JP2005281260A - Dental restorative material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a dental restorative material, a dental adhesive, a dental filler and a dental cement composition excellent in adhesive strength with dentine. <P>SOLUTION: The dental restorative material comprises a polymer containing a unit expressed by the formula (I) in side chains; -CONHR<SP>1</SP>COOX or -NHCOR<SP>2</SP>COOX (I) [wherein R<SP>1</SP>and R<SP>2</SP>express each a 1-4C carbon chain; X expresses H, NH<SB>4</SB>or 1/mM (M expresses a metal atom selected from alkali metals, alkaline earth metals, transition metals, Zn and Cd; (m) expresses the valence of the metal)]. The dental adhesive comprises the organic polymer, a polymerizable monomer and a curing agent. The dental filler comprises the organic polymer, the polymerizable monomer, a filler and the curing agent. The dental cement composition comprises the organic polymer and inorganic powder containing a polyvalent metal compound or compounds. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a dental restoration material.

Conventionally, in a dental treatment, a treatment using a restoration is performed, but various techniques have been used to ensure the bonding between the tooth and the restoration.
The restoration material was initially used as a cemented material such as silicate cement, and after that, the material has progressed to filling and restoration with acrylic resin and composite resin, but the restoration and the tooth are sufficiently bonded. Rather, it has caused secondary caries and prosthetic dropouts caused by the lack of adhesion between the restoration and the tooth.

Recently, glass ionomer cements utilizing the fact that polycarboxylic acids react with glass such as fluoroaluminosilicate glass powder and harden have been developed and widely used as dental cements.
This glass ionomer cement has many features such as biocompatibility, adhesion to teeth, and durability in the oral cavity, as well as a cured product that is translucent and excellent in aesthetics. Inlays, crowns, etc., filling in carious cavities, lining, preventive filling of pits, etc. (see, for example, Patent Document 1).

On the other hand, from the 1970s to the 1980s, the idea of adhering a tooth and a restoration was introduced, and various adhesion methods were developed for the purpose of adhering the restoration to both enamel and dentin.
Among them, the most reliable method adopted in the dental industry was a method using an adhesive functional monomer. That is,
1) Impregnating a tooth with a low molecular functional monomer having a functional group that binds to Ca in the tooth.
2) A tough resin layer is formed by polymerization in combination with a monomer copolymerizable with the low molecular functional monomer.
3) The resin layer serves as a protective layer at the boundary between the living tissue and the artificial object, and blocks external stimuli, and at the same time plays an effective role for integration by adhesion with the artificial object as a restoration.
With the improvement of etching technology and primer technology, it still contributes greatly to dentistry as a basic technology in dental treatment today.

The most effective low molecular weight functional monomers to date are 1) carboxylic acid-based monomers having a carboxyl group at the end represented by 4-methacryloyloxyethyl trimellitic anhydride (4-META) and the like Anhydrides such as 4-methacryloyloxyethyl trimellitic acid (4-MET), 4-acryloyloxyethyl trimellitic anhydride (4-AETA), ω, ω-dicarboxydodecyl methacrylate (MAC-10) (For example, refer to Patent Document 2).
2) Another effective monomer is a phosphate ester-based monomer having a phosphate group represented by 2-methacryloyloxyethyl phosphate (2-MEP) at the terminal or in the molecule. There are Phenyl-P, MDP, and the like (for example, see Patent Document 3).

Japanese Patent Laid-Open No. 9-255515 Japanese Patent Publication No.58-17513 Japanese Patent Publication No. 55-30768

However, the biggest drawback of the glass ionomer cement as described in Patent Document 1 is that when it comes into contact with moisture such as saliva in the early stage of curing immediately after kneading, the curing reaction is inhibited and finally the physical properties deteriorate. That is, the glass ionomer cement is a material in which a polycarboxylic acid and a polyvalent metal contained in an inorganic compound such as fluoroaluminosilicate glass undergo a curing reaction by a chelate formation reaction in the presence of water. While water for releasing ions is essential, water present in the curing system or cured product also has a negative effect on increasing the curing rate and initial strength.
Therefore, there is a problem that initial adhesiveness with a tooth is low and other physical properties are further lowered with time.

