Dental glass powder and dental composition

Abstract

To provide a dental glass powder that enables improvement of the antibacterial effect, the transparency, and the dental decalcification inhibitory effect of a cured product of glass ionomer cement.SOLUTION: A dental glass powder includes zinc, silicon, aluminum, calcium and fluorine. In the dental glass powder, the content of zinc is 15-40 mass% in terms of zinc oxide (ZnO), the content of silicon is 20-55 mass% in terms of silicon oxide (SiO2), the content of aluminum is 6-20 mass% in terms of aluminum oxide (Al2O3), the content of calcium is 1-13 mass% in terms of calcium oxide (CaO), and the content of fluorine (F) is 1-19 mass%.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a dental glass powder and a dental composition. [Background technology]

[0002] Aluminosilicate glass powders are well known as dental glass powders. Among aluminosilicate glass powders, fluoroaluminosilicate glass powders are widely used because they are expected to have an effect of inhibiting demineralization of dentin (see, for example, Patent Documents 1 and 2).

[0003] One known application of fluoroaluminosilicate glass powder is glass ionomer cement.

[0004] Glass ionomer cement generally has a powder component containing fluoroaluminosilicate glass powder, and a liquid component containing a polycarboxylic acid-based polymer and water. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 62-67008 [Patent Document 2] Japanese Patent Application Publication No. 63-201038 Summary of the Invention [Problem to be solved by the invention]

[0006] However, it is desired to improve the antibacterial effect, transparency, and tooth demineralization inhibitory effect of the hardened glass ionomer cement.

[0007] An object of one aspect of the present invention is to provide a dental glass powder and a dental composition that can improve the antibacterial effect, transparency, and tooth demineralization inhibitory effect of a hardened glass ionomer cement. [Means for solving the problem]

[0008] One aspect of the present invention is a dental glass powder comprising zinc, silicon, aluminum, calcium and fluorine, the zinc content being, in terms of zinc oxide (ZnO), 20 The silicon content is 40 mass% or less, and the silicon content is silicon oxide (SiO 2 ) is 30 to 55 mass %, and the aluminum content is aluminum oxide (Al 2 O 3 The content of calcium, converted into calcium oxide (CaO), is 1 to 13 mass%, and the content of fluorine (F) is 3 to 19 mass%.

[0009] Another aspect of the present invention is a dental composition comprising a glass powder, the glass powder comprising zinc, silicon, aluminum, calcium and fluorine, the zinc content being, in terms of zinc oxide (ZnO), 20 The silicon content is 40 mass% or less, and the silicon content is silicon oxide (SiO 2 ) is 30 to 55 mass %, and the aluminum content is aluminum oxide (Al 2 O 3 The content of calcium, converted into calcium oxide (CaO), is 1 to 13 mass%, and the content of fluorine (F) is 3 to 19 mass%. Effect of the Invention

[0010] According to one aspect of the present invention, a dental glass powder and a dental composition are provided that can improve the antibacterial effect, transparency, and tooth demineralization inhibitory effect of a hardened glass ionomer cement. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Next, an embodiment of the present invention will be described.

[0012] <Dental glass powder> The dental glass powder of this embodiment contains zinc, silicon, aluminum, calcium and fluorine.

[0013] The content of zinc in the dental glass powder of this embodiment, calculated as zinc oxide (ZnO), is 15 to 40 mass %, and preferably 20 to 30 mass %. When the content of zinc in the dental glass powder of this embodiment, calculated as zinc oxide (ZnO), is 15 mass % or more, the antibacterial effect of the cured body of the glass ionomer cement containing the dental glass powder of this embodiment is improved, and when it is 40 mass % or less, the transparency of the cured body of the glass ionomer cement containing the dental glass powder of this embodiment is improved.

