A cuttable lithium disilicate glass-ceramic blank, its production and use

Abstract

The application provides a cuttable lithium disilicate glass ceramic blank and a preparation method and application thereof, the lithium disilicate glass ceramic blank comprises lithium disilicate crystals and lithium metasilicate crystals, the lithium disilicate crystals comprise spherical lithium disilicate crystals and rod-shaped lithium disilicate crystals, and the lithium metasilicate crystals comprise spherical lithium metasilicate crystals; the cuttable lithium disilicate glass ceramic blank has high strength, does not need one-step sintering, and can be directly cut, so that the dental treatment time can be shortened, and a dentist can conveniently judge the repair effect before operation, which has important significance for improving the repair effect of teeth and the diagnosis and treatment experience of patients.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of glass ceramics, and relates to a machinable lithium disilicate glass ceramic blank and a preparation method and application thereof. BACKGROUND

[0002] Although the rod-shaped interlocking structure of the dental lithium disilicate glass ceramic can greatly improve the strength of the material, direct mechanical processing such as cutting can easily damage the processing tools and cause large chipping at the edges of the dental restoration, thereby affecting the final placement of the restoration.

[0003] To solve this problem, an intermediate state, lithium metasilicate state, is prepared when preparing the lithium disilicate material. The microstructure of the intermediate state is in the form of plates or spheres, and is more easily machined than lithium disilicate. After cutting the lithium metasilicate blank to obtain the restoration, further sintering is required to obtain a lithium disilicate material restoration.

[0004] CN106413626A discloses a lithium disilicate blank that can be directly machined, but the content of alumina in the formula is too high. During the conversion of lithium metasilicate to lithium disilicate, the excess alumina reacts with lithium metasilicate and quartz to form lithium aluminosilicate impurities, which reduces the content of the main crystal phase lithium disilicate, blocks the crystal growth, and inhibits the continuity of the crystal, thereby reducing the mechanical strength. At the same time, the excess alumina and the small crystal size cause the light transmittance to be too high, which reduces the color hiding ability of the restoration prepared by machining the lithium disilicate blank.

[0005] CN110139626A discloses a lithium disilicate blank that can be directly machined, but the preparation process uses a method of pressing and sintering the original glass powder. Since the crystal surfaces of the original glass powder are irregular, even if pressure is applied, there are still pores between them. The contact surfaces of the original glass powder crystals are concave, the surface free energy is lowest, vacancies are easily generated, and the vacancy concentration is highest. There is a vacancy concentration gradient at the contact surfaces and in the crystal interior. When sintering is performed, vacancies diffuse through bulk diffusion and grain boundary diffusion, disappear at the grain boundaries, and cause the original glass powder crystals to shrink and form sintering necks at the contact surfaces. As sintering proceeds, vacancies continuously diffuse, sintering necks continuously grow, and the curvature radius of the sintering necks gradually increases, thereby increasing the surface free energy. Therefore, the vacancy concentration gradient between the sintering necks and the crystal interior decreases, the material movement slows down, and the pores that have not been timely moved out of the sintering necks and the original glass powder crystals are sealed. Therefore, the method of pressing and sintering the original glass powder will result in a large number of pores in the blank, which can easily cause cracks to propagate in the blank. In addition, the pores and the lithium disilicate crystals have large differences in optical properties such as refractive index, which causes uneven color and transparency, thereby affecting the mechanical properties and aesthetic effect.

[0006] The blank is prepared by the above scheme, and needs to be heat treated before use. The lithium metasilicate state restoration body will shrink after sintering. Due to the long heat treatment time, the actual diagnosis and treatment time of the patient is prolonged to a certain extent. SUMMARY

[0007] The purpose of the present application is to provide a cuttable lithium disilicate glass ceramic blank and its preparation method and application. The cuttable lithium disilicate glass ceramic blank has high strength and does not need to be sintered. It can be directly cut, which can shorten the dental diagnosis and treatment time, and facilitate the preoperative judgment of the restoration effect by dentists. It is of great significance to improve the restoration effect of teeth and the diagnosis and treatment experience of patients.

