FR2617398A1 - THIN SEALING AND THIN SEALING FOR DENTAL USE - Google Patents

Abstract

A fine filling process for dental use is characterized in that a powder, an aggregate, a solution (suspension) or a paste containing hydroxyapatite, with or without an adjuvant, is rubbed on the surface of the teeth. A fine seal which is used in this process is characterized in that a calcification promoter protein is incorporated in the hydroxyapatite or in the tetracalcium phosphate.

Description

- i -

  Fine filling process and fine filling for dental use.

  The present invention relates to a method of fine dental filling to protect or restore cavities and cracks or tiny lesions on the decalcified surface of the enamel by rubbing a powder, granules, solution (suspension) or paste comprising l hydroxyapatite or tetracalcium phosphate, with or without adjuvants, and then optionally covering the site with a polymer or fluoride, and a fine dental filling used for such filling, based on hydroxyapatite or tetracalcium phosphate which may or may not contain a promoter protein

  calcification or a coating agent.

  When a plaque of tartar deposits on the surface of the enamel, the acids produced inside by microorganisms gradually pickle up the enamel and produce tiny lesions there. (This process is called decalcification below. It is recognized that

  decalcified lesions are recalcified and restored by saliva).

  When the enamel is decalcified, the plaque quickly redeposit on the decalcified lesions, even if it is removed by brushing, which means that the enamel is subjected to repeated decalcification due to acids. Thus, decalcification progresses by repetitive appearance of a decalcification, elimination of the plaque, redepSt of the plaque and decalcification, ending in caries which are visually detectable. In conventional dental treatment, the hard tissue of a

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  - 2 - visually detectable decayed tooth, including its periphery, is resected, and various plastics, cements or metals are

  applied in the resected site as a replacement for the lesion.

  However, this process requires a high degree of technical skill. In addition, if the sealing is incomplete, the decay process continues from the periphery of the sealing material. In recent years, a sealing material process has been developed, whereby the cavities and cracks which are most susceptible to caries, or decalcified lesions caused by commenting decalcification, are closed with a sealing material which is a polyacrylate, polyurethane or other polymer to isolate them from the oral environment, thus preventing the appearance of cavities. According to the sealing material process, the cavities and cracks in decalcified lesions, which may have been treated with acids depending on the sealing agents used, are closed by them to prevent the plate from appearing and acting on the site. , thus avoiding cavities. However, in this process, insufficient or excessive acid treatment or saliva deposition on the acid treated surfaces can cause a decline in the bond strength between the sealants and the cavities and cracks or decalcified lesions. The sealing materials, if they are applied in too large a quantity to constitute the fillings,

  can also break due to chewing and bites.

  Thus, there is the possibility with the sealing material process that these sealing materials are dislodged according to their quality and the technical skill of the operator, and that the effectiveness of the process varies with the skill operator clinic. With the sealing material process, a difficulty arises in covering tiny decalcified lesions with sealing agents and in recalcifying decalcified and covered lesions because they do not come into contact with saliva . To increase cavity resistance by reinforcing or protecting dentin, fluoride ions are applied to the surface of the teeth, or added to the water we drink and liquid foods. However, a special technique must be used for handling the fluoride compounds. As a method of depSt of an enamel composition on the surface of the teeth, Japanese patent application open to public inspection (KOKAY) No 47-1567 proposes to form brassid on the surface of the teeth using as an agent a gelatinous substance prepared in such a way that its toxicity and its final pH are not harmful to the mouth, and to convert the brasside into hydroxyapatite. However, this process requires not only an extended period of time for the conversion of the brasside to hydroxyapatite, but also the use of the gelatinous substance to facilitate the connection between the brasside and the surface.

teeth.

  The application of fluoride exists as a method for strengthening the surface of the teeth, and the sealing material method or the method described in Japanese patent application open to public inspection (KOKAY) No 47-1567 are available. as methods of protecting cavities and cracks and restoring decalcified lesions. However, these procedures require clinical skill

  special and involve the difficulties mentioned above.

