JPS6239506A - Filler for lacuna after extraction of tooth - Google Patents

Abstract

PURPOSE:A filler for lacuna after extraction of tooth, to be expected to have alleviating and remedy promoting effect on pain by packing the filler to the lacuna of tooth extraction, having water insolubility, improved organism adaptability, improved shape retention in wetting, obtained by using sponge consisting of chitin, a material absorbable in organisms. CONSTITUTION:A filler for lacuna of tooth extraction consisting of chitin sponge (especially sponge having >=90% pore ratio in dry state of sponge), for example, obtained by dissolving water-insoluble chitin in a solvent to give chitin dope, blending the dope with a water-soluble high polymer substance, coagulating the blend and eluting and removing the water-soluble high polymer substance. The chitin sponge is naturally released from the wound face and absorbed with an enzyme when embedded in organism. It can be used not only in the lacuna of tooth extraction but also any tissue deficient part.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention aims to reduce pain by filling tooth extraction sockets,
The present invention relates to a tooth extraction socket filling made of chitin sponge that is useful in the field of dental and oral surgery, where it is expected to promote healing.

(Conventional technology) A tooth extraction wound is a wound that reaches the bone marrow, and bone cell regeneration is necessary for its healing.2 Because it is inside the oral cavity, it is constantly moistened with saliva.2 Food residue enters the wound. There are special circumstances such as the fact that it is easy to use, and that various oral bacteria are always present around it.

The healing mechanism of a tooth extraction wound is that the tissue defect caused by the tooth extraction is first filled with blood clots, and then granulation and capillary formation proceed toward the center of the socket along with proliferation of the gingival epithelium, while new growth occurs at the floor of the socket. Trabecular bone begins to form.

Through this process, the tooth extraction socket is filled with granulation around 10 days after tooth extraction, and tissue regeneration and proliferation is almost completed by around 5 weeks.

During this healing process, if a situation occurs in which a blood clot in the tooth extraction socket is removed, healing will be delayed. Therefore, research is being conducted on tooth extraction socket fillings for the purpose of protecting blood clots, preventing the intrusion of food residues, etc., and promoting healing.

For example, Oral Surgery, Volume 53, No. 44
Pages 1 to 449 (1982) describes a comparative study between polylactic acid and gelatin sponge.
Publication No. 1111 describes a method for manufacturing a tooth extraction socket filling for hemostasis, in which a thrombin solution is soaked into a sponge-like gelatin foam obtained by foaming gelatin and adding glyoxal to strengthen the denaturation. There is.

Also, the 11th Annual Meeting of the Biomaterials Society (1988)
April 25-28, 2005, held in Sun Diego, California, USA) Page 40 describes the results of histological research when a collagen sponge was filled into a tooth extraction socket in a dog.

As mentioned above, tooth extraction socket fillings made of various materials have been proposed, but the one currently in use is gelatin sponge reinforced with a protein denaturant.

Regarding sponges made of chitin, the Proceedings of the 1st International Chitin and Chitosan Conference (Proceedingo)
f the First International
nal Conference on Chitin
/Chitosan) Page 300, lines 16 to 24 describes a production method in which sodium sulfate is mixed with a chitin solution obtained in a process similar to the cellulose viscose method, and then the sodium sulfate is eluted.

(Problems to be Solved by the Invention) Gelatin sponges currently used as fillings for tooth extraction sockets have the drawback of low shape retention and strength when absorbing water. Since gelatin is water-soluble, it is easy to imagine that if it is used in a wet state such as in the oral cavity, it will dissolve.

Therefore, in order to maintain its strength in a wet state, gelatin is modified using protein denaturants such as formaldehyde, diacetyl, and glyoxal. The reality is that it cannot maintain its form and dissolves.

Therefore, a first object of the present invention is to provide a tooth extraction socket filling that is insoluble in water and has excellent biocompatibility. A second object of the present invention is to provide a tooth extraction socket filling material that exhibits excellent shape retention when wet.

(Means for Solving the Problems) As a result of extensive studies to achieve the above objectives, the present inventors have found that a sponge made of chitin, which is a bioabsorbable material, is suitable for filling tooth extraction sockets. The present invention was completed based on the discovery that

That is, the present invention is a tooth extraction socket filling characterized by being made of a water-insoluble chitin sponge.

In the present invention, water-insoluble chitin refers to crustaceans.

Poly(N-acetyl-D-glucosamine) or its derivatives, which are insoluble in water, obtained by treating the exoskeleton of insects with hydrochloric acid and hydrochloric acid to separate and purify the calcium content and protein. means. Examples of chitin derivatives include those in which acetylglucosamine groups are partially deacetylated, etherified products, and esterified products.

Carboxymethylated products, hydroxyethylated products.

