Dental polymerizable pulp capping material composition

Abstract

This dental polymerizable pulp capping material composition contains glass and a polymerizable monomer, wherein the glass contains phosphorus, calcium, zinc, and fluorine.

Description

TITLE OF INVENTION: DENTAL POLYMERIZABLE PULP CAPPING MATERIAL COMPOSITION TECHNICAL FIELD

[0001] The present invention relates to dental polymerizable pulp capping material compositions. BACKGROUND OF THE INVENTION

[0002] In dental treatments, a pulp capping material directly or indirectly covers an exposed dental pulp surface during a dental caries treatment to protect the dental pulp from external stimuli, and also regenerates the demineralized dentin and sterilizes the treatment site. A conventional pulp capping material called a mineral trioxide aggregate (MTA) cement is cured by a hydraulic reaction to form calcium hydroxide, which makes the surroundings alkaline, thereby sterilizing a treatment site, and exhibiting dentin regeneration ability owing to release of calcium ions (see, for example, Patent Document 1).

[0003] In addition, a polymerizable pulp capping material, in which polymerizability is imparted to a pulp capping material composition to improve operability, is also widely used (see, for example, Patent Document 2). RELATED-ART DOCUMENT Patent Document

[0004] Patent Document 1: US Patent No. 7892342 Patent Document 2: US Patent Application Publication No. 2008 / 0318190 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] However, it is desired to improve affinity of a conventional polymerizable pulp capping material with cells (dental pulp cells).

[0006] An object of the present invention is to provide a dental polymerizable pulp capping material composition having excellent cell affinity. MEANS FOR SOLVING THE PROBLEMS

[0007] One aspect of the present invention is a dental polymerizable pulp capping material composition including glass and one or more polymerizable monomers, wherein the glass includes phosphorus, calcium, zinc, and fluorine. EFFECTS OF THE INVENTION

[0008] According to one aspect of the present invention, a dental polymerizable pulp capping material composition having excellent cell affinity can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiments for carrying out the present invention will be described in detail hereinafter.

[0010] The dental polymerizable pulp capping material composition according to the present embodiment includes glass. In the present specification, the dental polymerizable pulp capping material composition refers to a polymerizable composition used as a pulp capping material for dental applications. In addition, the glass refers to a solid in a non-crystalline state or amorphous state.

[0011] The glass included in the dental polymerizable pulp capping material composition of the present disclosure includes phosphorus (P), calcium (Ca), zinc (Zn), and fluorine (F). Examples of such glass include phosphate glass. The phosphate glass is glass including phosphoric acid as a glass network component. The phosphate glass is a water-soluble glass, in which components included in the glass are dissolved in water and gradually released in the form of ions (referred to as sustained release, or having sustained releasability hereinafter).

[0012] In the dental polymerizable pulp capping material composition of the present disclosure, phosphorus (P) in the glass is included in the state of an oxide (phosphorus pentoxide (P2O5)). An amount of phosphorus included in the glass is not particularly limited, and the amount of P2O5 calculated as an oxide is, for example, 30 percent by mass or greater and 60 percent by mass or less, preferably 35 percent by mass or greater and 55 percent by mass or less, and more preferably 40 percent by mass or greater and 50 percent by mass or less.

[0013] Since the glass in the dental polymerizable pulp capping material composition includes phosphorus (P), water solubility of the glass can be enhanced, and sustained releasability of ions of the components included in the glass can be enhanced. In addition, since the glass in the dental polymerizable pulp capping material composition includes P2O5, phosphate ions (PO43-) released from the glass can impart an effect of remineralization of dental tissues or an effect of prevention of dental caries to the dental polymerizable pulp capping material composition.

[0014] In the dental polymerizable pulp capping material composition of the present disclosure, calcium (Ca) in the glass is included in the state of an oxide (calcium oxide (CaO)). An amount of calcium included in the glass is not particularly limited, and the amount of CaO calculated as an oxide is, for example, 1 percent by mass or greater and 20 percent by mass or less, preferably 3 percent by mass or greater and 15 percent by mass or less, and more preferably 5 percent by mass or greater and 10 percent by mass or less.

[0015] Since the glass in the dental polymerizable pulp capping material composition includes calcium (Ca), calcium ions (Ca2+) released from the glass can impart an effect of remineralization of dental tissues or an effect of prevention of dental caries to the dental polymerizable pulp capping material composition.

[0016] In the dental polymerizable pulp capping material composition of the present disclosure, zinc (Zn) in the glass is included in the state of an oxide (zinc oxide (ZnO)). An amount of zinc included in the glass is not particularly limited, and the amount of ZnO calculated as an oxide is, for example, 1 percent by mass or greater and 20 percent by mass or less, preferably 3 percent by mass or greater and 15 percent by mass or less, and more preferably 5 percent by mass or greater and 10 percent by mass or less.

