Dental ceramic coloring method and dental ceramic coloring liquid

Abstract

A coloring method for coloring a dental ceramic (10) comprises a step for bringing a coloring liquid (30) containing at least two types of metal ions having a standard oxidation-reduction potential difference of 0.5-4.0 (inclusive) into contact with the dental ceramic (10).

Description

Technical Field

[0001] The present invention relates to a method for coloring dental ceramics and a coloring liquid for dental ceramics. Background Art

[0002] Patent Document 1 discloses a technique for manufacturing a dental filling of a desired shape by grinding and cutting a gradient block made of ceramics such as zirconia using CAD / CAM (Computer Aided Design / Computer Aided Manufacturing).

[0003] Patent document 2 discloses a method for manufacturing a colored dental pre-sintered body or a dental sintered body for making dental restorations using CAD / CAM, in which a plurality of coloring liquids of different colors are sequentially dripped onto a pre-sintered body of a ceramic such as molded zirconia to allow the pre-sintered body to penetrate.

[0004] [Prior art literature]

[0005] [Patent Literature]

[0006] [Patent Document 1] International Publication No. 2009 / 154301

[0007] [Patent Document 2] Patent No. 6093900 Summary of the invention

[0008] [Problems to be solved by the invention]

[0009] However, conventional dental ceramics require preparation of a plurality of coloring liquids and multiple coloring steps, which is labor-intensive.

[0010] An object of the present invention is to provide a method for coloring dental ceramics, which is capable of forming gradation inside the dental ceramics in a single coloring step using a single coloring liquid.

[0011]

Methods to solve the problem

[0012] A method for coloring dental ceramics according to one embodiment of the present invention is a method for coloring dental ceramics, comprising the step of bringing a coloring liquid containing at least two metal ions having a standard oxidation-reduction potential difference of 0.5 or more and 4.0 or less into contact with the dental ceramic.

[0013] [Effects of the invention]

[0014] According to one aspect of the present invention, there is provided a method for coloring dental ceramics, which forms gradation inside the dental ceramics in a single coloring step using a single coloring liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0015]

Figure 1

[0016]

Figure 2

[0017]

Figure 3

[0018]

Figure 4

[0019]

Figure 5

[0020]

Figure 6

[0021]

Figure 7

[0022]

Figure 8

[0023]

Fig. 9

[0024] Hereinafter, embodiments of the present invention will be described in detail.

[0025] <Coloring Method for Dental Ceramics>

[0026] Figure 1 is a diagram showing an example of dental ceramics. Figure 2 : is a figure which shows an example of the coloring method of dental ceramics. The coloring method of dental ceramics is a method of coloring dental ceramics with a coloring liquid.

[0027] The form of the dental ceramic is not particularly limited, but a molded body (ceramic molded body) or a calcined body (ceramic calcined body) is preferred from the viewpoint of harmonizing the coloring of the dental ceramic.

[0028] The molded body is formed by molding ceramics. The molded body can be manufactured by any method, for example, a method of adding ceramic powder to a mold and compression molding, a method of adding ceramic slurry to a mold and fixing it (slip casting molding, gel casting, etc.), and a layered molding method (additive manufacturing, 3D printing, etc.).

[0029] The calcined body is obtained by pre-sintering the molded body (for example, heating at 600 to 1500° C.). The calcined body is a state where ceramic powders are temporarily bonded to each other and have continuous pores between particles through which a coloring liquid described later can penetrate.

[0030] Furthermore, the form of the dental ceramic is not particularly limited, and may be a bulk or a shaped object.

[0031] The block is a molded body or a pre-burned body before being processed into a shaped object such as a dental filling. The shape of the block is not particularly limited, for example, a cubic shape, a rectangular parallelepiped shape, a cylindrical shape, etc. In addition, in this embodiment, Figure 1 As shown in the figure, although the dental ceramic 10 is described using a rectangular parallelepiped (quadrangular prism) block, the dental ceramic is not limited to this.

[0032] The shaped object has a predetermined shape such as a dental filling, etc. The shaped object is obtained by cutting a molded body or a calcined body using CAD / CAM (computer-aided design / computer-aided manufacturing) or the like.

