Dental porcelain composition and method for manufacturing the same

Abstract

The present invention provides a dental porcelain composition and a method for manufacturing the same, which do not require skilled techniques, suppress sagging during the dental laboratory work and shrinkage after firing, and provide a porcelain layer with excellent aesthetics after firing. [Solution] A dental porcelain composition comprising glass (A) and an organic solvent (B) having a boiling point of 100 to 300°C, wherein glass (A) comprises a base glass (A-1) with a particle size D50 of 2 to 8 μm and a base glass (A-2) with a particle size D50 of 25 to 45 μm, and the particle size of glass (A) is D10 ≤ 5 μm, 5 μm

Description

[Technical Field]

[0001] The present invention relates to a dental porcelain composition and a method for producing the same, which can be used in dental prosthetic devices, particularly those made of ceramics, glass ceramics, or glass. [Background technology]

[0002] There is a growing demand for core materials that are less allergenic and offer excellent strength and aesthetics, such as alumina and zirconia (oxide ceramics) and feldspar-based glass and lithium silicate glass (glass ceramics), for the fabrication of dental prosthetic devices such as inlays, crowns, and bridges. In recent years, with the development of CAD / CAM technology, the shapes of dental prosthetic devices can be easily fabricated from these core materials. However, in order to ensure a proper fit for the actual patient, there are cases where a small porcelain layer (add-on) is needed to be added to the shape of the adjacent tooth surface of the dental prosthetic device or the pontic portion of the bridge, which has been fabricated in a dental laboratory. Such minor adjustments are performed not only in dental laboratories but also in dental clinics, and require speed.

[0003] Patent Document 1 discloses dental porcelain powder as a material for partial modification of dental prosthetic devices made of ceramics or glass ceramics. The method is characterized by forming a slurry of porcelain powder with a mixing liquid, repeatedly condensing and absorbing water to create a porcelain layer, and then firing it.

[0004] Patent Document 2 discloses a dental porcelain paste that is less likely to dry out and harden during use. It is characterized by being a paste made by mixing 7 to 45 parts by weight of an organic solvent with a viscosity of 50,000 to 1,500,000 cps, which is a dissolved polymer material, with 100 parts by weight of a base glass powder with an average particle size of 10 μm. By applying the porcelain paste and firing it, the organic components are burned away, and only the porcelain layer can be applied. In particular, operations such as condensation and water absorption are not required, making dental laboratory work simpler. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2017-193492 [Patent Document 2] Japanese Patent Publication No. 2001-079019 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, the prior art described in Patent Documents 1 and 2 has its problems. The method described in Patent Document 1, which involves slurrying porcelain powder with a mixing liquid and repeatedly condensing and absorbing water, requires skilled techniques and is undesirable, especially for partial restoration work where speed is required in a dental clinic. Furthermore, when a porcelain paste that does not require skilled techniques is used, as described in Patent Document 2, organic components that have not been removed remain until the firing of the porcelain begins, which can lead to paste dripping during the laboratory work and shrinkage such as peeling or cracking of the porcelain layer after firing.

[0007] The problem that the present invention aims to solve is to provide a dental porcelain composition and a method for manufacturing the same that can be used in dental prosthetic devices, particularly those made of ceramics, glass ceramics, or glass, that does not require skilled techniques, suppresses sagging during laboratory work and shrinkage after firing, and exhibits excellent aesthetics after firing. [Means for solving the problem]

[0008] As a result of diligent research to solve the above problems, we have found that the above problems can be solved by combining two types of base glass having a specific particle size distribution and adding an organic solvent having a specific boiling point. The present invention encompasses the following:

[0009] The present invention relates to a dental porcelain composition comprising glass (A) and an organic solvent (B) having a boiling point of 100 to 300°C, Glass (A) contains base glass (A-1) with a particle size D50 of 2 to 8 μm and base glass (A-2) with a particle size D50 of 25 to 45 μm, and A dental ceramic composition is provided in which the particle size of glass (A) is D10 ≤ 5 μm, 5 μm < D50 < 28 μm, and 28 μm ≤ D90.

[0010] The present invention is a method for producing a dental ceramic composition, which is produced by mixing base glass (A-1) with a particle size D50 of 2 to 8 μm, base glass (A-2) with a particle size D50 of 25 to 45 μm, and an organic solvent (B) with a boiling point of 100 to 300 °C. Here, a production method is provided, characterized in that the particle size of glass (A) containing base glass (A-1) and base glass (A-2) is D10 ≤ 5 μm, 5 μm < D50 < 28 μm, and 28 μm ≤ D90.

[0011] The present invention provides a method for manufacturing a dental prosthetic device by applying and firing the dental ceramic composition of the present invention to a core material.

[0012] The present invention is a kit for a dental ceramic composition for producing a dental ceramic composition, comprising: Base glass (A-1) with a particle size D50 of 2 to 8 μm, Base glass (A-2) with D50 of 25 to 45 μm, and An organic solvent (B) with a boiling point of 100 to 300 °C A kit for a dental ceramic composition is provided.

Advantages of the Invention

[0013] According to the present invention, it can be used for dental prosthetic devices, particularly those made of ceramics, glass ceramics, and glass. It does not require skilled techniques, suppresses sagging during the technician's work and shrinkage after firing, and provides a dental ceramic composition and its manufacturing method with excellent aesthetics after firing. Also, according to the present invention, a dental ceramic composition and its manufacturing method with excellent sagging properties during the technician's work and aesthetics after firing can be provided.

Brief Description of the Drawings

[0014] [Figure 1] It is an external view showing the shape of the zirconia base material used in the test. [Figure 2] It is a front view showing the shape of the zirconia base material used in the test. [Figure 3] It is a cross-sectional view showing the shape of the zirconia base material used in the test.

Embodiments for Carrying out the Invention

[0015] The dental ceramic material composition of the present invention is a dental ceramic material composition containing glass (A) and an organic solvent (B) having a boiling point of 100 to 300 °C. The glass (A) includes a base glass (A-1) having a particle size D50 of 2 to 8 μm and a base glass (A-2) having a particle size D50 of 25 to 45 μm, and the particle size of the glass (A) satisfies D10 ≤ 5 μm, 5 μm < D50 < 28 μm, and 28 μm ≤ D90.

[0016] In the present invention, the mixing ratio of the base glass (A-1) and the base glass (A-2) can be 9:1 to 1:9 by mass ratio.

[0017] In the present invention, (D90 - D10) / D50 of the particle size of the glass (A) can be 2.8 or more.

[0018] In the present invention, the softening point of the base glass (A-1) and the base glass (A-2) conforming to "Dentistry - Ceramic materials" of ISO6872:2015 / Amd.1:2018 can be 650 °C or lower.