Examples include 0-ethylated products, and specific examples include poly-(N
-Acetyl-6-0-(2-hydroxyethyl)-D-
glucosamine], poly[N-acetyl-6-0(ethyl)-D-glucosamine], and the like.

The chitin sponge in the present invention means a porous molded body made of chitin, and preferably has a porosity (
-X100: B, volume of pores contained in porous molded body of unit weight, A: total volume of porous molded body of unit weight) is 9
0% or more.

The shape and size thereof may be any suitable for the purpose of filling the tooth extraction socket, and examples thereof include a sheet shape, a rod shape, one cylinder, one sphere, or a rice grain shape. When the shape is sheet-like or cylindrical.

The size of the chitin sponge can be partially regulated because it can be cut to fit the volume of the tooth extraction socket, and if the shape is spherical or rice grain-like, multiple chitin sponges can be filled. Not though.

For example, in the case of a sheet, the thickness is 0.1 to 51 and 10 to
In the case of a 50 mm square 9 cylindrical shape, the diameter is 2 to 201 mm. length 5
~50 mm, and in the case of a spherical shape, a diameter of 2 to 20 am is preferably used.

To manufacture the chitin sponge according to the present invention.

For example, a water-soluble polymer substance may be added to a chitin dope obtained by dissolving chitin in a solvent, mixed, solidified, and then the water-soluble polymer substance may be eluted and removed.

The solvent may be a known chitin solvent, such as a mixture of tochloroacetic acid and a halogen hydrocarbon, lithium chloride and N-
A mixture of methylpyrrolidone or a mixture of lithium chloride and dimethylacetamide can be used.

The concentration of chitin dissolved in these solvents varies depending on the degree of polymerization of chitin used, but is preferably 0.05 to 50.
．． More preferably 0.1 to 25. Optimally 0.3-1
It is in the range of 0 w/w%.

What is the water-soluble polymer substance added to chitin dope?

Natural and synthetic polymer substances that are solid at room temperature and dissolve in water, such as polyvinyl alcohol, polyethylene glycol, polypropylene glycol,
Agar, soluble starch, etc. are preferably used, especially polyvinyl alcohol.

Agar is preferably used.

Polyvinyl alcohol has a degree of saponification of 60 mol% or more and is soluble in water at low or high temperatures.

Those with a degree of polymerization of 50 to 2,000 are preferably used, and those that can be dissolved in water at a high temperature of 3, for example, 60°C or higher,
Those having a saponification degree of 95 mol% or more are preferably used. Agar refers to a mucilage that exists as a cell membrane component in Amanita and other Amanita species, or a freeze-dehydrated and dried product of the mucilage, as well as agarose, agaropectin, and derivatives thereof separated from the mucilage. Polypropylene glycol and polyethylene glycol have a molecular weight of 10.
00 or more is preferably used. All of these water-soluble polymeric substances are preferably used in the form of a dispersed powder.

These water-soluble polymeric substances are mixed with the chitin dope, but generally water-soluble polymeric substances are not dissolved in the chitin dope, so they are allowed to exist in a monodispersed state. The mixing ratio is chitin dope/water-soluble polymer substance = 115 to 5 by weight.
A range of /1 is preferred. The coagulating liquid for chitin dope containing a water-soluble polymer substance is water, methanol, or ethanol.

Alcohols such as propatool, butanol, and ketones such as acetone are preferably used.

Next, the aqueous solution used to treat the solidified molded article means water or water containing a small amount of salts, etc. The treatment temperature and time are selected depending on the solubility of the water-soluble polymer substance in water, but generally For example, a method of treating at a high temperature of 80 to 125° C. for a long time of one hour or more is preferably used.

Chitin molded bodies treated with hot water have a soft spongy shape when wet, and can be used as is in the wet state. In the case of drying, ordinary drying methods such as air drying and vacuum drying may be used, but since these methods tend to reduce the degree of porosity, it is preferable to perform freeze drying.

According to the above method, the wet strength is preferably Ig
/nun'' or more, more preferably 3 g/+am'' or more, optimally 5 g/mm2 or more, and such a sponge can be suitably used as a tooth extraction socket filling material.

In the present invention, the term tooth extraction socket filling refers to something that is filled into a defective part of the U fabric caused by a tooth extraction, etc., and protects the injured area. The effects can be expected.

(Example) EXAMPLES The present invention will be explained in more detail with reference to Examples below.