[0033] In addition, the shaped object can be obtained as a molded body having a predetermined shape by a layered molding method (such as additive manufacturing, 3D printing, etc.). That is, the molded body obtained by the layered molding method can directly constitute a shaped object such as a dental filling.

[0034] Furthermore, the obtained shaped article may be sintered (for example, heated at 900 to 2100° C.) as required.

[0035] In addition, examples of ceramics include glasses containing silicates, borosilicates, aluminosilicates, phosphates, fluorophosphates, and the like, and glass ceramics thereof, zirconium oxide, alumina, feldspar, leucite, sansitol, spinel, mica, apatite, zircon, or mixtures thereof.

[0036] The coloring method of the dental ceramic involved in the present embodiment includes a coloring step. In the coloring step, a coloring liquid is brought into contact with the dental ceramic. There are no particular restrictions on the method of bringing the coloring liquid into contact with the dental ceramic, and examples thereof include applying, spraying or dripping the coloring liquid on the dental ceramic, or immersing all or part of the dental ceramic in the coloring liquid.

[0037] In this embodiment, as a coloring step, it is preferable to have a step (coloring step) of immersing one end 10A of the dental ceramic 10 in the coloring liquid 30. Thus, the coloring liquid 30 can be infiltrated from the bottom surface 11 to the top surface 12 of the dental ceramic 10 ( Figure 2 ).

[0038] In the coloring process, Figure 2 As shown, a coloring liquid 30 is placed in a cylindrical container 20, and a rectangular parallelepiped dental ceramic 10 is placed in the container 20 with the bottom surface 11 (one end 10A) of the dental ceramic 10 immersed in the coloring liquid 30. In this way, the dental ceramic 10 is left to stand for 1 to 20 hours (18 hours in this embodiment) while immersed in the coloring liquid 30.

[0039] The dental ceramic 10 is placed in the container 20 by, for example, spreading a 40-mesh net in the container 20 and placing the dental ceramic 10 on the 40-mesh net without contacting the dental ceramic 10 with the bottom surface 21 of the container 20 ( Figure 2 ).

[0040] In addition, the range of the dental ceramic 10 immersed in the coloring liquid 30 is, for example, the following range, the side surface (periphery 13) of the dental ceramic 10 is covered with the covering material 50, and about 1 / 10 to 1 / 4 of the dental ceramic 10 is exposed in the height direction (Z direction) from the lower end (bottom surface 11) of the dental ceramic 10 ( Figure 2 ). In addition, the side surface (circumference 13) of the dental ceramic 10 is four rectangular surfaces when the shape of the dental ceramic 10 is a quadrangular prism, and is one curved surface when the shape of the dental ceramic 10 is a cylindrical shape.

[0041] The material of the covering material 50 is not particularly limited, and examples thereof include silicone rubber, resin, wax, and the like. In addition, when the covering material 50 covers the side surface 13 of the dental ceramic 10, the adhesion with the dental ceramic 10 is improved, and a flexible material is preferably used. Furthermore, from the viewpoint of resistance to the coloring liquid, silicone rubber and the like are preferred among the flexible materials. In the present embodiment, as the covering material 50, for example, a silicone impression material can be used.

[0042] The covering material 50 covers the entire circumference of the side surface 13 of the dental ceramic 10 except for the portion of the dental ceramic 10 immersed in the coloring liquid 30. In the present embodiment, the side surface 13 of the dental ceramic 10 is covered with the covering material 50 in a state where the bottom surface 11 and the top surface 12 of the dental ceramic 10 are exposed (bare state).

[0043] Furthermore, the covering material 50 has a height protruding above the top surface 12 of the dental ceramic 10 . Thus, when the dental ceramic 10 is placed in the container 20 , the coloring liquid 30 can be prevented from penetrating from the top surface 12 of the dental ceramic 10 .

[0044] The shape of the covering material 50 is not particularly limited. For example, if the shape of the dental ceramic 10 is a quadrangular prism, the shape of the covering material 50 is a hollow quadrangular prism with both ends open. In addition, if the shape of the dental ceramic 10 is a cylindrical shape, the shape of the covering material 50 is a hollow cylindrical shape with both ends open.