  The object of the present invention is to provide a method of - fine dental filling which can be easily implemented for a short period of time and which does not require any special clinical skill, with a view to safe protection and restoration of cavities

  and decalcified cracks and lesions.

  According to the present invention, the above object is achieved by means of a fine sealing process for dental use, characterized in that a powder, a granulate, a solution (suspension) or a paste comprising hydroxy- apatite, with or without adjuvant, is rubbed on the surface

teeth.

  Another object of the present invention is to provide a seal

  fine dental used in the process of the invention.

  According to the present invention, the above object is achieved by means of a fine filling for dental use, characterized in that a calcification-promoting protein is incorporated in the hydroxyapatite or in the

tetracalcium phosphate.

  According to the method of the invention, finely divided hydroxyapatite-4 suspensions containing radioactive calcium and finely divided brassid were prepared and added to an artificial tooth prepared by sintering hydroxyapatite for immersion . The upper side of the artificial tooth was abraded by rotation using a rubber membrane. After a certain period of time has elapsed, the artificial tooth has been removed and, soon after, a large quantity of distilled water has been added dropwise to it, for washing, followed by the addition of a PSC cocktail. The radioactivity of the artificial tooth was measured by means of a liquid scintillation counter, by means of which the amounts of hydroxyapatite and brassid linked to the artificial tooth were determined. It was thus found that the amounts retained by adhesion depended on the pH of the suspensions, but that the amount of hydroxyapatite retained by adhesion was much greater than the amount of brasside retained by adhesion in any pH range. It has also been confirmed by nominal experimentation that tetracalcium phosphate (Ca4 (P04) 20) obtained by sintering an equimolar mixture of tricalcium phosphate and calcium oxide at 1500 C easily binds to the tooth, thus that this was the case with hydroxyapatite, and that the bound tetracalcium phosphate changed to hydroxyapatite immediately after contact with saliva to determine the recalcification of the tooth. The fact that these substances promote the recalcification of the teeth and protects the teeth from decay has been confirmed by the following experiment. A third molar extracted and subjected to artificial caries was immersed with stirring in a paste of hydroxyapatite or tetracalcium phosphate at 37 C for 5 hours, and the surface enamel layer of the tooth was then observed using a polarization microscope. The result is that decalcified lesions were found over a wide range of the control group; while the group treated with hydroxyapatite or tetracalcium phosphate was recalcified on the surface layer, the decalcified lesions being thinner than those of the control group. This indicates that hydroxyapatite or tetracalcium phosphate is effectively bound to the surfaces of the teeth to cover or heal decalcified lesions and causes recalcification of the enamel on contact with saliva. Thus, the present invention provides a method of protecting cavities and cracks and restoring decalcified lesions by taking advantage of the properties of hydroxyapatite and tetracalcium phosphate which selectively bind to decalcified lesions on the surface of the teeth. The invention also provides a

  fine sealing used in the process.

  It is desirable that hydroxyapatite or tetracalcium phosphate be used in as finely divided a form as possible. In general, they are finely divided down to around 0.02 microns for their use. The finely divided tetracalcium hydroxyapatite or phosphate is formulated as a solution (suspension) or a paste of 5 to 95%, with or without water or a coating agent. These materials are rubbed on a tooth from which the plate has been removed, with the end of a finger, a brush, a rod, a cloth or the like for at least 1 minute and preferably for 3 minutes. During this operation, hydroxyapatite or tetracalcium phosphate divides even more finely and binds to cavities and cracks or to tiny decalcified surface lesions of the enamel. Since hydroxyapatite or tetracalcium phosphate is the most highly nutritious calcium substance, the patient can swallow the excess calcium salts that remain in the mouth. Preferably, rinsing the mouth with water should be done lightly and limited to about once. Recalcification of hydroxyapatite or tetracalcium phosphate bound to the surface of

  the tooth is facilitated due to the presence of saliva.

