WO2009098531A1

WO2009098531A1 - Dental composition for desensitization and disinfection of exposed dentin

Info

Publication number: WO2009098531A1
Application number: PCT/IB2008/000271
Authority: WO
Inventors: Alessandro Tosetti
Original assignee: Italmed S.R.L.
Priority date: 2008-02-07
Filing date: 2008-02-07
Publication date: 2009-08-13

Abstract

Dental composition for desensitization and disinfection of exposed dentin comprising a determined amount of a disinfectant, at least one soluble salt selected from the group comprised of : a soluble zinc salt, a soluble potassium salt, a soluble strontium salt, a combination thereof. In particular, the disinfectant is a cationic disinfectant selected from the group comprised of: benzalkonium chloride, benzethonium chloride, chlorhexidine gluconate, cetrimide, cetylpyridinium chloride, a combination thereof. The composition can be used replacing underlayers, or for desensitising and disinfecting treatment and replacing underlayers or for treatment of pillars at a prosthesis application for treatment of gingival withdrawal in consequence of uncovering amelo-cement junctions, after scaling and root planning treatments, and after whitening treatments. In particular, the dental composition is can be fixed topically with a small brush or microsponge on a zone of interest, or as a mouthwash, or in the form of gel, or toothpaste, by a toothbrush.

Description

TITLE

DENTAL COMPOSITION FOR DESENSITIZATION AND DISINFECTION OF

EXPOSED DENTIN

DESCRIPTION Field of the invention

The present invention relates to the dental field and, in particular, it relates to a composition for treatment of dentinal ^■ hypersensitivity and for disinfection of the teeth and of periodontium. The composition, according to the invention, can be used as a solution, as a mouthwash or as a gel toothpaste. Description of the technical problem

Dentinal hypersensitivity is a symptom that dentists find frequently in the odontostomatologic anamnesis. The Patients suffer from pain often intensified when eating hot or cold food, sweet or acidulous food, as well as when brushing teeth.

In teeth sensitive zones enamel is found often eroded or worn away and dentin is more or less seriously exposed. In other cases, gingival recession uncovers the most sensitive portions of the teeth, i.e. the enamel- cement junction.

Normal dentin is coated peripherally by enamel (in crown dentin) and by cement (in radicular dentin) . In these areas dentin is not actually permeable.

The absence of cover exposes the dentinal tubules. In addition, pulp is rich of nerves many of which are centrifugally directed towards dentin. Dentin is crossed radially by dentinal tubules which contain dentinal fluid. Through the tubules a nervous stimulus reaches sensorial areas of the dental pulp.

A first known way to reduce dentinal sensitivity is to close the orifices of dentinal tubules. To this extent, natural substances are known able to reduce sensitivity by closing the tubules, such as tartar, collagen or mineral salts precipitated in saliva.

Chemical compounds, like solutions, gel compounds or pastes, as well as physical treatments are also known capable of mechanically obliterating the orifices of the dentinal tubules .

Some of these compounds or treatments are:

- potassium and iron oxalate, which react with ionised calcium present in the saliva and form calcium oxalate which precipitates and obliterates the dentinal tubules orifices;

- silver nitrate which acts through the precipitation of silver compounds; - tin fluoride, which acts through the precipitation of tin compounds;

- strontium salts;

- insoluble salts such as calcium phosphate, hydroxyapatite, colloidal silica etc. which directly obliterate the tubular orifices;

- glass-ionomeric cement;

- some types of resins.

In any case the obliteration of the dentinal tubules by means of soluble or insoluble salts used up to now, even if they are simple to use, is not enough effective and last only a short time.

Compounds are known, moreover, such as potassium chloride or nitrate or oxalate capable of reducing the dentinal sensitivity through a depolarising effect of the nervous fibres, without obliterating the dentinal tubules. Therefore, desensitization treatments are known using said compounds, capable of stopping the pulpal nervous activity by varying the dentinal tubules nervous fibres excitability. However, also in this case, the effect duration is short.

New techniques, not yet used in clinical practice, use glass-ionomeric cement or photo-induced resins. Desensitization is improved, but they are not easy to use and are good for deep erosions only.

Finally, treatments are known using either laser or ultrasounds sealers, which cause the formation of smear layers and tubules obliteration. These treatments give results, such as effectiveness and duration, similar to the topical treatment with the above described soluble or insoluble salts, but they require expensive apparatus. Summary of the invention

It is an object of the present invention to provide a dental composition for dentinal desensitization which has good mechanical obliteration properties of the dentinal tubules in addition to depolarising properties of the nervous dentinal fibres, and is capable of obtaining good effectiveness, as well as of being easy to use.

It is also a feature of the present invention to provide such a dental composition that can be used for desensitising and disinfecting dental recesses adapted to receive filling material.

