阅读说明：本技术 使用沉淀剂的牙科切削加工用氧化锆被切削体的制造方法 (Method for producing zirconia workpiece for dental cutting using precipitant ) 是由 野中和理 高桥周平 于 2021-03-25 设计创作，主要内容包括：本发明的课题是在牙科切削加工用氧化锆被切削体上无偏差地负载金属,该牙科切削加工用氧化锆被切削体是通过低温度条件下的预烧并调节至能切削加工的硬度的牙科切削加工用氧化锆被切削体。本发明的解决方案是通过牙科切削加工用氧化锆被切削体的制造方法制造牙科切削加工用氧化锆被切削体,该牙科切削加工用氧化锆被切削体的制造方法包含：含浸工序,该工序使包含至少一种金属离子和至少一种沉淀剂的含浸液含浸于多孔质氧化锆成型体；以及析出工序,该工序使多孔质氧化锆成型体中的沉淀剂分解,并使金属化合物析出。(The present invention addresses the problem of providing a dental cutting zirconia body with a metal supported thereon without variation, the dental cutting zirconia body being adjusted to a hardness enabling cutting by pre-firing at a low temperature. The present invention provides a method for manufacturing a zirconia cutting object for dental cutting by a method for manufacturing a zirconia cutting object for dental cutting, the method comprising: an impregnation step of impregnating a porous zirconia molded body with an impregnation solution containing at least one metal ion and at least one precipitant; and a precipitation step of decomposing the precipitant in the porous zirconia molded body to precipitate the metal compound.)

1. A method for manufacturing a zirconia workpiece for dental cutting, comprising,

which comprises the following steps:

an impregnation step of impregnating a porous zirconia molded body with an impregnation solution containing at least one metal ion and at least one precipitant; and

and a precipitation step of decomposing the precipitant in the porous zirconia molded body to precipitate the metal compound.

2. The method for manufacturing a zirconia cutting object for dental cutting according to claim 1, wherein,

at least one of the metal ions is a rare earth metal ion.

3. The method for producing a zirconia cutting object for dental cutting according to claim 1 or 2, wherein,

at least one of the metal ions is a transition metal ion.

4. The method for producing a zirconia cutting object for dental cutting according to any one of claims 1 to 3, wherein,

at least one of the metal ions is any one of aluminum ions, gallium ions, and indium ions.

5. The method for producing a zirconia cutting object for dental cutting according to any one of claims 1 to 4,

in the precipitation step, the precipitant is decomposed by heating.

6. The method for producing a zirconia cutting object for dental cutting according to any one of claims 1 to 5, wherein,

the precipitant is urea.

7. A zirconia cutting object for dental cutting, comprising,

the method for producing a zirconia cutting object for dental cutting according to any one of claims 1 to 6.

8. A dental prosthetic device, wherein,

the dental cutting zirconia material according to claim 7.

9. A dental zirconia cutting object for cutting, which is a pre-fired dental zirconia cutting object for cutting, characterized in that,

at least one of a metal oxide, a metal hydroxide, a metal oxyhydroxide, a metal carbonate hydroxide, and a metal oxalate is precipitated between the zirconia particles.

10. The zirconia cutting object for dental cutting processing according to claim 9,

the dental cutting zirconia workpiece is a heat-treated dental cutting zirconia workpiece.

11. A dental prosthetic device, wherein,

the zirconia-based material for dental cutting according to claim 10.

Technical Field

The present invention relates to a method for manufacturing a zirconia cutting object for dental cutting.

Background

In recent years, a technique for manufacturing a prosthetic device by cutting using a dental CAD/CAM system has rapidly spread. Thus, it becomes possible to easily manufacture the prosthetic device by processing the body to be cut, which is manufactured using a ceramic material such as zirconia, alumina, or lithium disilicate, or a resin material such as an acrylic resin or a hybrid resin.

In particular, zirconia is clinically used in various cases because of its high strength. On the other hand, since fully sintered zirconia (hereinafter, referred to as a zirconia fully sintered body) has a very high hardness, a dental zirconia cutting object for cutting work which is calcined at a temperature lower than the fully sintered temperature and adjusted to a hardness capable of cutting work is often used, and the zirconia fully sintered body is obtained by sintering after cutting work.

In the specification of chinese patent application No. 108472110, a method is described in which after a solution containing metal ions is impregnated in a porous zirconia molded body, NH is used₄The OH solution treatment is performed to precipitate a metal hydroxide in the pores of the porous zirconia molded body. However, in this method, since NH is reacted with the catalyst₄Since the portion contacted with the OH solution begins to precipitate, it is difficult to uniformly precipitate the metal hydroxide in the pores of the porous zirconia molded body.