Example 1 10g of chitin powder (manufactured by Shin Nihon Kagaku) was mixed with 8W/Wχ Li
Cj! After dissolving the mixture in 490 g of N-methylpyrrolidone containing it, it was filtered under pressure using a 1480 mesh stainless steel net to obtain a uniform and transparent chitin dope. The viscosity of the chitin dope measured using a B-type viscometer was 850 poise at 30°C. This chitin dope 100
g, polyvinyl alcohol powder [Poval tlF-1
70GS manufactured by Unitika Chemical; degree of polymerization 170. 50 g of saponification degree of 95 mol % or more] was added and sufficiently stirred and mixed to uniformly disperse the polyvinyl alcohol powder. This dispersion was pressurized and extruded into methanol through a circular nozzle with a diameter of 7 mm, solidified to a length of about 5 cm, then immersed in a sufficient amount of water and treated at 100°C for about 5 hours to form two cylindrical shapes. I got a chitin sponge. The obtained chitin sponge had a porosity of 98% and a wet strength of 13.8 g/+m''. After thoroughly washing the chitin sponge with distilled water, it was placed in a sterilization bag and heat-sealed.

The mixture was autoclaved at 120° C. for 20 minutes and then freeze-dried to obtain a sterile tooth extraction socket filling.

Example 2 5 g of chitin powder (Shin Nihon Kagaku type) was mixed with 8 W/-% Li.
After dissolving in 495 g of dimethylacetamide containing Clt, it was filtered under pressure using a 1480 mesh stainless steel net to obtain a uniform and transparent chitin dope.

60 g of purified agar powder was added to 100 g of this chitin dope, and the mixture was sufficiently stirred and mixed to be uniformly dispersed.

This dispersion was dropped into methanol from a nozzle with a diameter of 3III+1 and coagulated into two spheres, then immersed in a sufficient amount of water and heat treated at 120°C for 30 minutes, which was repeated 4 times while exchanging water each time. A spherical chitin sponge with a diameter of 4 to 5 mm was obtained. The porosity of the obtained chitin sponge was 96%.
The wet strength was 12.58/mm2. After thoroughly washing this chitin sponge with distilled water, it was freeze-dried, packed in a sterile bag, and sterilized with ethylene oxide gas.
A chitin sponge for filling a tooth extraction socket was obtained.

Example 3 10g of chitin powder (Shin Nihon Kagaku type) was mixed with 8W/W% Li
After dissolving in 490 g of dimethylacetamide containing C1, it was filtered under pressure using a 1480 mesh stainless steel net to obtain a uniform and transparent chitin dope. 50 g of polyvinyl alcohol powder (Poval UF-170GS) was added to 100 g of this chitin dope and thoroughly stirred and mixed to uniformly disperse the Poval powder. Approximately 3 g of this dispersion was gradually extruded into methanol through a nozzle with a diameter of 12 mm to coagulate it into a football shape. Next, soak it in enough water.

The heat treatment at 120° C. for 15 minutes was repeated 5 times while exchanging water each time to obtain a football-shaped chitin sponge with a short axis of about 8 mm and a long axis of about 20 mm. The obtained chitin sponge had a porosity of 98% and a wet strength of 14.3 g/I.
After washing this chitin sponge thoroughly with distilled water, it was placed in a sterilized bag, heat-sealed, and heated at 120°C.
Sterilize with high pressure steam for 20 minutes.

It was then freeze-dried to obtain a sterile tooth extraction socket filling.

Reference Example 1 An animal experiment was conducted using the chitin sponge for tooth extraction socket filling of the present invention. A mongrel dog weighing approximately 8 kg was given general anesthesia.
Four molar teeth were extracted, and the chitin sponge obtained in Example 3 and the gelatin sponge denatured and strengthened with formaldehyde were separately filled into two extraction sockets.

After the surgery, the dog was given a liquid diet to protect the tooth extraction site as much as possible, and when the tooth extraction site was observed, it was found that after 24 hours, the gelatin sponge had already almost dissolved due to blood and saliva and was used to protect the tooth extraction socket. Although it didn't help.

The chitin sponge retained its original shape. Five days later, the chitin sponge was pushed out of the tooth extraction socket.

When it was removed, the wound surface was found to be healing nicely.

The above results show that chitin sponges are effective in protecting tooth extraction sockets and promoting healing.

The wet strength of gelatin sponge was measured and was 1.8g.
/mm2, and lost shape retention due to moisture, making it extremely difficult to handle.

(Effect of the invention) The tooth extraction socket filling of the present invention is a sponge made of chitin that is insoluble in water, and has excellent shape retention and strength when wet, and protects the tooth extraction socket without being dissolved by blood or saliva. can do. In addition, chitin sponge has the very interesting property of naturally peeling off from the wound surface as the wound heals.
When implanted in a living body, chitin sponges can be broken down and absorbed by enzymes, and from this point of view, chitin sponges can be used not only for tooth extraction sockets, but also as fillings for all kinds of tissue defects. Furthermore, chitin sponges can be sterilized using high-pressure steam, so there is no need to worry about sterilizing agent remaining.

It is expected to have a wide range of applications in the medical field.

Claims (2)

[Claims] (1) A tooth extraction socket filling characterized by being made of a water-insoluble chitin sponge. (2) The tooth extraction socket filling according to claim 1, wherein the sponge has a porosity of 90% or more in a dry state.