[0017] Since the glass in the dental polymerizable pulp capping material composition includes zinc (Zn), zinc ions (Zn2+) released from the glass can impart a function of soothing an inflamed site to the dental polymerizable pulp capping material composition.

[0018] An amount of fluorine (F) included in the glass in the dental polymerizable pulp capping material composition of the present disclosure is not particularly limited, and the amount of the fluorine (F) included in the glass is, for example, 1 percent by mass or greater and 20 percent by mass or less, preferably 3 percent by mass or greater and 15 percent by mass or less, and more preferably 5 percent by mass or greater and 10 percent by mass or less.

[0019] Since the glass in the dental polymerizable pulp capping material composition includes fluorine (F), fluorine ions (F-) released from the glass can impart an effect of remineralization of dental tissues or an effect of prevention of dental caries to the dental polymerizable pulp capping material composition.

[0020] The glass included in the dental polymerizable pulp capping material composition of the present disclosure optionally further includes aluminum (Al) and potassium (K).

[0021] In the case where the glass in the dental polymerizable pulp capping material composition includes aluminum (Al), aluminum (Al) is included in the state of an oxide (aluminum oxide (Al2O3)). An amount of aluminum included in the glass is not particularly limited, and the amount of Al2O3 calculated as an oxide is, for example, 1 percent by mass or greater and 10 percent by mass or less, preferably 2 percent by mass or greater and 9 percent by mass or less, and more preferably 3 percent by mass or greater and 8 percent by mass or less.

[0022] Since the glass in the dental polymerizable pulp capping material composition includes aluminum (Al), water solubility of the glass is suppressed to reduce sustained releasability of ions of the components included in the glass, thereby improving cell affinity of the dental polymerizable pulp capping material composition.

[0023] In the case where the glass in the dental polymerizable pulp capping material composition includes potassium (K), potassium (K) is included in the state of an oxide (potassium oxide (K2O)). An amount of potassium included in the glass is not particularly limited, and the amount of K2O calculated as an oxide is, for example, 10 percent by mass or greater and 60 percent by mass or less, preferably 15 percent by mass or greater and 55 percent by mass or less, and more preferably 20 percent by mass or greater and 50 percent by mass or less.

[0024] Since the glass in the dental polymerizable pulp capping material composition includes potassium (K), potassium ions (K+) released from the glass can impart an effect of relieving symptoms, such as discomfort and pains due to external stimuli, to the dental polymerizable pulp capping material composition.

[0025] An amount of the glass in the dental polymerizable pulp capping material composition is not particularly limited, and is, for example, 30 percent by mass or greater and 70 percent by mass or less, preferably 35 percent by mass or greater and 65 percent by mass or less, and more preferably 40 percent by mass or greater and 60 percent by mass or less.

[0026] When the amount of the glass is 30 percent by mass or greater, concentrations of the components released from the glass are high, and sufficient remineralization and anti-inflammatory effects are likely to be obtained. When the amount of the glass is 70 percent by mass or less, the concentrations of the components released from the glass in the dental polymerizable pulp capping material composition are low, and cytotoxicity is less likely to be exhibited.

[0027] A method for producing the glass included in the dental polymerizable pulp capping material composition is not particularly limited. As the method for producing the glass, for example, raw materials corresponding to a composition of the glass are weighed and mixed to prepare a raw material composition (raw material composition preparation step), and the prepared raw material composition is placed in a crucible and heated at a temperature corresponding to melting points of the raw materials included in the raw material composition, for example, 700°C or higher and 1,500oC or lower, to melt the raw material composition, followed by cooling (heating and cooling step).

[0028] The cooling rate during the cooling is not particularly limited. For example, the melted raw material composition is preferably rapidly cooled by various quenching methods, such as a twin-roll method, a method of pouring a melt onto a metal plate and pressing, and the like. After the cooling and solidifying, the solidified composition is pulverized to a desired particle size (pulverization step), thereby producing the present glass in the form of a powder.

[0029] The method for producing the glass further includes an optional step in addition to the above-described steps. For example, classification or the like may be performed so that the particle size distribution of the obtained glass becomes a desired distribution.

[0030] In the case where the glass is blended in the dental polymerizable pulp capping material composition, the form of the glass is preferably a powder. The particle size of the powder of the glass (referred to as the glass powder hereinafter) is preferably 2 pm or greater and less than 10 pm, more preferably 3 pm or greater and less than 9 pm, and further preferably 4 pm or greater and less than 8 pm. The particle size refers to an average particle size defined by a median diameter (D50).

