydrophilic particulate silica in the powder composition may be the amount described in (Amount of surface-treated particulate silica).

The present disclosure will be explained in detail below using examples, but the present disclosure is not limited to these examples.

The components used in the examples and comparative examples are shown below.
<Tooth polishing powder>
The following powders were used as shown in Table 1:
・Aminoethylsulfonic acid (taurine)
・Sodium bicarbonate (baking soda)
・Amino acid: glycine ・Sugar alcohol: sorbitol ・Disaccharide: trehalose <anti-caking agent>
- Hydrophilic fine particle silica (primary particle diameter 12 nm)
Dimethylsilylated silica fine particle (primary particle diameter 16 nm)
- Trimethylsilylated fine silica particles (primary particle diameter 12 nm)

Preparation of a Powder Composition for Polishing Teeth
(Examples 1 to 20 and Comparative Examples 1 to 7)
Powder compositions of Examples and Comparative Examples were prepared by mixing the components according to the formulations shown in Tables 2-1 and 2-2.

(Reference example)
As a reference example, the following powders were prepared.
Reference Example 1: Airflow Powder Plus (manufactured by EMS) Main ingredient: erythritol Reference Example 2: Periomate Powder (manufactured by Nakanishi Co., Ltd.) Main ingredient: glycine Reference Example 3: Lunos Prophy Powder Perio Combi (manufactured by Dürr Dental Co., Ltd.) Main ingredient: trehalose

<Test method and results>
The test procedure is as follows:

[Solubility Measurement]
50 g of water was added to five times the expected amount of powder, and the mixture was sealed and mixed using a shaker at a test temperature of 20°C for 24 hours. The mixed test solution was centrifuged to recover the supernatant, and the weight of the powder contained in the supernatant was measured by the dry weight method to obtain the solubility in water at 20°C. The results are shown in Table 1.

[Density measurement]
The density of the powder was calculated in accordance with Japanese Industrial Standard JIS Z8837:2018 Measurement of density by volume displacement (ISO 12154:2014). The results are shown in Table 1.

[Measurement of average particle size]
The average particle size (μm) of the powder was measured by dry dispersion using a laser diffraction particle size distribution measuring device (Mastersizer 3000, manufactured by Malvern Panalytical). The results are shown in Tables 2-1 and 2-2.

[Powder flowability (angle of repose measurement)]
As an indicator of powder flowability, the angle of repose was measured according to the following procedure.
1. Powder was placed in the funnel and allowed to fall freely (to a height of 45 mm) from the tip of the funnel (inner diameter 6 mm) toward the center of the stage, allowing a sufficient amount of powder to fall until it spilled over the stage (diameter 40 mm).
2. The inclination angle of the pile of powder placed on the stage (the angle of elevation between the side and bottom of the pile) was measured using a protractor.
3. This procedure was repeated three times, and the average was calculated as the angle of repose (°), which was used to evaluate powder fluidity. An angle of repose of less than 40° indicates high fluidity.
The results of powder flowability (angle of repose measurement) are shown in Table 3.

Table 3 shows that Examples 1 to 20 showed values (40° or less) roughly equivalent to those of Reference Examples 1 to 3, demonstrating that they have fluidity suitable for use as powder for air polishing. In Examples 1 to 20, the powder in the powder chamber is easily agitated by air, which is thought to reduce the risk of powder clogging.

[Sticky (adhesiveness)]
Stickiness (degree of adhesion) was measured according to the following procedure.
1. The powder chamber of a powder spraying device (product name: Mersage Epic 2 in 1, manufactured by Shofu Co., Ltd.) was filled with powder up to the MAX line, and the powder was sprayed onto a glass slide for 10 seconds at an air supply pressure of 0.6 MPa and a water supply pressure of 0.3 MPa, followed by drying (37°C, 5 minutes).
2. After the sprayed material had dried, a piece of paper with a diameter of about 6 mm was pressed onto the entire surface of the slide glass.
3. The paper on the slide glass was gently shaken off, and the degree of adhesion of the paper was confirmed (N=3).
-Evaluation criteria-
○ (Good): Not a single piece of paper adheres to the slide glass, and no stickiness is felt.
△ (Acceptable): 1 to 5 sheets of paper adhere to the slide glass, and it feels slightly sticky.
× (bad): 10 or more sheets of paper adhered to the slide glass, and it felt very sticky.
The results of stickiness (degree of adhesion) are shown in Table 3.

As can be seen from Table 3, in Examples 1 to 20, not a single piece of paper adhered to the teeth, just like in Reference Examples 1 and 2. Stickiness can lead to clogging of powder and make cleaning after treatment difficult. Examples 1 to 20, which are less sticky, are thought to be able to clean teeth more efficiently.

[Cleaning power (polishing power)]
The cleaning power (abrasive power) was measured according to the following procedure.
1. Using a powder spraying device (product name: Mersage Epic 2in1, manufactured by Shofusha), various powders were sprayed in sequence onto a board coated with pseudo-stain, divided into 1cm squares, under conditions of a spray angle of 45°, a spray nozzle/object distance of 3mm, a supply air pressure of 0.6MPa, and a supply water pressure of 0.3MPa, and the pseudo-stain was scraped off (n=1).
2. The cumulative removed area was calculated using a microscope at 5, 10 and 15 minutes after the start of spraying, and the area was evaluated as an index of cleaning power (abrasive power).
-Evaluation criteria-
⊚ (Very good): The cleaning ability is very good and it can be used for both under-edge and over-edge applications.
○ (Good): Easy to clean and can be used under the rim.
× (bad): Poor cleaning ability, cannot be used for polishing.
The cleaning power results are shown in Table 3.