[0019] In the present invention, the difference in the softening point of the base glass (A-1) and the base glass (A-2) conforming to "Dentistry - Ceramic materials" of ISO6872:2015 / Amd.1:2018 can be less than 100 °C.

[0020] In the present invention, the amount of organic solvent (B) blended with 100 parts by mass of glass (A) can be 10 to 200 parts by mass.

[0021] In the present invention, the organic solvent (B) can consist only of organic solvents having a boiling point of 250°C or lower.

[0022] In the present invention, glass (A) may include only base glass (A-1) and base glass (A-2).

[0023] The present invention provides a method for producing a dental porcelain composition, which involves mixing a base glass (A-1) with a particle size D50 of 2 to 8 μm, a base glass (A-2) with a D50 of 25 to 45 μm, and an organic solvent (B) with a boiling point of 100 to 300°C, wherein the particle size of the glass (A) containing base glass (A-1) and base glass (A-2) is D10 ≤ 5 μm, 5 μm. <D50<28μm、28μm≦D90である。

[0024] The present invention provides a method for producing a dental porcelain composition comprising the steps of: mixing a base glass (A-1) and a base glass (A-2) to produce a powder; and mixing an organic solvent (B) with the powder.

[0025] The present invention provides a method for producing a dental porcelain composition comprising the steps of: kneading a base glass (A-1) and an organic solvent (B) to produce a paste; and mixing a base glass (A-2) into the paste.

[0026] The method for manufacturing a dental prosthetic device according to the present invention involves applying the dental porcelain composition of the present invention to a core material and firing it to manufacture the dental prosthetic device.

[0027] In the present invention, the core material can be made of ceramics, glass ceramics, or glass.

[0028] The kit for producing the dental ceramic composition of the present invention is Substrate glass (A-1) with particle size D50 of 2-8 μm, Substrate glass (A-2) with a D50 of 25-45 μm, and Organic solvents (B) with a boiling point of 100-300°C This is a kit for dental porcelain compositions that includes [the specified features].

[0029] [Regarding dental ceramic compositions] The glass layer obtained by firing the dental porcelain composition of the present invention once or multiple times is not particularly limited, but can be built up with a layer thickness of 1.0 mm or less, preferably 0.8 mm or less, and more preferably 0.5 mm or less, relative to the core material. The "core material" in the present invention is a material that constitutes a dental prosthesis, particularly a dental prosthesis made of ceramics, glass ceramics, or glass. For example, it can be an oxide ceramic such as alumina or zirconia, or a glass or glass ceramic such as feldspar-based glass or lithium silicate glass. The "layer thickness" of the glass layer in the present invention represents the numerical value of the rise of the porcelain layer surface after firing relative to the core material surface before firing, and can be easily measured using a micrometer, caliper, dental laboratory thickness gauge, etc., with the core material surface before firing as the reference plane.

[0030] The firing temperature for the dental porcelain composition of the present invention (hereinafter referred to as the firing temperature) is generally selected to be in the range of 650 to 1000°C. If firing is performed at a temperature below 650°C, the organic solvent applied at the same time may not be fired sufficiently and may carbonize, making it impossible to obtain the desired color tone. Furthermore, if firing is performed at a temperature higher than 1000°C, deformation of the core material itself or sagging of the dental porcelain composition may occur. In particular, the dental porcelain composition of the present invention can be fired at 650 to 850°C, making it applicable to core materials made of lithium disilicate-based glass ceramics, which may deform if fired at temperatures higher than 850°C.

[0031] The dental porcelain composition of the present invention may be fired only once. Alternatively, it can be fired multiple times, such as by building up and firing the dental porcelain composition, then building up and firing it again. Such firing can be carried out using a dental laboratory porcelain firing furnace equipped with an external drying mechanism, capable of vacuum firing at a heating rate of 10 to 100°C / min and a firing temperature range of 100 to 1200°C.

[0032] [Glass (A)] The dental porcelain composition of the present invention contains glass (A). Glass (A) is a glass component that melts upon firing and bonds with the core material. The dental porcelain composition of the present invention may contain only glass (A) as the glass component. In other words, the dental porcelain composition of the present invention may not contain any glass components other than glass (A).

[0033] Glass (A) is composed of two or more base glass materials, including at least two base glass materials (A-1) and base glass materials (A-2). Glass (A) may include base glass materials (A-3) other than base glass materials (A-1) and base glass materials (A-2). Glass (A) can be composed of base glass materials (A-1) and base glass materials (A-2). The dental porcelain composition of the present invention may not contain base glass materials (A-3) other than base glass materials (A-1) and base glass materials (A-2). By using only base glass materials (A-1) and base glass materials (A-2) as glass components in the dental porcelain composition of the present invention, the effort of mixing multiple glasses and the process of manufacturing multiple glasses are not required, thus simplifying the manufacturing process of the dental porcelain composition of the present invention.

[0034] The glass (A) satisfies D10, D50, and D90 which are particle diameters, where D10≤5 μm, 5 μm<D50<28 μm, and 28 μm≤D90, respectively. Furthermore, it can be D10≤4 μm, 6 μm<D50<25 μm, and 32 μm≤D90, and it can be D10≤3 μm, 7 μm<D50<20 μm, and 36 μm≤D90. By setting such numerical ranges, the range of the adjustment amount of the organic solvent (B) for enabling the use of the paste-like or slurry-like dental ceramic composition prepared by mixing the glass (A) and the organic solvent (B) without dripping becomes wider, and it may be possible to suppress the occurrence of sink marks. In the present invention, "D10", "D50", and "D90" respectively indicate the particle diameters at which the cumulative distribution functions of the particle size distribution are 10%, 50%, and 90%. The particle diameter of the glass (A) can be determined by a measurement method using, for example, a laser diffraction / scattering method, a dynamic light scattering method, a centrifugal sedimentation method, an electrical sensing zone method, a sieving method, a photon correlation method, or the like.

[0035] The value calculated from (D90 - D10) / D50 in the particle diameter of the glass (A) can be 2.8 or more. Furthermore, it can be 3.0 or more, and it can be 3.2 or more. The larger this numerical value is, the wider the particle size distribution can be recognized. Thereby, the range of the adjustment amount of the organic solvent (B) for enabling the use of the paste-like or slurry-like dental ceramic composition prepared by mixing the glass (A) and the organic solvent (B) without dripping becomes wider, and it may be possible to suppress the occurrence of sink marks. Also, for example, when the value calculated from (D90 - D10) / D50 is less than 2.8, the range of the adjustment amount of the organic solvent (B) for enabling the use of the paste-like or slurry-like dental ceramic composition prepared by mixing with the organic solvent (B) without dripping becomes narrower, and it may cause sink marks.