[0014] The content of silicon in the dental glass powder of this embodiment is silicon oxide (SiO 2 The content of silicon in the dental glass powder of the present embodiment is 20 to 55 mass %, and preferably 30 to 50 mass %, calculated as silicon oxide (SiO 2 When the content, calculated as the total mass of the dental glass powder, is 20 mass % or more, the transparency of the hardened body of the glass ionomer cement containing the dental glass powder of the present embodiment is improved, and when the content is 55 mass % or less, the dental glass powder of the present embodiment is easily produced.

[0015] The content of aluminum in the dental glass powder of this embodiment is aluminum oxide (Al 2 O 3 The content of aluminum in the dental glass powder of the present embodiment is 6 to 20 mass %, and preferably 7 to 16 mass %, calculated as aluminum oxide (Al 2 O 3 When the content, calculated as the total mass of the dental glass powder, is 6 mass % or more, the transparency of the hardened body of the glass ionomer cement containing the dental glass powder of the present embodiment is improved, and when the content is 20 mass % or less, the dental glass powder of the present embodiment is easily produced.

[0016] The content of calcium in the dental glass powder of this embodiment, calculated as calcium oxide (CaO), is 1 to 13 mass%, and preferably 5 to 13 mass%. When the content of calcium in the dental glass powder of this embodiment, calculated as calcium oxide (CaO), is 1 mass% or more, the effect of inhibiting dentin demineralization of the hardened body of the glass ionomer cement containing the dental glass powder of this embodiment is improved, and when it is 13 mass% or less, the dental glass powder of this embodiment is easily produced.

[0017] The fluorine (F) content in the dental glass powder of this embodiment is 1 to 19 mass%, and preferably 3 to 15 mass%. When the fluorine (F) content in the dental glass powder of this embodiment is 1 mass% or more, the dentin demineralization inhibitory effect of the hardened body of the glass ionomer cement containing the dental glass powder of this embodiment is improved, and when it is 19 mass% or less, the dental glass powder of this embodiment is easily produced.

[0018] The dental glass powder of this embodiment may further contain boron, phosphorus, sodium, and the like.

[0019] The content of boron in the dental glass powder of this embodiment is boron oxide (B 2 O 3 The boron content in the dental glass powder of the present embodiment is preferably 0 to 15% by mass, and more preferably 0 to 10% by mass, calculated as boron oxide (B 2 O 3 When the content, calculated as the total amount of the inorganic particles, is 15 mass % or less, the dental glass powder of the present embodiment can be easily produced.

[0020] The content of phosphorus in the dental glass powder of this embodiment is phosphorus (V) oxide (P 2 O 5 The content of phosphorus in the dental glass powder of the present embodiment is preferably 0 to 10 mass %, and more preferably 0 to 7 mass %, calculated as phosphorus (V) oxide (P 2 O 5When the amount of the dental glass powder is 10 mass % or less, calculated as the total mass of the glass ionomer cement, the handling properties of the glass ionomer cement containing the dental glass powder of this embodiment are improved.

[0021] The sodium content in the dental glass powder of the present embodiment is sodium oxide (Na 2 The content of sodium in the dental glass powder of the present embodiment is preferably 0 to 10 mass %, and more preferably 1 to 5 mass %, calculated as sodium oxide (Na O). 2 When the amount calculated as total amount of fluorine-containing compound (C) is 10 mass % or less, the dental glass powder of this embodiment can be easily produced.

[0022] An example of the composition of the dental glass powder of this embodiment is shown below.

[0023] ZnO: 15~40% by mass SiO 2 :20~55% by mass Al 2 O 3 :6~20% by mass CaO: 1~13% by mass F: 1~19% by mass B 2 O 3 :0~10% by mass P 2 O 5 :0~10% by mass Na 2 O: 0~10% by mass The number average particle size of the dental glass powder of this embodiment is preferably 0.02 to 30 μm, and more preferably 0.02 to 20 μm. When the number average particle size of the dental glass powder of this embodiment is 0.02 μm or more, the operability of the glass ionomer cement containing the dental glass powder of this embodiment is improved, and when it is 30 μm or less, the wear resistance of the hardened glass ionomer cement containing the dental glass powder of this embodiment is improved.