[0008] To achieve the purpose of the present application, the following technical solutions are adopted:

[0009] In a first aspect, the present application provides a cuttable lithium disilicate glass ceramic blank, which comprises lithium disilicate crystals and lithium metasilicate crystals. The lithium disilicate crystals comprise spherical lithium disilicate crystals and rod-shaped lithium disilicate crystals. The lithium metasilicate crystals comprise spherical lithium metasilicate crystals.

[0010] The cuttable lithium disilicate glass ceramic blank comprises lithium disilicate crystals and lithium metasilicate crystals. The lithium disilicate crystals are a mixture of nanoscale spherical crystals and nanoscale rod-shaped crystals. The lithium metasilicate crystals are nanoscale spherical crystals, which are uniformly dispersed in the lithium disilicate crystals. These crystals do not form an interlocking structure and are arranged more loosely, thus improving the cuttability of the blank.

[0011] Preferably, the molar ratio of Si atoms to Li atoms in the cuttable lithium disilicate glass ceramic blank is 0.45-0.75, for example, 0.45, 0.5, 0.55, 0.6, 0.7 or 0.75, etc.

[0012] Preferably, the particle size of the spherical lithium disilicate crystals is 150-900 nm, for example, 150 nm, 200 nm, 300 nm, 500 nm or 900 nm, etc.

[0013] Preferably, the length of the rod-shaped lithium disilicate crystals is 200-950 nm, for example, 200 nm, 300 nm, 500 nm, 800 nm or 950 nm, etc.

[0014] Preferably, the particle size of the spherical lithium metasilicate crystals is 100-900 nm, for example, 100 nm, 200 nm, 400 nm, 600 nm or 900 nm, etc.

[0015] In a second aspect, the present application provides a method for preparing the cuttable lithium disilicate glass-ceramic blank as described in the first aspect, the method comprising the following steps:

[0016] (1) mixing the main raw materials, performing one-step high-temperature melting treatment, and obtaining glass slag after water quenching;

[0017] (2) performing two-step high-temperature melting treatment on the glass slag, pouring into a mold, and obtaining a glass blank;

[0018] (3) performing heat treatment on the glass blank to obtain the cuttable lithium disilicate glass-ceramic blank.

[0019] The principle of the preparation method of the present application is shown as follows (taking silicon oxide and lithium oxide as an example):

[0020] Li2O (glass) + SiO2 (glass) = Li2SiO3 (lithium metasilicate, crystal), Li2SiO3 (crystal) + SiO2 (glass) = Li2Si2O5 (lithium disilicate, crystal), as can be seen from the reaction equation, more silicon dioxide is required to form the same molar amount of lithium disilicate than lithium metasilicate. Therefore, the ratio of the content of lithium disilicate and lithium metasilicate in the finally prepared glass-ceramic blank is mainly affected by the ratio of the content of silicon and lithium. When the ratio of the content of silicon and lithium is high, more lithium metasilicate can react with silicon dioxide to form lithium disilicate, and the ratio of the content of lithium disilicate and lithium metasilicate in the finally prepared glass-ceramic blank is also high; otherwise, the conversion of lithium metasilicate to lithium disilicate is incomplete, and the ratio of the content of lithium disilicate and lithium metasilicate is low.

[0021] Because the machinability of lithium metasilicate crystal is much better than that of lithium disilicate crystal, under the condition of not excessively affecting the mechanical properties and acid corrosion resistance of the blank, the present application reduces the molar ratio of SiO2 and Li2O in the glass blank from the general 1.7-3.0 to 0.9-1.5 (the molar ratio of Si atoms and Li atoms is 0.45-0.75), improves the content of lithium metasilicate crystal in the finally prepared lithium disilicate glass-ceramic blank, makes lithium metasilicate also become one of the main crystal phases, and thus improves the machinability of the blank.

[0022] Preferably, the main raw materials in step (1) include silicon oxide, lithium oxide, phosphorus oxide, aluminum oxide, zirconium oxide, and potassium oxide.

[0023] The main raw materials of the present application are not limited to oxides, and under the premise of not changing the molar content of the required elements, the main raw materials can also be chlorides or phosphates.

[0024] Preferably, in the main raw materials, the molar ratio of Si atoms and Li atoms is 0.45-0.75, for example: 0.45, 0.53, 0.62, 0.70, or 0.75, etc.

[0025] Preferably, the mass fraction of the lithium oxide is 17-26%, for example, 17%, 19%, 20%, 24%, or 26%, etc., based on 100% of the mass of the main raw material.