[0031] Since the particle size of the glass powder is 2 pm or greater, when the glass powder is used as a glass powder of the polymerizable pulp capping material, cell affinity of the dental polymerizable pulp capping material composition improves. When the particle size of the glass powder is less than 10 pm, the concentrations of the components released from the polymerizable pulp capping material including the glass are high, and sufficient remineralization and anti-inflammatory effects can be imparted to the dental polymerizable pulp capping material composition.

[0032] The dental polymerizable pulp capping material composition according to the present embodiment further includes one or more polymerizable monomers. The polymerizable monomer is a polymerizable compound, and the polymerizable monomer is cured by polymerization of the polymerizable monomer.

[0033] The polymerizable monomer included in the dental polymerizable pulp capping material composition of the present disclosure is not particularly limited, and examples of the polymerizable monomer include (meth)acrylates. The (meth)acrylates refer to compounds including a methacryloyloxy group, or an acryloyloxy group, or both, and refers to acrylates, methacrylates, or both.

[0034] Examples of the (meth)acrylates include 2,2-bis[4-(3-(meth)acryloxy-2-hydroxypropoxy)phenyl]propane, [2,2,4-trimethylhexamethylene bis(2-carbamoyloxyethyl)] di(meth)acrylate, triethylene glycol di(meth)acrylate, 2-hydroxy-1,3-di(meth)acryloxypropane, methyl (meth)acrylate, isobutyl (meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, 2,3-dibromopropyl(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 6-hydroxyhexyl(meth)acrylate, 10-hydroxydecyl (meth)acrylate, propylene glycol mono(meth)acrylate, glycerol mono(meth)acrylate, erythritol mono(meth)acrylate, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 2,2-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]propane, 2,2-bis[4-(meth)acryloyloxypolyethoxyphenyl]propane, 1,2-bis[3-(meth)acryloyloxy-2-hydroxypropoxy]ethane, pentaerythritol di(meth)acrylate, trimethylol propane tri(meth)acrylate, trimethylol ethane tri(meth)acrylate, tetramethylol methane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, N,N’-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetra(meth)acrylate, and the like.

[0035] One of the above polymerizable monomers may be used alone, or two or more of the above polymerizable monomers may be used in combination. By including one or more polymerizable monomers each having low viscosity, operability of the dental polymerizable pulp capping material composition is improved. Examples of the one or more polymerizable monomers each having low viscosity include triethylene glycol dimethacrylate (viscosity at 25°C: 9 mPa^s), 2-hydroxy-1,3- dimethacryloxypropane (viscosity at 25°C: 37 mPa^s), and the like.

[0036] An amount of the one or more polymerizable monomers included in the dental polymerizable pulp capping material composition is not particularly limited. For example, the amount of the one or more polymerizable monomers is 10 percent by mass or greater and 60 percent by mass or less, preferably 15 percent by mass or greater and 50 percent by mass or less, and more preferably 20 percent by mass or greater and 40 percent by mass or less.

[0037] When the amount of the one or more polymerizable monomers is 10 percent by mass or greater, adhesion of the dental polymerizable pulp capping material composition to a dental pulp surface improves. When the amount of the one or more polymerizable monomers is 60 percent by mass or less, an amount of the glass is relatively increased, the concentrations of the components released from the polymerizable pulp capping material increase, and remineralization and antiinflammatory effects improve.

[0038] The dental polymerizable pulp capping material composition of the present disclosure may further include a radiopaque material. Examples of the radiopaque material include: oxides, such as barium oxide, zirconium oxide, strontium oxide, bismuth oxide, and yttrium oxide; sulfates, such as barium sulfate, strontium sulfate, and bismuth sulfate; carbonates, such as barium carbonate, zirconium carbonate, strontium carbonate, and lanthanum carbonate; fluorides, such as ytterbium fluoride, yttrium fluoride, and lanthanum fluoride; glass including a heavy metal, such as barium glass, strontium glass, cesium glass, and lanthanum glass; and the like. The above radiopaque materials may be used alone or in combination of two or more.

[0039] An amount of the radiopaque material in the dental polymerizable pulp capping material composition is not particularly limited, and is, for example, 1 percent by mass or greater and 25 percent by mass or less, preferably 5 percent by mass or greater and 20 percent by mass or less, and more preferably 10 percent by mass or greater and 15 percent by mass or less.

[0040] When the amount of the radiopaque material is 1 percent by mass or greater, radiopacity of the polymerizable pulp capping material after being polymerized and cured improves. When the amount of the radiopaque material is 25 percent by mass or less, the amount of the glass is relatively increased, the concentrations of the components released from the polymerizable pulp capping material are increased, and remineralization and anti-inflammatory effects improve.

