KR101141744B1 - High strength ceramic block for teeth and manufacturing method of the same - Google Patents

Abstract

The present invention, 45 to 85% by weight of SiO ₂ , 7 to 25% by weight of Al ₂ O ₃ , 0.5 to 15% by weight of Na ₂ O, 0.5 to 15% by weight of K ₂ O, 0.01 to 7% by weight of CaO, Fe ₂ O _{3 It} contains a glass phase containing 0.001 to 5% by weight and 0.001 to 3% by weight of MgO, zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), alumina (Al ₂ O ₃ ) and mullite (mullite; 3Al ₂ O _It relates to a high strength ceramic block for teeth containing 0.01 to 30% by weight of one or more crystalline additives selected from _{3 to 2} SiO ₂ ) and a method for producing the same. The high-strength ceramic block for teeth of the present invention is less harmful to human body because of using natural raw materials, and because it uses low-cost natural raw materials, the manufacturing cost is low, the manufacturing process is simple, mass production is possible, and the reproducibility is reliable. It is possible to manufacture restorations and has higher strength than conventional glass-ceramic dental restorations, so it can be used not only for veneers, inlays and onlays, but also for crowns of posterior teeth. have.

Teeth, veneers, inlays, onlays, crowns, ceramic blocks, dental restorations

Description

High strength ceramic block for teeth and manufacturing method of the same

The present invention relates to a ceramic block for a tooth and a method of manufacturing the same. More specifically, since natural raw materials are used, there is little human risk, and since low cost natural raw materials are used, manufacturing costs are low, and the manufacturing process is simple, so that mass production is easy. It is possible and reproducible to produce reliable dental restorations and has a higher strength than conventional glass-ceramic dental restorations, so that not only veneers, inlays, onlays, but also molar teeth It relates to a high strength ceramic block for teeth that can also be used for crowns and a method of manufacturing the same.

Dental restorations such as veneers, inlays, onlays, stumps, crowns, and the like have been heavily used with precious metal alloys such as Au alloys. However, precious metal alloys, such as gold (Au) alloys, are expensive, and in recent years gold (Au) has risen steeply in line with global trends, and thus the cost of manufacturing precious metal alloy restorations has also increased rapidly. . In addition, because the precious metal alloy is different from the natural teeth, there are many disadvantages for users who are reluctant to use it for aesthetic reasons.

Attempts have been made to use inexpensive metal alloys instead of precious metal alloys as dental restorations, but metal alloys are controversial.

In recent years, there has been a study to produce dental restorations with ceramics that can produce appearances that correspond to natural teeth as much as possible for aesthetic reasons.

Glass-ceramics are mainly used as such dental restorations. For example, U.S. Patent No. 4,798,536 describes a restoration comprising ceramics with a feldspar-based glass-ceramic that contains at least 45% by weight of zirconia in crystal form, and Korean Patent Publication No. 10-0642533 Glass-ceramic 40 to 95% by weight of SiO ₂ , 5 to 25% by weight of Al ₂ O _3, 5 to 25% by weight of K ₂ O, 0 to 25% by weight of Na ₂ O, 0 to 20% by weight of CaO, B ₂ O 20 to 20 garnet containing ₃ 0 to 8% by weight, P ₂ O ₅ 0 to 0.5% and F 0 to 3% by weight and present as the only crystal phase in an amount of at least 80% of the theoretically produceable amount It contains a total ratio of 45% by weight and has a linear thermal expansion coefficient α _{(20-500 ° C)} of _12.5-10 ^-6 to 15.5-10 ^-6 K ^-1 . Is disclosed.

Dental restorations consisting of glass-ceramic are represented as glass-ceramics in which one or more crystalline phases are present in a distributed manner on the glass, which can be obtained by controlled partial crystallization processing of the amorphous primary glass.

According to the ISO6872 standard, it can be used if the strength exceeds 100MPa. However, conventional general glass-ceramic dental restorations can be used for veneers, inlays, onlays, etc., but they cannot be used for crowns of posterior teeth because of their low strength. There are disadvantages.

In addition, glass-ceramic dental restorations that are sold in Korea are expensive and have a heavy cost burden on the user.

In addition, glass-ceramic dental restorations have difficulty in mass production due to complex manufacturing processes, and have been inferior in reproducibility.

The present invention has been made to solve the above problems, the object of the present invention is to use a natural raw material is less harmful to the human body, because it uses a low-cost natural raw material, the production cost is low, the manufacturing process is simple, mass production It is possible to produce tooth restorations that are reliable and reproducible, and have a higher strength than conventional glass-ceramic tooth restorations, as well as veneers, inlays and onlays, as well as posterior teeth. To provide a high-strength ceramic block for teeth that can also be used for crowns (crown) and its manufacturing method.

The present invention, 45 to 85% by weight of SiO ₂ , 7 to 25% by weight of Al ₂ O ₃ , 0.5 to 15% by weight of Na ₂ O, 0.5 to 15% by weight of K ₂ O, 0.01 to 7% by weight of CaO, Fe ₂ O ₃ A glass phase containing 0.001 to 5% by weight and 0.001 to 3% by weight of MgO, 1 selected from zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ) and mullite (mullite; 3Al ₂ O ₃ ~ 2SiO ₂ ) Provided is a dental high strength ceramic block containing from 0.01 to 30% by weight of at least crystalline additives.

The glass phase will have a feldspar frit is molten flower, flower frit as the volatilization of boron oxide (B ₂ O ₃₎ wherein the glass phase does not contain a component, boron oxide (B ₂ O _3).