[0024] <Method of manufacturing dental glass powder> The dental glass powder of this embodiment can be produced by melting a raw material composition and then pulverizing the melt.

[0025] Examples of raw materials corresponding to zinc include zinc oxide and zinc fluoride, and two or more of these may be used in combination.

[0026] Examples of raw materials corresponding to silicon include silicic anhydride, and two or more of these may be used in combination.

[0027] Examples of raw materials corresponding to aluminum include aluminum oxide, aluminum fluoride, and artificial cryolite, and two or more of these may be used in combination.

[0028] Examples of raw materials corresponding to calcium include calcium fluoride, calcium phosphate, calcium carbonate, calcium hydroxide, etc., and two or more of these may be used in combination.

[0029] Examples of raw materials corresponding to fluorine include calcium fluoride, strontium fluoride, sodium fluoride, etc., and two or more of these may be used in combination.

[0030] Examples of raw materials corresponding to phosphorus include calcium phosphate, strontium phosphate, sodium dihydrogen phosphate, etc., and two or more of them may be used in combination.

[0031] The raw material corresponding to boron includes, for example, boron oxide, etc., and two or more kinds of them may be used in combination.

[0032] Examples of raw materials corresponding to sodium include sodium dihydrogen phosphate, sodium carbonate, sodium fluoride, etc., and two or more of these may be used in combination.

[0033] <Dental Composition> The dental composition of this embodiment contains the dental glass powder of this embodiment.

[0034] Examples of the dental composition of the present embodiment include cements such as glass ionomer cements and resin cements, polymerizable compositions such as composite resins, primers, adhesives, etc., with glass ionomer cements being preferred.

[0035] <Glass ionomer cement> Examples of glass ionomer cements include powder-liquid type glass ionomer cements having a powder component containing the dental fluoroaluminosilicate glass powder of this embodiment, a polycarboxylic acid polymer, and a liquid component containing water.

[0036] The polycarboxylic acid polymer is not particularly limited, but for example, a homopolymer or copolymer of an α,β-unsaturated carboxylic acid can be used.

[0037] Examples of the α,β-unsaturated carboxylic acid include acrylic acid, methacrylic acid, 2-chloroacrylic acid, 3-chloroacrylic acid, aconitic acid, mesaconic acid, maleic acid, itaconic acid, fumaric acid, glutaconic acid, and citraconic acid.

[0038] The polycarboxylic acid polymer may also be a copolymer of an α,β-unsaturated carboxylic acid and a monomer capable of copolymerizing with the α,β-unsaturated carboxylic acid.

[0039] Examples of components capable of copolymerizing with the α,β-unsaturated carboxylic acid include acrylamide, acrylonitrile, methacrylic acid esters, acrylates, vinyl chloride, allyl chloride, and vinyl acetate.

[0040] In this case, the ratio of the α,β-unsaturated carboxylic acid to the monomers constituting the polycarboxylic acid polymer is preferably 50% by mass or more.

[0041] The polycarboxylic acid polymer is preferably a homopolymer or copolymer of acrylic acid or itaconic acid.

[0042] The content of the polycarboxylic acid polymer in the liquid component is usually 5 to 60% by mass.

[0043] The water content in the liquid component is usually 30 to 70 mass %.

[0044] The liquid component may further contain an organic polybasic acid.

[0045] Examples of organic polybasic acids include polybasic carboxylic acids such as citric acid, malic acid, succinic acid, and gluconic acid, and ascorbic acid.

[0046] The content of the organic polybasic acid in the liquid component is usually 5 to 30 mass %.

[0047] At least a part of the polycarboxylic acid polymer may be contained as a powder component.

[0048] The powder component may further include a fluoroaluminosilicate glass powder.

[0049] Fluoroaluminosilicate glass powders typically contain silicon, aluminum, fluorine, phosphorus, sodium, and strontium.

[0050] The silicon content in fluoroaluminosilicate glass powder is determined by the amount of silicon oxide (SiO 2 ) and is usually 15 to 50 mass %.