[0045] The coloring liquid 30 contains at least two kinds of metal ions. The difference in standard oxidation-reduction potential of the two kinds of metal ions is 0.5 to 4.0, preferably 0.7 to 3.5, and more preferably 0.72 to 3.2.

[0046] In this specification, the redox potential refers to the electrode potential (standard electrode potential) generated by electron transfer in a system (reaction system) that causes a redox reaction in an aqueous solution, etc. The standard redox potential difference refers to the absolute value of the standard redox potential difference between two metal ions contained in the coloring liquid 30.

[0047] Specifically, the coloring liquid 30 contains a pigment and a solvent.

[0048] The solvent contained in the coloring liquid 30 is not particularly limited, and for example, a polar solvent such as water or alcohol can be used. In the present embodiment, water is used as the solvent.

[0049] The solvent may contain any water-soluble polymer. As the water-soluble polymer, polyalkylene glycols such as polyethylene glycol, sucrose, agarose and the like are preferably used. In the coloring liquid of the present embodiment, polyethylene glycol is contained in water.

[0050] The content of the water-soluble polymer is, for example, 0.001 mass % to 20 mass %, preferably 2.0 mass % to 18.0 mass %, and more preferably 4.0 mass % to 15 mass %, relative to 100 mass % of the colored liquid.

[0051] The pigment contained in the colored liquid 30 corresponds to at least two types of metal ions having a standard oxidation-reduction potential difference of 0.5 or more and 4.0 or less.

[0052] Of these two types of metal ions, one metal ion (hereinafter sometimes referred to as metal ion A) preferably has a standard redox potential of -1.0 V to 2.0 V, more preferably -0.7 V to 1.5 V, and even more preferably -0.5 V to 1.0 V.

[0053] The metal ion A is not particularly limited as long as it constitutes a pigment. Examples of the metal ion A include Cr 3+ , Fe 3+ , Fe 2+ , Pd 2+ 、Bi 3+ ,Ge 2+ Sn4+ 、Ni 2+ , Yb 3+ , Nb 3+ 、Co 2+ etc. In addition, the metal ion A may be a metal salt such as chloride, sulfide, acetate, nitrate, etc. Examples of the metal salt include CrCl3, FeCl3, PdCl2, BiCl3, GeCl4, SnCl2, NiCl2, YbCl3, NbCl5, CoCl2, etc. In addition, these metal salts may be hydrates.

[0054] The metal ion A may be used alone or in combination of two or more. As the metal ion A, Fe is preferred because it is easy to produce a hue or color tone close to that of tooth texture. 3+ , Fe 2+ 、Ni 2+ , Yb 3+ , Nb 3+ 、Co 2+ .

[0055] The content of the metal ion A is not particularly limited, but is preferably 0.0001% by mass to 5.0% by mass, more preferably 0.0005% by mass to 3.0% by mass, and even more preferably 0.001% by mass to 2.0% by mass as a metal salt in 100% by mass of the colored liquid.

[0056] When the metal ion A is contained in the form of a metal salt at 0.0001 mass % or more and 5.0 mass % or less in 100 mass % of the coloring liquid, an appropriate hue or color tone corresponding to the metal ion A can be imparted to the dental ceramic 10 .

[0057] The standard redox potential of the other of the two metal ions (hereinafter sometimes referred to as metal ion B) is preferably -3.0 V to 0.7 V, more preferably -2.5 V to 0.9 V, and even more preferably -2.4 V to 1.0 V.

[0058] The metal ion B is not particularly limited as long as it constitutes a pigment. Examples of the metal ion B include Mn 2+ 、Ce 3+ 、Nd 3+ , Pr 3+ 、Sm 3+ 、Eu 3+ , Tb 3+ 、Dy 3+ 、Ho 3+ , Er 3+ , Y 3+ wait.

[0059] In addition, the metal ion B may be a metal salt such as chloride, sulfide, acetate, nitrate, etc. Examples of the metal salt include MnCl2, CeCl3, NdCl3, PrCl3, SmCl3, EuCl3, TbCl3, DyCl3, HoCl3, ErCl3, YCl3, etc. In addition, these metal salts may be hydrates.