[0036] Substrate glass (A-1) and substrate glass (A-2) have different particle sizes D50. The particle size D50 of substrate glass (A-1) is 2-8 μm, and can be 4-6 μm. The particle size D50 of substrate glass (A-2) is 25-45 μm, and can be 30-40 μm. When substrate glass (A-1) or (A-2) is used alone, the range of adjustment for the amount of organic solvent (B) required to use the paste-like or slurry-like dental porcelain composition prepared by mixing it with organic solvent (B) without dripping becomes narrow, making the dental laboratory work more difficult. If the D50 of the base glass (A-1) is less than 2 μm or greater than 8 μm, or if the D50 of the base glass (A-2) is less than 25 μm or greater than 45 μm, the range of adjustment for the mixing of organic solvent (B) to ensure that the paste-like or slurry-like dental porcelain composition prepared by mixing with organic solvent (B) does not drip becomes narrower, which can make the dental laboratory work more difficult.

[0037] The mixing ratio of base glass (A-1) and base glass (A-2) in glass (A) is not particularly limited, but can be 1:9 to 9:1 by mass, 1:4 to 4:1, or even 2:3 to 3:2. This broadens the range of adjustment for the mixing of organic solvent (B) so that the paste-like or slurry-like dental porcelain composition prepared by mixing with organic solvent (B) can be used without dripping, and a sufficient coating thickness for a single coat can be secured without causing shrinkage. In particular, by using glass (A) of the present invention, for example, even if the dental porcelain composition applied to the core material does not require repeated condensation and / or water absorption treatment (i.e., even if the applied dental porcelain composition contains organic solvent (B)), a coating thickness of 0.6 mm or less, 0.4 mm or less, or even 0.2 mm or less can be applied in a single coat without causing shrinkage after firing. In this invention, "coating thickness" refers to the numerical value of the rise of the dental porcelain composition layer surface before firing, with the core material surface before firing as the reference plane. If the mixing ratio of base glass (A-1) and base glass (A-2) in glass (A) is outside the range of 1:9 to 9:1 by mass ratio, the range of adjustment for the mixing of organic solvent (B) that allows the paste-like or slurry-like dental porcelain composition prepared by mixing with organic solvent (B) to be used without dripping becomes narrower, and shrinkage may occur.

[0038] The manufacturing methods for base glass (A-1) and base glass (A-2) can be carried out without limitation using the general glass composition manufacturing equipment and methods owned by the company. A general manufacturing method involves blending various inorganic compounds (which may include colorants (C), fluorescent agents (D), and paste-forming stabilizers (E) if present) to obtain the desired glass composition, and melting them at 1300-1500°C using a glass melting furnace. The molten mixture is then rapidly cooled (quenched) in water to obtain glass frit. To obtain base glass with the desired particle size from the glass frit obtained by this method, it is necessary to powder it. As a method of powdering, for example, the glass frit mentioned above can be crushed using a crusher such as a rotary ball mill, vibrating ball mill, planetary mill, jet mill, bead mill, roll crusher, or jaw crusher. In addition to crushing the base glass, classification can be performed using sieves or elutriation as needed to uniformly adjust the particle size of the base glass. Furthermore, if present, colorants (C), fluorescent agents (D), and paste-forming stabilizers (E) can be mixed in.

[0039] Substrate glass (A-1) and substrate glass (A-2) have an elution amount of 50 μg / cm³, for example, in accordance with ISO 6872:2015 / Amd.1:2018 "Dentistry - Ceramic materials". 2 The following is possible: 35 μg / cm³ 2 It can be as follows: 20 μg / cm³ 2 The following is possible: Elution amount of 50 μg / cm³ 2 By doing the following, a dental porcelain composition that satisfies the requirements of the ISO standard can be obtained.

[0040] The base glass (A-1) and the base glass (A-2) can have a flexural strength of 50 MPa or more, 80 MPa or more, and 100 MPa or more, for example, in accordance with "Dentistry-Ceramic materials" of ISO6872:2015 / Amd.1:2018. By setting the flexural strength to 50 MPa or more, a dental ceramic composition that meets the required values of the ISO standard can be obtained.

[0041] The base glass (A-1) and the base glass (A-2) have a coefficient of thermal expansion in the range of 7.0 to 14.0×10 -6 K -1 and can be in the range of 7.5 to 11.0×10 -6 K -1 The dental ceramic paste of the present invention is used, for example, for the purpose of adhering to the upper part of a core material made of oxide ceramics or glass ceramics. The coefficient of thermal expansion of these core materials is about 10.0 to 11.0×10 -6 K -1 Therefore, by setting the coefficient of thermal expansion of the dental ceramic composition to a slightly lower range than this, the occurrence of cracks during the production of dental prosthetic devices can be suppressed.

[0042] The glass transition temperature of the base glass (A-1) and the base glass (A-2) is not particularly limited, but for example, the glass transition temperature (Tg) in accordance with "Dentistry-Ceramic materials" of ISO6872:2015 / Amd.1:2018 can be 400 to 600 °C, and further can be 450 to 550 °C. By using a base glass with a glass transition temperature of 400 to 600 °C, it becomes possible to fire the dental ceramic composition in a temperature range of 650 to 850 °C, and it becomes applicable to a core material made of a lithium disilicate-based glass ceramic that may deform when fired at a temperature higher than 850 °C.

[0043] The base glass (A-1) and base glass (A-2) can have a softening point (Ts) of 450 to 650°C, for example, in accordance with ISO 6872:2015 / Amd.1:2018 "Dentistry - Ceramic materials". By using base glass with a softening point of 450 to 650°C, it becomes possible to fire dental porcelain compositions in the temperature range of 650 to 850°C, making it applicable to core materials made of lithium disilicate-based glass ceramics, which may deform if fired at temperatures higher than 850°C. In particular, in this invention, the softening point can be set to 650°C or lower.

[0044] The base glass (A-1) and base glass (A-2) can have a difference in softening points of less than 100°C, preferably 50°C or less, and more preferably 0°C (a combination of base glass having the same softening point), in accordance with, for example, ISO 6872:2015 / Amd.1:2018 "Dentistry - Ceramic materials". If the difference in softening points is 100°C or more, undissolved areas or interfaces of the glass composition may occur within the layers of the dental porcelain composition, which may result in clouding of the surface after firing.

[0045] The base glass (A-1) and base glass (A-2) constituting glass (A) can be mixed without limitation using conventionally known manufacturing equipment and methods. For example, they can be mixed manually by a dental technician during dental laboratory work, or mechanically by grinding and mixing using a rotary ball mill, vibrating ball mill, or planetary mill, or by mixer mixing or sieving.

