HK1028878A - Oral and dental hygiene products for sensitive teeth - Google Patents

Description

Oral and dental hygiene composition for sensitive teeth

The present invention relates to an oral and dental hygiene composition comprising an active ingredient for reducing the sensitivity of teeth to mechanical and thermal stimuli.

When teeth are subjected to thermal or mechanical stimuli, for example when enjoying cold or cold drinks or when in contact with a toothbrush, some people suffer from the bruising caused by the particular sensitivity of the teeth, particularly in the neck portion, and have an unpleasant and even painful sensation.

Water soluble salts of potassium and strontium are known to reduce this insensitivity to some extent. Thus, for example, in DE 2419384 potassium nitrate is recommended for toothpaste and in US3,122,483 strontium chloride is recommended.

It has also been known for a long time that clove oil and its main ingredient eugenol can be used as a fragrant oil with antibacterial properties in oral and dental hygiene compositions (see for example german patent application DE 2445676C 2).

However, it has now been found that a certain content of eugenol or clove oil can more significantly enhance the desensitizing effect of potassium or strontium salts on hypersensitive teeth. In particular, this effect was observed to occur rapidly. It has not been known to date that eugenol will increase in efficacy when used with other desensitizing active ingredients.

It is therefore an object of the present invention to provide oral and dental hygiene compositions in the form of aqueous-, aqueous-ethanolic-or anhydrous preparations containing active ingredients consisting of a water-soluble potassium or strontium salt and eugenol or clove oil for desensitizing sensitive teeth.

The oral and dental hygiene compositions of the invention may be present in the form of toothpastes, liquid dental emulsions, tooth powders, mouthwashes or, if desired, as chews, for example chewing gums. Preferably, however, as a more or less flowable or pasty toothpaste, for example a toothpaste which is used for cleaning teeth in the case of a toothbrush.

In a ready-to-use formulation, it is preferred to include at least 0.5% by weight of potassium or strontium ions in the form of dissolved salts and at least 0.01% by weight of eugenol, either neat or in the form of clove oil. Generally clove oil contains 10-15 wt% eugenol acetate (odor component) in addition to 70-90 wt% eugenol, and small amounts of alcohols, methyl esters, ketones and sesquiterpenes.

Suitable water-soluble potassium salts are, for example, potassium chloride, potassium sulfate, potassium bicarbonate, potassium citrate, potassium acetate, potassium lactate and potassium nitrate. Potassium nitrate is preferred.

Suitable water-soluble strontium salts are strontium chloride, strontium nitrate, strontium citrate, strontium acetate and strontium lactate.

The content of potassium or strontium salts is preferably 0.5 to 10% by weight (calculated as potassium or strontium ions).

In the oral and dental hygiene compositions, eugenol can also be mixed with other aromatic oils. Preferably, from 0.01 to 1% by weight (calculated as eugenol) of eugenol is included in the formulation, in the form of clove oil.

The toothpaste or liquid dentifrice of the present invention typically comprises 5-50% by weight of a polishing agent and 10-60% by weight of a humectant.

Polishing agents are all known abrasives for toothpastes, for example silicic acid, aluminum hydroxide, aluminum oxide, calcium pyrophosphate, chalk, dibasic calcium phosphate dihydrate, sodium aluminum silicates such as zeolite a, organic polymers such as polymethacrylates or mixtures of these abrasives. The addition of a polishing agent, which itself has a reparative effect on damaged and open root canals, which may be dibasic calcium phosphate dihydrate, has proven particularly suitable. Dibasic calcium phosphate dihydrate (CaHPO)₄2H2O) exists in nature as brushite and is commercially available in suitable particle sizes of 1 to 50 microns.

Thus, a particularly preferred embodiment of the present invention is an oral and dental hygiene composition in the form of a toothpaste or dental emulsion comprising 5 to 50% by weight of a polishing agent and 10 to 60% by weight of a humectant comprising at least 1% by weight of dibasic calcium phosphate dihydrate as the polishing agent component. Particularly effective polishing compositions consist of 10-20% by weight silicic acid and 1-10% by weight dibasic calcium phosphate dihydrate (the% in each case being for a ready-to-use toothpaste).