[0060] The metal ion B may be used alone or in combination of two or more. As the metal ion B, Mn is preferred because it is easy to produce a hue or color tone close to that of tooth texture. 2+ 、Ce 3+ 、Nd 3+ , Pr 3+ , Er 3+ , Y 3+ .

[0061] The content of the metal ion B is not particularly limited, but is preferably 0.0001% by mass to 5.0% by mass, more preferably 0.0005% by mass to 3.0% by mass, and even more preferably 0.001% by mass to 2.0% by mass as a metal salt in 100% by mass of the colored liquid.

[0062] When the metal ion B is contained in an amount of 0.0001 mass % to 5.0 mass % in 100 mass % of the coloring liquid as a metal salt, an appropriate hue or color tone corresponding to the metal ion B can be imparted to the dental ceramic 10 .

[0063] The coloring liquid 30 may further contain a chelating agent. The chelating agent forms a complex with a portion of the metal ions contained in the coloring liquid, and the metal ions (metal ion complex) that form the complex have large steric hindrance and move relatively slowly in the dental ceramic 10. Therefore, when the coloring liquid contains a chelating agent, the movement speed of the metal ions that easily form a complex with the chelating agent in the dental ceramic 10 can be controlled.

[0064] The chelating agent is not particularly limited. Examples of the chelating agent include ethylenediamine-N,N,N′,N′-tetraacetic acid (EDTA), diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid (DTPA), N-hydroxyethylethylenediamine-N,N′,N′-triacetic acid (HEDTA), nitrilotriacetic acid (NTA), O,O′-bis(2-aminoethyl)ethylene glycol-N,N,N′,N′-tetraacetic acid (EGTA), trans-1,2-diaminocyclohexane-N,N,N′,N′-tetraacetic acid (CyDTA), citric acid, tartaric acid, malic acid, oxalic acid, gluconic acid, tripolyphosphoric acid, 12-crown 4-ether, and salts thereof.

[0065] The chelating agent may be used alone or in combination of two or more. As the chelating agent, Fe is easy to bind to the hue or color of the tooth. 3+ , Er 3+ The point for forming the complex is preferably EDTA.

[0066] The content of the chelating agent is not particularly limited, but is preferably 0.00001% by mass to 10.0% by mass in 100% by mass of the coloring liquid. When the content of the chelating agent is less than 0.00001% by mass, the effect of the chelating agent is difficult to obtain, and when it exceeds 10.0% by mass, the effect is almost unchanged.

[0067] The pH of the coloring liquid is preferably 8 or less, more preferably 5 or less, and further preferably 3 or less. When the pH of the coloring liquid is 8 or less (almost neutral or acidic), some metal ions (such as Fe 3+ , Pr 3+ , Er 3+ ) In the coloring liquid, there is a tendency for the ionic type to be maintained or increased (the molecular type to be maintained or decreased). Therefore, by setting the pH of the coloring liquid to 8 or less, when the concentration in the coloring liquid is low, the migration speed in the dental ceramic 10 is also fast, and the coloring is stable.

[0068] The coloring method of dental ceramics according to the present embodiment optionally includes a drying step and a sintering step after the coloring step.

[0069] In the drying step, the dental ceramic 10 impregnated with the coloring liquid 30 in the coloring step is taken out from the container 20 and dried at room temperature for 1 to 6 hours. The dried dental ceramic 10 is cut into a desired size. In this embodiment, the cutting (slicing) is performed with a thickness of about 1.5 mm.

[0070] In the sintering step, the dental ceramic 10 cut into a desired size in the drying step is sintered at 1000 to 2100° C. (about 1500° C. in the present embodiment) for 30 minutes to 5 hours (2 hours in the present embodiment). The sintering in this sintering step corresponds to the main sintering (which is different from the preliminary sintering).

[0071] In this embodiment, as described above, there is a step (coloring step) of bringing a coloring liquid containing at least two metal ions having a standard oxidation-reduction potential difference of 0.5 or more and 4.0 or less into contact with the dental ceramic. Thus, a dental ceramic having a gradient formed inside the dental ceramic can be obtained by a single coloring step using a single coloring liquid.