[0046] The base glass (A-1) and base glass (A-2) may be, for example, glass or glass ceramics whose main component (the component with the highest content) is SiO2. Such glass may also contain Al2O3, B2O3, ZnO, K2O, Na2O, Li2O, ZrO2, CaO, MgO, F, etc., in addition to SiO2. Furthermore, the glass may be glass ceramics containing crystals, and the inclusion of crystals can be expected to adjust the thermal expansion coefficient of the dental porcelain composition and improve its mechanical properties. Specifically, examples include amorphous potassium aluminosilicate glass, amorphous potassium borosilicate glass, crystalline potassium aluminosilicate glass, crystalline fluoroapatite glass, and crystalline lithium silicate glass. Moreover, the base glass (A-1) and base glass (A-2) of the present invention may be glass that does not contain crystals.

[0047] Glass (A) may include base glass (A-3) other than base glass (A-1) and base glass (A-2). For example, glass (A) may include base glass (A-3) as a base glass other than base glass (A-1) and base glass (A-2) whose particle size D50 does not meet the requirements of 2 to 8 and 25 to 45 μm. For example, the amount of base glass (A-3) can be 0 to 10.0 parts by mass or 0.1 to 5.0 parts by mass when the total amount of glass (A) is 100.0 parts by mass. When glass (A) contains base glass (A-3), the particle sizes D10, D50, and D90 of glass (A) are calculated including base glass (A-3). Furthermore, glass (A) may not include base glass (A-3) as a base glass other than base glass (A-1) and base glass (A-2) whose particle size D50 does not meet the requirements of 2 to 8 and 25 to 45 μm. This narrows the range of adjustment required for the mixing of organic solvent (B) to prevent the paste-like or slurry-like dental porcelain composition prepared by mixing with organic solvent (B) from dripping, and also reduces the risk of shrinkage. For example, glass (A) may include only base glass (A-1) and base glass (A-2).

[0048] [Organic solvent (B)] The dental porcelain composition of the present invention contains an organic solvent (B). The organic solvent (B) is used to mix with glass (A) to form a paste. The organic solvent used in the present invention can be fired simultaneously with the base glass without the need for removal by condensation and water absorption. Furthermore, the organic solvent used in the present invention is destroyed by incineration after the firing of the dental porcelain composition. Therefore, it is a component that does not ultimately remain in the dental prosthetic device.

[0049] The organic solvent (B) used in this invention has a boiling point of 100 to 300°C. Furthermore, in this invention, an organic solvent with a boiling point of 270°C or lower can be used, and even an organic solvent with a boiling point of 250°C or lower can be used. If the boiling point of the organic solvent is below 100°C, the organic solvent will volatilize even at room temperature, causing drying and deterioration of workability during dental work. If the boiling point of the organic solvent exceeds 300°C, it will remain unburned during firing, causing carbonization and bubbles.

[0050] The organic solvent (B) used in the present invention is not particularly limited as long as its boiling point is between 100 and 300°C, but examples include ester solvents such as dimethyl phthalate and diethyl phthalate; polyhydric alcohol solvents such as 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, glycerin, diethylene glycol, triethylene glycol, propylene glycol, and dipropylene glycol; polyhydric alcohol monoether solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monopropyl ether, tripropylene glycol monomethyl ether, diethylene glycol monobutyl ether, and triethylene glycol monomethyl ether; and aromatic alcohol solvents such as 2-phenoxyethanol and benzyl alcohol. Among these organic solvents, polyhydric alcohol solvents, polyhydric alcohol monoether solvents, and aromatic alcohol solvents are available, and 1,3-butanediol, propylene glycol, and 2-phenoxyethanol are also available. These organic solvents (B) can be used individually or in combination of two or more as appropriate. When using two or more organic solvents in combination, the boiling point used is the sum of the boiling points of each organic solvent used multiplied by their respective addition ratios.

[0051] The organic solvent (B) used in the present invention consists only of organic solvents with a boiling point of 250°C or lower, and the dental porcelain composition of the present invention can have a composition that does not contain organic solvents with a boiling point higher than 250°C. If organic solvents with a boiling point higher than 250°C are included, they may remain unburned during firing, causing carbonization or bubbles.

[0052] The organic solvent (B) used in the present invention can be an alcohol having a hydroxyl group. This is to improve compatibility with the substrate glass having a hydroxyl group and to improve the coatability.

[0053] If the organic solvent (B) is a component that is soluble in water, the dental porcelain composition of the present invention may contain water. In this case, the organic solvent may be an alcohol having a hydroxyl group. When the dental porcelain composition of the present invention contains water, the amount of water may be 30 parts by mass or less, when the total amount of water and organic solvent is 100 parts by mass.

[0054] In this invention, the amount of organic solvent (B) can be 10 to 200 parts by mass, or 20 to 150 parts by mass, per 100 parts by mass of glass (A). In particular, since this invention can be used while suppressing sagging, the amount of organic solvent (B) can be 20 to 80 parts by mass per 100 parts by mass of glass (A). If the amount of organic solvent is too small, it becomes difficult to form a paste. If the amount of organic solvent is too large, the paste tends to sag, especially when applying a thick coating.

[0055] [Other ingredients] The base glass (A-1) and base glass (A-2) in the present invention may include a coloring agent (C), a fluorescent agent (D), and / or a paste-forming stabilizer (E). Furthermore, the dental porcelain composition of the present invention may include a coloring agent (C), a fluorescent agent (D), and / or a paste-forming stabilizer (E) as forms (other components) not included in base glass (A-1) and base glass (A-2). The coloring agent (C) and / or the fluorescent agent (D) impart color and fluorescence to the dental prosthesis. The paste-forming stabilizer (E) can impart a sedimentation-inhibiting effect to a paste made by mixing glass (A) and an organic solvent (B), which keeps the paste state for a longer period of time, or an effect that makes it easier to return sedimented solids back into the paste.

[0056] As the coloring agent (C), for example, an inorganic material commonly used in dental materials can be used. Specifically, coloring agents made by mixing and firing multiple metal oxides such as SiO2, Al2O3, CaO, TiO2, SnO, Cr2O3, MnO, Sb2O3, V2O5, ZnO, Fe2O3, W2O3, Co2O3, and ZrO2 are examples of coloring agents. The amount of coloring agent can be 0.0 to 40.0 parts by mass when the total of glass (A), coloring agent (C) if included, fluorescent agent (D), and paste-forming stabilizer (E) is set to 100.0 parts by mass. If the content exceeds 40 parts by mass, the glass layer may not adhere well, and there is a risk of insufficient adhesion to the core material.

[0057] As the fluorescent material (D), for example, an inorganic material commonly used in dental materials can be used. Specifically, coloring materials made by mixing and firing multiple metal oxides such as SiO2, Al2O3, CaO, TiO2, SnO, Cr2O3, MnO, Sb2O3, V2O5, ZnO, Fe2O3, W2O3, Co2O3, and ZrO2 are examples. The amount of this material can be 0.0 to 40 parts by mass, and can be 40 parts by mass or less, when the total of glass (A), coloring material (C) if included, fluorescent material (D), and paste-forming stabilizer (E) is set to 100.0 parts by mass. If the content exceeds 40 parts by mass, the glass layer may not adhere well, and there is a risk of insufficient adhesion to the core material.