In addition, the dental cement described in Patent Document 1 and the dental cement and the dental adhesive using the functional monomer described in Patent Documents 2 and 3 are actually used in the treatment of teeth. These newly developed dental cements and dental adhesives are used for adhesion to prosthetics such as quality, but the adhesive strength is still insufficient, the adhesive strength is insufficient, or the adhesive layer Due to mechanical deterioration, troubles due to secondary caries, dropout of prosthesis, and frequent retreatment are frequently occurring.
In addition, it is carried out by filling a polymerizable monomer or the like containing a filler into a dental dent or the like for polymerization, but from the viewpoint of preventing the filler from falling off, the dental filler can also be used as a dental filler. Those having excellent adhesive properties are required. However, the adhesiveness of the dental filler to the tooth is still not sufficient.

In the secondary caries, particularly dentin caries, it is assumed that the adhesive is not sufficiently diffused onto the dentin surface. That is, if the diffusion of the adhesive to the dentin surface is not sufficient, a gap is formed between the resin-impregnated layer formed after polymerization and the healthy dentin, and in this part, the adhesive layer ( It is considered that the resin layer on the surface of the dentin is degraded over time due to hydrolysis.
One of the causes of this phenomenon is that the bond between the polycarboxylic acid and adhesive monomer used and the tooth, that is, calcium in the tooth, is mainly due to weak bond strength based on ionic reaction. Can be given.
In addition, when these adhesive monomers are applied to dentin, if the monomers penetrate into the spongy dentin, a resin-impregnated layer formed by covering the surface of the dentin accordingly. Therefore, it is considered that the protective layer is insufficiently formed.

  The present invention provides a dental restorative material, such as a dental adhesive, a dental filler and a dental cement composition, which has improved the drawbacks of such conventional dental restorative materials and has excellent adhesive strength with the tooth structure. The purpose is to do.

As a result of studies to solve such problems of conventional dental adhesives, an organic polymer in which a carboxy group and a group represented by -CONH- are present in the vicinity is strongly bonded to an object containing a metal such as calcium. The present invention has been reached from the idea of applying this organic polymer to dental adhesives, dental fillers and dental cement compositions as dental restorative materials.
This strong bond is because the oxygen atom of the carboxy group and the hydrogen atom in the group represented by -CONH- form an intramolecular hydrogen bond, so that the acid strength of the carboxy group increases and coordinates with calcium in the tooth. It is presumed to be expressed by forming a complex.

That is, the dental restorative material of the present invention is characterized by containing a polymer containing a unit represented by the following formula (I) in the side chain.
-CONHR ¹ COOX or -NHCOR ² COOX (I)
[In Formula (I), R ¹ and R ² represent a carbon chain having 1 to 4 carbon atoms, X is a hydrogen atom, —NH ₄ , or 1 / mM (M is an alkali metal, an alkaline earth metal, a transition metal) Represents a metal atom selected from Zn, Cd, and m represents the valence of the metal.]

In the present invention, the (substituted) carboxy group refers to a carboxy group and / or a carboxy group in which a hydrogen atom is substituted with a metal atom selected from —NH ₄ , alkali metal, alkaline earth metal, transition metal, Zn, and Cd. Say.

  In the present invention, the dental restorative material means one or more selected from a dental cement composition, a dental adhesive, and a dental filler.

  Moreover, the dental cement composition of the present invention is characterized by containing the organic polymer and an inorganic powder containing a polyvalent metal compound.

  The dental adhesive of the present invention is characterized by containing the organic polymer, a polymerizable monomer, and a curing agent.

  The dental filler of the present invention is characterized by containing the organic polymer, polymerizable monomer, filler and hardener.

Since the dental restorative material of the present invention exhibits an unprecedented high adhesive strength with respect to the tooth, the protective layer formed on the tooth surface or the tooth recess using these materials is changed over time. It is less likely to cause a decrease in adhesion due to hydrolysis, and exhibits an extremely excellent effect on dental treatment.
That is, according to the present invention, compared to a copolymer of acrylic acid and an acryloyloxy group-containing monomer or a conventional glass ionomer cement using polyacrylic acid, adhesion to teeth, curing rate, initial strength It is possible to provide a dental cement composition which is excellent in quality and does not deteriorate over time.
Further, even when the restoration material of the present invention is used as a dental adhesive or a dental filler, it is possible to provide a dental adhesive or a dental filler that exhibits an unprecedented high adhesive strength. .