[0072] In this embodiment, as described above, one end of the dental ceramic is immersed in the coloring liquid in the coloring step, whereby a dental ceramic having a gradation formed inside the dental ceramic can be reliably obtained in a single coloring step using a single coloring liquid.

[0073] In addition, in the present embodiment, as described above, the standard redox potential of one of the two metal ions (metal ion A) is -1.0 V or more and 2.0 V or less, and thus, the metal ion with a relatively high standard redox potential (unstable ion state) is present in the coloring liquid. As a result, the metal ion A has a large steric hindrance, and based on the point that the movement speed is relatively slow in the dental ceramic 10, the balance of coloring in the dental ceramic can be adjusted.

[0074] In addition, in this embodiment, as described above, the standard redox potential of the other metal ion (metal ion B) of the two metal ions is -3.0 V or more and -0.7 V or less, and thus, the metal ion with a relatively low standard redox potential (stable ion state) is present in the coloring liquid. As a result, the metal ion B has a small steric hindrance and moves relatively quickly in the dental ceramic 10, so that the balance of coloring in the dental ceramic can be adjusted.

[0075] Furthermore, in the present embodiment, as described above, the coloring liquid further contains a water-soluble polymer, whereby the dispersibility of the metal ions in the coloring liquid is improved, and thus uneven coloring in the dental ceramic 10 can be suppressed.

[0076] In addition, in the present embodiment, as described above, the coloring liquid further contains a chelating agent, whereby the chelating agent forms a complex (metal ion complex) with a portion of the metal ions contained in the coloring liquid. In addition, the metal ion complex has a larger steric hindrance than the non-complex metal ions, and thus moves slowly in the dental ceramic 10. In the present embodiment, from such a point of view, the movement speed of the metal ions that easily form a complex with the chelating agent in the dental ceramic 10 can be controlled.

[0077] In this embodiment, as described above, the pH of the coloring liquid is 8 or less, and thus the ionic type tends to be maintained or increased (the molecular type tends to be maintained or decreased) in the coloring liquid. Therefore, when the concentration in the coloring liquid is low, the migration speed in the dental ceramic 10 is also fast, and the coloring is stable.

[0078] <Coloring liquid for dental ceramics>

[0079] The coloring liquid for dental ceramics according to the present embodiment is a coloring liquid for coloring dental ceramics. As the coloring liquid, for example, the coloring liquid used in the coloring method for dental ceramics described above can be used.

[0080] That is, the dental ceramic coloring liquid according to the present embodiment contains at least two types of metal ions having a standard oxidation-reduction potential difference of 0.5 or more and 4.0 or less.

[0081] Therefore, in the dental ceramic coloring liquid according to the present embodiment, the effect obtained in the above-mentioned dental ceramic coloring method can be directly obtained.

[0082] That is, the coloring liquid of the dental ceramic involved in this embodiment is as described above, and the one end 10A of the dental ceramic 10 is immersed in the coloring liquid containing at least two metal ions having a standard oxidation-reduction potential difference of 0.5 to 4.0, thereby, a dental ceramic with a gradient formed inside the dental ceramic can be obtained by a single coloring step using one coloring liquid.

[0083] [Example]

[0084] Hereinafter, the present invention will be further described using experimental examples.

[0085] <Preparation of test pieces>

[0086] The following test pieces were prepared from commercially available dental zirconia pseudo-sintered bodies (manufactured by GC, Aadva zirconia disc EI) using a cutting machine such as Figure 3 As shown, a test piece (dental ceramic) 10 (width W: about 18 mm, length L: about 50 mm, thickness: 1.5 mm) was cut into a plate shape.

[0087] 2 g of the coloring liquid 30 was added to a cylindrical container 20 (Maruemu container No. 6), and the test piece 10 was placed upright in the container 20 so that one end 10A of the test piece 10 (the area of ​​about 5 mm from the lower end) was immersed in the coloring liquid 30. After standing for 1 to 15 hours, the test piece 10 was taken out of the container 20 and dried at room temperature for 1 to 6 hours. The dried test piece 10 was sintered at 1500° C. for 2 hours to obtain a dental ceramic (ceramic sintered body).