[0058] As the paste-forming stabilizer (E), for example, inorganic materials or inorganic salts, which are commonly used in dental materials, can be used. Examples of inorganic materials include fine particle silica and fine particle titanium with an average primary particle size of 1 to 50 nm, 5 to 45 nm, or 7 to 40 nm, and can be used individually or in combination of two or more as appropriate. Examples of inorganic salts include chlorides, nitrates, sulfates, carbonates, and / or hydrates thereof, composed of elements selected from Al, Zn, K, Na, Li, Ca, and Mg. Further specific examples include aluminum chloride, aluminum nitrate, zinc chloride, zinc nitrate, potassium chloride, potassium sulfate, sodium chloride, sodium sulfate, lithium chloride, lithium nitrate, calcium chloride, calcium nitrate, calcium sulfate, magnesium nitrate, magnesium sulfate, and / or hydrates thereof, and can be used individually or in combination of two or more as appropriate. The amount of this additive can be 0.0 to 10 parts by mass, and can be 10 parts by mass or less, based on a total of 100.0 parts by mass of glass (A), and any colorants (C), fluorescent agents (D), and paste-forming stabilizers (E) included in the additive. If the content exceeds 10 parts by mass, the glass layer may not adhere properly, and there is a risk of insufficient adhesion to the core material.

[0059] The dental porcelain composition of the present invention contains virtually no organic polymer materials. In this invention, "organic polymer materials" refers to organic components with a molecular weight of 200 or more that are added separately for purposes other than surface treatment. Such organic components have low volatility and may remain in the porcelain layer during firing. The dental porcelain composition of the present invention may contain no solvents other than organic solvent (B). In this invention, "virtually no" means less than 0.1 parts by mass when the total dental porcelain composition is 100 parts by mass. The amount of organic polymer materials contained in the dental porcelain composition of the present invention may be 0.00 parts by mass.

[0060] [Method for manufacturing dental ceramic composition] The dental porcelain composition of the present invention can be manufactured without limitation by general paste composition manufacturing methods owned by the manufacturer. A general manufacturing method involves blending a base glass, an organic solvent, a coloring agent, a fluorescent agent, and a paste-forming stabilizer to obtain the desired paste composition, and mixing them in a device equipped with stirring and / or defoaming functions to obtain a paste. This can be done by known kneading methods using rotary mixers equipped with stirring blades, rotary mixers, grinders, roll mills, ball mills, kneaders, etc., and these methods can be used individually or in combination.

[0061] The dental porcelain composition of the present invention can be manufactured without mechanical manufacturing methods by a dental technician in a dental laboratory by mixing glass (A) (base glass) and an organic solvent on a mixing plate to obtain the desired paste composition. A general dental laboratory spatula or glass rod can be used for mixing on the mixing plate. Using this method, for example, a paste can be made by mixing a powder containing a pre-mixed base glass (A-1) and base glass (A-2) with an organic solvent (B). Alternatively, a paste can be made by mixing base glass (A-1) with an organic solvent (B), and then mixing base glass (A-2) into this paste. In particular, by mixing base glass (A-2) with a larger particle size into a paste made by mixing base glass (A-1) with an organic solvent (B), the viscosity change behavior can be reduced, making it easier to adjust to the desired viscosity.

[0062] [Dental porcelain composition kit] The components constituting the dental porcelain composition of the present invention can be combined to form a kit for the dental porcelain composition. Specifically, a dental porcelain composition kit can be made comprising a base glass (A-1) and a glass obtained by pre-mixing base glass (A-2), and an organic solvent (B). Furthermore, a dental porcelain composition kit can be made comprising a base glass (A-1), a base glass (A-2), and an organic solvent (B). Furthermore, a dental porcelain composition kit can be made comprising a base glass (A-1), a base glass (A-2), an organic solvent (B), and an organic solvent (B') with a different composition from organic solvent (B), or a mixed glass obtained by pre-mixing base glass (A-1) and base glass (A-2), an organic solvent (B), and an organic solvent (B') with a different composition from organic solvent (B). Since different organic solvent compositions result in different viscosity properties of the paste (dental porcelain composition) produced by mixing with glass, providing two types of organic solvents with different compositions makes it easier for dental technicians to select the optimal viscosity in this dental porcelain composition kit. [Examples]

[0063] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited in any way to these examples and comparative examples.

[0064] The methods for manufacturing glass and substrate glass in the examples and comparative examples, methods for measuring particle size, methods for measuring the presence or absence of crystals, methods for measuring various physical properties, and various evaluation methods for dental ceramic compositions are shown below.

[0065] [Base glass] Glasses G1 to G5, containing SiO2, Al2O3, K2O, Na2O, and other components (B2O3, Li2O, CaO, ZnO, F, MgO, etc.) in the proportions shown in Table 1, were prepared by melting and then pulverized using various general-purpose pulverizers to obtain base glass (A-1-1) to (A-3-1). Vintage Art Universal (manufactured by Shofu), a commercially available coloring material for dental ceramics, in AS (A shade) was used as base glass (A-1-10). Base glass (A-1-10) contains, in addition to the base glass components, a coloring agent (C) selected from inorganic materials and a fluorescent agent (D) selected from inorganic materials, with a D50 of 5 μm.

[0066] Details of each type of glass are as follows:

[0067] [Table 1]

[0068] <Manufacturing of base glass (A-1-1)> Glass G1 was ground in a bead mill until the D50 size reached 2.0 μm.

[0069] <Manufacturing of base glass (A-1-2)> Glass G1 was pulverized using a vibrating ball mill until the D50 size reached 4.0 μm.

[0070] <Manufacturing of base glass (A-1-3)> Glass G1 was pulverized using a vibrating ball mill until the D50 size reached 5.0 μm.

[0071] <Manufacturing of base glass (A-1-4)> Glass G1 was pulverized using a vibrating ball mill until the D50 size reached 6.0 μm.

[0072] <Manufacturing of base glass (A-1-5)> Glass G1 was pulverized using a vibrating ball mill until the D50 size reached 8.0 μm.

[0073] <Manufacturing of base glass (A-1-6)> Glass G2 was pulverized using a vibrating ball mill until the D50 size reached 5.0 μm.

[0074] <Manufacturing of base glass (A-1-7)> Glass G3 was ground using a vibrating ball mill until the D50 size reached 6.0 μm.

[0075] <Manufacturing of base glass (A-1-8)> After subjecting glass G4 to a heat treatment process that precipitates leucite crystals, it was pulverized using a jet mill until the D50 size reached 5.0 μm.