International publication No. 2019/083967 describes a method in which a porous zirconia molded body is impregnated with a solution containing molybdenum ions, and a molybdenum compound is supported in the pores.

However, in this method, when the molybdenum solution is dried, the molybdenum compound segregates on the surface of the porous zirconia molded body, and therefore it is difficult to uniformly support the molybdenum compound.

Disclosure of Invention

In a dental cutting zirconia workpiece adjusted to a hardness capable of cutting by pre-firing under low temperature conditions, it is necessary to carry a metal without variation.

The present inventors have found that a method for producing a zirconia cutting object for dental cutting machining, which comprises an impregnation step of impregnating a porous zirconia molded body with an impregnation liquid containing at least one metal ion and at least one precipitant, and a precipitation step of decomposing the precipitant in the porous zirconia molded body to precipitate a metal compound, is effective for suppressing the segregation of a supported metal compound.

In the precipitation step, heating is preferred as a method of decomposing the precipitant.

Preferably, at least one of the metal ions is a rare earth metal ion, a transition metal ion, or any of an aluminum ion, a gallium ion, and an indium ion, and the precipitating agent is urea.

The present invention also provides a zirconia cutting object for dental cutting obtained by the production method of the present invention.

The present invention also provides a dental prosthesis device produced from the zirconia cutting body for dental cutting according to the present invention.

The present invention also provides a dental cutting zirconia workpiece which is a calcined dental cutting zirconia workpiece, characterized in that at least one of a metal oxide, a metal hydroxide, a metal oxyhydroxide, a metal carbonate hydroxide, and a metal oxalate is precipitated between zirconia particles. The dental cutting zirconia workpiece may be a dental cutting zirconia workpiece that has been heat-treated.

The present invention also provides a dental prosthesis device produced from the zirconia cutting body for dental cutting according to the present invention.

The method for producing a molded body of a zirconia cutting object for dental cutting according to the present invention can deposit metal ions impregnated in a porous zirconia molding as a metal compound without segregation, and can obtain a molded body of a zirconia cutting object for dental cutting in which a metal compound is uniformly supported.

Detailed Description

Hereinafter, one embodiment of the present invention will be described in detail.

The method for producing a zirconia cutting object for dental cutting according to the present invention is characterized in that at least one metal ion is supported on a porous zirconia compact by an impregnation step of impregnating a porous zirconia compact with an impregnation liquid containing at least one kind of precipitant and a precipitation step of decomposing the precipitant in the porous zirconia compact to precipitate a metal compound.

The method for producing a dental cutting zirconia workpiece according to the present invention can suppress segregation of the supported metal compound and can obtain a dental cutting zirconia workpiece to which one or more metal ions are uniformly added.

The metal ion in the present invention can be used without any particular limitation as long as it can be precipitated in the pores of the porous zirconia molded body by the precipitant. Specific examples thereof include yttrium ions as a stabilizer for zirconia; erbium ions, iron ions used as coloring components; aluminum ions, gallium ions, indium ions, and the like are used for the purpose of controlling sinterability.

At least one of the metal ions may be a rare earth metal ion. The rare earth metal ion is specifically yttrium ion. The inclusion of rare earth metal ions can improve the light transmittance of the zirconia sintered body or can color the zirconia sintered body. The metal ions can be only rare earth metal ions.

At least one of the metal ions can be a transition metal ion. The transition metal ion is iron ion. The zirconia sintered body can be colored by containing a transition metal ion. The metal ions can be only transition metal ions.

At least one of the metal ions can be any one of aluminum ions, gallium ions, and indium ions. By containing any of aluminum ions, gallium ions, and indium ions, the sinterability of the zirconia sintered body can be improved, or the light transmittance can be improved. The metal ions can be only aluminum ions, gallium ions and/or indium ions. The metal ions can be only rare earth metal ions, transition metal ions, aluminum ions, gallium ions, and/or indium ions.

The precipitant in the present invention can be used without limitation as long as it can precipitate a compound containing a metal ion by decomposing the precipitant. Examples thereof include urea, hexamethylenetetramine, dimethyl oxalate, etc., and urea is preferably used.

In the present invention, the metal ion source is preferably a metal ion organic acid salt. Examples thereof include acetate and citrate.