[0041] The dental polymerizable pulp capping material composition of the present invention may further include a polymerization initiator. In the case where visible light is applied to the polymerizable pulp capping material to polymerize and cure the polymerizable pulp capping material, a photopolymerization initiator may be used. In the case where the polymerizable pulp capping material is polymerized and cured by chemical polymerization, a chemical polymerization initiator may be used. The above polymerization initiators may be used alone or in combination of two or more.

[0042] Examples of the photopolymerization initiator include camphorquinone, benzyl, diacetyl, benzyl dimethyl ketal, benzyl diethyl ketal, benzyl bis(2-methoxyethyl) ketal, 4,4’-dimethylbenzyl-dimethyl ketal, anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1,2-benzanthraquinone, 1-hydroxyanthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, 1-bromoanthraquinone, thioxanthone, 2-isopropylthioxanthone, 2-nitrothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chloro-7-trifluoromethylthioxanthone, thioxanthone-10,10-dioxide, thioxanthone-10-oxide, benzoin methyl ether, benzoin ethyl ether, isopropyl ether, benzoin isobutyl ether, benzophenone, bis(4-dimethylaminophenyl) ketone, 4,4’-bisdiethylaminobenzophenone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and the like. The above photopolymerization initiators may be used alone or in combination of two or more.

[0043] The chemical polymerization initiator is not particularly limited, and for example, a redox initiator, such as a cumene hydroperoxide / thiourea system-based initiator, an ascorbic acid / Cu2+ salt-based initiator, organic sulfinic acid or a salt of organic sulfinic acid / amine / inorganic peroxide-based initiator may be used, and also tributyl borane, organic sulfinic acid, or the like may be used.

[0044] An amount of the polymerization initiator in the dental polymerizable pulp capping material composition is not particularly limited, and is, for example, 0.001 percent by mass or greater and 10 percent by mass or less, preferably 0.01 percent by mass or greater and 5 percent by mass or less, and more preferably 0.05 percent by mass or greater and 1 percent by mass or less. When the amount of the polymerization initiator in the dental polymerizable pulp capping material composition is 0.001 percent by mass or greater, biocompatibility of the dental polymerizable pulp capping material composition improves. When the amount of the polymerization initiator in the dental polymerizable pulp capping material composition is 10 percent by mass or less, storage stability of the dental polymerizable pulp capping material composition improves.

[0045] The dental polymerizable pulp capping material composition of the present disclosure optionally further includes a thickening agent, a tertiary amine, a polymerization inhibitor, and an ultraviolet absorber.

[0046] As the thickening agent, an inorganic thickening agent or an organic thickening agent may be used. The above thickening agents may be used alone or in combination of two or more.

[0047] The inorganic thickening agent is not particularly limited. Examples of the inorganic thickening agent include fumed silica, zirconia, silica alumina, alumina, glass, titania, calcium carbonate, kaolin, clay, mica, aluminum sulfate, barium sulfate, calcium sulfate, titanium oxide, calcium phosphate, and the like.

[0048] The organic thickening agent is not particularly limited. Examples of the organic thickening agent include calcium carboxymethyl cellulose, sodium carboxymethyl cellulose, starch, sodium starch glycolate, sodium starch phosphate, methyl cellulose, sodium polyacrylate, alginic acid, sodium alginate, propylene glycol alginate, casein, sodium caseinate, polyethylene glycol, ethyl cellulose, hydroxyethyl cellulose, gluten, locust bean gum, gelatin, and the like.

[0049] An amount of the thickening agent in the dental polymerizable pulp capping material composition is not particularly limited, and is, for example, 0.1 percent by mass or greater and 20 percent by mass or less, preferably 0.3 percent by mass or greater and 10 percent by mass or less, and more preferably 0.5 percent by mass or greater and 5 percent by mass or less. When the amount of the thickening agent in the dental polymerizable pulp capping material composition is 0.1 percent by mass or greater and 20 percent by mass or less, the viscosity of the dental polymerizable pulp capping material composition is easily adjusted according to use or the like.