It is a particular feature of the present invention to provide such a dental composition that is used for replacing underlayers, or for desensitising and disinfecting treatment or for treatment of pillars at a prosthesis application, for treatment of gingival withdrawal in consequence of uncovering amelo-cement junctions, after scaling and root planning treatments, and after whitening treatments.

It is another particular feature of the present invention to provide such a dental composition which can be fixed topically with a small brush or microsponge on a zone of interest, or as a mouthwash. It is another particular feature of the present invention to provide such a dental composition which is applicable in the form of a gel, or toothpaste, by a toothbrush. These and other objects, are achieved by the dental composition, according to the invention, whose main feature is that it comprises: - a disinfectant at least one soluble salt selected from the group comprised of:

- a soluble zinc salt;

- a soluble potassium salt;

- a soluble strontium salt;

- a combination thereof. Advantageously, the chosen disinfectant is a cationic disinfectant.

In particular, the cationic disinfectant can be selected from the group comprised of: benzalkonium chloride, benzethonium chloride, chlorhexidine gluconate, cetrimide, cetylpyridinium chloride, or a combination thereof.

Preferably, the cationic disinfectant is cetylpyridinium chloride.

In particular, the soluble potassium salt can be selected from the group comprised of: potassium chloride, potassium fluoride, potassium citrate, potassium nitrate, potassium acetate, potassium ascorbate, a combination thereof.

Preferably, the soluble potassium salt is potassium citrate.

In particular, the soluble zinc salt can be selected from the group comprised of: zinc chloride, zinc citrate, zinc sulphate, zinc gluconate, zinc acetate, or a combination thereof. Preferably, the soluble zinc salt is zinc citrate. In particular, the soluble strontium salt can be selected from the group comprised of: strontium chloride, strontium citrate, strontium lactate, strontium gluconate, strontium acetate, or a combination thereof.

Preferably, the soluble strontium salt is strontium chloride .

The pharmaceutical composition, according to the invention, allows to overcome the above described problems owing to the partial properties present in the desensitizing compositions used in clinical practice. The association of a cationic disinfectant with a zinc salt, with at least one potassium salt, and/or strontium salt allows, surprisingly, to obtain a high desensitization significantly higher than a soluble strontium salt

(desensitising action by obliteration of the dentinal tubules) , and/or by a soluble potassium salt

(desensitising action by reduction of the transmission of pain owing to depolarization of the nervous fibres) . This surprising activity is responsive to a synergistic action of the cation disinfectants with the zinc ions (which have disinfecting properties) and with the desensitising activity the potassium and strontium ions.

It is known from the prior art, in fact, a desensitising activity of disinfectants when application exposed dentin, since they reduce the bacterial plaque and reduce also all the synthesis or degradation products the bacteria same that can penetrate in the dentinal tubules, that can be permeated owing to exposition of dentin. Such substances would act on the nervous fibres contained in the dentinal tubules reducing thus the sensitivity threshold.

The following are some experimental results of some tests carried out on the dental composition, according to the invention.

Results experimental

An experimental evaluation of the composition according to the present invention (mouthwash and gel toothpaste), has been carried out in 60 subjects, by measuring the reduction of dentinal sensitivity (after about 15 days) (n° 20 subjects) in comparison with a same composition without the cationic disinfectant and the soluble zinc salt (1^st control, n°20 subjects) and a composition consisting of the only cationic disinfectant and zinc salt (2^nd control, n°20 patients) , obtaining surprisingly results of efficiency significantly higher than the controls. In particular, the rate of sensitivity has been evaluated responsive to the patient using an analog visual scale of the pain in 10 steps.

It has been defined:

- disappearance of sensitivity: a result with 100% reduction of pain;

- excellent: a result with reduction of pain set between 81% and 99%

- good: a result with reduction of pain set between 40% and 80%

- poor: a result with reduction of pain less than 40%. - zero: with 0% reduction of pain.

The mouthwashes have done two times a day, one in the morning and one the evening, for a period of 2 weeks and the subjects have been required furthermore, to brush the teeth 2 times a day with the gel toothpaste. In particular, after 15 days in the group for patients treated with the products of the invention

(mouthwash and gel toothpaste) surprisingly a 96% reduction of dentinal sensitivity was observed, whereas in the 1^st control a 58% reduction of dentinal sensitivity and in the 2^nd a 27% reduction of dentinal sensitivity have been observed.

The general weight proportion for mouthwash is the following:

- Zinc chloride: 0,01-1%

- Potassium citrate: 0,5-10%

- Potassium fluoride: 0,05-2%

- Cetylpyridinium chloride: 0,01-2% - Xylitol: 1-20%

- Sodium benzoate: 0,1-0,5%

- polyvinylpyrrolidone: 0,1-5%

- Peg-40 Hydrogenated Castor oil: 0,1-2%

- Strong mint flavour 72103: 0,05-0,5% - Pink color eritrosine: g.b.