The concentration of the metal ions in the immersion liquid in the present invention is not particularly limited, and for example, the yttrium ions are preferably about 2.0 wt% to 10.0 wt%. When the amount is 2.0 wt% or less, the amount of yttrium supported is small, and sufficient characteristics may not be obtained. In the case of 10.0 wt% or more, the amount of yttrium supported is large, and the physical properties may be adversely affected. Since the optimum metal loading varies depending on the kind of metal or the desired characteristics, the metal ion concentration of the immersion liquid is preferably determined according to the desired metal loading and the solubility of the metal ion source in the solvent.

The amount of the precipitant in the impregnation fluid of the present invention is preferably an amount that causes all the metal ions in the impregnation fluid to be precipitated. When the amount of the precipitant is decreased, the time taken until all the metal ions are precipitated tends to be longer, and when the amount of the precipitant is increased, the time taken until all the metal ions are precipitated tends to be shorter. When the amount of the precipitant is smaller than the amount of all the metal ions to be precipitated in the immersion liquid, all the metal ions are not precipitated, and the metal ions may be segregated, which is not preferable. When the amount of the precipitant is excessive, the effect of the present invention is not affected, but the precipitant is not preferably left in a large amount after the precipitation step. The amount of the precipitant is not particularly limited, but is preferably 5 to 30 times the amount of all the metal ions to be precipitated.

The solvent used in the impregnation solution of the present invention is not particularly limited, and a solvent having a boiling point higher than the decomposition temperature of the precipitant is preferable. From the viewpoint of easy availability and handling, water is preferably used.

Examples of the metal compound deposited by decomposing the precipitant in the deposition step include, but are not particularly limited to, metal oxides, metal hydroxides, metal oxyhydroxides, metal carbonates, metal carbonate hydroxides, and metal oxalates. The form is not particularly limited. The resin composition may be in any form such as spherical, plate-like, needle-like, amorphous, etc., and may be in any form of crystal or amorphous. By these precipitations, a zirconia cutting object for dental cutting in which metal ions are supported on a porous zirconia molded body can be obtained.

In the immersion liquid of the present invention, an acid, an alkali, and a pH adjuster may be added for the purpose of controlling pH. The acid or base to be used is not particularly limited, and it is preferable to use an organic acid such as acetic acid or citric acid, or ammonia water, from the viewpoint of not leaving a residue in the porous zirconia molded body.

The primary particle diameter of the zirconia powder used for producing the porous zirconia molded body of the present invention is preferably 1 to 500 nm. When the primary particle diameter is less than 1nm, although the light transmittance of the zirconia sintered body is improved, it tends to be difficult to impart sufficient strength. On the other hand, when the primary particle diameter is larger than 500nm, it tends to be difficult to impart sufficient strength to the zirconia sintered body.

The porous zirconia molded body of the present invention may contain a stabilizer. Examples of the stabilizer include yttrium oxide, cerium oxide, calcium oxide, and magnesium oxide.

The porous zirconia molded body of the present invention may contain a coloring agent. Specifically, iron oxide for imparting yellow color, erbium for imparting red color, and the like can be given. In addition, in addition to these colorants, there is no problem in combination with colorants containing elements such as cobalt, manganese, and chromium for color tone adjustment. The present invention can be easily colored in tooth color by including a colorant.

The porous zirconia molded body in the present invention may contain a sintering aid, and alumina is exemplified.

The crystal phase of the porous zirconia molded body in the present invention is preferably tetragonal and/or cubic. When the crystal phase is monoclinic, sufficient light transmittance cannot be imparted after the zirconia is completely sintered, which is not preferable.

The method for producing the porous zirconia molded body in the present invention is not particularly limited, and any known method can be used without any problem. Specifically, a method of molding zirconia powder by pressure molding is preferable.

The porous zirconia molded body in the present invention is preferably subjected to isotropic pressing by a hydrostatic isotropic pressure application method (CIP treatment) such as cold after press molding.

The maximum load pressure of the CIP treatment in the present invention is preferably 50MPa or more. When the maximum load pressure is less than 50MPa, sufficient light transmittance and strength may not be imparted to the zirconia sintered body.

The holding time at the maximum load pressure in the CIP treatment of the present invention is not particularly limited, but is preferably 0 to 150 seconds, and more preferably 0 to 60 seconds.

The time taken for the series of steps is not particularly limited, but is preferably 30 seconds to 10 minutes, and more preferably 3 minutes to 7 minutes. If the time is too short, the molded article may be broken, and if the time is too long, the productivity may be deteriorated, which is not preferable.