  It is preferable to use powder, granules, solution (suspension) or pastes of hydroxyapatite or tetracaleium phosphate which are prepared by mixing with an appropriate quantity of an adjuvant chosen from a phosphate such as tricalcium phosphate and monohydrogen calcium phosphate; a fluoride such as sodium fluoride, sodium monofluorophosphate, hapatite fluoride and stannous fluoride; a calcification promoter protein such as phosvitin, casein and a histidine rich protein (these proteins have been found to act as catalysts and accelerators for the calcification of hydroxyhapatite); or a mixture of these substances because the adjuvant promotes the recalcification of decalcified lesions and strengthens the covered layer. The quantities of these adjuvants to be added can be chosen arbitrarily according to their types. However, in general, the phosphate should be used in amounts of about 1 to 60%, the fluoride in the amount of 1000 ppm at most and the calcification promoter protein in the amount of about 1% at most, based on hydroxyapatite and / or tetracalcium phosphate. The coating agent used for the paste can be vinyl acetate, glue, polyacrylic acid, gum arabic or the like. v Thus, hydroxyapatite or tetracalcium phosphate is bound to the surface of the teeth simply by rubbing on them the paste containing hydroxyapatite or tetracalcium phosphate, and is recalcified by saliva. The presence of adjuvants serves to improve this recalcification and the strength of the teeth. The process according to the present invention can be easily implemented without resorting to acid treatments, humidity monitoring and polymerization treatments applied when it comes to the process

  with conventional sealing material, and without special clinical skill.

  In addition, hydroxyapatite, tetracalcium phosphate, adjuvants and coating agents have no opposite influence on the living body. In addition, hydroxyapatite is a compound that is the same as that found in teeth, while tetracalcium phosphate is easily converted to hydroxyapatite by saliva. Thus, as these substances do not constitute a foreign substance with regard to the teeth, unlike sealants of the prior art, and as they firmly bind to cavities and cracks and decalcified lesions without the risk of being dislodged, you get completely restored teeth. In addition, plasticizers, solvents, thinners, etc. can be added. to the paste comprising hydroxyapatite or tetracalcium phosphate and the calcification promoter protein and the coating agent so that the resulting system has a viscosity capable of covering the surface of the teeth and determining a film of uniform thickness. The application of such a system to the surface of the teeth is advantageous since the surface of the teeth can be reinforced and

  improved in appearance.

  It is also possible to strengthen the teeth by rubbing powders, granules, solutions (suspensions) or pastes containing hydroxyapatite or tetracalcium phosphate on their surface, followed by the application of fluoride. It is particularly preferable to rub the paste containing hydroxyapatite or tetracalcium phosphate and the calcification promoter protein, and then apply the fluoride over it in the conventional manner. It is also possible to rub the paste on the surface of the teeth and then cover and protect the site with a polymer. The polymers used for this purpose can be chosen from the polymers used up to now as sealing materials such as Epoxylight 9070, Nuva-Seal, Epoxylight 9075, Enamelight, Delton, White Sealant , P&F Sealant, Fissureseal, Teethmata S, Prisma Shield, Helioseal, or polymers used with sustained release preparations for pharmaceuticals such as shellac, polyvinyl acetate, butyral de polyvinyl, ethyl cellulose, cellulose acetate phthalate, polyvinyl alcohol phthalate, styrene acrylic acid copolymers, methyl acrylate-methacrylic acid copolymers, vinyl pyridine or alkyl pyridine copolymers with other vinyl monomers, cellulose acetate diethylaminoacetate, polyvinyl acetate diethylaminoacetate, polyvinyl aminoacetal, polyvinyl alcohol derivatives, aminocellulose derivatives, methacrylate copolymers methyl dimethylaminoethyl methacrylate and copolymers of vinyl pyridine or alkyl vinyl pyridine with acrylic acid. These polymers can be applied on site in a conventional manner. Hydroxyapatite or tetracalcium phosphate and the adjuvants that are rubbed in place by this coating are retained on the surface of the teeth for an extended period without being dislodged, and are sufficiently recalcified. Hydroxyapatite or tetracalcium phosphate and the paste containing the calcification promoter protein can be added, for example, to pharmaceutically active components such as an abrasive chosen from calcium carbonate, calcium hydrogen phosphate, aluminum hydroxide, silicic anhydride and other abrasives; a humectant such as glycerin, sorbitol and propylene glycol; a foaming agent such as sodium lauryl sulfate and soap powders; a binder such as carboxymethylcellulose and carrageenan; a perfume; a sweetener; a preservative; and a bad breath eliminator and a tooth extender. Using these systems in a manner similar to toothpaste is a workable process that allows plaque to be removed during friction of the hydroxyapatite or tetracalcium phosphate and the calcification promoter protein