The organic polymer used for the dental restorative material of the present invention is a polymer containing a unit represented by the above formula (I) in the side chain.
Here, including the unit represented by the formula (I) in the side chain means that the side chain consists of the unit or that the unit constitutes a part of the side chain.
The carbon chain having 1 to 4 carbon atoms represented by R ¹ and R ² in the above formula (I) may be a methylene group or a polymethylene chain, or a carbon chain containing an unsaturated bond having 2 to 4 carbon atoms. Further, the carbon chain may constitute a part of an aromatic ring or an aliphatic ring. Examples of aromatic rings include benzene rings, and examples of aliphatic rings include cyclohexane rings.
Moreover, the C1-C4 carbon chain may have a substituent.

The main chain of the polymer containing the unit represented by the formula (I) in the side chain is not particularly limited, but a main chain obtained by polymerization of a vinyl group, a polyester main chain, a polyamide main chain, etc. Can be mentioned. The side chain containing the unit represented by the above formula (I) preferably occupies 20 mol% or more, more preferably 40 mol% or more, further preferably 60 mol% or more of the repeating unit constituting the main chain, The repeating unit may have a side chain containing a unit represented by the above formula (I).
When all the repeating units of the organic polymer are not (100%) polymers having a side chain containing the unit represented by the above formula (I), other repeating units may be units having no side chain. It may be a unit having a side chain that does not contain the unit represented by the above formula (I). The side chain that does not contain the unit represented by the above formula (I) which may be contained in the organic polymer is not particularly limited, but an alkyl group, an aromatic group, an alkyloxycarbonyl group may be included in the side chain, etc. Can be mentioned.

In the side chain containing the unit represented by the formula (I), the (substituted) carboxy group and the group represented by -CONH- are adjacent to each other via a carbon chain having 1 to 4 carbon atoms. The oxygen atom of the group and the hydrogen atom in the group represented by —CONH— tend to form an intramolecular hydrogen bond. It is considered that the presence of this hydrogen bond increases the acid strength of the carboxy group and binds strongly to calcium in the tooth.
That is, as an example of benzoic acid having no group represented by -CONH- in the vicinity of the carboxy group, the pKa of 2,4,6-trimethylbenzoic acid having a steric hindrance, which is relatively low, is 4. In contrast, 2- (2,2-dimethylpropanoylamino) -6-methylbenzoic acid having a group represented by -CONH- in the vicinity of the carboxy group has a strong pKa of 3.9 and strong acid strength. Thus, 2,6-di (2,2-dimethylpropanoylamino) benzoic acid having a group represented by —CONH— on both sides of the carboxy group has a pKa of 3.1, which further increases the acid strength. This is considered to indicate that when a group represented by -CONH- is present in the vicinity of the carboxy group, an intramolecular hydrogen bond is formed, and the formation of this hydrogen bond increases the acid strength of the carboxy group. It is done.

  In addition, the side chain containing the unit shown by the said Formula (I) of the carbon chain from which carbon number differs in the range of 1-4 may be mixed in one organic polymer molecule.

  Further, the organic polymer used in the present invention is irregular in that the side chain containing the unit represented by the formula (I) is partly present in a part of the polymer and is not present at all in the other part. It is preferable that the side chain containing the unit represented by the formula (I) is relatively uniformly distributed in the polymer molecular chain by adopting the production method described later, rather than adopting such a present form. It is thought that the dental adhesive composition and the dental filler using the organic polymer adhere more firmly to the tooth substance when distributed uniformly in this way. When this organic polymer is produced by the method described later, the side chain containing the unit represented by the formula (I) is dispersed relatively uniformly in the polymer molecule.

  The degree of polymerization of the organic polymer is preferably 5 or more, more preferably 10 or more, further preferably 50 or more, and most preferably 100 or more. Protective layer that blocks extraneous stimuli at the boundary between living tissue and the prosthesis prosthetic when it becomes a tough resin layer when the higher degree of polymerization adheres to the tooth and forms an adhesive layer It is advantageous to work. That is, a tougher resin layer can be formed by setting the degree of polymerization to 5 or more. Moreover, it is preferable that the polymerization degree of an organic polymer is 10,000 or less from the ease of preparation of a dental adhesive agent, a dental filler, and a dental cement material, and workability.