[0076] <Manufacturing of base glass (A-1-9)> Glass G5 was subjected to a heat treatment process that precipitated leucite crystals, and then pulverized using a jet mill until the D50 size reached 5.0 μm.

[0077] <Manufacturing of base glass (A-2-1)> Glass G1 was ground in a ball mill until the D50 size reached 25.0 μm.

[0078] <Manufacturing of base glass (A-2-2)> Glass G1 was ground in a ball mill until the D50 size reached 30.0 μm.

[0079] <Manufacturing of base glass (A-2-3)> Glass G1 was ground in a ball mill until the D50 size reached 35.0 μm.

[0080] <Manufacturing of base glass (A-2-4)> Glass G1 was ground in a ball mill until the D50 size reached 40.0 μm.

[0081] <Manufacturing of base glass (A-2-5)> Glass G1 was ground in a ball mill until the D50 size reached 45.0 μm.

[0082] <Manufacturing of base glass (A-3-1)> Glass G1 was ground using a jet mill until the D50 size reached 20.0 μm.

[0083] [Method for measuring particle size D50 of substrate glass] The particle size D50 of the base glass can be determined by measurement using methods such as laser diffraction / scattering, dynamic light scattering, centrifugal sedimentation, electrical detector method, sieving method, and photon correlation method. The particle size of the glass powders in the examples and comparative examples was measured by laser diffraction / scattering. Specifically, the measurement was performed using a Microtrac MT-3000II laser diffraction particle size distribution analyzer (manufactured by Microtrac Bell) under the conditions of dispersion medium: water, sample refractive index: 1.51, and particle shape: amorphous.

[0084] [Method for measuring the presence or absence of crystals in a substrate glass] The presence or absence of crystals in the substrate glass can be confirmed by measurement using an X-ray diffractometer. Specifically, measurements were taken using a SmartLab SE X-ray diffractometer (manufactured by Rigaku) ​​with a scanning range of 10-70° and a scan speed of 2.0° / min.

[0085] [Method for measuring the glass transition temperature, softening point, and thermal expansion coefficient of a substrate glass] Each base glass was mixed with distilled water, and the mixture was packed into a silicone rod-shaped mold (6 x 6 x 25 mm). The mixture was then repeatedly condensed and water-absorbed to produce a molded body. The molded body was removed from the silicone mold and subjected to two firings using a dental laboratory porcelain firing furnace, Esthemat Slim (Matsukaze), consisting of one vacuum firing and one atmospheric firing. The ends of the resulting double-fired specimens were polished to create parallel surfaces, and the size of the specimens, adjusted to 5 x 5 x 20 mm, was used as a test specimen. The glass transition temperature, softening point, and thermal expansion coefficient were measured using a thermal expansion meter TM8140C (Rigaku) ​​in accordance with the procedure for "Dentistry - Ceramic materials" in ISO 6872:2015 / Amd.1:2018.

[0086] [Method for measuring the amount of elution from the base glass] Each base glass was mixed with distilled water, and the mixture was filled into a silicone disc mold (φ12mm x 2mm). The mixture was then repeatedly condensed and water-absorbed to produce a molded body. The molded bodies were removed from the silicone mold and vacuum-fired using a dental laboratory porcelain firing furnace, Esthemat Slim (manufactured by Matsukaze), to produce 10 fired objects. After polishing both sides of these fired objects, a second atmospheric firing was performed. These test specimens were tested according to the procedures of ISO 6872:2015 / Amd.1:2018 "Dentistry - Ceramic materials".

[0087] [Method for measuring the bending strength of a substrate glass] Each base glass was mixed with distilled water, and the mixture was filled into a silicone rod-shaped mold (3 x 6 x 25 mm). The mixture was then repeatedly condensed and water-absorbed to produce molded bodies. The molded bodies were removed from the silicone molds and vacuum-fired using a dental laboratory porcelain firing furnace, Esthemat Slim (manufactured by Matsukaze), to produce 10 fired objects. The entire surface of the obtained fired objects was polished to create parallel surfaces, and samples were adjusted to a size of 1.2 x 4 x 20 mm. These samples were used as test specimens, and their bending strength was measured using a universal testing machine (manufactured by Shimadzu) in accordance with the procedure for "Dentistry - Ceramic materials" in ISO 6872:2015 / Amd.1:2018.

[0088] [Evaluation 1: Measurement of D10, D50, and D90 of glass (A), calculation of (D90-D10) / D50] Substrate glass (A-1-1) to (A-3-1) were sieved and mixed to prepare substrate glass (A). The particle sizes D10, D50, and D90 of substrate glass (A) were measured using a laser diffraction particle size distribution analyzer Microtrac MT-3000II (manufactured by Microtrac Bell) under the conditions of dispersion medium: water, sample refractive index: 1.51, and particle shape: amorphous. Furthermore, the numerical values ​​of D10, D50, and D90 obtained for each glass were used to calculate the numerical value using the formula "(D90-D10) / D50". The evaluation criteria for this numerical value are shown below. 3.2 or higher: The particle size distribution is sufficiently broad. 3.0 or higher and less than 3.2: A broad particle size distribution. 2.8 or higher and less than 3.0: This indicates a particle size distribution with an applicable range. Less than 2.8: Narrow particle size distribution

[0089] [Rating 2: Drooping] The glass, solvent, and equipment used for evaluation were left in a constant temperature room at 23°C for one hour before the evaluation was conducted. The glass and solvent used in each example and comparative example shown in Tables 3-5 were mixed to prepare pastes. At this time, the solvent was weighed and mixed in the following proportions: 0.70 parts by mass, 0.65 parts by mass, 0.60 parts by mass, 0.55 parts by mass, 0.50 parts by mass, 0.45 parts by mass, 0.40 parts by mass, 0.35 parts by mass, and 0.30 parts by mass per 1.0 part by mass of glass. In this way, nine mixtures were prepared for each type of glass. The following tests were conducted using the samples (compositions) in which the mixtures had become a uniform paste. A sample of 0.1 ± 0.01 g was weighed and gently placed in the center of a glass plate (70 mm × 70 mm × 1 mm). It was left to stand for 30 seconds. The diameter of the paste's spread circle after standing (pre-slip value) was recorded. The glass plate on which the sample was placed was tilted at a 90° angle so that the 70 mm × 70 mm surface was perpendicular, and it was left to stand for 30 seconds. The length of the paste that had dripped after standing (post-slip value) was recorded. The "slip value" of the sample was calculated by subtracting the pre-slip value from the post-slip value. The calculated "slip value" of the sample was evaluated as the "slipperiness" of the dental porcelain composition in the corresponding example and comparative example. The evaluation criteria for "slipperiness" are shown below. AA: There are five or more samples that maintain a paste-like consistency with a drip value of 0-10 mm. This indicates a wide range of adjustment for the solvent (organic solvent (B)) that makes the porcelain composition less prone to dripping. A: There are four samples that maintain a paste-like consistency with a drip value of 0-10 mm. It can be concluded that the adjustment range for the solvent (organic solvent (B)) that makes the porcelain composition less prone to dripping is slightly wide. B: Three samples maintained a paste-like consistency with a drip value of 0-10 mm. This indicates that the adjustment range for the solvent (organic solvent (B)) that makes the porcelain composition less prone to dripping is slightly wide. C: There are two or fewer samples that maintain a paste-like consistency and have a drip value of 0-10 mm. The adjustment range for the solvent (organic solvent (B)) that makes the porcelain composition less prone to dripping can be judged to be the same as or less than that of conventional porcelain compositions.