[0050] The tertiary amine is not particularly limited. Examples of the tertiary amine include: tertiary aliphatic amines, such as N,N-dimethylaminoethyl methacrylate and triethanol amine; alkyl p-dialkylaminobenzoate, such as methyl p-dimethylaminobenzoate, ethyl p-dimethylaminobenzoate, propyl p-dimethylaminobenzoate, amyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, ethyl p-diethylaminobenzoate, and propyl p-diethylaminobenzoate; tertiary aromatic amines, such as 7-dimethylamino-4-methylcoumarin, N,N-dimethylaniline, N,N-dibenzylaniline, N,N-dimethyl-p-toluidine, N,N-diethyl-p-toluidine, N,N-bis(2-hydroxyethyl)-p-toluidine, N,N,2,4,6-pentamethylaniline, N,N,2,4-tetramethylaniline, and N,N-diethyl-2,4,6-trimethylaniline; and the like.

[0051] The above tertiary amines may be used alone or in combination of two or more. Among the above tertiary amines, tertiary aromatic amines are preferable, and alkyl p-dialkylaminobenzoate is more preferable.

[0052] An amount of the tertiary amine in the dental polymerizable pulp capping material composition is not particularly limited, and is, for example, 0.01 percent by mass or greater and 10 percent by mass or less, preferably 0.05 percent by mass or greater and 5 percent by mass or less, and more preferably 0.1 percent by mass or greater and 1 percent by mass or less. When the amount of the tertiary amine in the dental polymerizable pulp capping material composition is 0.01 percent by mass or greater, biocompatibility of the dental polymerizable pulp capping material composition improves. When the amount of the tertiary amine in the dental polymerizable pulp capping material composition is 10 percent by mass or less, storage stability of the dental polymerizable pulp capping material composition improves.

[0053] The polymerization inhibitor is not particularly limited. Examples of the polymerization inhibitor include 6-tert-butyl-2,4-xylenol, 2,6-di-tert-butyl-p-cresol, hydroquinone, dibutyl hydroquinone, dibutyl hydroquinone monomethyl ether, 2,6-di-tert-butylphenol, 4-methoxyphenol, and the like. The above polymerization inhibitors may be used alone or in combination of two or more.

[0054] An amount of the polymerization inhibitor in the dental polymerizable pulp capping material composition is not particularly limited, and is, for example, 0.0001 percent by mass or greater and 5 percent by mass or less, preferably 0.001 percent by mass or greater and 3 percent by mass or less, and more preferably 0.08 percent by mass or greater and 1 percent by mass or less. When the amount of the polymerization inhibitor in the dental polymerizable pulp capping material composition is 0.0001 percent by mass or greater, storage stability of the dental polymerizable pulp capping material composition improves. When the amount of the polymerization inhibitor in the dental polymerizable pulp capping material composition is 5 percent by mass or less, biocompatibility of the dental polymerizable pulp capping material composition improves.

[0055] As described above, the dental polymerizable pulp capping material composition of the present disclosure includes glass and one or more polymerizable monomers, and the glass includes phosphorus, calcium, zinc, and fluorine. Therefore, cell affinity can be improved. In addition, the dental polymerizable pulp capping material composition of the present disclosure can achieve an excellent dental tissue remineralization effect, excellent cell affinity, and an excellent anti-inflammatory effect, while maintaining high sustained releasability of ions. Examples

[0056] The present invention will be described further with reference to Examples hereinafter. In the following description, “parts” and “%” are based on mass, unless otherwise specified. In addition, various tests and evaluations were performed according to the following methods.

[0057] <Glass Powder> After blending zinc oxide (ZnO), calcium fluoride (CaF2), aluminum oxide (Al2O3), phosphorus pentoxide (P2O5), and potassium hydrogen carbonate (KHCO3), and other corresponding raw materials at a predetermined ratio, the resultant mixture was sufficiently mixed and stirred using a mortar. The obtained mixture was placed in a platinum crucible, and the platinum crucible was set in an electric furnace. After rising the temperature of the electric furnace to 1,300oC to melt and sufficiently homogenize the mixture, the melt was poured onto a metal plate or metal roller, and rapidly cooled to room temperature (approximately 25C), thereby obtaining plateshaped or fritted glass. After pulverizing the obtained glass for 20 hours using an alumina ball mill, the pulverized glass was passed through a 120-mesh sieve, thereby preparing glass in the form of a powder (a glass powder).

[0058] <Composition of Inorganic Particles (Glass Powder)> The composition of the obtained inorganic particles including the glass powder was determined using an X-ray fluorescence analyzer (ZSX Primus II, manufactured by Rigaku Holdings Corporation). The composition (unit: percent by mass) of the inorganic particles is presented in Table 1. In Table 1, A-1 to A-3 are the obtained glass powders, and B-1 is a powder of tricalcium silicate (3CaO^SiO2).

[0059] <Particle Size of Inorganic Particles> The particle size distribution of the obtained inorganic particles including the glass powder was measured using a laser diffraction / scattering particle size distribution analyzer (LA-950, manufactured by HORIBA, Ltd.), and a median diameter (D50) was determined as a particle size of the inorganic particles. The particle size (unit: pm) of the inorganic particles is presented in Table 1.