- Depurated water: q.b. to 100 ml

The general weight proportion for gel toothpaste is the following:

- Potassium fluoride 0,05-2% - Potassium chloride 1-8%

- Strontium chloride 6H₂O 0,5-10%

- Zinc citrate 0,01-1%

- Cetylpyridinium chloride 0,01-2%

- Sorbitol sol. 70% 10-35% - Xylitol 1-10%

- Colloidal silica 5-15%

- Tegobetaine L7 2-10%

- Sodium carboxymethylcellulose MV 0,5-1,5%

- Sodium benzoate 0,1-0,8% - Sodium saccharinate 0,03-0,3%

- Mint flavour 0,2-0,8%

- Colorants q.b.

- Depurated water q.b. to 100 ml

The general weight proportion for the solution is the following:

- Strontium chloride 0,5-10%

- Zinc chloride 0,1-3%

- Potassium acetate 0,5-10% - Cetylpyridinium chloride 0,01-2%

- Ethyl alcohol 96° 10-60%

- Depurated water: q.b. to 100 ml

The use of a cationic disinfectant added to a soluble zinc salt joined to the soluble potassium salt (substances with depolarizing capacity of the nervous fibres) , and/or with a soluble strontium salt (which obstructs the dentinal tubules with the production of a "crystal plug") , is not known in dental techniques, and instead can be valuably used according to the present invention.

In order to better show the composition according to the present invention, hereinafter some examples of composition are indicated.

The following are examples of some possible dental compositions, according to the present invention, for desensitization and disinfection of exposed dentin.

In the examples that follow the locution "q.b." is "quanto basta", i.e. indicates that the associated substance is used in a minimum amount, in particular set between 0.0001% and 0,001% by weight of the composition.

EXAMPLE 1 A composition fo desensitising and disinfecting exposed dentin used as a mouthwash based on cetylpyridinium chloride and zinc chloride along with potassium citrate and potassium fluoride, with the following weight proportions: - Zinc chloride 0,3%

- Potassium citrate 5%

- Potassium fluoride 0,6%

- Cetylpyridinium chloride 0,1% - Xylitol 5%

- Sodium benzoate 0,3%

- polyvinylpyrrolidone 0,5%

- Peg-40 Hydrogenated Castor oil 0,4%

- Strong mint flavour 72103 0,2% - Pink color eritrosine q.b.

- Depurated water q.b. to 100 ml

It is used in the following way for desensitising and disinfecting treatments:

Mouthwashing for about 1 minute with 15 ml of solution, (by using a small measuring vessel) . The application is repeated two times a day, twelve hours from each other, or according to the dentists advice. It is advisable after the mouthwash not to rinse the mouth with water and not to have food or drinks for at least thirty minutes.

EXAMPLE 2

A composition fro desensitising and disinfecting exposed dentin that uses a gel toothpaste based on cetylpyridinium chloride and zinc citrate integrally to fluoride and potassium chloride and strontium chloride, with the following weight proportions:

- Potassium fluoride 0,6%

- Potassium chloride 4.47%

- Strontium chloride 6H₂O 5% - Zinc citrate 0,2%

- Cetylpyridinium chloride 0,05%

- Sorbitol sol. 70% 33%

- Xylitol 1-10%

- Colloidal silica 11% - Tegobetaine Ll 7%

- Sodium carboxymethylcelluloseMV 1%

- Sodium benzoate 0,2%

- Sodium saccharinate 0,08% - Strong mint flavour 0,6%

- Colorants q.b.

- Depurated water q.b. to 100 ml

Such composition is used following way for desensitising and disinfecting treatments: It is used on a toothbrush with a desired amount of gel, then is gently brushing the dental jaws with movement from the above towards below for about two minutes.

Brushing has to be repeated on the regions that are sensitive to hot or cold sensations as well as to sweet and acidulous substances.

Then the mouth is repeatedly rinsed with water.

EXAMPLE 3

A composition for desensitising and disinfecting exposed dentin that uses a hydro-alcoholic solution based on cetylpyridinium chloride and zinc chloride along with potassium acetate and strontium chloride, with the following weight proportions:

- Strontium chloride 10%

- Zinc chloride 1% - Potassium acetate 6%

- Cetylpyridinium chloride 0,2%

- Ethyl alcohol 96° 40%

- Depurated water q.b. to 100 ml

Such composition is used in the following way for desensitising and disinfecting treatments:

Washing the surface of the dentin for removing the bacterial plaque;

Drying gently with an air jet for about 10 seconds, and if a severe hypersensitivity is present, drying simply with cotton flock; applying the liquid (direct method) : positioning the single-dose liquid near the region to treat, applying the solution, gently brushing a small brush or microsponge for about 10 seconds. applying the liquid (indirect method) : squeezing the content of the single-dose a recess of a disposable base, picking up then the solution with a small brush or microsponge and applying in the above described way. A relief from dentinal hypersensitivity is immediate. The above described procedure can be repeated if necessary. The composition can be applied to the dental regions where an erosion is present or a worn enamel region, or in those patients where a gingival part has to be raised to reach an amelo-cement junction. The composition can also be used for desensitising and disinfecting treatments of before filling deep dental recesses and replacing underlayers, or on prosthesis pillars, after scaling and root planning, or after whitening treatments.