[0026] Preferably, the mass fraction of the lithium oxide is 17-26%, for example, 17%, 19%, 20%, 24%, or 26%, etc., based on 100% of the mass of the main raw material.

[0027] Preferably, the mass fraction of the lithium oxide is 17-26%, for example, 17%, 19%, 20%, 24%, or 26%, etc., based on 100% of the mass of the main raw material.

[0028] Preferably, the mass fraction of the lithium oxide is 17-26%, for example, 17%, 19%, 20%, 24%, or 26%, etc., based on 100% of the mass of the main raw material.

[0029] Preferably, the mass fraction of the lithium oxide is 17-26%, for example, 17%, 19%, 20%, 24%, or 26%, etc., based on 100% of the mass of the main raw material.

[0030] Preferably, the mass fraction of the lithium oxide is 17-26%, for example, 17%, 19%, 20%, 24%, or 26%, etc., based on 100% of the mass of the main raw material.

[0031] Preferably, the mass fraction of the lithium oxide is 17-26%, for example, 17%, 19%, 20%, 24%, or 26%, etc., based on 100% of the mass of the main raw material.

[0032] The phosphorus source and the zirconium source can change the rod-like interlocking structure of the lithium disilicate glass-ceramics as nucleating agents because P2O5 can form lithium phosphate crystals with Li2O in the heat treatment process, and both of them can serve as the core of lithium metasilicate crystal formation. The more the number of cores, the more the number of lithium metasilicate crystals, because the total amount of lithium metasilicate is fixed, the smaller the size of lithium metasilicate crystals, and the smaller the lithium disilicate crystals converted from lithium metasilicate crystals. In addition, ZrO2 crystals that are not used as cores can also occupy part of the growth space of lithium metasilicate crystals and lithium disilicate crystals. The crystals cannot fully grow in size, are tiny, and are not sufficient to hinder the crystals from each other in spatial position, forming rod-like interlocking structures, but forming nanoscale spherical crystals and nanoscale rod-like crystals.

[0033] Preferably, an additive is further added in the mixing of step (1).

[0034] Preferably, the additive comprises any one or a combination of at least two of oxides, chlorides or phosphates of B, Na, Mg, Ca, Ba, Ti, V or rare earth elements.

[0035] Preferably, the one-step high-temperature melting treatment in step (1) comprises a first high-temperature melting treatment and a second high-temperature melting treatment.

[0036] Preferably, the temperature of the first high-temperature melting treatment is 1450-1650°C, for example, 1450°C, 1500°C, 1550°C, 1600°C or 1650°C, etc.

[0037] Preferably, the time of the first high-temperature melting treatment is 2-5h, for example, 2h, 2.5h, 3h, 4h or 5h, etc.

[0038] Preferably, the temperature of the second high-temperature melting treatment is 1200-1400°C, for example, 1200°C, 1250°C, 1300°C, 1350°C or 1400°C, etc.

[0039] Preferably, the cooling rate from the first high-temperature melting treatment to the second high-temperature melting treatment is 2-5°C / min, for example, 2°C / min, 2.5°C / min, 3°C / min, 4°C / min or 5°C / min, etc.

[0040] Preferably, the two-step high-temperature melting treatment in step (2) comprises a third high-temperature melting treatment and a fourth high-temperature melting treatment.

[0041] Preferably, the temperature of the third high-temperature melting treatment is 1450-1650°C, for example, 1450°C, 1500°C, 1550°C, 1600°C or 1650°C, etc.

[0042] Preferably, the time of the third high-temperature melting treatment is 2-5h, for example, 2h, 2.5h, 3h, 4h or 5h, etc.

[0043] Preferably, the temperature of the fourth high-temperature melting treatment is 1200-1400°C, for example, 1200°C, 1250°C, 1300°C, 1350°C or 1400°C, etc.

[0044] Preferably, the cooling rate from the third high-temperature melting treatment to the fourth high-temperature melting treatment is 2-5°C / min, for example, 2°C / min, 2.5°C / min, 3°C / min, 4°C / min or 5°C / min, etc.

[0045] Preferably, the mold is preheated before pouring into the mold.

[0046] Preferably, the temperature of the pre-heating treatment is 300-600℃, for example, 300℃, 350℃, 400℃, 500℃ or 600℃, etc.