The silicic acid polishing agents are all silicic acid gels, silicic acid hydrogels and precipitated silicic acids known as abrasive bodies (Putzkorper). Silicic acid gels are obtained by reacting a sodium silicate solution with a strong aqueous mineral acid under hydrogel-forming conditions, aging to a hydrogel, washing and drying. If drying under suitable conditions to a water content of 15-35% here, so-called silicic acid hydrogels are obtained, see for example U.S. Pat. No. 4,153,680. By drying to a water content of less than 15% by weight, the above-mentioned loose hydrogel structure irreversibly shrinks into a so-called dry-coagulated compact structure. Such silicic xerogels are described, for example, in US3,538,230.

A second preferred suitable silicic acid polishing agent is precipitated silicic acid. Which is precipitated from a dilute alkali metal silicate solution by addition of a strong acid under conditions in which aggregation to form sols and gels does not occur. Suitable processes for preparing precipitated silicic acid are described, for example, in DE-OS 2522486 and DE-OS 3114493. Particularly suitable are precipitated silicic acids prepared according to DE-OS 3114493, which have a BET surface area of 15 to 110 m/g, a particle size of 0.5 to 20 μm, at least 80% by weight of the primary particles being smaller than 5 μm, and a viscosity in a 30% glycerol-water (1: 1) dispersion of 30 to 60Pa.s (20 ℃) at 10 to 20% by weight of the toothpaste.

In addition, particularly suitable precipitated silicic acids have rounded corners and may be sold under the trade name Sident^12 DS (DEGUSSA).

In order to obtain a sufficiently high content of silicic acid having an average particle size of less than 5 μm, and in particular to obtain at least 3% by weight, based on the total toothpaste, of silicic acid having a primary particle size of 1 to 3 μm, it is preferred to use, in addition to the abovementioned precipitated silicic acid, a finely divided silicic acid having a BET surface area of 150-. A suitable silicic acid of this type is Sipernat^22ls (degussa), used in an amount of 1-5% by weight of the toothpaste.

The invention proves particularly advantageous for forming smooth tooth surfaces when it contains small amounts of freshly precipitated silicic acid, that is to say, generated in situ during the preparation of the toothpaste. This can be achieved, for example, by maintaining the pH at 3 to 5, for example by citric acid, and then raising the pH to 7 to 7.5 by adding a small amount of aqueous sodium silicate solution when preparing the toothpaste. The silicic acid formed in situ in this way is very finely dispersed and amounts to less than 0.1% by weight of the amount of toothpaste.

For example, about 1 to 5 wt.% of alumina in the form of gamma-and alpha-alumina-containing dead alumina may be included as the other polishing agent component. Suitable such aluminas are available under the trade name "Poliertonerde P10 feinst" (gilulini Chemie).

It was furthermore found that magnesium ions have a favourable effect on the controlled crystal growth of hydroxyapatite, which grows when the tooth is damaged, which promotes accelerated hardening of the enamel and thus contributes to the solution of the task of the present invention. Thus, a further aspect of the invention is a toothpaste according to the invention comprising 0.1-0.5 wt% water soluble magnesium salt calculated as Mg. Suitable magnesium salts are all salts which dissolve at least up to 0.5% by weight (calculated as Mg) in water at 20 ℃, for example MgSO₄、MgCl₂And magnesium monofluorophosphate (MgPO)₃F)。

It was finally found that fluorophosphate ions have a favourable effect on controlling the crystal growth of hydroxyapatite. It is therefore preferred that the toothpaste of the invention comprises PO₃F^-Monofluorophosphate in an amount of 0.2 to 2.0% by weight as a fluorine compound. Suitable for this purpose are, for example, alkali metal salts, such as commercially available sodium monofluorophosphate. Particularly advantageously, the preferred magnesium ion and fluorophosphate content can be obtained by magnesium monofluorophosphate as the fluorine compound.