[0051] The aluminum content in the fluoroaluminosilicate glass powder is expressed as aluminum oxide (Al 2 O 3 ) and is usually 15 to 35 mass %.

[0052] The fluorine (F) content in the fluoroaluminosilicate glass powder is usually 1 to 30 mass %.

[0053] The phosphorus content in fluoroaluminosilicate glass powder is phosphorus(V) oxide(P2 O 5 ) and is usually 0 to 10 mass %.

[0054] The sodium content in the fluoroaluminosilicate glass powder is expressed as sodium oxide (Na 2 O), and is usually 0 to 15 mass %.

[0055] The strontium content in the fluoroaluminosilicate glass powder is usually 0 to 40 mass % calculated as strontium oxide (SrO).

[0056] The fluoroaluminosilicate glass powder may further contain calcium, potassium, lanthanum, and the like.

[0057] The mass ratio of the fluoroaluminosilicate glass powder to the dental fluoroaluminosilicate glass powder of this embodiment is preferably 0.3 to 4, and more preferably 0.5 to 3. When the mass ratio of the fluoroaluminosilicate glass powder to the dental fluoroaluminosilicate glass powder of this embodiment is 0.3 or more, the strength of the hardened body of the glass ionomer cement is improved, and when it is 4 or less, the antibacterial effect, transparency, and tooth demineralization inhibitory effect of the hardened body of the glass ionomer cement are improved.

[0058] Powder-liquid type glass ionomer cement is used by mixing the powder component and the liquid component.

[0059] When the powder component and the liquid component are mixed, the mass ratio of the powder component to the liquid component (hereinafter referred to as the powder-liquid ratio) is preferably 1 to 5, and more preferably 2.8 to 4.0. When the powder-liquid ratio is 1 or more, the compressive strength of the hardened body of the glass ionomer cement is improved, and when it is 5 or less, the powder component and the liquid component are easily mixed.

[0060] Other examples of glass ionomer cements include two-paste type glass ionomer cements having a first paste containing the dental glass powder of this embodiment and water or (meth)acrylate, and a second paste containing a polycarboxylic acid polymer and water.

[0061] Two-paste glass ionomer cements are used by mixing the first and second pastes. EXAMPLES

[0062] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0063] <Examples 1 to 6 and Comparative Examples 1 to 7> Zinc oxide (ZnO), silica (SiO 2 ), aluminum oxide (Al 2 O 3 ), aluminum fluoride (AlF 3 ), artificial cryolite (Na 3 AlF 6 ), calcium fluoride (CaF 2 ), calcium carbonate (CaCO 3 ), phosphorus oxide (P 2 O 5 ), boron oxide (B 2 O 3 ), sodium fluoride (NaF), strontium fluoride (SrF 2 ), strontium carbonate (SrCO 3 ), lanthanum oxide (La 2 O 3 ) were mixed in a predetermined ratio, and then thoroughly mixed and stirred in a mortar to obtain a raw material composition. The raw material composition was placed in a platinum crucible, which was then placed in an electric furnace. The electric furnace was heated to 1450°C to melt the raw material composition and thoroughly homogenize it, and then poured into water to obtain a lump of glass. The lump of glass was pulverized for 4 hours using an alumina ball mill, and then passed through a 120 mesh sieve to obtain glass powder.

[0064] Next, the composition and number average particle size of the glass powder were evaluated.

[0065] <Glass powder composition> The glass powder was analyzed using a fluorescent X-ray analyzer ZSX Primus II (manufactured by Rigaku) ​​to determine the composition.

[0066] <Number average particle size of glass powder> The number average particle size of the glass powder was measured using a laser diffraction scattering type particle size distribution analyzer LA-950 (manufactured by Horiba, Ltd.).

[0067] Next, the antibacterial effect, transparency, and tooth demineralization inhibitory effect of the hardened glass ionomer cement containing glass powder were evaluated.