The organic polymer used for the dental restorative material of the present invention can be produced by the following method.
First, using an amino group-containing vinyl monomer, for example, allylamine, an amino group-containing polymer in which 20 mol% or more of all side chain units constituting the polymer is an amino group unit is produced by a conventional method.

Next, the resulting amino group-containing polymer is treated with hydrochloric acid to obtain polyallylamine hydrochloride.
Then, this polymer is subjected to ring-opening addition under known conditions and monoamidation using acid anhydride, acid chloride or the like, so that (substituted) carboxy group and —NHCO— are carbon atoms having 1 to 4 carbon atoms. An organic polymer having a structure (C) bonded through a chain can be obtained.

At this time, as the acid anhydride to be used, a saturated dicarboxylic acid anhydride such as succinic acid anhydride or glutaric acid anhydride and an acid anhydride having an unsaturated bond such as maleic acid anhydride or phthalic anhydride may be used. Saturated dicarboxylic acid anhydride is preferred.
Examples of the acid chloride include ethyl-3-chloro-3-oxopropionate.

Alternatively, after synthesizing a vinyl monomer having an amino acid group by reaction of (meth) acrylic acid chloride with a compound that has blocked the acid group of the amino acid, a polymer is formed by a known method using this monomer, The organic polymer which has the structure (C) used for the dental restoration material of this invention can also be obtained.
In synthesizing a vinyl monomer having an amino acid group, α, β, γ, and δ-amino acids can be used as amino acids to be used, and β or γ-amino acids are more preferable among them. Examples include β- or γ-type amino acids such as alanine, valine, leucine, and isoleucine.

In the polymerization of the vinyl monomer having an amino acid group, another monomer copolymerizable with the monomer may be used.
Since a polymer using amino acid is an amino acid unit itself represented by the formula (I), if the side chain having an amino acid group in the polymer is 20% or more of all side chains, a random copolymer It may be.

  Examples of the copolymerizable monomer include esters of (meth) acrylic acid, allyl monomers such as allyl alcohol, vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether, cyclic ether monomers such as p-dioxene, and vinyl acetate. Examples include vinyl ester monomers, olefins such as ethylene and propylene, and styrenes.

In the dental adhesive of the present invention, the adhesive component may be composed only of the above organic polymer, but may contain a polymerizable monomer and a curing agent in addition to the organic polymer. That is, when the dental adhesive composition of the present invention is used as an adhesive for bonding a tooth and a filler, a solvent and / or a polymerizable monomer containing the organic polymer is used. Can be used. When the adhesive component is composed only of the organic polymer, it can be used as a solution in which the organic polymer is dissolved in an organic solvent. When it contains a polymerizable monomer, for example, an organic polymer, a curing agent, etc. It can be used as a solution dissolved in a polymerizable monomer.
The dental adhesive preferably contains 2% by mass or more of the organic polymer,
What contains 98 mass% is more preferable.
Examples of the solvent include ethanol, ethyl ether, chloroform, methylene dichloride, acetone, methyl ethyl ketone and the like.

  As the polymerizable monomer used in the dental adhesive of the present invention, any monomer can be used as long as it is a polymerizable monomer used in a dental adhesive. Polyfunctional monomers or combinations of these with monofunctional monomers are used. Specific examples of such polymerizable monomers include bisphenol A dimethacrylate, bisphenol A diglycidyl methacrylate, 2,2-bis (4-methacryloyloxyethoxyphenyl) propane, and 2,2-bis (4-methacryloyloxy). Aromatic methacrylate esters such as propoxyphenyl) propane; multifunctional methacrylates such as polyfunctional methacrylate esters such as ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, and trimethylolpropane trimethacrylate Examples include monomer, monofunctional monomer such as methyl methacrylate and 2-hydroxyethyl methacrylate.

The curing agent used in the dental adhesive of the present invention can be used without particular limitation as long as it can be cured in a few minutes at room temperature, and camphorquinone, amine / peroxide, p-toluenesulfinic acid / peroxide. Examples thereof include oxides, combinations of trialkylboron / peroxide, photosensitizers, and the like.
As these curing agents, known ones can be used.

The dental adhesive of the present invention contains the above-mentioned organic polymer, and the organic polymer adheres firmly to the tooth and has an affinity for the polymerizable monomer. It functions as a protective layer that suppresses penetration inside and forms a resin layer on the surface layer to block external stimuli.
This protective layer is less likely to hydrolyze with time and cause a decrease in adhesiveness, and the composite resin and prosthesis adhered by this adhesive can be prevented from falling off over a long period of time.