[0047] Preferably, the heat treatment in step (3) comprises a first-stage heat treatment and a second-stage heat treatment.

[0048] Preferably, the temperature of the first-stage heat treatment is 500-700℃, for example, 500℃, 550℃, 600℃, 650℃ or 700℃, etc.

[0049] Preferably, the time of the first-stage heat treatment is 2-5h, for example, 2h, 2.5h, 3h, 4h or 5h, etc.

[0050] Preferably, the temperature of the second-stage heat treatment is 750-900℃, for example, 750℃, 800℃, 820℃, 850℃ or 900℃, etc.

[0051] Preferably, the time of the second-stage heat treatment is 1-30min, for example, 1min, 5min, 10min, 20min or 30min, etc.

[0052] In a third aspect, the present application provides an application of the machinable lithium disilicate glass-ceramic blank as described in the first aspect, wherein the machinable lithium disilicate glass-ceramic blank is used for dental restoration materials.

[0053] Compared with the prior art, the present application has the following beneficial effects:

[0054] (1) The machinable lithium disilicate glass-ceramic blank can be directly machined to prepare dental restorations without further heat treatment, thereby reducing the risk of deformation. The machinable lithium disilicate glass-ceramic blank has high strength and can be used to prepare dental restorations such as inlays, veneers and single crowns, thereby replacing natural teeth to achieve mastication function and aesthetic effect.

[0055] (2) The machinable lithium disilicate glass-ceramic blank has high strength and can be directly machined, thereby shortening the dental treatment time and facilitating the preoperative judgment of the restoration effect by dentists, which is of great significance to improve the restoration effect of teeth and the diagnosis and treatment experience of patients.

[0056] (3) The machinable lithium disilicate glass-ceramic blank has a strength of more than 345MPa and good machinability. BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1 Figure 1 is a SEM image of the machinable lithium disilicate glass-ceramic blank according to Example 1 of the present application.

[0058] Figure 2 This is the XRD pattern of the machinable lithium disilicate glass-ceramic blank described in Embodiment 1 of the present invention. Detailed Implementation

[0059] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0060] Unless otherwise specified, all proportions in the embodiments and comparative examples of this invention refer to parts by mass.

[0061] Example 1

[0062] This embodiment provides a machinable lithium disilicate glass-ceramic preform, which is prepared by the following method:

[0063] (1) SiO2, Li2O, P2O5, Al2O3, ZrO2, K2O, ZnO, CeO2, Er2O3, V2O5 and TiO2 are mixed in a mass ratio of 52:22:9:1.5:8.5:4:2:1:0.5:0.5:1, heated to 1500℃ at a rate of 10℃ / min, held for 3h, cooled to 1250℃ at a rate of 4℃ / min, and the high-temperature melt is poured into water for water quenching to obtain glass slag material;

[0064] (2) The glass slag is heated to 1500°C at a rate of 10°C / min and held for 3 hours. Then it is cooled to 1250°C at a rate of 4°C / min. The resulting high-temperature melt is poured into a mold that has been preheated to 500°C to obtain a glass blank. The glass blank is heated to 700°C and held for 4 hours. Then it is heated to 900°C and held for 16 minutes. After that, it is cooled to room temperature to obtain the machinable lithium disilicate glass ceramic blank. The molar ratio of Si atoms to Li atoms in the blank is 0.59:1.

[0065] SEM image of the machinable lithium disilicate glass-ceramic preform as shown in... Figure 1 As shown, by Figure 1 As can be seen, the machinable lithium disilicate glass-ceramic blank of the present invention contains rod-shaped lithium disilicate crystals, spherical lithium disilicate crystals and spherical lithium metasilicate crystals, wherein the particle size of the spherical lithium disilicate crystals is 300 nm, the length of the rod-shaped lithium disilicate crystals is 300 nm, and the median particle size D50 of the spherical lithium metasilicate crystals is 200 nm.

[0066] The XRD pattern of the machinable lithium disilicate glass-ceramic preform is shown below. Figure 2 As shown, by Figure 2 It can be seen that the machinable lithium disilicate glass-ceramic blank of the present invention contains two compounds: lithium disilicate and lithium metasilicate.

[0067] Example 2

[0068] The embodiment provides a machinable lithium disilicate glass ceramic blank, which is prepared by the following method.