The titanium oxide (TiO ₂ ) is preferably made of rutile titanium oxide.

In addition, the present invention, SiO ₂ 45 ~ 85 _{wt%, Al 2 O 3 7 ~} 25 wt%, Na ₂ O 0.5 ~ 15 wt%, K ₂ O 0.5 ~ 15 wt%, CaO 0.01 ~ 7 wt%, Fe Preparing a glass powder containing 0.001 to 5% by weight of ₂ O ₃ and 0.001 to 3% by weight of MgO, zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), alumina (Al ₂ O ₃ ) and mullite ( 0.01-30% by weight of one or more crystalline additives selected from mullite; 3Al ₂ O ₃ ˜ 2SiO ₂ ), mixing the glass powder and the organic binder, and the crystalline additive, the glass powder and the organic binder. Shaping the mixture into the desired form; And it provides a method for producing a high strength ceramic block for teeth comprising the step of firing the molded mixture at a temperature of 850 ~ 1300 ℃.

The step of preparing the glass powder, SiO ₂ 45 ~ 85% by weight, Al ₂ O ₃ 7-25% by weight, Na ₂ O 0.5-15% by weight, K ₂ O 0.5-15% by weight, CaO 0.01-7% by weight Pulverizing feldspar containing 0.001-5% by weight of Fe ₂ O ₃ and 0.001-3% by weight of MgO into a powder having a uniform particle size, and heat-treating the crushed feldspar powder Quenching the melt produced by the heat treatment in distilled water to quench the glass, and pulverizing the quenched glass to have a uniform particle size distribution to obtain a glass powder. The present invention provides a method of manufacturing a high strength ceramic block.

The step of obtaining the glass powder by pulverizing the glass formed by quenching may be performed by pulverizing the glass powder having a size of 800 μm˜5 mm by primary grinding using a pulverizer and by secondary grinding using a disk mill. It may include the step of grinding into a glass powder having a size of ~ 300㎛.

The mixing of the crystalline additive, the glass powder, and the organic binder may include charging the crystalline additive, the glass powder, and the organic binder to a ball mill, and having a size of 0.1 to 20 μm by grinding using a ball mill. Grinding into glass powder.

The heat treatment is preferably performed for 1 to 48 hours at a temperature of 1250-1600 ° C. which is higher than the temperature at which the boron oxide (B ₂ O ₃ ) is volatilized.

The firing is preferably performed at normal pressure for 10 minutes to 6 hours in an oxidizing atmosphere.

The organic binder is composed of at least one organic material selected from polyvinyl alcohol (PVA) and paraffin wax, which serves to bind the glass powder and the crystalline additive, and the organic binder is 1 to 100 parts by weight of the glass powder. It is preferable to add -50 weight part.

According to the high-strength ceramic block for teeth according to the present invention, it has a high strength compared to general glass-ceramic dental restorations, so that not only veneers, inlays, onlays, but also crowns of molar teeth Can also be used for.

In addition, according to the manufacturing method of the high-strength ceramic block of the present invention, since natural raw materials are used, there is little harm to human body, and since low-cost natural raw materials are used, manufacturing cost is low, and the manufacturing process is simple, mass production is possible, and reproducibility is achieved. This allows for the manufacture of reliable dental restorations.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the following embodiments are provided to those skilled in the art to fully understand the present invention, and may be modified in various forms, and the scope of the present invention is limited to the embodiments described below. It doesn't happen.

High-strength ceramic block for teeth according to a preferred embodiment of the present invention is SiO ₂ 45 to 85% by weight, Al ₂ O ₃ 7-25% by weight, Na ₂ O 0.5-15% by weight, K ₂ O 0.5-15% by weight, Zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), alumina (Al ₂ O), containing a glass phase containing 0.01-7% by weight of CaO, 0.001-5% by weight of Fe ₂ O ₃ and 0.001-3% by weight of MgO. ₃ ) and mullite (mullite; 3Al ₂ O ₃ ~ 2SiO ₂ ) It contains 0.01 to 30% by weight of one or more crystalline additives.

Zirconium oxide (ZrO ₂ ) is a monoclinic substance with a molecular weight of about 123.22, a melting point of about 2,700 ° C., a large refractive index, high melting point, and high corrosion resistance. Since zirconium oxide (ZrO ₂ ) is a white crystal, it harmonizes well with the color of teeth, has a high strength, and has a strong resistance to rapid temperature changes.

Titanium oxide (TiO ₂ ) can be divided into rutile type, which is stable at high temperature, abrutic type, which is stable at low temperature, and brookite type, which is stable at medium temperature.The rutile type is not corroded to various inorganic acids, organic acids, alkalis, gases, etc. It does not melt until ℃. In the present invention, rutile titanium oxide stable at high temperature is used.

Mullite _{(3Al 2 O 3? 2SiO 2} ) is a mineral compound of aluminum oxide and silicon oxide in the orthorhombic (斜方晶系), a hardness of 7.5, a specific gravity of 3, and a colorless or light pink, high temperature? Even under high pressure It is a stable substance.

These high strength ceramic blocks for teeth are used to make veneers, inlays, onlays, crowns, stumps, occlusal facets, artificial teeth, dentures, root structures, etc. Dental subjects may be selectively prepared.

Hereinafter, a method of manufacturing a high strength ceramic block for teeth according to a preferred embodiment of the present invention.