[0088] <Preparation of Test Specimen of Embodiment>

[0089] The following test pieces were prepared from commercially available dental zirconia pseudo-sintered bodies (manufactured by GC, Aadva zirconia disc EI) using a cutting machine such as Figure 1 As shown, a test piece 10 cut into a block shape (width (Y direction): about 15 mm, length (X direction): about 18 mm, height (Z direction): 13 mm).

[0090] The periphery 13 of the test piece 10 was covered with a silicone impression material (Duplicone (registered trademark) manufactured by Matsukaze Co., Ltd.) so that one eighth of the area was exposed from the bottom surface 11 toward the top surface 12. The test piece 10 was placed in a container 20 with a 40-mesh net, and a coloring liquid 30 was poured into the container 20. The test piece 10 was immersed in the coloring liquid 30 ( Figure 2After standing for 18 hours, the test piece 10 was taken out of the container 20, dried at room temperature for 1 to 6 hours, cut (sliced) with a thickness of about 1.5 mm in the width (Y direction), and sintered at 1500° C. for 2 hours to obtain a dental ceramic (ceramic sintered body).

[0091] As the test piece 10 of the embodiment, Experimental Examples 27 to 28 having different compositions of the colored liquid 30 are shown in Tables 1 and Figures 4 to 9 shown.

[0092]

Table 1

[0093]

[0094] From Table 1, when the metal ion concentration is relatively high (the metal ion content is 10 mass %), the change in migration speed due to pH cannot be confirmed ( Figure 4 , Experimental Examples 1 to 4, 9 to 10). On the other hand, when the concentration of metal ions was relatively low (the content of metal ions was 1% by mass), it was confirmed that the migration speed in the test piece 10 became faster as the pH was more acidic ( Figure 4 、Experimental Examples 5 to 8、 Figure 5 , Experimental Examples 11-12).

[0095] In addition, it was confirmed that the moving speed in the test piece 10 tended to be faster when the metal ion concentration was relatively high (the metal ion content was 10 mass %) than when it was relatively low (the metal ion content was 1 mass %). Figure 4 , Experimental Examples 1 to 8).

[0096] In addition, the metal ion is Er 3+ When the hydrate (ErCl·7H2O) and the anhydrous form (ErCl anhydrous) were confirmed, there was almost no difference in the migration speed in the test piece 10 (Experimental Examples 1, 3, 9, and 10).

[0097] In addition, the metal ion is Fe 3+ , Er 3+ When the coloring solution contained a chelating agent (EDTA), it was confirmed that the migration speed in the test piece 10 decreased ( Figure 5 、Experimental Examples 13-14、 Figure 6 , Experimental Examples 15-16). On the other hand, the metal ion is Pr 3+ Even when the chelating agent (EDTA) is contained, no change in the migration speed in the test piece 10 can be confirmed ( Figure 6 , Experimental Examples 17-18).

[0098] In addition, it was confirmed that the metal ions were Fe at the same concentration (the content of metal ions was 1 mass%). 3+ , Er 3+, Pr 3+ At that time, 3+ , Pr 3+ Compared with Fe 3+ , the moving speed in the test piece 10 is fast. That is, it is confirmed that Fe 3+ Compared to Er 3+ , Pr 3+ , the moving speed in the test piece 10 slows down ( Figure 4 、Experimental Examples 5, 6, Figure 5 , Experimental Example 12).

[0099] In addition, when the colored liquid further contained a water-soluble polymer (polyethylene glycol (PEG) 400), it was confirmed that the coloring unevenness in the test piece 10 was suppressed ( Figure 7 、Experimental Examples 19-22、 Figure 8 、Experimental Examples 23-26、 Fig. 9 , Experimental Examples 27-28).

[0100] Based on these results, it is understood that the type of metal ions, the concentration of metal ions, the presence or absence of a chelating agent (complex formation), the presence or absence of a water-soluble polymer, and the pH of the coloring liquid affect the migration speed of the metal ions in the test piece 10 .