[0069] (1) SiO2, Li2O, P2O5, Al2O3, ZrO2, K2O, ZnO, CeO2, Er2O3, V2O5, TiO2 and B2O3 are mixed in a mass ratio of 48:18:8:4:9:6:3:2:1:1:1:0.5, and then heated to 1450 DEG C at a rate of 10 DEG C / min, kept for 5 h, cooled to 1200 DEG C at a rate of 3 DEG C / min, and then poured into water for water quenching to obtain glass slag;

[0070] (2) the glass slag is heated to 1450 DEG C at a rate of 10 DEG C / min, kept for 5 h, cooled to 1200 DEG C at a rate of 3 DEG C / min, and then poured into a mold preheated to 300 DEG C to obtain a glass blank, the glass blank is heated to 500 DEG C and kept for 5 h, then heated to 750 DEG C and kept for 30 min, and then cooled to room temperature to obtain the machinable lithium disilicate glass ceramic blank, in the blank, the molar ratio of Si atoms to Li atoms is 0.67:1, the particle size of spherical lithium disilicate crystals is 400 nm, the length of rod-shaped lithium disilicate crystals is 500 nm, and the particle size of spherical lithium metasilicate crystals is 350 nm.

[0071] Example 3

[0072] The embodiment provides a machinable lithium disilicate glass ceramic blank, which is prepared by the following method.

[0073] (1) SiO2, Li2O, P2O5, Al2O3, ZrO2, K2O, ZnO, CeO2, Nd2O3, Er2O3, V2O5, Tb4O7 and TiO2 are mixed in a mass ratio of 50:20:10:4:5:7:2:1:1.5:0.5:0.5:1.5:1:1, and then heated to 1650 DEG C at a rate of 10 DEG C / min, kept for 2 h, cooled to 1400 DEG C at a rate of 3 DEG C / min, and then poured into water for water quenching to obtain glass slag;

[0074] (2) the glass cullet is heated at a rate of 10℃ / min to 1650℃, and then kept for 2h, and then cooled at a rate of 3℃ / min to 1400℃, the high-temperature melt obtained is poured into a mold preheated to 600℃, a glass blank is obtained, the glass blank is heated to 700℃ and kept for 2h, and then heated to 900℃ and kept for 1min, and then cooled to room temperature, to obtain the machinable lithium disilicate glass-ceramic blank, in the blank, the molar ratio of Si atoms to Li atoms is 0.63:1, the particle size of the spherical lithium disilicate crystal is 500nm, the length of the rod-shaped lithium disilicate crystal is 500nm, and the particle size of the spherical lithium metasilicate crystal is 400nm.

[0075] Example 4

[0076] The difference between this example and Example 1 is only that the mass ratio of SiO2 and Li2O is 40:25 (the molar ratio of Si atoms to Li atoms is 0.4:1), and other conditions and parameters are completely the same as those in Example 1.

[0077] Example 5

[0078] The difference between this example and Example 1 is only that the mass ratio of SiO2 and Li2O is 54:17 (the molar ratio of Si atoms to Li atoms is 0.79:1), and other conditions and parameters are completely the same as those in Example 1.

[0079] Example 6

[0080] The difference between this example and Example 1 is only that the added mass ratio of P2O5 and ZrO2 is 1:5 (the total mass fraction of phosphorus source and zirconium source is 6%), and other conditions and parameters are completely the same as those in Example 1.

[0081] Example 7

[0082] The difference between this example and Example 1 is only that the added mass ratio of P2O5 and ZrO2 is 15:13 (the total mass fraction of phosphorus source and zirconium source is 28%), and other conditions and parameters are completely the same as those in Example 1.

[0083] Comparative Example 1

[0084] In this comparative example, SiO2, Li2O, P2O5, Al2O3, ZrO2, K2O, CeO2, Er2O3, V2O5 and TiO2 are mixed in a mass ratio of 72:12:6:2:2:2:1:0.5:0.5:2, heated at a rate of 10℃ / min to 1650℃, kept for 2h, and then cooled at a rate of 3℃ / min to 1400℃, and the high-temperature melt is poured into water for water quenching, to obtain glass cullet.