Exemplary embodiments and/or changes can be made to the composition according to the present invention without departing from the extent of the invention same.

Claims

1. Dental composition for desensitization and disinfection of exposed dentin, for desensitising dental recesses treatment and replacing underlayers or for treatment of pillars at prosthesis application for treatment gingival withdrawal in consequence of uncovering amelo-cement junctions, after scaling and root planning treatments, and after whitening treatments, characterised in that it comprises: - a disinfectant, in particular, a cationic disinfectant selected from the group comprised of:

- benzalkonium chloride,

- benzethonium chloride,

- clorhexidine gluconate, - cetrimide,

- cetylpyridinium chloride,

- a combination thereof;

- at least one soluble salt selected from the group comprised of: - a soluble zinc salt,

- a soluble potassium salt,

- a soluble strontium salt,

- a combination thereof.

2. Dental composition, according to claim 1, wherein said soluble zinc salt is selected from the group comprised of:

- zinc chloride,

- zinc citrate,

- zinc sulphate, - zinc gluconate,

- zinc acetate,

- a combination thereof.

3. Dental composition, according to claim 1, characterised in that it is applied in one form selected from the group comprised of:

- Mouthwash;

- gel toothpaste; - solution.

4. Dental composition, according to claim 6, characterised in that said soluble zinc salt is selected from the group comprised of:

- zinc chloride, for application as mouthwash or as solution;

- zinc citrate, for application as gel toothpaste.

5. Dental composition, according to claim 1, wherein said soluble potassium salt is selected from the group comprised of: - potassium chloride,

- potassium fluoride,

- potassium citrate,

- potassium nitrate,

- potassium acetate, - potassium ascorbate,

- a combination thereof.

6. Dental composition, according to claim 3, characterised in that said soluble potassium salt is selected from the group comprised of: - potassium fluoride;

- potassium citrate;

- a combination thereof.

7. Dental composition, according to claim 3, characterised in that for said application as a solution said soluble potassium salt is the potassium acetate .

8. Dental composition, according to claim 1, wherein said soluble strontium salt is selected from the group comprised of:

- strontium chloride,

- strontium citrate, - strontium lactate,

- strontium gluconate,

- strontium acetate,

- a combination thereof.

9. Dental composition, according to claim 6, characterised in that it comprises, for an application as mouthwash, the following components, in the following weight amount:

- Zinc chloride: 0,01÷l% by weight,

- Potassium citrate: 0,5÷10% by weight, - Potassium fluoride: 0,05÷2%,

- Cetylpyridinium chloride: 0,01÷2%

- Xylitol: l÷20%,

- Sodium benzoate: 0,l÷0,5%

- polyvinylpyrrolidone: 0,l÷5% - Peg-40 Hydrogenated Castor Oil: 0,l÷2%

- Strong mint flavour 72103: 0,05÷0,5%

- Pink color eritrosine: q.b.

- Depurated water q.b. to 100 ml

10. Dental composition, according to claims 1 and 7, characterised in that it comprises, for an application as mouthwash, the following components in the following weight proportion:

- Potassium fluoride: 0,05÷2%

- Potassium chloride: 1÷8% - Strontium chloride 6H₂O: 0,5÷10%

- Zinc citrate: 0,01÷l%

- Cetylpyridinium: chloride 0,01÷2%

- Sorbitol sol.: 70% 10÷35% - Xylitol: l÷10%

- Colloidal silica: 5÷15%

- Tegobetaine L7 : 2÷10%

- Sodic Carboxymethylcellulose: MV 0,5÷l,5% - Sodium benzoate: 0,l÷0,8%

- Sodium saccharinate : 0,03÷0,3%

- mint Flavour: 0,2÷0,8%

- Colorants: q.b.

- Depurated water q.b. to 100 ml 11. Dental composition, according to claim 6, characterised in that it comprises, for an application as a solution, the following components in the following weight amount:

- Strontium chloride: 0,5÷10% - Zinc chloride: 0,l÷3%

- Potassium acetate: 0,5÷10%

- Cetylpyridinium chloride: 0,01÷2%

- Ethyl alcohol 96°: 10÷60%

- Depurated water: q.b. to 100 ml