45 to 85 weight percent SiO ₂ , 7 to 25 weight percent Al ₂ O ₃ , 0.5 to 15 weight percent Na ₂ O, 0.5 to 15 weight percent K ₂ O, 0.01 to 7 weight percent CaO, 0.001 to 5 Fe ₂ O ₃ Feldspar containing wt% and 0.001-3% by weight of MgO is pulverized into a powder having a uniform particle size. In order to supplement the amount of alkali-based feldspar and improve meltability, K ₂ O 1-10% by weight, SiO ₂ 0.1-10% by weight, CaO 0-5% by weight, MgO 0-5% by weight, Na ₂ 0-5% by weight of O may be further added as a reagent.

The grinding may use a ball milling process. The feldspar is charged into a ball milling machine and wet mixed with a solvent such as water and alcohol. The ball mill is rotated at a constant speed to mechanically crush the feldspar and achieve a uniform particle size. Balls used for ball milling may use balls made of ceramics such as zirconia and alumina, and the balls may be all the same size or may be used with balls having two or more sizes. Grind to the size of the target particles by adjusting the size of the ball, milling time, rotation speed per minute of the ball mill. For example, in consideration of the particle size, the size of the ball can be set in the range of about 1 mm to 10 mm, and the rotational speed of the ball mill can be set in the range of about 50 to 500 rpm. Ball milling is performed for 1 to 24 hours, taking into account the target particle size. By ball milling, the feldspar is pulverized into fine sized particles, has a uniform particle size distribution, and is mixed uniformly.

The pulverized feldspar powder slurry is dried. The drying is preferably carried out for 30 minutes to 12 hours at a temperature of 60 ~ 120 ℃.

The feldspar powder formed by pulverization is placed in a crucible such as chamotte, alumina and platinum, and the crucible containing feldspar powder is charged into a furnace and heat-treated to melt the feldspar powder. Here, melting means that the feldspar powder is changed into a material state having a viscosity of a liquid state rather than a solid state. The heat treatment is preferably performed for 1 to 48 hours at 1250 ~ 1600 ℃. If the heat treatment temperature is less than 1250 ℃ feldspar powder may not be melted at all, if the heat treatment temperature exceeds 1600 ℃ it is not economical to consume excessive energy is preferable to heat treatment at the temperature of the above range Do. If the heat treatment time is too short, the feldspar powder may not be sufficiently melted, and if the heat treatment time is too long, it is not economical to consume excessive energy. It is preferable that the temperature increase rate of the furnace is about 5 to 50 ° C./min. If the temperature rising rate of the furnace is too slow, it takes a long time and the productivity decreases, and if the temperature rising rate of the furnace is too fast, the feldspar powder is rapidly increased. Since thermal stress may be applied and physical properties of the frit may not be good, it is preferable to raise the temperature of the furnace at a temperature rising rate in the above range.

The boron oxide (B ₂ O ₃ ) is generally pyrolyzed and volatilized at a temperature of 1200 ° C. or higher, and the boron oxide (B ₂ O ₃ ) contained in the feldspar powder is volatilized and removed by the heat treatment. Boron oxide (B ₂ O ₃ ) is a volatilization during sintering may cause the formation of pores (pores) or voids between the grains (pores formed between the grains by the boron oxide (B ₂ O ₃ ) ( pore) or voids can interfere with crystal growth and degrade the mechanical properties of high-strength ceramic blocks for teeth, so heat treatment should be performed above the temperature at which boron oxide (B ₂ O ₃ ) is volatilized. carried out it is preferred to remove the boron oxide (B ₂ O _3).

The melt produced by the heat treatment is poured into distilled water and quenched. By the quenching, the melt is fritted into glass.

The quenched glass is ground to have a uniform particle size distribution. The grinding may be performed by primary grinding using a pulverizer, secondary grinding using a disk mill, and tertiary grinding using a ball mill. It is pulverized into a glass powder having a size of about 800 μm to 5 mm by primary grinding using the pulverizer, and is pulverized into a glass powder having a size of about 50 to 300 μm by a secondary grinding using the disk mill. By the third grinding using the ball mill, it can be ground into a glass powder having a size of about 0.1 ~ 20㎛. The pulverizer and the disk mill may use a commercially available device, and thus detailed description thereof is omitted here.

At least one crystallinity selected from zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), alumina (Al ₂ O ₃ ) and mullite (3Al ₂ O _{3 to} 2SiO ₂ ) in the tertiary grinding process using a ball mill Additives and organic binders are added to the ball mill to ensure uniform mixing with the glass powder. The organic binder serves to bind the glass powder and the crystalline additive, and may be made of organic materials such as polyvinyl alcohol (PVA) and paraffin wax. It is preferable to add 1-50 weight part of said organic binders with respect to 100 weight part of glass powders.

The ball mill is rotated at a constant speed to mechanically grind the glass powder, the crystalline additive and the organic binder and to have a uniform particle size. Balls used for ball milling may use balls made of ceramics such as zirconia and alumina, and the balls may be all the same size or may be used with balls having two or more sizes. Grind to the size of the target particles by adjusting the size of the ball, milling time, rotation speed per minute of the ball mill. For example, in consideration of the particle size, the size of the ball can be set in the range of about 1 mm to 10 mm, and the rotational speed of the ball mill can be set in the range of about 50 to 500 rpm. Ball milling is performed for 1 to 24 hours, taking into account the target particle size. By ball milling, the feldspar is pulverized into fine sized particles, has a uniform particle size distribution, and is mixed uniformly.