[0085] The glass cullet was heated to 1650℃ at a rate of 10℃ / min, and then kept for 2h, and then cooled to 1400℃ at a rate of 3℃ / min, and then the high-temperature melt was poured into a mold preheated to 600℃, to obtain a glass blank, and then the glass blank was heated to 700℃ and kept for 2h, and then heated to 900℃ and kept for 1min, and then cooled to room temperature, to obtain a lithium disilicate glass-ceramic blank.

[0086] Performance test:

[0087] The glass-ceramics prepared from the examples and comparative examples were tested, wherein the strength was tested according to the method described in GB 30367-2013, and the test results are shown in Table 1:

[0088] Table 1

[0089]

[0090] As can be seen from Table 1, it can be obtained from Examples 1-3 that the strength of the machinable lithium disilicate glass-ceramic blank according to the present application can reach more than 345MPa, while showing good machinability.

[0091] As can be seen from the comparison between Example 1 and Examples 4-5, in the machinable lithium disilicate glass-ceramic blank according to the present application, the ratio of silicon and lithium will affect the performance, and when the molar ratio of Si atoms and Li atoms is controlled to be 0.45-0.75:1, the machinable lithium disilicate glass-ceramic blank has better performance, and if the silicon ratio is too high, the machinable lithium disilicate glass-ceramic blank will contain too much lithium disilicate, resulting in a decrease in machinability; and if the lithium ratio is too high, the machinable lithium disilicate glass-ceramic blank will contain too much lithium metasilicate, resulting in a decrease in mechanical properties and acid corrosion resistance.

[0092] As can be seen from the comparison between Example 1 and Examples 6-7, in the preparation process of the machinable lithium disilicate glass-ceramic blank according to the present application, the addition amount of the phosphorus source and the zirconium source will affect the performance of the machinable lithium disilicate glass-ceramic blank, and when the total mass fraction of the phosphorus source and the zirconium source is controlled to be 10-25%, the machinable lithium disilicate glass-ceramic blank has better performance, and if the addition amount is too large, the glass blank will easily precipitate crystals at this stage, resulting in uneven crystal precipitation and change of the main crystal phase, affecting the mechanical properties and aesthetic effect of the final product, and if the addition amount is too small, the spherical crystal content is too low, and the machinability decreases significantly.

[0093] As can be seen from the comparison between Example 1 and Comparative Example 1, the glass-ceramic containing lithium disilicate crystals and lithium metasilicate crystals can be prepared by a simple method according to the present application, the lithium disilicate crystals are a mixture of nanoscale spherical crystals and nanoscale rod-shaped crystals, the lithium metasilicate crystals are nanoscale spherical crystals, and the lithium disilicate crystals and the lithium metasilicate crystals are uniformly dispersed in the lithium disilicate crystals, these crystals do not form an interlocking structure, and the arrangement is more loose, so that the machinability of the blank is improved.

[0094] The applicant states that the above description is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. It should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the present application can be easily conceived by any person skilled in the art, and all such changes and replacements fall within the protection scope and disclosure scope of the present application.

Claims

1. A cuttable lithium disilicate glass-ceramic blank, characterized in that, The lithium disilicate glass ceramic blank comprises lithium disilicate crystals and lithium metasilicate crystals, the lithium disilicate crystals comprise spherical lithium disilicate crystals and rod-shaped lithium disilicate crystals, the lithium metasilicate crystals comprise spherical lithium metasilicate crystals; the spherical lithium disilicate crystals and the rod-shaped lithium disilicate crystals are mixed, the lithium metasilicate crystals are uniformly dispersed in the lithium disilicate crystals, and the crystals do not form an interlocking structure; the particle size of the spherical lithium disilicate crystals is 300-500 nm; the length of the rod-shaped lithium disilicate crystals is 300-650 nm; the particle size of the spherical lithium metasilicate crystals is 300-600 nm; and the molar ratio of Si atoms to Li atoms in the machinable lithium disilicate glass ceramic blank is 0.45-0.