[0090] [Rating 3: Hike] For each ceramic composition, among the samples that maintained a paste-like consistency and had a drip value of 0-10 mm in Evaluation 2, the ceramic composition corresponding to the combination with the highest ratio of solvent to glass was manufactured. Zirconia substrates with the shapes shown in Figures 1-3 were prepared using Matsukaze's "Matsukaze Disc ZR-SS Colored, Shade: Peach Light," and the ceramic composition was applied to the 10.0 mm x 10.0 mm recessed surface of the substrate using a dental laboratory brush until it was completely used up. After drying outside the furnace for 7 minutes using a dental laboratory porcelain firing furnace Esthemat Slim II (Matsukaze), vacuum firing was performed at 750°C. For each ceramic composition, tests were conducted using three types of substrates with different recess depths (0.2 mm, 0.4 mm, 0.6 mm), and the presence or absence of shrinkage such as cracks in the coated layer and peeling from the recessed wall surface of the substrate was visually evaluated after firing. The evaluation criteria are shown below. AA: No shrinkage was observed in the three types of substrates. It can be concluded that no shrinkage will occur even when the ceramic composition is fired with a coating thickness of up to 0.6 mm. A: No shrinkage was observed in the two substrates (depression depths of 0.2 mm and 0.4 mm). It can be concluded that shrinkage will not occur even when the ceramic composition is fired with a coating thickness of up to 0.4 mm. B: No shrinkage was observed in one type of substrate (depression depth 0.2 mm). It can be concluded that no shrinkage will occur even when the ceramic composition is fired with a coating thickness of up to 0.2 mm. C: Shrinkage was observed in all three types of substrates. It can be concluded that shrinkage occurs when the ceramic composition is fired with a coating thickness of 0.2 mm or more.

[0091] [Rating 4: Cloudiness of fired product] The ceramic layer of the fired product prepared in Evaluation 3 was visually evaluated. The evaluation criteria are shown below. AA: No clouding was observed in the three types of substrates. It can be concluded that clouding will not occur even when the ceramic composition is fired with a coating thickness of up to 0.6 mm. A: No opacity was observed in the two substrates (depression depths of 0.2 mm and 0.4 mm). It can be concluded that opacity will not occur even when the ceramic composition is fired with a coating thickness of up to 0.4 mm. B: No opacity was observed in one type of substrate (depression depth 0.2 mm). It can be concluded that opacity will not occur even when the ceramic composition is fired with a coating thickness of up to 0.2 mm. C: White clouding was observed in all three substrate types. It can be concluded that white clouding occurs when the ceramic composition is fired with a coating thickness of 0.2 mm or more.

[0092] [Rating 5: Blackening of fired products] The ceramic layer of the fired product prepared in evaluation 3 was visually evaluated. AA: No blackening was observed in the three types of substrates. It can be concluded that blackening will not occur even when the ceramic composition is fired with a coating thickness of up to 0.6 mm. A: No blackening was observed in the two substrates (depression depths of 0.2 mm and 0.4 mm). It can be concluded that blackening will not occur even when the ceramic composition is fired with a coating thickness of up to 0.4 mm. B: No blackening was observed in one type of substrate (depression depth 0.2 mm). It can be concluded that blackening will not occur even when the ceramic composition is fired with a coating thickness of up to 0.2 mm. C: Blackening was observed in three types of substrates. It can be concluded that blackening occurs when the ceramic composition is fired with a coating thickness of 0.2 mm or more.

[0093] Table 2 shows the test results for each substrate glass (A-1-1) to (A-3-1).

[0094] [Table 2]

[0095] Details of each example and comparative example are shown below.

[0096] <Examples 1-20, Comparative Examples 2, 3> Substrate glass (A-1) and substrate glass (A-2) were sieved together to obtain glass (A). 2-phenoxyethanol (boiling point: 247°C, molecular weight: 138.16) was used as the organic solvent (B) and the mixture was kneaded on a glass mixing plate to obtain a paste-like ceramic composition.

[0097] <Example 21> The base glass (A-1) was kneaded on a glass mixing plate with 2-phenoxyethanol (boiling point: 247°C, molecular weight: 138.16) as the organic solvent (B) to form a paste, and the remaining base glass (A-2) was further mixed and kneaded to obtain a paste-like ceramic composition.

[0098] <Example 22> Glass (A-1) and glass (A-2) were sieved together to obtain glass (A). A solvent (calculated boiling point: 227°C) was obtained by mixing 1,3-butanediol (boiling point: 207°C, molecular weight: 90.12) and 2-phenoxyethanol (boiling point: 247°C, molecular weight: 138.16) in a mass ratio of 1:1, and this mixture was used as an organic solvent (B). The mixture was kneaded on a glass mixing plate to obtain a paste-like ceramic composition.

[0099] <Example 23> A ceramic material composition was prepared using a mixture of base glass (A-1) and base glass (A-2), fine particle silica R974 (average primary particle size 12 nm, manufactured by Nippon Aerosil Co., Ltd.) and the inorganic salt calcium nitrate as a paste-forming stabilizer (E), and 1,3-butanediol (boiling point: 207°C, molecular weight: 90.12) and water as an organic solvent (B). In this case, the amount of water was 25 parts by mass when the total amount of water and organic solvent was 100 parts by mass. This ceramic material composition was mixed using a rotation-orbit mixer to obtain a paste-like ceramic material composition.

[0100] <Example 24> Glass (A-1) and glass (A-2) were sieved together to obtain glass (A). A solvent (calculated boiling point: 262°C) was obtained by mixing 2-phenoxyethanol (boiling point: 247°C, molecular weight: 138.16) and glycerin (boiling point: 290°C, molecular weight: 92.09) in a mass ratio of 2:1, and this mixture was kneaded on a glass mixing plate as organic solvent (B) to obtain a paste-like ceramic composition.