on the surface of the teeth.

  Thus, a method is proposed to remedy the decalcification which constitutes the onset state of a cavity, this method using the properties of hydroxyapatite containing an adjuvant or free, which is the same compound as that of teeth , or tetracalcium phosphate which selectively and firmly binds to decalcified cavities and cracks or lesions, and in which hydroxyapatite or tetracalcium phosphate is rubbed on the surface of the teeth with or without an adjuvant to protect the surface of the teeth or cover the decalcified lesions in order to exploit the spontaneous healing capacity obtained by recalcification with saliva. It is

  also proposed sealing used in the process described above.

  The process and the filling of tooth reinforcement and means for preventing cavities which were not previously available require no special technical skill and have considerable technical advantages over fluoride coating processes and

  conventional sealing material processes.

  - Other characteristics and advantages of the present invention

  will appear on reading the description which follows.

  The present invention will now be described in detail in detail.

  referring to a number of examples.

Example 1

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  -9- Fifty (50) g of finely divided hydroxyapatite was treated to microns or less, to which 50 ml of water was added, in a vertical mill to obtain a paste. Shortly after, the teeth were brushed with toothpaste, followed by rinsing, the paste was carefully rubbed on the surface of the teeth with the tip of the fingers, for 3 minutes. Then the excess dough was removed from the inside of the mouth by a light rinse. This procedure was

  performed each time the teeth were brushed.

Example 2

  Fifty (50) g of finely divided hydroxyapatite was treated to microns or less, to which 50 ml of an aqueous solution containing 500 ppm of sodium chloride was added, in a vertical mill to obtain a paste. The ordinary brushing being finished, the teeth were brushed for 3 minutes with a toothbrush to which the paste had been applied. This was followed by a light rinse. This brushing has always been carried out after ordinary brushing.

Example 3

  Fifty (50) g of finely divided hydroxyapatite was treated at 10 microns or less, to which 50 ml of water containing 0.01 mg was added

  casein, in a vertical grinder to obtain a paste.

  The ordinary brushing being finished, the paste was carefully rubbed

  on the surface of the teeth by the tip of the finger for 3 minutes.

  This procedure was used whenever the teeth were

brushed.

Example 4

  In a similar manner to Example 3, the paste was rubbed on the surface of the teeth and the excess paste in the mouth was removed by rinsing. After drying, the NuvaSeal liquid was finely applied to the surface of the teeth and hardened by means of a lamp.

  to make it waterproof.

Example 5

  In a similar manner to that described in Example 3, the paste was rubbed onto the surface of the teeth and the excess paste in the mouth was removed by rinsing. Diamine silver fluoride was applied

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in a classic way.

Example 6

  Four (4) g of finely divided hydroxyapatite up to 10 microns or less and 0.04 mg of casein were added, and sufficiently mixed with 100 ml of vinyl acetate to prepare a homogeneous dispersion. After ordinary brushing, the teeth were dried with hot air and then coated uniformly with the dispersion by means of a brush. Drying gave a white, shiny and fine coating

on the surface of the teeth.