The dental filler of the present invention contains the organic polymer, a polymerizable monomer, a filler, and a curing agent. When such a dental filler is filled in a tooth cavity and cured (polymerization of the monomer), the organic polymer adheres firmly to the tooth and is formed by polymerization of the monomer. Is tightly entangled with the organic polymer in a state in which the filler is confined, so that the filler does not easily fall out of the tooth dent and exhibits excellent performance as a dental filler.
Therefore, the filler firmly adheres to the tooth without using an adhesive between the tooth and the filler. Of course, after applying the dental adhesive, the dental filler of the present invention may be filled.

As the polymerizable monomer and the curing agent used for the dental filler, the same monomers as described in the section of the dental adhesive can be used.
As the filler, any filler can be used as long as it is usually used in dental fillers. Specific examples of such fillers include silica powder, glass beads, aluminum oxide powder, and quartz powder. The filler is preferably surface-treated with a silane coupling agent. The surface treatment with a silane coupling agent can be performed by a known method using a known silane coupling agent.

If necessary, the dental filler of the present invention may contain a polymer such as polymethyl methacrylate, a tackifier, a polymerization accelerator, a polymerization regulator, a polymerization inhibitor, and the like.
As a tackifier, a polymerization accelerator, a polymerization regulator, and a polymerization inhibitor that may be blended in the dental filler of the present invention, known tackifiers, polymerization accelerators used for dental fillers, A polymerization regulator and a polymerization inhibitor can be used.

  The compounding ratio in the dental filler of the present invention is appropriately selected according to the use form and is not particularly limited. For example, the filler is 40 to 90% by mass, the organic polymer is 2 to 20% by mass, and the polymerization property The monomer may be in the range of 0.5 to 5 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

The dental cement composition of the present invention contains an inorganic powder containing a polyvalent metal compound together with the above organic polymer.
Examples of the polyvalent metal compound include polyvalent metal oxides, hydroxides, carbonates, sulfates, phosphates, and silicates.
As the polyvalent metal oxide, zinc oxide, magnesium oxide, calcium oxide, aluminum oxide, strontium oxide, or the like can be used.
Examples of the polyvalent metal hydroxide include zinc hydroxide, calcium hydroxide, and aluminum hydroxide.
Examples of the polyvalent metal carbonate include zinc carbonate, calcium carbonate, aluminum carbonate, and strontium carbonate.
Examples of the polyvalent metal sulfate include gypsum and barium sulfate.
Examples of the polyvalent metal phosphate include calcium phosphate, zinc phosphate, and aluminum phosphate.
Examples of silicates include aluminum silicate, calcium silicate, and aluminum borosilicate.
Among these, polyvalent metal ion leaching glass belonging to silicates is particularly preferable, and examples of such glass include aluminosilicate glass and fluoroaluminosilicate glass, but are not limited thereto. .

When inorganic powder containing a polyvalent metal compound is used, a metal such as aluminum or calcium in the powder is coordinated with a carboxyl group having an acid strength strengthened by intramolecular hydrogen bonding in the organic polymer and is strong. Form a bond.
The mass average particle diameter of the inorganic powder containing the polyvalent metal compound is preferably 10 μm or less. By setting the mass average particle size to 10 μm or less, fluidity, miscibility, and polishing properties are improved.
When the adhesive component is composed only of the organic polymer, it can be used as a solution in which the organic polymer is dissolved in water or a mixed solvent of water and an organic solvent.
Examples of the organic solvent used for the mixed solvent include ethyl alcohol, propyl alcohol, and acetone.

The dental cement composition of the present invention may further contain a polymerizable monomer and a hardener.
When a polymerizable monomer is contained, for example, an organic polymer, a polymerization catalyst and the like can be used as a solution in which the polymerizable monomer is dissolved.
As the polymerizable monomer and the curing agent used in the dental cement composition, the same monomers as described in the section of the dental adhesive can be used.