75. The machinable lithium disilicate glass ceramic blank is prepared by a preparation method comprising the following steps: (1) mixing main raw materials, performing one-step high-temperature melting treatment, and obtaining glass slag after water quenching; the main raw materials comprise silicon oxide, lithium oxide, phosphorus oxide, aluminum oxide, zirconium oxide and potassium oxide; the mass fraction of the phosphorus oxide is 8-17% and the mass fraction of the zirconium oxide is 1-15% based on 100% of the mass of the main raw materials; the mass fraction of the lithium oxide is 19-26%; and the mass fraction of the aluminum oxide is 4-9%; (2) performing two-step high-temperature melting treatment on the glass slag, pouring into a mold, and obtaining a glass blank; (3) performing heat treatment on the glass blank to obtain the machinable lithium disilicate glass ceramic blank.

2. A method of producing a cuttable lithium disilicate glass-ceramic blank according to claim 1, characterized in that The preparation method comprises the following steps: (1) mixing main raw materials, performing one-step high-temperature melting treatment, and obtaining glass slag after water quenching; the main raw materials comprise silicon oxide, lithium oxide, phosphorus oxide, aluminum oxide, zirconium oxide and potassium oxide; the mass fraction of the phosphorus oxide is 8-17% and the mass fraction of the zirconium oxide is 1-15% based on 100% of the mass of the main raw materials; the mass fraction of the lithium oxide is 19-26%; and the mass fraction of the aluminum oxide is 4-9%; and the molar ratio of Si elements to Li elements in the main raw materials is 0.45-0.75; (2) performing two-step high-temperature melting treatment on the glass slag, pouring into a mold, and obtaining a glass blank; (3) performing heat treatment on the glass blank to obtain the machinable lithium disilicate glass ceramic blank.

3. The production method according to claim 2, wherein The mass fraction of the silicon oxide is 55-70% based on 100% of the mass of the main raw materials.

4. The production method according to claim 2, wherein The mass fraction of the potassium oxide is 2-10% based on 100% of the mass of the main raw materials.

5. The production method according to claim 2, wherein The total mass fraction of the phosphorus oxide and the zirconium oxide is 10-25% based on 100% of the mass of the main raw materials.

6. The production method according to claim 2, wherein An additive is further added in the mixing process of step (1).

7. The production method according to claim 6, wherein The additive comprises any one or a combination of at least two of oxides, chlorides or phosphates of B, Na, Mg, Ca, Ba, Ti, V or rare earth elements.

8. The production method according to claim 2, wherein The one-step high-temperature melting treatment in step (1) comprises a one-stage high-temperature melting treatment and a two-stage high-temperature melting treatment.

9. The production method according to claim 8, wherein The temperature of the one-stage high-temperature melting treatment is 1450-1650℃.

10. The production method according to claim 8, wherein The time of the one-stage high-temperature melting treatment is 2-5h.

11. The production method according to claim 8, wherein The temperature of the two-stage high-temperature melting treatment is 1200-1400℃.

12. The production method according to claim 8, wherein The cooling rate from the one-stage high-temperature melting treatment to the two-stage high-temperature melting treatment is 2-5℃ / min.

13. The production method according to claim 2, wherein The two-stage high-temperature melting treatment in step (2) comprises three-stage high-temperature melting treatment and four-stage high-temperature melting treatment.

14. The production method according to claim 13, wherein The temperature of the three-stage high-temperature melting treatment is 1450-1650℃.

15. The production method according to claim 13, wherein The time of the three-stage high-temperature melting treatment is 2-5h.

16. The production method according to claim 13, wherein The temperature of the four-stage high-temperature melting treatment is 1200-1400℃.

17. The production method according to claim 13, wherein The cooling rate from the three-stage high-temperature melting treatment to the four-stage high-temperature melting treatment is 2-5℃ / min.

18. The production method according to claim 13, wherein The mold is preheated before pouring into the mold.

19. The production method according to claim 18, wherein The temperature of the preheating treatment is 300-600℃.

20. The production method according to claim 2, wherein The heat treatment in step (3) comprises one-stage heat treatment and two-stage heat treatment.

21. The production method according to claim 20, wherein The temperature of the one-stage heat treatment is 500-700℃.

22. The production method according to claim 20, wherein The time of the one-stage heat treatment is 2-5h.

23. The production method according to claim 20, wherein The temperature of the two-stage heat treatment is 750-900℃.

24. The production method according to claim 20, wherein The time of the two-stage heat treatment is 1-30min.

25. Use of a cuttable lithium disilicate glass-ceramic blank according to claim 1, characterized in that, The cuttable lithium disilicate glass-ceramic blank is used for dental restoration materials.

Images