The porous zirconia molded body in the present invention is fired at a pre-firing temperature condition, and thereby a fired state of the zirconia cutting object for dental cutting is obtained. The pre-sintering temperature of the porous zirconia molded body in the invention is preferably 800-1200 ℃. When the pre-firing temperature is less than 800 ℃, the vickers hardness and/or the bending strength are too low, and thus chipping and breaking tend to occur easily during cutting. On the other hand, when the pre-firing temperature is 1200 ℃ or higher, the vickers hardness and/or the bending strength become too strong, and therefore the wear of the grinding rod of the cutting machine becomes severe, and the running cost tends to increase.

In the present invention, the method for producing the zirconia powder used for producing the porous zirconia compact is not particularly limited, and a known method can be used. Specifically, the zirconia powder used in the present invention is preferably produced by a hydrolysis method.

The method of impregnating the porous zirconia molded body of the present invention with the impregnation liquid is not particularly limited as long as the impregnation liquid can be impregnated into the pores of the porous zirconia molded body. A simple and preferable method is a method of immersing the whole and/or a part of the porous zirconia molded body in the immersion liquid. In this case, the immersion liquid can be infiltrated into the inside by the capillary phenomenon. The immersion time is 3 minutes or more, preferably 10 minutes to 10 hours.

The impregnation solution may be impregnated into the entire porous zirconia molded body or may be impregnated into only an arbitrary portion. The method of impregnating only an arbitrary portion is not particularly limited, and examples thereof include controlling the weight and volume of the impregnation liquid and controlling the impregnation time.

A plurality of kinds of impregnation liquids may be used for one porous zirconia molded body. Specific examples thereof include impregnation with a first impregnation liquid from one end and impregnation with a second impregnation liquid from the same end or the other end.

The environment in the impregnation with the impregnation solution is not particularly limited, and air, an inert gas, or the like can be used under normal pressure, reduced pressure, or increased pressure. Since no special equipment is required, it is preferably carried out in an atmospheric pressure atmosphere.

The method for decomposing the precipitant in the present invention is not particularly limited. Examples thereof include hydrolysis by heating and hydrolysis by an enzyme, but hydrolysis by heating is preferable because of its simplicity.

The method of hydrolysis by heating is not particularly limited as long as a constant temperature can be maintained. Examples thereof include a method using a thermostat, a dryer, a water bath, and an oil bath.

When hydrolysis is performed by heating, the porous zirconia molded body is preferably sealed in order to prevent evaporation of the solvent. The method is not particularly limited, and examples thereof include a method in which a resin sheet is used for covering and, in some cases, degassing is performed.

The temperature at which hydrolysis is carried out by heating is not particularly limited as long as it is equal to or higher than the decomposition temperature of the precipitant, but when it is too low, it is not preferable because a long time of heating treatment is required until all the metal compound is precipitated. When the temperature exceeds the boiling point of the solvent, the solvent evaporates during the heating treatment, and the supported metal compound is segregated, which is not preferable.

The time required for hydrolysis by heating varies depending on the metal ion concentration, the precipitant concentration, the heat treatment temperature, and the like, and thus it is necessary to appropriately adjust the time, usually about 10 minutes to several days. Preferably 10 minutes to 24 hours.

It is preferable to have a drying step after the deposition step. The drying step is a step of drying the porous zirconia molded body on which the metal compound is precipitated. The drying step is preferably performed in a dryer. The drying temperature is 90-200 deg.C, and the time is preferably 15 min-5 hr. Preferably, after drying, the solvent is sufficiently vaporized. In some cases, the drying step may be followed by a heat treatment step. The drying step may be included in the heat treatment step.

The porous zirconia molded body on which the metal compound thus obtained is deposited and supported preferably undergoes heat treatment because a solvent, an unreacted material, a by-product, and the like remain. The heat treatment method is not particularly limited, and since no special equipment is required, it is preferable to perform the heat treatment in an atmospheric pressure atmosphere. The heat treatment temperature is not particularly limited, and is preferably 500 to 1200 ℃. Impurities, organic substances, and odors can be removed by heat treatment.

Thus, a zirconia cutting object for dental cutting can be obtained by the production method of the present invention. The obtained zirconia cutting object for dental cutting is preferably cut, and surface-ground to a desired size as needed.