Suitable carriers for the toothpaste of the present invention are compositions of humectants, binders and water which may suitably adjust the amount and consistency of extrusion from a toothpaste tube, application container (Spendebellann) or flexible bottle, based on the polishing agent component of the present invention. The humectant may be, for example, glycerin, sorbitol. Xylose, propylene glycol, polyethylene glycol, in particular those having an average molecular weight of from 200 to 800. Consistency regulators (or binders) are, for example, natural and/or synthetic water-soluble polymers such as alginates, carrageenans, tragacanth, starch and starch ethers, cellulose ethers such as carboxymethylcellulose (Na salt), hydroxyethylcellulose, methylhydroxypropylcellulose, guar gum, acacia gum, agar, synthetic biopolymer gums, succinoglycol, Johannis bread flour, pectin, water-soluble carboxyvinyl polymers (e.g. Carbopol @)^-species), polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, in particular those having a molecular weight of 1500 to 1000000.

Other substances suitable for controlling the viscosity are, for example, layered silicates, such as montmorillonite-clay, colloidal concentrated silicic acid, such as silicic acid gas condensate, pyrogenic silicic acid or finely ground precipitated silicic acid.

The viscosity of the toothpaste can be adjusted to be so low that it is distributed on the toothbrush as a "liquid tooth cleaner" with a viscosity of 2000 to 10000m.pa.s (25 ℃) when it comes out of the flexible plastic bottle, where it penetrates between the bristles, but does not drip from the toothbrush. For this purpose, suitable for use as adhesives are preferably compositions consisting of from 0.1 to 1% by weight of a synthetic biopolymer gum and from 0.01 to 5% by weight of viscosity-stabilizing additives selected from the group consisting of:

cationic, zwitterionic or amphoteric nitrogen-containing surfactants

-hydroxypropyl-substituted hydrocolloids or

-polyethylene/polypropylene glycol copolymers with an average molar weight of 1000 to 5000 or mixtures of the above compounds.

Also, the toothpaste of the present invention further comprises 0.1 to 5% by weight of a surface active material in order to aid the cleaning effect and, if necessary, in order to generate foam when the toothbrush is used and to stably disperse the polishing agent in the carrier.

Suitable surfactants are, for example, sodium linear alkyl sulfates having from 12 to 18 carbon atoms in the alkyl backbone. The substance has an additional enzyme inhibiting effect on the metabolism of bacteria in the tartar. Other suitable surfactants are alkali metal salts, preferably sodium salts of the following compounds: alkyl polyglycol ether sulfates having 12 to 16 carbon atoms in the linear alkyl radical and 2 to 6 glycol ether groups in the molecule, linear alkanes (C)₁₂-C₁₈) Sulfonates, sulfosuccinic acid monoalkyl radicals (C)₁₂-C₁₈) Esters, sulfated fatty acid monoglycerides, sulfated fatty acid alkanolamides, alkyl sulfoacetates (C)₁₂-C₁₆) Esters, acyl sarcosines having 8 to 18 carbon atoms in each of the acyl radicals, acyl tauridesSulfonamide (Acyl tauride) and Acyl isethionate. Also suitable are zwitterionic, amphoteric and nonionic surfactants, such as the oxyethanolates of fatty acid mono-and diglycerides, sorbitol fatty acid esters and oxyethanolates of alkyl (oligo) glucosides.

Other conventional toothpaste additives are

Preservatives and antimicrobials, such as methyl, -ethyl or-propyl p-hydroxybenzoate, sodium sorbate, sodium benzoate, bromochlorophenol, eicosatriane, phenyl salicylate, biguanides, such as chlorhexidine, thymol and the like.