[0068] <Preparation of glass ionomer cement mixture> A powder component was obtained by mixing 40% by mass of glass powder and 60% by mass of fluorosilicate glass powder. Here, the fluorosilicate glass powder has a composition of SiO 2 (26.8% by mass), Al 2 O 3 (23.9% by mass), F (14.3% by mass), SrO (33.0% by mass), P 2 O 5 (1.4% by mass), Na 2 O (0.6 mass%) and the number average particle size is 7.6 μm.

[0069] A liquid component was obtained by mixing 40% by mass of polyacrylic acid, 50% by mass of water, and 10% by mass of citric acid.

[0070] The powder and liquid components were mixed at a powder-liquid ratio of 2.8 to obtain a glass ionomer cement mixture.

[0071] <Antibacterial effect> A mold with a diameter of 10 mm and a thickness of 2 mm was filled with the glass ionomer cement mixture, and then left to stand for 1 hour at 37°C and 90% RH to harden the glass ionomer cement mixture and obtain a hardened body. The hardened body was then removed from the mold and immersed in 10 mL of brain heart infusion (BHI) medium for 24 hours. After removing the hardened body from the BHI medium, Streptococcus mutans (S. mutans) was seeded so that the OD540 value was 0.01 and cultured at 37°C for 24 hours. The OD540 value of the BHI medium in which S. mutans was cultured was then measured to evaluate the antibacterial effect.

[0072] Here, the OD540 value means the optical density of light with a wavelength of 540 nm, and was measured using a plate reader SpectraMax M2 (Molecular Devices Japan).

[0073] The criteria for judging the antibacterial effect are as follows: The smaller the OD540 value, the higher the antibacterial effect.

[0074] Excellent: OD540 value is less than 0.10 Good: OD540 value is 0.10 or more but less than 0.15 Not acceptable: OD540 value is 0.15 or more <Transparency> The glass ionomer cement mixture was filled into a mold with a diameter of 15 mm and a thickness of 0.5 mm, and then left to stand for 1 hour in an environment of 37°C and 90% RH to harden the glass ionomer cement mixture and obtain a hardened body. Next, the hardened body was removed from the mold, and the L value on a white background and the L value on a black background were measured using a colorimeter. Next, the difference (ΔL) between the L value on a white background and the L value on a black background was calculated.

[0075] The criteria for judging transparency are as follows: Here, the larger ΔL is, the higher the transparency is.

[0076] Excellent: ΔL is 13 or more Good: ΔL is 10 or more and less than 13 Not acceptable: If ΔL is less than 10 <Effect of inhibiting tooth demineralization> Bovine dentin was polished with waterproof abrasive paper #1200 under water injection, and a polytetrafluoroethylene seal with a 3 mm diameter hole was attached to the polished surface. Next, a glass ionomer cement mixture was applied to half of the polished surface that corresponded to the seal hole, and the glass ionomer cement mixture was left in a constant temperature and humidity chamber at 37°C and 100% RH for 24 hours to harden, forming a hardened body.

[0077] The bovine dentin on which the hardened body had formed was immersed for 24 hours in a demineralizing solution (50 mM acetic acid, 1.5 mM calcium chloride, 0.9 mM potassium dihydrogen phosphate, pH 4.5) at 37°C. At this time, the surface of the polished surface that did not form a hardened body and that came into contact with the demineralizing solution corresponding to the hole in the seal was used as the test surface.

[0078] Using a precision cutting machine, the bovine dentin on which the hardened body had formed was cut to a thickness of 1 mm to obtain a test specimen.

[0079] The test surface of the test specimen was photographed using an X-ray device, and the image of the test surface was then analyzed using image processing software to determine the amount of mineral loss and evaluate the effect of inhibiting tooth demineralization.

[0080] The dentin demineralization inhibitory effect was evaluated based on the following criteria: The smaller the amount of mineral loss, the higher the dentin demineralization inhibitory effect.

[0081] Excellent: Mineral loss is less than 2300 vol%·μm Good: Mineral loss is between 2300 vol%·μm and 2600 vol%·μm Not acceptable: Mineral loss is 2600 vol%·μm or more Next, the inhibitory effect on dentin demineralization was evaluated in the same manner as above, except that the glass ionomer cement mixture was not applied. The amount of mineral loss was found to be 4557 vol.%·μm or more.