The method for completely sintering the zirconia cutting body for dental cutting of the present invention to obtain the fired state of the patch device is not particularly limited, and the simple and preferable method is atmospheric pressure firing. The firing temperature is not particularly limited, but is preferably 1400 to 1600 ℃ and more preferably 1450 to 1550 ℃. The residence time under the maximum firing temperature condition is not particularly limited, but is preferably 1 minute to 12 hours, and more preferably 2 to 4 hours. The temperature rise rate is not particularly limited, but is preferably 1 to 400 ℃/min, and more preferably 3 to 100 ℃/h.

The type of the prosthetic device for cutting using the zirconia cutting object for dental cutting of the present invention is not particularly limited, and any prosthetic device such as an inlay, a laminate, a crown, and a bridge does not have any problem. Therefore, the shape of the dental cutting zirconia object for producing a prosthetic device by cutting is not particularly limited, and any dental cutting zirconia object having any shape such as a block shape corresponding to an inlay, a laminate, a crown, or the like, or a disc shape corresponding to a bridge can be used.

In order to obtain the zirconia cutting object for dental cutting of the present invention, it is preferable that the porous zirconia molded body is fired at least once at a pre-firing temperature of 800 to 1200 ℃.

The heat treatment of the porous zirconia molded body deposited and supported with the metal compound is preferably 500 to 1200 ℃. When the pre-firing temperature is exceeded during the main heat treatment, this state becomes the fired state of the dental cutting zirconia material.

The dental cutting zirconia material of the present invention is cut and fired at 1400 to 1600 ℃ to obtain a prosthetic device.

The dental cutting zirconia material of the present invention is fired at 1400 to 1600 ℃ without cutting to obtain a dental cutting zirconia material in a fired state of a prosthetic device, and then cut to obtain a prosthetic device.

The relative density of the dental cutting zirconia body in the fired state of the prosthetic device or the prosthetic device is preferably 98% or more of the theoretical density. The relative density was determined by measuring density/theoretical density. When the relative density is 98% or less, the strength or light transmittance tends to be lowered.

[ examples ]

The present invention will be described in more detail and specifically with reference to examples, but the present invention is not limited thereto.

(preparation of porous zirconia molded body)

A zirconia powder containing 5.5 mol% of solid-solution yttrium was filled in a mold (. phi.100 mm), and press-molded (surface pressure: 50MPa) to obtain a molded body. The molded body obtained was subjected to CIP treatment (maximum load pressure: 200MPa, holding time: 1 minute) and then calcined in an electric furnace (1000 ℃ C., 30 minutes) to obtain a porous zirconia molded body.

(preparation of infusion solution)

Table 1 shows the composition of the immersion liquid. According to the composition shown in Table 1, 1000g of an impregnation solution was prepared by adding a metal salt and a precipitant to ion-exchanged water and stirring for 1 hour.

[ Table 1]

(supporting of Metal Compound on porous zirconia molded body)

The porous zirconia molded body was placed in a container, the immersion liquid was injected thereinto in such a manner that only the top surface of the porous zirconia molded body was exposed, and the container was allowed to stand under atmospheric pressure for 24 hours. Thereafter, the porous zirconia molded body was taken out from the impregnation solution, and after removing the excess impregnation solution, the porous zirconia molded body was packed into a resin bag and degassed. The porous zirconia molded body was placed in a bag made of resin and degassed, and the resultant was placed in a dryer, and heat-treated at 95 ℃ for 15 hours to precipitate a metal compound. After the heat treatment, the porous zirconia molded body was taken out from the bag made of resin, and dried (120 ℃ C., 1 hour) to obtain a metal compound-supported porous zirconia molded body. The porous zirconia molded body was heat-treated using an electric furnace (500 ℃ C., 30 minutes) to obtain a zirconia cutting object for dental cutting.

(measurement of Metal Supported amount (% by weight))

Each dental zirconia workpiece for cutting was cut into a disk shape (φ 24 mm. times.1.6 mm) to prepare test pieces (5 pieces each) for metal supporting amount evaluation. The amounts of metals on the upper and lower surfaces of each test piece were measured using a fluorescent X-ray analyzer (manufactured by Nippon chemical Co., Ltd. (リガク)). The metal loading (wt%) is all expressed in terms of oxide. In addition, since the zirconia powder used contains a certain amount of yttrium and aluminum, when the supported metal is yttrium and aluminum, a value obtained by subtracting the amount contained in the zirconia powder from the measured value is expressed as a supported amount.

(evaluation of Metal Supported amount (% by weight) bias)

The metal amounts on the upper and lower surfaces of each of the 5 test pieces measured in the "measurement of metal supported amount (% by weight)" were referred to as measured values at 10 points in each dental zirconia cutting material for cutting, and the "maximum value-minimum value" and "standard deviation" of the measured values were calculated.