Sweeteners such as sodium saccharin, sodium cyclamate, sucrose, lactose, maltose, fructose,

fragrances such as peppermint oil, spearmint oil, eucalyptus oil, anise oil, carvacrol oil, 3-terpineol acetate, cinnamaldehyde, anethole, vanillin, thymol and mixtures thereof with other natural and synthetic fragrances,

pigments such as titanium dioxide

-colorants

Buffers such as primary, secondary or tertiary alkali metal phosphates or citric acid/sodium citrate,

substances for wound healing and inflammation inhibition such as allantoin, urea and azulene, chamomile active ingredients, acetyl salicylic acid derivatives.

In mouthwashes, the carrier consists essentially of water, ethanol, an etherified oil, emulsifiers and solvents for eugenol, and conventional flavors, flavors (sweeteners) and, if desired, drug extracts having an astringent or exciting effect and, if desired, colorants. In addition to the desensitizing potassium or strontium salt and eugenol, an antimicrobial agent such as chlorhexidine or triclosan may be included as another active ingredient.

The following examples further illustrate the invention in detail:

examples the following oral and dental hygiene compositions were prepared:

1. toothpaste tube

	1	2	3	4
					Precipitated silicic acid	10.0	12	15	18
Precipitated silicic acid	3.0	3.0-	-	-
					Poliertonerde P10feinst(1)	-	-	-	1.0
Calcium hydrogen phosphateDihydrate of a mineral acid	4.0	4.0	-	-
					MgSO4 7H2O	1.7	1.4	-	-
Sodium monofluorophosphate Na2PO3F	1.2	0.8	0.5	0.6
					KNO3Without water	5.0	4.0	4.5	3
Glycerol (86% DAB)	21.0	18.0	10	17.5
					Sorbitol (70% DAB)	20.0	14.0	5	17.5
Polyethylene glycol (MG: 400)	2.0	2.0	1.0	1.0
					Concentrated silicic acid (FK 320DS)	1.0	1.0	5.0	0.8

Synthesis of biopolymer glue (Keltrol)F)	0.6	0.6	0.6	0.5
					Titanium dioxide	1.0	1.0	-	-
Sodium lauryl sulfate	1.5	1.5	-	2.0
					Tego Betain BL215(2)	0.6	0.6	-	-
Trisodium citrate	0.2	0.2	-	-
					Saccharin sodium salt	0.2	0.2	0.1	0.2
Clove oil	0.05	0.1	0.07	0.1
					Perfume	1.0	0.8	0.1	1.0
Cremophor RH60(3)	-	-	0.2	-
					Water (W)	To 100 of	To 100 of	To 100 of	To 100 of

2. Liquid tooth cream

	5
		Precipitated silicic acid (Sident 12 DS)	12.0
NaF	0.25
		KNO3	5.0
Na2HPO4	0.2
		Synthetic biopolymer glue (Keltrol F)	0.2
Azepane-2, 2-diphosphonate (Na-salt)	1.0
		Saccharin sodium salt	0.2
Ethanol	5.0
		Glycerol	28.0
Sorbitol	22.0
		Polyethylene glycol (MG: 400)	3.0

PEG 30-glyceryl stearate	1.0
		Tego Betain BL 215(2)	0.8
Aromatic oil	1.0
		Clove oil	0.1

3. Mouthwash (instant use)

	6
		Ethanol	5.0
Chlorhexidine gluconate	0.03
		Plantaren 2000 (4)	0.05
Na2PO3F	0.25
		KNO3	4.0
Saccharin sodium salt	0.05
		Sorbitol	3.0
Cremophor RH 60(3)	0.1
		Essential oil (mint oil)	0.1
Clove oil	0.05
		Colorant (blue, C.J.42090)	0.1
Water (W)	To 100 of

The following commercial products were used

(1)Poliertonerde P10 feinst：

Dead calcined alumina (about 20 wt% gamma alumina, about 80 wt% alpha-alumina)

Aluminum, primary particle size 0.5 to 1.5 microns) (2) Tego^Betain BL 215：

An aqueous 30% solution of cocamidopropyl betaine (3) Cremophor^RH 60：

Hydrogenated castor oil +60 moles EO

(4) Plantaren 2000：

Alkyl radical- (C)₈-C₁₆) -oligo- (1, 4) -glucoside (50% in water)

Clinical effect verification

In clinical comparisons:

example 1

Example 1 without clove oil V1 (substituted with water)

VM ═ sensitive toothpaste (commercially available products)

The test method comprises the following steps:

with three groups of trials, each group of subjects had 50 people. The sensitivity of the teeth was diagnosed by the dentist at the start of the test and after the end of the test period of 8 weeks. At the same time, a single evaluation is made from a questionnaire.