The mixed powder slurry of the ground glass powder, the crystalline additive and the organic binder is dried. The drying is preferably carried out for 30 minutes to 12 hours at a temperature of 60 ~ 120 ℃.

The mixed powder of the glass powder, the crystalline additive and the organic binder is placed in a mold and pressurized to form a shaped body of a desired shape. The mold may be provided in a cylinder or prismatic shape, and may be molded into a desired shape by putting mixed powder in the mold and then compressing the mold. At this time, the pressure applied to the mixed powder (the pressure compressed by the mold) is preferably about 20 to 150 MPa. If the pressurization pressure is too small, there are many voids between the mixed powder particles, so that a high-strength dental ceramic block of high density is desired. If the pressure is too high and the pressure is too large, further effects can not be expected, and the production cost of equipment may increase due to the addition of a mold, a hydraulic device, etc. according to the high pressure.

It fires at the temperature of 850-1300 degreeC with respect to the shape | molded mixed powder. The firing may be performed in the following manner.

The shaped mixed powder is charged to a furnace, such as an electric furnace, and raised to the desired firing temperature. At this time, it is preferable that the temperature increase rate of the furnace is about 5 to 50 ° C./min. If the temperature rising rate of the furnace is too slow, it takes a long time and the productivity decreases. If the temperature rising rate of the furnace is too fast, the mixed powder is rapidly increased. Since thermal stress can be applied to it, it is preferable to raise the temperature of the furnace at a temperature rising rate in the above range. At this time, the pressure in the furnace is preferably maintained at atmospheric pressure.

When the furnace temperature rises to 300-400 ° C in the process of rising to the firing temperature, the organic binder is burned away.

When the temperature of the furnace rises to the target firing temperature, a constant time (eg, 10 minutes to 6 hours) is maintained. The firing is preferably carried out in an oxidizing atmosphere such as oxygen (O ₂ ), air. If the furnace temperature is kept constant at the firing temperature, crystal growth takes place and a high strength ceramic block for the tooth is obtained.

The firing temperature is preferably about 850 ~ 1300 ℃ in consideration of the diffusion of particles, necking (necking) between the particles, crystallization, etc., if the firing temperature is too high, mechanical properties due to excessive growth of particles may be degraded In the case where the firing temperature is too low, the ceramic block may have poor characteristics due to incomplete firing, and therefore, firing at the firing temperature in the above range is preferable. The microstructure, particle size, etc. of the ceramic block vary depending on the firing temperature, because the surface diffusion is dominant when the firing temperature is low, but the lattice diffusion and grain boundary diffusion proceed when the firing temperature is high. The firing time is preferably about 10 minutes to 6 hours in the case of using a general furnace (electric furnace). However, when the firing time is too long, energy consumption is high, so it is not economical and expects further heat treatment effect. It is difficult to increase the size of the ceramic block particles, and when the firing time is small, the characteristics of the ceramic block may be poor due to incomplete firing. At this time, it is preferable that the pressure of the furnace is maintained at normal pressure.

After the firing process, the furnace temperature is lowered to unload the ceramic block. The furnace cooling may be allowed to cool down in a natural state by turning off the furnace power source, or to set a temperature drop rate (eg, 10 ° C./min) arbitrarily. The pressure inside the furnace is preferably kept constant while the furnace temperature is lowered.

The high-strength ceramic block for teeth manufactured as described above has a flexural strength of 140 to 210 MPa and is about 40 to 110 MPa higher than that of a conventional dental restoration. The high-strength ceramic block for teeth of the present invention can be used not only for veneers, inlays and onlays, but also for crowns of posterior molars requiring high strength and using natural raw materials. Therefore, there is little harm to the human body, there is an advantage that the manufacturing cost is low because the use of low-cost natural raw materials.

The invention is described in more detail with reference to the following examples, which do not limit the invention.

≪ Example 1 >

67.9 wt% SiO ₂ , 18.5 wt% Al ₂ O ₃ , 6.92 wt% Na ₂ O, 4.36 wt% K ₂ O, 1.54 wt% Ca, 0.05 wt% Fe ₂ O ₃ , 0.001 wt% MgO and 0.03 wt% TiO ₂ Feldspar containing% was ground into a powder form having a particle size of uniform size.

Feldspar was charged to a ball mill and wet mixed with ethanol. The oxide powders were mechanically ground and uniformly mixed by rotating at a speed of 350 rpm using a ball mill. The ball used for ball milling used a 5 mm size ball made of zirconia, and ball milling was performed for 6 hours.

The crushed feldspar powder slurry was dried. The drying was carried out in an oven at 80 ° C. for 6 hours.

The crushed feldspar powder was placed in a chamotte crucible and the crucible containing feldspar powder was charged to a furnace and subjected to heat treatment to melt the feldspar powder. The heat treatment was performed for 24 hours at 1500 ℃ temperature higher than the temperature at which the boron oxide (B ₂ O ₃ ) is volatilized. The temperature increase rate of the furnace was set at about 10 ° C / min.

The melt produced by the heat treatment was poured into distilled water and quenched. By the quenching, the melt is fritted into glass.

The quenched glass was ground to have a uniform particle size distribution. The grinding was performed by primary grinding using a pulverizer, secondary grinding using a disk mill, and tertiary grinding using a ball mill. The first powder was ground to a glass powder having a size of about 1 to 2 mm by the pulverizer, and the second powder was milled to a glass powder having a size of about 150 μm by a second mill using the disk mill. It was made to crush into glass powder having a size of about 12.44㎛ by the third grinding using the ball mill.