The results of the property tests of the dental cutting zirconia bodies produced in examples and comparative examples are shown in table 2.

(color measurement)

Color measurement tests were performed for example 1, example 3, comparative example 1, and comparative example 3. A color test piece was prepared from the test piece for metal loading evaluation. Each test piece for metal loading evaluation was completely sintered using a sintering furnace (sintering temperature: 1550 ℃, rate of temperature rise: 5 ℃/min, holding time: 2 hours). Thereafter, the thickness (1.0mm) of each test piece was adjusted using a surface grinder. Color measurement was performed using a spectrophotometer (manufactured by Konika Meinenda Co., Ltd. (コニカミノルタ)). From the obtained data,. DELTA.E was calculated by the following equation^*. The results of the colorimetric test are shown in Table 3.

ΔE^*＝[(L^* _a-L^* _b)²+(a^* _a-a^* _b)+(b^* _a-b^* _b)]^1/2

(evaluation of light transmittance)

The light transmittance was evaluated for example 1, example 3, comparative example 1 and comparative example 3. The transmittance was evaluated by measuring the contrast. The contrast was measured using a spectrocolorimeter (manufactured by Konika Meinenda). The Y value when a white plate was placed under each test specimen for color measurement was designated Yw, and the Y value when a black plate was placed under each test specimen for color measurement was designated Yb. The contrast was calculated from the following equation.

The closer the contrast is to 0, the more transparent the material, the closer the contrast is to 1, the more opaque the material. The evaluation results of the light transmittance are shown in table 3.

Contrast ratio (Yb/Yw)

[ Table 2]

*: 1.2 wt% iron was contained as a colorant.

[ Table 3]

In example 1, since the impregnation solution contains the precipitant and the metal compound is supported by precipitation accompanying decomposition of the precipitant, a zirconia cutting object for dental cutting use having little variation in the amount of the metal supported at different portions and little variation in light transmittance after complete sintering was obtained.

In example 2, since the immersion fluid contains the precipitant and the metal compound is supported by precipitation accompanying decomposition of the precipitant, a zirconia cutting body for dental cutting with little variation in the amount of metal supported at different portions is obtained.

In example 3, since the impregnation solution contains the precipitant and the metal compound is supported by precipitation accompanying decomposition of the precipitant, a zirconia cutting body for dental cutting processing having little variation in the amount of the metal supported at different portions and little variation in color tone after completely sintering was obtained.

In examples 4 to 8, since the impregnation solution contains the precipitant and the metal compound is supported by precipitation accompanying decomposition of the precipitant, the zirconia cutting body for dental cutting with less variation in the amount of the metal supported at different portions was obtained.

In comparative example 1, since the immersion fluid does not contain a precipitant and the metal compound is supported by evaporation of the solvent in the drying step, a zirconia cutting object for dental cutting use in which variation in the amount of the metal supported at different portions is large and variation in the light transmittance after complete sintering is large was obtained. In general, although the transmittance tends to be improved in the portion where the amount of yttrium is large, the amount of yttrium supported is excessively large in the portion where the amount of metal supported is the largest in comparative example 1, and thus the transmittance is observed to be reduced.

In comparative example 2, since the immersion fluid does not contain a precipitant and the metal compound is supported by evaporation of the solvent in the drying step, the zirconia cutting object for dental cutting with large variation in the amount of metal supported at different portions was obtained.

In comparative example 3, since the impregnation solution did not contain a precipitant, and the metal compound was supported by evaporation of the solvent in the drying step, the dental cutting zirconia substrate for cutting had a large variation in the amount of the metal supported at different portions and a large variation in the color tone after completely firing was obtained.

In comparative examples 4 and 5, since the impregnation solution does not contain a precipitant and the metal compound is supported by evaporation of the solvent in the drying step, the zirconia cutting object for dental cutting having a large variation in the amount of metal supported at different portions was obtained.

In the present specification, when a constituent element of the invention is described as either a singular or a plural, or when it is not described as being limited to a singular or a plural, the constituent element may be either a singular or a plural, unless otherwise clear from the context.

Although the present invention has been described with reference to the detailed embodiments, it should be understood that various changes and modifications can be made by those skilled in the art based on the matters disclosed in the present specification. Therefore, the scope of the embodiments of the present invention is intended to include any alterations or modifications.

The present invention relates to a zirconia workpiece for dental cutting and a method for producing the same, and is a technique that can be used in the dental field.