  Example 7 Fifty (50) g of finely divided tetracalcium phosphate up to 10 microns or less, to which 50 ml of water was added, was treated in a vertical mill to obtain a paste. Shortly after, the teeth were brushed with toothpaste, followed by a thorough rinse, the paste was carefully rubbed on the surface of the teeth with the tip of the finger for 3 minutes. Then the excess dough was removed from the mouth by a light rinse. This procedure

  was performed each time the teeth were brushed.

Example 8

  Fifty (50) g of finely divided tetracalcium phosphate up to 10 microns or less, to which 50 ml of an aqueous solution countering 500 ppm of sodium fluoride was added, in a vertical mill to obtain a dough. At the end of ordinary brushing, the teeth were brushed for 3 minutes with a toothbrush on which the paste had been applied. This was followed by a light rinse. This brushing has always been carried out after ordinary brushing.

Example 9

  Fifty (50) g of finely divided tetracalcium phosphate up to 10 microns or less, to which 50 ml of water containing 0.01 mg of casein was added, in a vertical mill to obtain a paste. At the end of the ordinary brushing, the paste was carefully rubbed against the surface of the teeth with the tip of the finger for 3 minutes. This procedure was performed whenever

teeth were brushed.

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Example 10

  In a similar manner to that described in Example 3, the paste was rubbed on the surface of the teeth and the excess paste in the mouth was then rinsed off. Following drying, a NuvaSeal liquid was finely applied to the surface of the teeth and was

  hardened by an ultraviolet lamp in order to obtain sealing.

Example 11

  Four (4) g finely divided tetracalcium phosphate to microns or less and 0.04 mg of casein were added to each other and sufficiently mixed with 100 ml of vinyl acetate to prepare a homogeneous dispersion . After ordinary brushing, the teeth were dried with hot air and then coated uniformly with the dispersion using a brush. Drying provided a coating

  shiny, white and fine on the surface of the teeth.

Reference examples.

  To measure the amount of hydroxyapatite bound to the surface of a tooth, the following in vitro tests were carried out:

  (A) Synthesis of hydroxyapatite and brasside.

  One hundred (100) ml of a 0.1 M CaCl2 solution (containing 45CaCl2) made by Aeroham) was slowly added dropwise to 100-200 mm of 0.1M Na2HPO4 solutions to synthesize hydroxyapatite in the conventional manner. In addition, a 0.1M CaCl 2 solution at 100 to 200 ml was added in a similar fashion and dropwise to a 0.01 M NaH2 PO solution to

2 2 4

  prepare the brew. After preparation, the hydroxyapatite and the brasside were stored in the corresponding solutions of 0.1 M Na2HPO4 and 0.1 M NaH2PO4. For their use, they were then resuspended in buffers. phosphoric acid to

0.01 M of the corresponding pH.

  (B) Preparation of the artificial tooth.

  The hydroxyapatite was molded into a disc with a diameter of 1 cm and a thickness of 3 mm, and the disc was sintered to form a tablet of hydroxyapatite, the surface of which was abraded. regularly with No. 600 sandpaper. Then the tablet was brushed to carefully remove the powders, then

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  that distilled water was flowing over it, creating an artificial tooth. (C) A 12 cm long, 4 cm wide and 10 mm deep acrylic tank was fitted at the bottom with five blind holes for fixing hydroxyapatite shelves, each of which had a diameter of 1 cm and a thickness of 2 mm. Five tablets of hydroxyapatite were fixed in the blind holes and 5 ml of a suspension of hydroxyapatite or brasside was added to immerse the tablets. The upper surface of the shelves was abraded at the speed of 1 rpm. When a certain time has elapsed, the tablets were removed and soon after washed by adding dropwise a large amount of distilled water. Two (2) ml of a PSC cocktail was added to the tablets to measure the

  radioactivity of tablets with a liquid scintillation counter.