  The compounding ratio of each component in the dental cement composition is not particularly limited. For example, the inorganic powder containing a polyvalent metal compound is 40 to 90% by mass, the organic compound is 2 to 20% by mass, 0 to 55% by mass of a monomer, 0 to 50% by mass of polymethyl methacrylate, and 0.5 to 5 parts by mass of a curing agent based on a total of 100 parts by mass of the organic compound and the polymerizable monomer. % Range can be exemplified.

  Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to these examples.

(Reference Example 1) Synthesis of organic polymer A 10.0 g of polyallylamine hydrochloride (manufactured by Nittobo) and 10.8 g of succinic anhydride were dissolved in 20 mL of ethylene glycol, and 10.0 mL of triethylamine was added thereto. Stir at 60 ° C. for 12 hours. After stirring for 12 hours, a 3.5% aqueous hydrochloric acid solution was added, and the solution was poured into THF to precipitate a white precipitate. After filtration, it was dried over phosphorus pentoxide under reduced pressure to obtain poly (3-allylcarbamoylpropionic acid). (Yield: 55%)
From the elemental analysis, it was confirmed that the proportion of carboxyl groups introduced into the side chain was 51%.
From the analysis by ¹ H-NMR, it was judged that an organic polymer A in which —COOH and —CONH are adjacent to each other via an ethylene group was obtained.
Elemental analysis:
Calculated values: C 42.00, H 8.07, N 9.70
Measurements: C 42.01, H 8.08, N 9.69
¹ H-NMR (DMSO-d ₆ ): 8.04 (NH), 4.6 (α-CH ₂ ), 3.1 (CH ₂ COOH), 2.48 (NHCOCH ₂ ), 1.77 (CH )

(Example 1)
Cement powder was obtained by adding 0.1 g of ethyl dimethylaminobenzoate to 50 g of fluoroaluminosilicate glass powder and mixing.
On the other hand, 5 g of the organic polymer A obtained in Reference Example 1 was dissolved in a mixed solution of 20 g of 2-hydroxyethyl methacrylate and 1 g of water to obtain a solution, and 0.1 g of ammonium persulfate was uniformly dissolved in this solution to obtain a cement solution. It was.
1.0 g of this cement solution was added to 1.8 g of the cement powder and mixed for 30 seconds to obtain a dental cement composition.
Grinding the crown of the bovine teeth horizontally and polishing the surface with # 600 water-resistant abrasive paper to expose the enamel and the exposed dentin, and prepare these underwater The sample was immersed for 1 day or longer and the surface moisture was wiped off immediately before the test.
Using the above dental cement composition, bovine enamel and dentin bond strengths were measured. The results are shown in Table 1.

(Comparative Example 1)
A mixture of acrylic acid / acryloyloxyethyl phosphoric acid = 95/5 (mass ratio) monomer mixture 8 g ammonium persulfate 0.36 g and hydroquinone 50 mg is put in a glass tube, sealed with nitrogen and sealed at 80 ° C. Polymerized for 15 hours.
The obtained copolymer was dialyzed, lyophilized and pulverized to obtain a copolymer powder.
A cement solution was prepared by uniformly dissolving 0.1 g of ammonium persulfate in a solution of 5 g of the obtained copolymer powder in 20 g of 2-hydroxyethyl methacrylate.
1.0 g of this cement solution was added to 1.8 g of cement powder obtained in the same manner as in Example 1 and mixed for 30 seconds to obtain a dental cement composition.
Using this dental cement composition, bovine enamel and dentin bond strengths were measured. The results are shown in Table 1.

  From Table 1, the dental cement composition of the present invention using a specific organic polymer as compared with a conventional glass ionomer cement using an acrylic acid / acryloyloxyethyl phosphate copolymer as an organic polymer is It can be seen that it exhibits high adhesion to the tooth.

(Example 2)
10 parts by mass of the organic polymer A of the organic polymer A obtained in Reference Example 1 was diluted to 90 parts by mass of 2-hydroxyethyl methacrylate, and a solution containing 1% by mass of camphorquinone with respect to 2-hydroxyethyl methacrylate (Liquid A) ) Was prepared.
Moreover, the solution (B liquid) which added 1 mass% of camphorquinone to the 1: 1 mixture of 2-hydroxyethyl methacrylate and methyl methacrylate was prepared.
Grinding the crown of the bovine teeth horizontally and polishing the surface with # 600 water-resistant abrasive paper to expose the enamel and the exposed dentin, and prepare these underwater The sample was immersed for 1 day or longer and the surface moisture was wiped off immediately before the test. The A liquid was applied to the surface of each of these teeth, and then the B liquid was applied thereon, and an acrylic bar having a diameter of 5 mm was placed thereon and irradiated with visible light to be cured.
After curing, a thermal recycling test was repeated 5000 times at 5 ° C and 55 ° C, and then pulled using a universal testing machine (product name: Autograph, manufactured by Shimadzu Corporation) at a crosshead speed of 1 mm / min. I asked for strength.
The results are shown in Table 1.