In the third grinding process using a ball mill, zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), and mullite (mullite; 3Al ₂ O _{3 2} 2SiO ₂ ) are added, and an organic binder made of polyvinyl alcohol is also a ball mill. Was added to ensure uniform mixing with the glass powder. The change in flexural strength was observed depending on the content of zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ) and mullite (mullite; 3Al ₂ O ₃ ˜ 2SiO ₂ ). The tertiary grinding was rotated at a speed of 350 rpm using a ball mill to mechanically grind and uniformly mix the oxide powders. The ball used for ball milling used a 5 mm size ball made of zirconia, and ball milling was performed for 6 hours.

The mixed powder slurry of the pulverized glass powder, the crystalline additive and the organic binder was dried. The drying was carried out in an oven at 80 ° C. for 6 hours.

The dried glass powder was sieved with a mesh having a pore size of 100 μm.

The mixed powder of the glass powder, the crystalline additive, and the organic binder was placed in a 20 mm x 40 mm bar mold and molded into a prismatic shaped body by applying a pressure of 50 MPa.

The molded mixed powder was fired at temperatures of 850 ° C, 900 ° C, 950 ° C and 1000 ° C, respectively. The firing was carried out as follows. The mixed powder was charged into an electric furnace and raised to a target firing temperature. At this time, the rising temperature of the furnace was set to about 10 ℃ / min, the pressure in the furnace was maintained at atmospheric pressure. When the furnace temperature rose to the target firing temperature, the furnace was kept for 1 hour and fired. If the furnace temperature is kept at the firing temperature for a certain time, crystal growth occurs to obtain a ceramic block. After carrying out the firing process, the furnace temperature was naturally cooled to obtain a high strength ceramic block for teeth.

<Example 2>

71.3 wt% SiO ₂ , 16.3 wt% Al ₂ O ₃ , 2.62 wt% Na ₂ O, 8.91 wt% K ₂ O, 0.11 wt% CaO, 0.08 wt% Fe ₂ O ₃ , 0.03 wt% MgO and 0.01 wt% TiO ₂ The feldspar containing was ground to a powder form having a uniform particle size.

Feldspar was charged to a ball mill and wet mixed with ethanol. The oxide powders were mechanically ground and uniformly mixed by rotating at a speed of 350 rpm using a ball mill. The ball used for ball milling used a 5 mm size ball made of zirconia, and ball milling was performed for 6 hours.

The crushed feldspar powder slurry was dried. The drying was carried out in an oven at 80 ° C. for 6 hours.

The crushed feldspar powder was placed in a chamotte crucible and the crucible containing feldspar powder was charged to a furnace and subjected to heat treatment to melt the feldspar powder. The heat treatment was performed for 24 hours at 1500 ℃ temperature higher than the temperature at which the boron oxide (B ₂ O ₃ ) is volatilized. The temperature increase rate of the furnace was set at about 10 ° C / min.

The melt produced by the heat treatment was poured into distilled water and quenched. By the quenching, the melt is fritted into glass.

The quenched glass was ground to have a uniform particle size distribution. The grinding was performed by primary grinding using a pulverizer, secondary grinding using a disk mill, and tertiary grinding using a ball mill. The first powder was ground to a glass powder having a size of about 1 to 2 mm by the pulverizer, and the second powder was milled to a glass powder having a size of about 150 μm by a second mill using the disk mill. It was made to grind | pulverized into the glass powder which has the magnitude | size of about 14.0 micrometers by the 3rd grinding | pulverization using the said ball mill.

In the third grinding process using a ball mill, zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), and mullite (mullite; 3Al ₂ O _{3 2} 2SiO ₂ ) are added, and an organic binder made of polyvinyl alcohol is also a ball mill. Was added to ensure uniform mixing with the glass powder. The change in flexural strength was observed depending on the content of zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ) and mullite (mullite; 3Al ₂ O ₃ ˜ 2SiO ₂ ). The tertiary grinding was rotated at a speed of 350 rpm using a ball mill to mechanically grind and uniformly mix the oxide powders. The ball used for ball milling used a 5 mm size ball made of zirconia, and ball milling was performed for 6 hours.

The mixed powder slurry of the pulverized glass powder, the crystalline additive and the organic binder was dried. The drying was carried out in an oven at 80 ° C. for 6 hours.

The dried glass powder was sieved with a mesh having a pore size of 100 μm.

The mixed powder of the glass powder, the crystalline additive, and the organic binder was placed in a 20 mm x 40 mm bar mold and molded into a prismatic shaped body by applying a pressure of 50 MPa.

The molded mixed powder was fired at temperatures of 950 ° C, 1000 ° C, 1050 ° C and 1100 ° C. The firing was carried out as follows. The mixed powder was charged into an electric furnace and raised to a target firing temperature. At this time, the rising temperature of the furnace was set to about 10 ℃ / min, the pressure in the furnace was maintained at atmospheric pressure. When the furnace temperature rose to the target firing temperature, the furnace was kept for 1 hour and fired. If the furnace temperature is kept at the firing temperature for a certain time, crystal growth occurs to obtain a ceramic block. After the firing process, the furnace temperature was naturally cooled to obtain a high strength ceramic block for teeth.

<Example 3>

Feldspar containing 78.10% SiO ₂ , 13.1% Al ₂ O ₃ , 4.91% Na ₂ O, 3.37% K ₂ O, 0.31% CaO, 0.07% Fe ₂ O ₃ and 0.01% MgO It was ground into a powder form having a particle size of uniform size.