[0060] [Table 1] Inorganic particles (glass powder) A-1 A-2 A-3 B-1 Composition [mass%] P2O5 48.0 48.0 48.0 k2o 29.0 29.0 29.0 CaO 5.8 5.8 5.8 AI2O3 4.0 4.0 4.0 ZnO 6.2 6.2 6.2 F 7.0 7.0 7.0 3CaO ■ SiO2 100 Total 100 100 100 100 Particle size [jU m] 15 6 1 6

[0061] <Production of Dental Polymerizable Pulp Capping Material Composition> The components were mixed according to the formulation presented in Table 2, thereby preparing a dental polymerizable pulp capping material composition.

[0062] Examples and Comparative Example will be described hereinafter.

[0063] [Example 1] By blending 18 parts of 2,2-bis[4-(3-methacryloxy-2-hydroxypropoxy)phenyl]propane (referred to as Bis-GMA hereinafter) and 15 parts of triethylene glycol dimethacrylate (referred to as TEGDMA hereinafter) serving as polymerizable monomers, 50 parts of the glass powder A-2 (particle size: 6 pm) serving as inorganic particles, 13 parts of strontium carbonate serving as a radiopaque material, 3.6 parts by mass of fumed silica serving as a thickening agent, 0.1 parts by mass of camphorquinone serving as a photopolymerization initiator, 0.2 parts of ethyl p-dimethylaminobenzoate serving as a tertiary amine, and 0.1 parts of 6-tert-butyl-2,4-xylenol serving as a polymerization inhibitor, a dental polymerizable pulp capping material composition was prepared. The formulation of Example 1 is presented in Table 1.

[0064] [Example 2] As polymerizable monomers, 14.4 parts of [2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)] dimethacrylate (referred to as UDMA hereinafter), 5.8 parts of TEGDMA, and 8.6 parts of 2-hydroxy-1,3-dimethacryloxypropane (referred to as GDMA hereinafter) were blended; and as inorganic particles, 54.2 parts of the glass powder A-2 (particle size: 6 pm) was blended. Other than the above, a dental polymerizable pulp capping material composition was prepared in the same manner as in Example 1. The formulation of Example 2 is presented in Table 1.

[0065] [Example 3] As polymerizable monomers, 21.7 parts of Bis-GMA and 8 parts of TEGDMA were blended; as inorganic particles, 56 parts of the glass powder A-2 (particle size: 6 pm) was blended; and as a thickening agent, 0.9 parts of fumed silica was blended. Other than the above, a dental polymerizable pulp capping material composition was prepared in the same manner as in Example 1. The formulation of Example 3 is presented in Table 1.

[0066] [Example 4] As inorganic particles, 40 parts of the glass powder A-2 (particle size: 6 pm) and inorganic particles B-1 (particle size: 6 pm) were blended. Other than the above, a dental polymerizable pulp capping material composition was prepared in the same manner as in Example 3. The formulation of Example 4 is presented in Table 1.

[0067] [Example 5] The blending amount of TEGDMA serving as the polymerizable monomer was set to 16 parts; instead of the glass powder A-2 serving as the inorganic particles, 50 parts of the glass powder A-1 (particle size: 15 pm) was blended; and the blending amount of fumed silica serving as the thickening agent was set to 2.6 parts. Other than the above, a dental polymerizable pulp capping material composition was prepared in the same manner as in Example 1. The formulation of Example 5 is presented in Table 1.

[0068] [Example 6] As polymerizable monomers, 16 parts of Bis-GMA and 22 parts of TEGDMA were blended; and as inorganic particles, 45 parts of the glass powder A-3 (particle size: 1 pm) was blended instead of the glass powder A-2. Other than the above, a dental polymerizable pulp capping material composition was prepared in the same manner as in Example 1. The formulation of Example 6 is presented in Table 1.

[0069] [Comparative Example 1] As inorganic particles, 54.2 parts of inorganic particles B-1 (particle size: 6 pm) was blended instead of the glass powder A-2. Other than the above, a dental polymerizable pulp capping material composition was prepared in the same manner as in Example 2. The formulation of Comparative Example 1 is presented in Table 1.