[0101] <Example 25> Glass (A-1) and glass (A-2) were sieved together to form glass (A). Glycerin (boiling point: 290°C, molecular weight: 92.09) was used as the organic solvent (B) and the mixture was kneaded on a glass mixing plate to form a paste-like ceramic composition.

[0102] <Example 26> Glass (A-1), glass (A-2), and glass (A-3) were sieved together to obtain glass (A). 2-phenoxyethanol (boiling point: 247°C, molecular weight: 138.16) was used as the organic solvent (B) and the mixture was kneaded on a glass mixing plate to obtain a paste-like ceramic composition.

[0103] <Comparative Examples 1 and 4> Glass was prepared using only base glass (A-1) or base glass (A-2). 2-phenoxyethanol (boiling point: 247°C, molecular weight: 138.16) was used as the organic solvent (B) and mixed on a glass mixing plate to obtain a paste-like ceramic composition.

[0104] <Comparative Example 5> Substrate glass (A-1) and substrate glass (A-2) were sieved together to obtain glass (A). Benzyl benzoate (boiling point: 323°C, molecular weight: 212.25) was used as the organic solvent (B) and the mixture was kneaded on a glass mixing plate to obtain a paste-like ceramic composition.

[0105] <Comparative Example 6> Glass (A-1) and glass (A-3-1) were sieved together to obtain glass (A). 2-phenoxyethanol (boiling point: 247°C, molecular weight: 138.16) was used as the organic solvent (B) and the mixture was kneaded on a glass mixing plate to obtain a paste-like ceramic composition.

[0106] <Comparative Example 7> Substrate glass (A-2) and substrate glass (A-3-1) were sieved together to obtain glass (A). 2-phenoxyethanol (boiling point: 247°C, molecular weight: 138.16) was used as the organic solvent (B) and the mixture was kneaded on a glass mixing plate to obtain a paste-like ceramic composition.

[0107] Tables 3-5 show the composition of the ceramic compositions prepared in each example and comparative example, as well as the results of various tests. For organic solvent (B), the type of organic solvent used is indicated by a checkmark, and its quantity is as described in "Evaluation 3" above.

[0108] [Table 3]

[0109] [Table 4]

[0110] [Table 5]

[0111] Examples 1-26 showed good results in terms of sagging and shrinkage, and no blackening or clouding of the fired products was observed.

[0112] On the other hand, the following problems arose in the comparative example. In Comparative Examples 1-4, only a single type of base glass was used, or the mixing state of the base glass was not appropriate, resulting in the particle sizes D10, D50, and D90 of glass (A) not being at appropriate values, leading to poor sagging and shrinkage.

[0113] In Comparative Example 5, benzyl benzoate was used as the organic solvent, resulting in blackening of the surface after firing.

[0114] In Comparative Examples 6 and 7, only one of the base glass (A-1) or base glass (A-2) was used, resulting in the particle sizes D10, D50, and D90 of glass (A) not being at appropriate values, leading to poor sagging and shrinkage.

[0115] Based on the above results, the dental porcelain composition provided by the present invention does not require a condensation operation that requires skilled techniques, and is characterized by excellent properties such as sagging resistance, shrinkage suppression, and aesthetic appeal after firing, thereby significantly improving upon the problems of the conventional technology. [Industrial applicability]

[0116] The dental porcelain composition provided by the present invention can be used in dental prosthetic devices made of ceramics, glass ceramics, or glass, and does not require a condensation process that requires skilled techniques. It is characterized by its excellent properties of sagging, shrinkage suppression, and aesthetics after firing. Therefore, it can be applied to various dental crowns in restorative treatments in the dental field.

Claims

1. A dental porcelain composition comprising glass (A) and an organic solvent (B) having a boiling point of 100 to 300°C, Glass (A) comprises a base glass (A-1) with a particle size D50 of 2 to 8 μm and a base glass (A-2) with a particle size D50 of 25 to 45 μm, and A dental porcelain composition in which the particle size of glass (A) is D10 ≤ 5 μm, 5 μm < D50 < 28 μm, and 28 μm ≤ D90.

2. The dental porcelain composition according to claim 1, wherein the mixing ratio of base glass (A-1) and base glass (A-2) is 9:1 to 1:9 by mass.

3. The dental porcelain composition according to claim 1, wherein the particle size of glass (A) is (D90-D10) / D50 is 2.8 or more.

4. The dental ceramic composition according to claim 1, wherein the base glass (A-1) and base glass (A-2) have a softening point of 650°C or less in accordance with ISO 6872:2015 / Amd.1:2018 "Dentistry-Ceramic materials".

5. The dental ceramic composition according to claim 1, wherein the difference in softening points between the base glass (A-1) and base glass (A-2) in accordance with ISO 6872:2015 / Amd.1:2018 "Dentistry-Ceramic materials" is less than 100°C.

6. The dental porcelain composition according to claim 1, wherein the amount of organic solvent (B) blended is 10 to 200 parts by mass per 100 parts by mass of glass (A).

7. The dental porcelain composition according to claim 1, wherein the organic solvent (B) consists only of an organic solvent having a boiling point of 250°C or lower.

8. The dental porcelain composition according to claims 1 to 7, wherein glass (A) comprises only base glass (A-1) and base glass (A-2).

9. A method for producing a dental porcelain composition, comprising mixing a base glass (A-1) having a particle size D50 of 2 to 8 μm, a base glass (A-2) having a D50 of 25 to 45 μm, and an organic solvent (B) having a boiling point of 100 to 300°C, wherein the particle size of the glass (A) containing the base glass (A-1) and base glass (A-2) is D10 ≤ 5 μm, 5 μm < D50 < 28 μm, and 28 μm ≤ D90.

10. A process of mixing base glass (A-1) and base glass (A-2) to produce a powder, A method for producing a dental porcelain composition according to claim 9, comprising the step of mixing an organic solvent (B) with a powder.

11. A process of mixing a base glass (A-1) and an organic solvent (B) to produce a paste, A method for producing a dental porcelain composition according to claim 9, comprising the step of mixing a base glass (A-2) with a paste.

12. A step of applying the dental porcelain composition of claim 1 to a core material, A method for manufacturing a dental prosthesis comprising the steps of firing a coated dental porcelain composition.

13. A method for manufacturing a dental prosthesis according to claim 12, wherein the core material is made of ceramics, glass ceramics, or glass.

14. The method for manufacturing a dental prosthesis according to claim 12, wherein the dental porcelain composition contains an organic solvent (B) in the step of firing the coated dental porcelain composition.

15. A kit for preparing dental ceramic compositions, A base glass (A-1) with a particle size D50 of 2 to 8 μm. A substrate glass (A-2) having a D50 of 25 to 45 μm, and Organic solvent (B) with a boiling point of 100-300°C A kit for dental porcelain compositions, comprising [the specified components].

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