[0101] It was further confirmed that the type of metal ion was selected in consideration of the standard redox potential difference of the metal ion, and thus, a gradual change ( Figure 7 , Experimental Examples 19 to 22).

[0102] As a result, it was found that the ceramic sintered body obtained by immersing the one end 10A of the dental ceramic 10 in the coloring liquid 30 containing at least two metal ions having a standard oxidation-reduction potential difference of 0.5 to 4.0 formed a gradation inside the dental ceramic in one coloring step using one coloring liquid.

[0103] Although the embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the invention described in the claims.

[0104] Examples of embodiments of the present invention are as follows.

[0105] <1> A method for coloring dental ceramics is a method for coloring dental ceramics, wherein:

[0106] The method comprises the step of bringing a coloring liquid into contact with dental ceramics,

[0107] The colored liquid contains at least two metal ions having a standard oxidation-reduction potential difference of 0.5 to 4.0.

[0108] <2> According to the <1> In the method for coloring a dental ceramic, the step of bringing the dental ceramic into contact with a coloring liquid is a step of immersing one end of the dental ceramic in the coloring liquid.

[0109] <3> According to the <1> or <2> The described method for coloring dental ceramics is characterized in that the standard oxidation-reduction potential of one of the two metal ions is not less than -1.0 V and not more than 2.0 V.

[0110] <4> According to the <1> to <3> The method for coloring dental ceramics according to any one of claims , wherein the standard redox potential of the other of the two metal ions is not less than -3.0 V and not more than 0.7 V.

[0111] <5> According to the <1> to <4> The method for coloring dental ceramics according to any one of claims , wherein the coloring liquid further contains a water-soluble polymer.

[0112] <6> According to the <1> to <5> The method for coloring dental ceramics according to any one of claims , wherein the coloring liquid further contains a chelating agent.

[0113] <7> According to the <1> to <6> The method for coloring dental ceramics according to any one of claims , wherein the pH of the coloring liquid is 8 or less.

[0114] <8> A dental ceramic coloring liquid is a coloring liquid for coloring dental ceramics, wherein:

[0115] Contains at least two metal ions having a standard oxidation-reduction potential difference of 0.5 or more and 4.0 or less.

[0116] This application claims priority based on Japanese Patent Application No. 2022-151021 filed on September 22, 2022, the entire contents of which are incorporated herein by reference.

[0117] [Reference Signs]

[0118] 10 Dental Ceramics

[0119] 10A one end

[0120] 11 bottom surface (lower end)

[0121] 12 Top surface

[0122] 13 Side (around)

[0123] 20 Containers

[0124] 21 Bottom

[0125] 30 Coloring fluid

[0126] 40 Net

[0127] 50 Covering material

Claims

1. A method for coloring dental ceramics, which is a method for coloring dental ceramics. The method comprises the step of bringing a coloring liquid into contact with dental ceramics, The colored liquid contains at least two metal ions having a standard oxidation-reduction potential difference of 0.5 to 4.

0. 2 . The method for coloring a dental ceramic according to claim 1 , wherein the step of bringing the coloring liquid into contact with the dental ceramic is a step of immersing one end of the dental ceramic in the coloring liquid. 3 . The method for coloring dental ceramics according to claim 1 , wherein the standard oxidation-reduction potential of one of the two metal ions is not less than −1.0 V and not more than 2.0 V. 4 . The method for coloring dental ceramics according to claim 3 , wherein the standard oxidation-reduction potential of the other of the two metal ions is from −3.0 V to −0.7 V. 5 . The method for coloring dental ceramics according to claim 1 , wherein the coloring liquid further contains a water-soluble polymer. 6 . The method for coloring dental ceramics according to claim 1 , wherein the coloring liquid further contains a chelating agent. 7 . The method for coloring dental ceramics according to claim 1 , wherein the coloring liquid has a pH of 8 or less.

8. A dental ceramic coloring liquid, which is a coloring liquid for coloring dental ceramics, wherein: Contains at least two metal ions having a standard oxidation-reduction potential difference of 0.5 or more and 4.0 or less.

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