[0070] <Sustained Releasability> The produced dental polymerizable pulp capping material composition was formed into a shape having a diameter of 15 mm and a thickness of 1 mm, and was cured by photopolymerization using a light irradiator (G-Light Prima II Plus, manufactured by GC International AG). The cured body was immersed in 5 mL of distilled water for 24 hours, and the extraction liquid was collected. The concentrations of calcium and zinc in the collected extraction liquid were measured by inductively coupled plasma emission spectrometry (manufactured by Thermo Fisher Scientific K.K.). The concentration of fluorine was measured by an anion electrode method (manufactured by HORIBA, Ltd.). As the sustained releasability, 30 ppm or greater and 170 ppm or less was evaluated as good for calcium, 30 ppm or greater was evaluated as good for zinc, and 30 ppm or greater was evaluated as good for fluorine. The results of the sustained releasability are presented in Table 2.

[0071] <pH Measurement> The acidity (pH) of the extraction liquid obtained in the sustained releasability test was measured using a pH electrode (manufactured by HORIBA, Ltd.). The pH was evaluated according to the following criteria. The results of pH are presented in Table 2.

[0072] [Evaluation Criteria] Acceptable: the pH was greater than 7 and lower than 10 Not Acceptable: the pH was 10 or greater

[0073] <Remineralization Effect> Dentin of bovine tooth was polished with waterproof abrasive paper #400, followed by immersing the polished dentin in a demineralizing aqueous solution for 7 days. To the dentin surface after the demineralization, a polytetrafluoroethylene seal having a thickness of 1 mm with a hole having a diameter of 5 mm was adhered to define an area of an adherend surface. The polymerizable pulp capping material was applied to the adherend surface of the dentin of the bovine tooth, the resultant dentin was pressed with a glass plate via a polyethylene film, and the polymerizable pulp capping material was cured by photopolymerization using a light irradiator (G-Light Prima II Plus, manufactured by GC International AG), thereby preparing a test specimen. The test specimen was immersed in a simulated body fluid for 30 days. After the immersion, the polymerizable pulp capping material was removed, and the surface hardness (unit: VH) of the adherend surface was measured using a Vickers hardness tester(manufactured by Mitutoyo Corporation). The remineralization effect was evaluated according to the following criteria. The results of the remineralization effect are presented in Table 2.

[0074] [Evaluation Criteria] Acceptable: the surface hardness of dentin after immersion in the simulated body fluid was 30 HV or higher Not Acceptable: the surface hardness of dentin after immersion in the simulated body fluid was lower than 30 HV

[0075] <Cell Affinity> The dental polymerizable pulp capping material was formed into a shape having a diameter of 8 mm and a thickness of 1 mm, followed by being set in a culture kit (Transwell (registered trademark), manufactured by Corning Incorporated), and 500 p.L of human-derived dental pulp cells were seeded on the bottom surfaces of a 24-well plate at a concentration of 105 cells / well, and cultured. The number of cells on the first day of culturing was measured by an absorption spectrophotometer using a WST-1 assay reagent. The cell affinity was evaluated according to the following criteria. The results of the cell affinity are presented in Table 2.

[0076] [Evaluation Criteria] Very Good: the number of cells on the third day of culturing was 90% or greater compared with the control group Good: the number of cells on the third day of culturing was 70% or greater and less than 90% compared with the control group Not Good: the number of cells on the third day of culturing was less than 70% compared with the control group

[0077] <Anti-Inflammatory Effect> The dental polymerizable pulp capping material was formed into a shape having a diameter of 8 mm and a thickness of 1 mm, followed by being set in a culture kit (Transwell (registered trademark), manufactured by Corning Incorporated), and 500 ^L of human-derived dental pulp cells were seeded on the bottom surfaces of a 24-well plate at a concentration of 105 cells / well, and were cultured with addition of lipopolysaccharide (LPS). The expression level of inflammatory cytokines (IL6) on the first day of culturing was measured by RT-PCR (Real Time PCR System, manufactured by Thermo Fisher Scientific K.K.). The anti-inflammatory effect was evaluated according to the following criteria. The results of the anti-inflammatory effect are presented in Table 2.

[0078] [Evaluation Criteria] Very Good: the expression level of the inflammatory cytokines (IL6) on the first day of the culturing was less than 50% compared with the control group Good: the expression level of the inflammatory cytokines (IL6) on the first day of the culturing was 50% or greater and less than 90% compared with the control group Not Good: the expression level of the inflammatory cytokines (IL6) on the first day of the culturing was 90% or greater compared with the control group

[0079] <Radiopacity> The radiopacity of the glass composition was measured by a radiopacity test method for dental materials in accordance with ISO 13116:2014. Specifically, first, the optical density or gray value of a test piece (photopolymerized dental polymerizable pulp capping material) with a thickness Ts (unit: mm) was measured. Next, a thickness Ta (unit: mm) of an aluminum plate having the same optical density or gray value as the test piece with the thickness Ts was determined. Then, a ratio (unit:%) of Ta to Ts was used as a value of radiopacity. The results of the radiopacity are presented in Table 2.