[0082] Table 1 shows the evaluation results of the antibacterial effect, transparency, and tooth demineralization inhibitory effect of the hardened glass ionomer cement.

[0083] [Table 1] From Table 1, it can be seen that the glass ionomer cements having a powder component containing the glass powder of Examples 1 to 6 have high antibacterial effect, transparency, and tooth demineralization inhibitory effect in the hardened body.

[0084] In contrast, since the glass powder of Comparative Example 1 does not contain zinc or calcium, the glass ionomer cement having a powder component including the glass powder of Comparative Example 1 has low antibacterial effect and tooth demineralization inhibitory effect of the hardened body.

[0085] The glass powder of Comparative Example 2 did not contain zinc and had a calcium content of 0.1 mass%, calculated as calcium oxide (CaO). Therefore, the glass ionomer cement having a powder component including the glass powder of Comparative Example 2 had low antibacterial effect and low tooth demineralization inhibitory effect in the hardened body.

[0086] The glass powder of Comparative Example 3 had a zinc content of 40.5 mass%, calculated as zinc oxide (ZnO), so the glass ionomer cement having a powder component including the glass powder of Comparative Example 3 had low transparency in the hardened body.

[0087] The glass powder of Comparative Example 4 had a zinc content of 10.6 mass%, calculated as zinc oxide (ZnO), so the glass ionomer cement having a powder component containing the glass powder of Comparative Example 4 had a low antibacterial effect when hardened.

[0088] Since the glass powder of Comparative Example 5 does not contain calcium, the glass ionomer cement having a powder component containing the glass powder of Comparative Example 5 has a low effect of inhibiting tooth demineralization in the hardened body.

[0089] Since the glass powder of Comparative Example 6 does not contain aluminum, the glass ionomer cement having a powder component including the glass powder of Comparative Example 6 has low transparency in the hardened body.

[0090] Since the glass powder of Comparative Example 7 does not contain fluorine, the glass ionomer cement having a powder component including the glass powder of Comparative Example 7 has a low effect of inhibiting tooth demineralization in the hardened body.

Claims

1. Contains zinc, silicon, aluminum, calcium and fluorine, The zinc content, calculated as zinc oxide (ZnO), is 20 to 40 mass %, The silicon content is silicon oxide (SiO ２ ) is 30 to 55 mass %, The aluminum content is aluminum oxide (Al ２ O ３ ) is 6 to 20 mass %, The calcium content, calculated as calcium oxide (CaO), is 1 to 13 mass %, A dental glass powder having a fluorine (F) content of 3 to 19 mass %.

2. further comprising boron; The boron content is boron oxide (B ２ O ３ 2. The dental glass powder according to claim 1, wherein the content of the glass powder in the dental glass powder is 0 to 15% by mass, calculated as the content of the glass powder in the dental glass powder.

3. Further containing phosphorus, The phosphorus content is phosphorus oxide (V) (P ２ O ５ 3. The dental glass powder according to claim 1, wherein the content of the glass powder in the dental glass powder is 0 to 10% by mass, calculated as the total mass of the glass powder.

4. It further contains sodium, The sodium content is sodium oxide (Na ２ 4. The dental glass powder according to claim 1, wherein the content of the glass powder in terms of the total amount of the inorganic filler is 0 to 10% by mass.

5. The dental glass powder according to claim 1 , which is used in a dental composition.

6. A dental composition comprising a glass powder, The glass powder contains zinc, silicon, aluminum, calcium, and fluorine, and the zinc content is 20 to 40 mass % in terms of zinc oxide (ZnO), and the silicon content is silicon oxide (SiO ２ The aluminum content is 30 to 55 mass % in terms of aluminum oxide (Al ２ O ３ %, the calcium content is 1 to 13 mass% calculated as calcium oxide (CaO), and the fluorine (F) content is 3 to 19 mass%.

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