  (D) Results The results of the tests carried out with a pH of 9.0 and 5.0, which are stable pH for hydroxyapatite and brasside respectively, were that the amount of hydroxyapatite bound to the tablets was 5 micrograms after 5 minutes. Then, this amount gradually increased to 164 mierograms after 40 minutes, calculated from 5.4 x 105 CPM / mg and 8.9 x 105 CPM / mg which

  constitute respectively the specific radioactivities of hydroxy-

  apatite and brasside used. This amount of binding was greater than that of the brasside by a factor of 20 after 5 minutes and

109 after 40 minutes.

  The result of the tests carried out at pHli of 5.5, 6.8, 7.4 and 8.5, the friction having been carried out at the same pH, made it possible to note that the resistance of the binding of the hydroxyapatite on the shelves

was significantly improved.

  These results are reported below:

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  Condition of pH A / B After 10 min. After 60 min. A: pH 9, B: pH 5 32.8201.7 A, B ph 8.5 2.0 5.4 pH 7.4 6.6 5.4 pH 6.8 2.3 6.4 "pH 5 , 5 11.2 8.4 A: hydroxyapatite; B: brasside The figures represent the quantities in weight ratios of

  hydroxyapatite and tetracalcium phosphate bound to the tablets.

  These results show that hydroxyapatite selectively binds

on the surface of the teeth.

  Thus, according to the method of the present invention, a fine filling containing hydroxyapatite, that is to say a biosubstance binding firmly to cavities and cracks or tiny lesions decalcified on the surface of teeth, or phosphate of tetracalcium with or without additives, is rubbed on the surface of the teeth, this being possibly followed by the coating of a site thus rubbed with a polymer to cover the cavities and cracks or lesions decalcified with fine sealing, so that a spontaneous healing capacity is favored by the action of saliva or adjuvants for the restoration of decalcified lesions. This process provides excellent results simply by rubbing the fine filling on the surface of the teeth. Since hydroxyapatite or tetracalcium phosphate is the most ideal calcium-based substance, it is harmless if swallowed and the seal can be used without fear of harmful effects. No special clinical skill is necessary to implement this process. Consequently, the process of the invention is advantageous in that it can be

  easily implemented by the patient himself.

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  The present method by which caries is eliminated at its early stage by using or by increasing the spontaneous curative capacity obtained by recalcification by saliva constitutes the most effective means for avoiding caries, and which is not found in prior art. The present invention may also be

  applied to the treatment of paraesthesia and alveolar pyorrhea.

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Claims (9)

  1. A fine sealing process for dental use, characterized in that a powder, an aggregate, a solution (suspension) or a paste comprising hydroxyapatite with or without an adjuvant is rubbed on the surface of a tooth . 2. Method according to claim 1, characterized in that said   adjuvant is fluoride or calcium phosphate.   3. Method according to claim 1, characterized in that said   adjuvant is a calcification promoter protein.   4. Fine sealing process for dental use, characterized in that a powder, an aggregate, a solution (suspension) or a paste containing tetracalcium phosphate with or without an adjuvant is rubbed on the surface of a tooth.   5. Method according to claim 4, characterized in that said   adjuvant is a calcification promoter protein.   6. A fine filling process for dental use, characterized in that a powder, an aggregate, a solution (suspension) or a paste containing hydroxyapatite with or without an adjuvant is rubbed on the surface of a tooth , and said rubbed site is then covered by a polymer or a fluoride.   7. A fine sealing process for dental use, characterized in that a powder, an aggregate, a solution (suspension) or a paste containing tetracalcium phosphate with or without an adjuvant is rubbed on the surface of a tooth, and said rubbed site is then   covered by a polymer or fluoride.   8. Sealing for dental use, characterized in that a calcification-promoting protein is incorporated into   hydroxyapatite or in tetracalcium phosphate.   9. Fine filling for dental use, characterized in that a calcification-promoting protein and a coating agent are   incorporated in hydroxyapatite or in tetracalcium phosphate.