Dental trials were performed with the aid of air jets directed at the neck of the tooth.

This is a double blind test. Prior to the test, the teeth were cleaned 2 times a day using a neutral toothpaste without desensitizing additives. Each of these three groups used one of the three test creams during the test, typically 2 times per day.

Subjects are only those whose tooth sensitivity corresponds to a rating of 2 or higher in the first trial at the start of the trial.

The following 5 grades were scored

0 ═ sufficient desensitization

Very low sensitivity to 1 ═

2-low sensitivity

Medium sensitivity 3 ═

High sensitivity 4 ═

High sensitivity to 5 ═

Statistical comparisons between test groups were performed according to the Log Rank test (according to Petowilcoxon).

Table 1 below shows the results of the sensitivity tests of the subjects who performed the test until the end.

TABLE I

	Group E		Group VI		Group VM
							Scoring	Start of	End up	Start of	End up	Start of	End up
0	-	1	-	1	-	3
							1	0	13	2	8	2	6
2	14	16	7	8	4	5
							3	21	9	13	16	8	8
4	6	4	12	5	14	13
							5	3	1	9	5	17	10
General of	44	44	43	43	45	45

The following table illustrates the dental condition of the subjects in each test group, which includes the score scale (1-5) determined from the start of the test (vertical) to the score scale (1-5) determined at the end of the test (horizontal). It can clearly be seen that the test group (group E) testing the product of the invention had a score rating of 4 or 5 for only 5 subjects after the test, whereas a score rating of 0 to 2 was found for 30 subjects.

TABLE II

The product is as follows: e
								Before/after	0	1	2	3	4	5	Total of
0
								1
2		6	7	1			14
								3	1	4	8	7	1		21
4		1	1	1	2	1	6
								5		2			1		3
Total of	1	13	16	9	4	1	44

TABLE III

The product is as follows: v1
								Before/after	0	1	2	3	4	5	Total of
0
								1			1			1	2
2		2	2	2	1		7
								3		5	2	3	1	2	13
4	1	1	1	7	2		12
								5			2	4	1	2	9
Total of	1	8	8	16	5	5	43

TABLE IV

The product is as follows: VM
								Before/after	0	1	2	3	4	5	Total of
0
								1	1	1					2
2		2	2				4
								3	1	2	1	3	1		8
4	1	1	2	5	4	1	14
								5					8	9	17
Total of	3	6	5	8	13	10	45

Claims (5)

1. Oral and dental hygiene compositions in the form of aqueous-, aqueous-alcoholic-or anhydrous preparations comprising an active ingredient combination consisting of a water-soluble potassium or strontium salt and eugenol or clove oil for desensitizing sensitive teeth.

2. Oral and dental hygiene composition according to claim 1, characterized in that the ready-to-use formulation comprises at least 0.5% by weight of potassium ions or strontium ions and at least 0.01% by weight of eugenol, preferably in the form of clove oil.

3. An oral and dental hygiene composition according to claim 1 or 2 in the form of a toothpaste having 5 to 50 wt.% polishing agent and 10 to 60 wt.% humectant, characterised in that it contains at least 1 wt.% of dibasic calcium phosphate dihydrate as polishing agent component.

4. Oral and dental hygiene composition according to claim 3, characterized in that it additionally comprises 0.1 to 0.5% by weight, calculated as Mg, of a water-soluble magnesium salt.

5. Oral and dental hygiene composition according to one of claims 1 to 4, characterized in that it comprises PO as₃F^-0.2-2.0% by weight of a fluorine compound, preferably a monofluorophosphate.