Feldspar was charged to a ball mill and wet mixed with ethanol. The oxide powders were mechanically ground and uniformly mixed by rotating at a speed of 350 rpm using a ball mill. The ball used for ball milling used a 5 mm size ball made of zirconia, and ball milling was performed for 6 hours.

The crushed feldspar powder slurry was dried. The drying was carried out in an oven at 80 ° C. for 6 hours.

The crushed feldspar powder was placed in a chamotte crucible and the crucible containing feldspar powder was charged to a furnace and subjected to heat treatment to melt the feldspar powder. The heat treatment was performed for 24 hours at 1500 ℃ temperature higher than the temperature at which the boron oxide (B ₂ O ₃ ) is volatilized. The temperature increase rate of the furnace was set at about 10 ° C / min.

The melt produced by the heat treatment was poured into distilled water and quenched. By the quenching, the melt is fritted into glass.

The quenched glass was ground to have a uniform particle size distribution. The grinding was performed by primary grinding using a pulverizer, secondary grinding using a disk mill, and tertiary grinding using a ball mill. The first powder was ground to a glass powder having a size of about 1 to 2 mm by the pulverizer, and the second powder was milled to a glass powder having a size of about 150 μm by a second mill using the disk mill. It was made to crush into glass powder having a size of about 16.59㎛ by the third milling using the ball mill.

In the third grinding process using a ball mill, zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), and mullite (mullite; 3Al ₂ O _{3 2} 2SiO ₂ ) are added, and an organic binder made of polyvinyl alcohol is also a ball mill. Was added to ensure uniform mixing with the glass powder. The change in flexural strength was observed depending on the content of zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ) and mullite (mullite; 3Al ₂ O ₃ ˜ 2SiO ₂ ). The tertiary grinding was rotated at a speed of 350 rpm using a ball mill to mechanically grind and uniformly mix the oxide powders. The ball used for ball milling used a 5 mm size ball made of zirconia, and ball milling was performed for 6 hours.

The mixed powder slurry of the pulverized glass powder, the crystalline additive and the organic binder was dried. The drying was carried out in an oven at 80 ° C. for 6 hours.

The dried glass powder was sieved with a mesh having a pore size of 100 μm.

The mixed powder of the glass powder, the crystalline additive, and the organic binder was placed in a 20 mm x 40 mm bar mold and molded into a prismatic shaped body by applying a pressure of 50 MPa.

The molded mixed powder was fired at temperatures of 950 ° C, 1000 ° C, 1050 ° C and 1100 ° C. The firing was carried out as follows. The mixed powder was charged into an electric furnace and raised to a target firing temperature. At this time, the rising temperature of the furnace was set to about 10 ℃ / min, the pressure in the furnace was maintained at atmospheric pressure. When the furnace temperature rose to the target firing temperature, the furnace was kept for 1 hour and fired. If the furnace temperature is kept at the firing temperature for a certain time, crystal growth occurs to obtain a ceramic block. After carrying out the firing process, the furnace temperature was naturally cooled to obtain a high strength ceramic block for teeth.

1 is a Scanning Electron Microscope (SEM) photograph after treatment of a high-strength ceramic block for teeth prepared according to Example 1 by hydrofluoric acid etching, and FIG. 2 is a high-strength ceramic block for teeth prepared according to Example 2 Is a scanning electron microscope (SEM) photograph after treatment with hydrofluoric acid etching, and FIG. 3 is a scanning electron microscope (SEM) image after treatment with hydrofluoric acid etching the high-strength ceramic block for teeth prepared according to Example 3. 1 is a case where firing is performed at 950 ° C. for one hour and titanium oxide (TiO ₂ ) is added as a crystalline additive, and FIG. 2 is one hour firing at 1150 ° C. and titanium oxide as a crystalline additive. (TiO ₂ ) is added, and FIG. 3 is a case where baking is performed at 1150 ° C. for 1 hour and titanium oxide (TiO ₂ ) is added as a crystalline additive.

1 to 3, the high strength ceramic block for dental teeth was confirmed by the presence of a crystalline additive through hydrofluoric acid (HF) etching, and as a result, it was confirmed that the crystalline additive was present.

4 is a graph showing a change in flexural strength according to the content of zirconium oxide (ZrO ₂ ), a crystalline additive. In Figure 4 (a) is for a high-strength ceramic block for teeth fired at 950 ℃ according to Example 1, (b) is for a high-strength ceramic block for teeth fired at 1050 ℃ according to Example 2, ( c) is for a high strength ceramic block for teeth fired at 1050 ° C. according to Example 3.

Referring to FIG. 4, the high-strength ceramic block for teeth manufactured according to Examples 1 and ₂ has a content of 0% by weight of zirconium oxide (ZrO ₂ ) when the content of zirconium oxide (ZrO ₂ ) is 10% by weight. It can be seen that the flexural strength is improved compared to the case. However, the high-strength ceramic block for teeth prepared according to Example 3 has a slightly higher flexural strength than the case where the content of zirconium oxide (ZrO ₂ ) is 0% by weight when the content of zirconium oxide (ZrO ₂ ) is 10% by weight. You can see the decrease. In both Examples 1 to 3, the content of zirconium oxide (ZrO ₂ ) is more than 15% by weight, it can be seen that the bending strength decreases as the content of zirconium oxide (ZrO ₂ ) increases. However, it can be seen that the high-strength ceramic block for teeth manufactured according to Examples 1 to 3 exhibits flexural strength of 145 MPa or more even when the content of zirconium oxide (ZrO ₂ ) is 25% by weight.