Table 3 shows that Examples 1, 2, 5, 8, and 11-17, despite having a small average particle size, exhibited cleaning performance equal to or better than that of the conventional Reference Examples 1-3. On the other hand, Examples 3, 4, and 18-20, which have a large average particle size, exhibited superior cleaning performance compared to the conventional Reference Examples 1-3, demonstrating their suitability for use on the edges. Furthermore, Examples 8-10, which replaced glycine-based Comparative Example 1 with an equal weight of taurine, demonstrated increased cleaning power as the amount of taurine added increased. Furthermore, Examples 1-5 and 11-20, which consisted of powder containing only taurine, showed almost no decrease in cleaning power even with extended spray times, exhibiting very stable cleaning performance. The low powder consumption over 15 minutes also suggests efficient cleaning.

[Evaluation of damage to dentin]
Damage to dentin was measured according to the following procedure.
- Test method -
1. Using a powder spraying device (product name: Mersage Epic 2in1, manufactured by Shofu Co., Ltd.), spraying treatment was performed on the dentin surface under conditions of a spray angle of 45°, a spray nozzle/dentin distance of 3 mm, a supply air pressure of 0.6 MPa, and a supply water pressure of 0.3 MPa. The dentin surface after treatment was observed using a tabletop scanning electron microscope ("G2pro" manufactured by Phenom-World). From the observation results, the damage to dentin of the powder mixture for spraying was evaluated according to the following evaluation criteria. This procedure was repeated three times and an overall evaluation was made.
-Evaluation criteria-
◎ (Very good): No change was observed on the dentin surface before and after the spraying treatment, and no damage such as scratches was observed on the dentin surface.
○ (Good): Damage such as some scratches was observed on the dentin surface, but no irregularities or peeling was observed on the dentin.
△ (Fair): After the spraying treatment, roughened surfaces (unevenness, etc.) were observed on parts of the dentin surface, and damage such as scratches was observed on the dentin surface to the extent that no dentin peeling was observed.
× (bad): Damage such as scratches on the dentin surface after spraying treatment, such as unevenness and peeling, is observed on the dentin surface.

Table 3 shows that, with the exception of Example 7, which consisted of a powder of sodium bicarbonate alone, Examples 1 to 6 and 8 to 20 did not cause significant damage to dentin, similar to the conventional products, Reference Examples 1 to 3.

[Storage stability (cohesiveness)]
The storage stability was evaluated according to the following criteria.
-Evaluation criteria-
Good (good): After storage for one month at a temperature of 40°C and a humidity of 75%, no agglomerates were observed in the powder.
Δ (Acceptable): After storage for one month at a temperature of 40°C and a humidity of 75%, slight agglomerations were observed in the powder.
× (bad): After storage at a temperature of 40° C. and a humidity of 75% for one month, many aggregates were observed in the powder.

Table 3 shows that Examples 1 to 20 exhibit excellent storage stability equivalent to or better than Comparative Examples 1 to 7 and conventional Reference Examples 1 to 3.

Therefore, it was revealed that the powder compositions of Examples 1 to 20 are polishing powders that combine superior fluidity and cleaning properties, and also have excellent storage stability. Furthermore, in addition to the above, it was revealed that the powder compositions of Examples 1 to 6 and 8 to 20 are polishing powders that are less damaging to dentin.

Claims (15)

A powder for polishing teeth, having a solubility in water at 20°C of 20% by mass or less. 2. The powder of claim 1, having a density of 2.0 g/ ^cm3 or less. The powder described in claim 1, having an average particle size of 5 μm to 80 μm. The powder described in claim 1, which is a compound containing an amino group and a sulfur atom in its molecule. The powder described in claim 4, which is a compound that does not contain a carboxyl group in its molecule. The powder described in claim 1, which is a compound having one or less hydroxyl groups in its molecule. The following formula:
R ^S (-R ^C -R ^N ) _n
[In the formula,
R ^N is -N(R ^N1 ) ₂ ,
R ^N1 each independently represents a hydrogen atom, a hydrocarbon group having 1 to 3 carbon atoms which may have a substituent, or a halogen atom;
n is an integer of 1 or 2,
R and ^C each independently represent a divalent hydrocarbon group having 1 to 5 carbon atoms which may have a substituent;
^RS is
When n is 1, it is —SO ₂ R ^S1 or —SOR ^S1 ;
R ^S1 each independently represents a hydrogen atom, a hydrocarbon group having 1 to 3 carbon atoms which may have a substituent, —OH, or —SH;
When n is 2, it is -S-.]
The powder according to claim 1, which is a compound represented by the formula: n is 1,
R ^N1 each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms,
R ^C is an alkylene group having 1 to 3 carbon atoms;
8. The powder of claim 7, wherein R 1 ^S is --SO ₃ H or --SO ₂ H. The powder described in claim 1, which is aminoethylsulfonic acid. A powder composition for polishing teeth, comprising 1% by weight or more of the powder described in claim 1. The powder composition of claim 10, further comprising at least one selected from the group consisting of sugars, sugar alcohols, amino acids, phosphate compounds, carbonate compounds, calcium compounds, anti-caking agents, bactericides, bioactive glass, and fragrances. The powder composition according to claim 11, wherein the saccharide is at least one selected from the group consisting of tagatose, trehalose, palatinose, and rhamnose. The powder composition according to claim 11, wherein the sugar alcohol is at least one selected from the group consisting of xylitol, erythritol, sorbitol, mannitol, and reduced palatinose. The powder composition according to claim 11, wherein the anti-caking agent is at least one selected from the group consisting of silicon dioxide, calcium carbonate, aluminum silicate, magnesium silicate hydrate, and/or aluminum hydroxide. The powder composition described in claim 14, wherein the silicon dioxide is surface-treated fine particle silica having a primary particle size of 1 to 100 nm.