[0080] [Evaluation Criteria] Acceptable: the value of radiopacity was 200% or greater 5 Not Acceptable: the value of radiopacity was less than 200%

[0081] [Table 2] Comp. Ex. 14.4 5.8 8.6 54.2 co 3.6 o 0.2 o 100 180 i i 10.8 CO CXI not good not good 220 CD CD 22 45 co 3.6 o 0.2 o 100 157 323 149 7.2 49 good very good 243 LO 00 CD 50 co 2.6 o 0.2 o 100 46 65 48 8.0 32 good good 259 CL E 21.7 co 40 CD co 60 o 0.2 o 100 102 178 59 8.9 42 good very good 234 ro X LU co 21.7 CO 56 co 0.9 o 0.2 o 100 56 LO CO 62 7.5 39 very good very good 270 CXJ 14.4 5.8 8.6 54.2 co 3.6 o 0.2 o 100 121 289 127 7.2 44 very good very good 267 00 LD 50 co 3.6 o 0.2 o 100 LO CO 214 84 00 43 very good very good 262 Compound name Bis-GMA UDMA TEGDMA GDMA A-1 A-2 A-3 B-1 strontium carbonate fumed silica camphorquinone ethyl p-dimethyl aminobenzonate 6-tert-buty|-2,4-xylenol Total calcium [ppm] zinc [ppm] fluorine [ppm] I Q. tion effect[VH] affinity matory effect Live to aluminum)[%] Polymerizable monomer Inorganic particles (glass powder) X-ray contrast agent Thickening agent Photopolymerization initiator Tertiary amine Polymerization inhibitor Sustained releasability Remineraliza Cell < anti-inflam Radiopacity (rela- [%ssew] UOI}ISOdlUOQ Evaluation results

[0082] According to Table 2, in Examples 1 to 6, the dental polymerizable pulp capping material composition, in which glass and polymerizable monomers were included, and the glass included phosphorus, calcium, zinc, and fluorine, had favorable results in all of the sustained releasability, pH, remineralization effect cell affinity, and anti-inflammatory effect. In addition, in Examples 1 to 6, the radiopaque material was further included, and therefore the favorable result of radiopacity was obtained.

[0083] Conversely, in Comparative Example 1, even though the dental polymerizable pulp capping material composition included the glass and the polymerizable monomer, the dental polymerizable pulp capping material composition, in which the glass did not include phosphorus, zinc, and fluorine, had unsatisfactory results in all of the sustained releasability, pH, remineralization effect cell affinity, and antiinflammatory effect.

[0084] Hereinafter, preferable aspects of the present invention will be additionally described.

[0085] <1> A dental polymerizable pulp capping material composition, including: glass; and one or more polymerizable monomers, wherein the glass includes phosphorus, calcium, zinc, and fluorine.

[0086] <2> The dental polymerizable pulp capping material composition according to <1>, wherein an amount of the glass is 30 percent by mass or greater and 70 percent by mass or less.

[0087] <3> The dental polymerizable pulp capping material composition according to <1>, or <2> wherein an amount of the one or more polymerizable monomers is 10 percent by mass or greater and 60 percent by mass or less.

[0088] <4> The dental polymerizable pulp capping material composition according to any one of <1> to <3>, wherein a particle size of the glass is 2 pm or greater and less than 10 pm.

[0089] <5> The dental polymerizable pulp capping material composition according to 5 any one of <1> to <4>, further including: a radiopaque material.

[0090] Although the embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments, and various 10 modifications and changes can be made within the invention described in the scope of the claims.

[0091] The present application claims priority to Japanese Patent Application No. 2024-048964 filed on March 26, 2024, the entire contents of which are incorporated 15 herein by reference.

Claims

SCOPE OF THE CLAIMS

1. A dental polymerizable pulp capping material composition,comprising:glass; andone or more polymerizable monomers, wherein the glass includes phosphorus, calcium, zinc, and fluorine.

2. The dental polymerizable pulp capping material compositionaccording to claim 1,wherein an amount of the glass is 30 percent by mass or greater and 70 percent by mass or less.

3. The dental polymerizable pulp capping material compositionaccording to claim 1,wherein an amount of the one or more polymerizable monomers is 10 percent by mass or greater and 60 percent by mass or less.

4. The dental polymerizable pulp capping material compositionaccording to claim 1,wherein a particle size of the glass is 2 pm or greater and less than 10 pm.

5. The dental polymerizable pulp capping material compositionaccording to any one of claims 1 to 4, further comprising:a radiopaque material.