5 is a graph showing the change in flexural strength according to the content of the crystalline additive mullite (mullite; 3Al ₂ O ₃ ~ 2SiO ₂ ). In Figure 5 (a) is for a high strength ceramic block for teeth fired at 950 ℃ according to Example 1, (b) is for a high strength ceramic block for teeth fired at 1050 ℃ according to Example 2, ( c) is for a high strength ceramic block for teeth fired at 1050 ° C. according to Example 3.

Referring to Figure 5, the high-strength ceramic block for a tooth prepared according to Example 1 can be seen that the flexural strength increases as the content of mullite (3Al ₂ O ₃ ~ 2SiO ₂ ) increases. Examples 1 and 2 the high-strength ceramic block tooth produced according to the mullite _{(3Al 2 O 3? 2SiO 2} ) content of 10% by weight of one when mullite _{(3Al 2 O 3? 2SiO 2} ) content of 0 parts by weight of the It can be seen that the flexural strength is improved compared to the case of%. However, in Example 3 the high strength ceramic block tooth produced according to the mullite _{(3Al 2 O 3? 2SiO 2} ) content of 10% by weight of one time is 0 wt% of mullite _{(3Al 2 O 3? 2SiO 2} ) of the Compared to the case, the bending strength can be seen to be slightly reduced. Examples 2 and 3 in a high-strength ceramic block tooth produced according to the mullite _{(3Al 2 O 3? 2SiO 2} ) , this amount of mullite _{(3Al 2 O 3? 2SiO 2} ) increases starting at least 15% by weight, the content of As As a result, the bending strength can be seen to decrease. However, it can be seen that the high-strength ceramic block for teeth manufactured according to Examples 1 to 3 exhibits flexural strength of 140 MPa or more even when the content of mullite (3Al ₂ O ₃ ˜ 2SiO ₂ ) is 25% by weight.

6 is a graph showing the change in flexural strength depending on the content of titanium oxide (TiO ₂ ), a crystalline additive. In Figure 6 (a) is for a high strength ceramic block for teeth fired at 1050 ° C according to Example 2, (b) is for a high strength ceramic block for teeth fired at 1050 ° C according to Example 3.

6, the Examples 2 and 3 The high-strength ceramic block made in accordance with the tooth can be seen that the flexural strength increases as the content of titanium oxide (TiO ₂₎ increases. High-strength ceramic blocks for teeth prepared according to Examples 2 and 3 can be seen that the flexural strength of 185 MPa or more when the content of titanium oxide (TiO ₂ ) is 10% by weight.

7 is a graph showing the density change of the high-strength ceramic block for teeth according to the firing temperature. In FIG. 7, (a) shows the density change when zirconium oxide (ZrO ₂ ) is added as a crystalline additive, and (b) shows the density change when alumina (Al ₂ O ₃ ) is added. (c) it is showing a density variation for the addition of mullite _{(3Al 2 O 3? 2SiO 2} ).

7, zirconium (ZrO _2), mullite _{(3Al 2 O 3? 2SiO 2} ) and alumina (Al ₂ O ₃₎ a tooth density of the high-strength ceramic blocks as the firing temperature increases in both the case of adding oxide It can be seen that is increasing.

8 is a graph showing a change in the hardness (vickness hardness) of the high-strength ceramic block for teeth according to the addition amount of the crystalline additive. In FIG. 8, (a) shows the hardness change when zirconium oxide (ZrO ₂ ) is added as a crystalline additive, and (b) shows the hardness change when alumina (Al ₂ O ₃ ) is added. (c) is to demonstrate the change in hardness in the case of addition of mullite _{(3Al 2 O 3? 2SiO 2} ).

8, a zirconium oxide (ZrO _2), mullite _{(3Al 2 O 3? 2SiO 2} ) and alumina (Al ₂ O ₃₎ a dental high-strength ceramic for as the amount of the crystalline additive increased both in the case of adding It can be seen that the hardness of the block is increasing.

9 shows the change in hardness according to the addition amount of TiO _{2 in} the crystalline additive in each example. In Figure 9 (a) shows the change in hardness of the high-strength ceramic block for the tooth prepared in accordance with Example 1 by adding a crystalline additive TiO ₂ , (b) is an example by adding TiO ₂ crystalline additive It shows the hardness change of the high-strength ceramic block for dental prepared in accordance with 2, (c) shows the change in hardness of the high-strength ceramic block for dental prepared according to Example 3 by adding a crystalline additive TiO ₂ .

9, when the TiO ₂ was added 5 wt% in Example 2, the hardness value was found to be excellent.

10-12 are graphs showing TG / DTA of glass powders. 10 to 12 the glass powder is for the powder made up to the disk mill process (secondary grinding process).

FIG. 10 is a TG / DTA graph of the glass powder prepared by Example 1, showing that primary nuclei are generated at about 750 ° C., and nuclei grow at about 954 ° C. FIG.

111 is a TG / DTA graph of the glass powder prepared according to Example 2, showing that primary nuclei are generated at around 765 ° C., and the nuclei grow at about 1011 ° C. FIG.

12 is a TG / DTA graph of the glass powder prepared according to Example 3, showing that primary nuclei are generated at around 763 ° C., and the nucleus is grown at around 981 ° C. FIG.