(Comparative Example 2)
A mixture of 95% by mass of methyl methacrylate containing tri-n-butylborane oxide as a polymerization initiator and 5% by mass of 4-methacryloyloxyethylethyl trimellitic anhydride was added with a small amount of polymethyl methacrylate. The same bovine teeth as used in Example 1 were applied, methyl methacrylate was polymerized at room temperature, and an acrylic rod having a diameter of 5 mm was adhered to the bovine teeth. After the thermal recycling test similar to that performed in Example 2 was performed on the bovine teeth with the acrylic rod adhered, the tensile adhesive strength was determined in the same manner as in Example 2. The results are shown in Table 1.

(Example 3)
As a polymerizable monomer, 40 parts by mass of 2,2-bis (4- (2-hydroxy-3-methacryloyloxypropoxy) phenyl) propane, 27 parts by mass of triethylene glycol dimethacrylate, 23 parts by mass of methyl methacrylate, polymerization As an initiator, 0.2 parts by mass of camphorquinone and 0.2 parts by mass of ethyl 4-dimethylaminobenzoate were added, and 10 parts by mass of organic polymer A and a polymerization initiator were added thereto to prepare a matrix monomer.
Next, 100 parts by mass of silane-treated fine powder silica as a filler and a matrix monomer were placed in an agate mortar, and kneaded thoroughly in a dark place to obtain a uniform paste to prepare a dental composite resin.
The enamel or dentin was exposed in the same manner as in Example 1, and the inner diameter of the bovine tooth that had been immersed in water for 1 day or more and then wiped off the moisture was 5.0 mm on the exposed enamel or dentin and the height. A 2.0 mm silicone rubber mold was placed, and the dental composite resin obtained above was injected and cured by irradiation with light to obtain a test specimen. After placing these specimens in a constant temperature bath at 37 ° C. and 100% relative humidity for 24 hours, a tension acrylic rod was attached to the top of the specimen, and a universal testing machine (product name: Autograph, manufactured by Shimadzu Corp.) The tensile bond strength was determined at a crosshead speed of 1 mm / min. The results are shown in Table 1.

(Comparative Example 3)
In place of the organic polymer A in Example 3, the same amount of 2,2-bis (4- (2-hydroxy-3-methacryloyloxypropoxy) phenyl) propane 40: triethylene glycol dimethacrylate 27, methyl methacrylate 23 (mass) A test specimen was obtained in the same manner as in Example 3 except that the polymerizable monomer of (R) was used, and the tensile adhesive strength was determined. The results are shown in Table 1.

  From Table 1, it can be seen that the dental restorative material of the present invention exhibits excellent adhesion to the tooth.

  According to the present invention, it is possible to prevent the secondary touch derived from the insufficient adhesive strength of the conventional dental restorative material.

Claims (5)

A dental restorative material comprising a polymer containing a unit represented by the following formula (I) in a side chain.
-CONHR ¹ COOX or -NHCOR ² COOX (I)
[In Formula (I), R ¹ and R ² represent a carbon chain having 1 to 4 carbon atoms, X is a hydrogen atom, —NH ₄ , or 1 / mM (M is an alkali metal, an alkaline earth metal, a transition metal) Represents a metal atom selected from Zn, Cd, and m represents the valence of the metal.]   The dental restorative material according to claim 1, wherein the restorative material is a dental cement composition containing an inorganic powder containing the organic polymer and the polyvalent metal compound.   The dental restorative material according to claim 2, wherein the restorative material is a dental cement composition further containing a copolymerizable monomer and a curing agent.   The dental restorative material according to claim 1, wherein the restorative material is a dental adhesive containing the organic polymer, a polymerizable monomer and a curing agent. The dental restorative material according to claim 1, wherein the restorative material is a dental filler containing the organic polymer, polymerizable monomer, filler and hardener.