As mentioned above, although preferred embodiment of this invention was described in detail, this invention is not limited to the said embodiment, A various deformation | transformation by a person of ordinary skill in the art within the scope of the technical idea of this invention is carried out. This is possible.

1 is a scanning electron microscope (SEM) photograph after treatment of a high-strength ceramic block for teeth prepared according to Example 1 by hydrofluoric acid etching.

FIG. 2 is a scanning electron microscope (SEM) photograph of a dental high strength ceramic block prepared in Example 2 after treatment with hydrofluoric acid etching.

FIG. 3 is a scanning electron microscope (SEM) photograph of the dental high-strength ceramic block prepared in Example 3 after treatment with hydrofluoric acid etching.

4 is a graph showing a change in flexural strength according to the content of zirconium oxide (ZrO ₂ ), a crystalline additive.

5 is a graph showing a change in flexural strength according to the content of the crystalline additive Mullite (3Al ₂ O ₃ ~ 2SiO ₂ ).

6 is a graph showing the change in flexural strength depending on the content of titanium oxide (TiO ₂ ), a crystalline additive.

7 is a graph showing the density change of the high-strength ceramic block for teeth according to the firing temperature.

8 is a graph showing the hardness change of the high-strength ceramic block for teeth according to the addition amount of the crystalline additive.

Figure 9 shows the change in hardness according to the addition amount of the crystalline additive TiO ₂ in Examples 1 to 3.

10 is a graph showing the TG / DTA of the glass powder prepared in the composition of Example 1.

FIG. 11 is a graph showing TG / DTA of glass powder prepared by the composition in Example 2.

12 is a graph showing TG / DTA of the glass powder prepared by the composition in Example 3.

Claims (10)

45 to 85 weight percent SiO ₂ , 7 to 25 weight percent Al ₂ O ₃ , 0.5 to 15 weight percent Na ₂ O, 0.5 to 15 weight percent K ₂ O, 0.01 to 7 weight percent CaO, 0.001 to 5 Fe ₂ O ₃ It contains a glass phase comprising a weight% and 0.001 to 3% by weight MgO, A high strength ceramic block for teeth containing 0.01-30% by weight of zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), alumina (Al ₂ O ₃ ) and mullite (3Al ₂ O ₃ ˜ 2SiO ₂ ) crystalline additives. According to claim 1, wherein the glass phase is a feldspar is melted and frit, and as the frit is boron oxide (B ₂ O ₃ ) is volatilized, the glass phase does not contain a boron oxide (B ₂ O ₃ ) component High strength ceramic block for teeth. The high-strength ceramic block for teeth according to claim 1, wherein the titanium oxide (TiO ₂ ) is made of rutile titanium oxide. 45 to 85 weight percent SiO ₂ , 7 to 25 weight percent Al ₂ O ₃ , 0.5 to 15 weight percent Na ₂ O, 0.5 to 15 weight percent K ₂ O, 0.01 to 7 weight percent CaO, 0.001 to 5 Fe ₂ O ₃ Preparing a glass powder containing weight percent and 0.001 to 3 weight percent MgO; 0.01-30 wt% of zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), alumina (Al ₂ O ₃ ) and mullite (3Al ₂ O ₃ ˜ 2SiO ₂ ) crystalline additives, the glass powder, and an organic binder Mixing; Shaping the mixture of the crystalline additive, the glass powder and the organic binder into a desired form; And Calcining the shaped mixture to a temperature of 850-1300 ° C., Preparing the glass powder, 45 to 85 weight percent SiO ₂ , 7 to 25 weight percent Al ₂ O ₃ , 0.5 to 15 weight percent Na ₂ O, 0.5 to 15 weight percent K ₂ O, 0.01 to 7 weight percent CaO, 0.001 to 5 Fe ₂ O ₃ Pulverizing feldspar containing 0.001% to 3% by weight of MgO into a powder having a uniform particle size; Heat-treating the feldspar powder formed by pulverizing the molten feldspar powder; Pouring the melt produced by the heat treatment into distilled water to quench the glass to obtain glass; And Quenching the glass formed by quenching to have a uniform particle size distribution to obtain a glass powder, The organic binder is composed of at least one organic material selected from polyvinyl alcohol (PVA) and paraffin wax, which serves to bind the glass powder and the crystalline additive, and the organic binder is 1 to 100 parts by weight of the glass powder. A method for producing a high strength ceramic block for teeth, characterized in that added to 50 parts by weight. delete The method of claim 4, wherein the step of obtaining the glass powder by pulverizing the glass formed by quenching, Grinding into glass powder having a size of 800 µm to 5 mm by primary grinding using a pulverizer; And A method of producing a high strength ceramic block for teeth comprising the step of pulverizing into a glass powder having a size of 50 ~ 300㎛ by secondary grinding using a disk mill. The method of claim 4, wherein the mixing of the crystalline additive, the glass powder, and the organic binder comprises: Charging the crystalline additive, the glass powder and the organic binder into a ball mill, and grinding the glass powder having a size of 0.1 to 20 μm by grinding using a ball mill. . The method of claim 4, wherein the heat treatment, Method for producing a high-strength ceramic block for dental, characterized in that carried out for 1 to 48 hours at a temperature of 1250 ~ 1600 ℃ that is higher than the temperature at which the boron oxide (B ₂ O ₃ ) is volatilized. The method of claim 4, wherein the firing, Method for producing a high-strength ceramic block for dental, characterized in that performed for 10 minutes to 6 hours at normal pressure in an oxidizing atmosphere. delete

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