CN116409935A - Lithium disilicate glass ceramic, preparation method thereof and dental restoration - Google Patents

Abstract

The application relates to a lithium disilicate glass ceramic, a preparation method thereof and a dental restoration. The lithium disilicate glass ceramic comprises the following components in percentage by weight: 58% -68% of SiO ₂ 3 to 6 percent of K ₂ O, 14-18% Li ₂ O, 0.6-3% Al ₂ O ₃ 2.5 to 5 percent of P ₂ O ₅ ZrO in 8.1-14 wt% ₂ Na 0.5-2.5% ₂ O, 0.5-3.5% CeO ₂ 0.5 to 3 percent of MgO and 0.2 to 2.5 percent of ZnO. The lithium disilicate glass ceramic can be directly cut without sintering, has good cutting performance, is easy to cut, has smooth cutting surface and good fracture toughness.

Description

Lithium disilicate glass-ceramic and its preparation method and dental restoration

technical field

The present application relates to the technical field of glass ceramics, in particular to a lithium disilicate glass ceramic, a preparation method thereof, and a dental restoration.

Background technique

Lithium disilicate crystals have a suitable photorefractive index and good biocompatibility, so lithium disilicate glass-ceramics have been more and more widely used in dental restorations in recent years. Lithium silicate glass-ceramic materials, especially when the porcelain block uses lithium metasilicate as the main crystalline phase, can be processed by CAD/CAM to achieve "chairside operation", but incompletely crystallized lithium metasilicate glass-ceramics are generally still It does not have the appearance of real teeth, it needs to be cut and then sintered to form lithium disilicate before it can be used, and the sintering time is long, requiring a long wait, and some restorations are prone to deformation during the sintering process. Therefore, in the research of dental restorations, products that are free from sintering after cutting are the research trend.

At present, the good products without sintering after cutting on the market focus on resin and glass-ceramic composite materials. The advantage is that no sintering is required and the time for visiting a doctor at the chair is shortened. However, this type of material still has some defects, such as low strength (only in Between 130MPa and 200MPa), and studies have shown that the light transmittance of resin-ceramic composites is not as good as that of glass ceramics, which greatly limits the scope of use of resin-ceramic composites. In addition, there is also a method to prepare lithium disilicate glass ceramics by adding an opacifying agent into the formula and cooperating with two sintering processes. It does not need to be further sintered after cutting to make the prosthetic body, and can achieve higher strength (275MPa～333MPa ), but this method only focuses on the improvement of the strength performance of the material, and does not pay attention to the machinability and fracture toughness of the material.

Contents of the invention

Based on this, the present application provides a lithium disilicate glass ceramic, a preparation method thereof, and a dental restoration. The lithium disilicate glass-ceramic does not need to be sintered, can be directly cut and processed, has good cutting performance, is easy to cut, has a smooth cutting surface, and has good fracture toughness.

The first aspect of the present application provides a lithium disilicate glass ceramic, which comprises the following components in weight percent:

58%~68% SiO ₂ , 3%~6% K ₂ O, 14%~18% Li ₂ O, 0.6%~3% Al ₂ O ₃ , 2.5%~5% P ₂ O ₅ , 8.1% to 14% of ZrO ₂ , 0.5% to 2.5% of Na ₂ O, 0.5% to 3.5% of CeO ₂ , 0.5% to 3% of MgO and 0.2% to 2.5% of ZnO.

In one of the embodiments, the lithium disilicate glass-ceramic includes the following components by weight percentage:

60%~67.5% SiO ₂ , 3.4%~4.5% K ₂ O, 14%~15.5% Li ₂ O, 0.6%~1.5% Al ₂ O ₃ , 2.5%~3.5% P ₂ O ₅ , 8.1% to 13.5% of ZrO ₂ , 1% to 1.5% of Na ₂ O, 0.5% to 2.5% of CeO ₂ , 1% to 2% of MgO and 0.2% to 1.5% of ZnO.

In one embodiment, the components further include 0.01%-3% of B ₂ O ₃ by weight percentage.

In one embodiment, the components further include 0.01% to 3% of colorants in weight percentage.

In one of the embodiments, the lithium disilicate glass-ceramic has one or more of the following characteristics:

(1) The average value of the three-point bending strength of the lithium disilicate glass-ceramic is 200MPa～240MPa;

(2) The diameter of the crystal grains in the lithium disilicate glass-ceramic is 200nm～900nm;

(3) the fracture toughness of the lithium disilicate glass-ceramic is 2.5～3.2MPa·m ^1/2 ;

(4) The hardness of the lithium disilicate glass-ceramic is 6200MPa～7300MPa;

(5) The transmittance of the lithium disilicate glass ceramic is 30% to 55%.

The second aspect of the present application provides the preparation method of the lithium disilicate glass-ceramic described in the first aspect, comprising the steps of:

Weighing raw materials according to the components of the lithium disilicate glass-ceramic;

mixing, melting and shaping the raw materials to produce glass blocks;

performing annealing, nucleation treatment, first heat treatment and second heat treatment on the glass block to prepare the lithium disilicate glass-ceramic;

Wherein, the temperature of the first heat treatment is 610°C-700°C, and the temperature of the second heat treatment is 800°C-850°C.

In one embodiment, the melting conditions include: a temperature of 1400° C. to 1600° C. and a time of 60 minutes to 300 minutes.

In one embodiment, the annealing conditions include: a temperature of 400° C. to 500° C. and a time of 30 minutes to 90 minutes.

In one embodiment, the nucleation conditions include: a temperature of 500° C. to 600° C. and a time of 60 minutes to 360 minutes.

In one embodiment, the time for the first heat treatment is 1 min to 120 min, and the time for the second heat treatment is 1 min to 20 min.

The third aspect of the present application provides a dental restoration, including the lithium disilicate glass-ceramic described in the first aspect.

The above-mentioned lithium disilicate glass ceramics are properly compatible with various components, among which SiO ₂ and Li ₂ O are the main raw materials for forming lithium disilicate crystal phase, and a relatively high proportion of ZrO ₂ and specific ranges of Na ₂ O and P ₂ O ₅ , MgO and ZnO, improve the conversion rate (content) and crystal size of lithium disilicate crystals and lithium metasilicate crystals, so that the prepared lithium disilicate glass ceramics can be directly cut without sintering, and have Good cutting performance, easy to cut, smooth cutting surface, and good fracture toughness. Specifically, the advantages of the above-mentioned lithium disilicate glass ceramics are as follows:

(1) It can be used directly after cutting and polishing without re-sintering. On the one hand, the waiting time for "chairside operation" is shortened. On the other hand, the prosthesis will not be deformed or not fit, and the edge adhesion is good; and The equipment is easy to process, can greatly reduce the cost, and is conducive to expanding the clinical application of lithium disilicate glass ceramics;

(2) It has good fracture toughness and suitable hardness, which makes the cutting performance better, the cutting surface is smooth, and the cutting edge integrity is good;

(3) The transmittance can be adjusted within 30% to 55%, with semi-permeability, which can well simulate the light transmittance and color of natural teeth;

(4) The production process is simple, the controllable coefficient is high, and the industrial application prospect is good.

Description of drawings

Fig. 1 is the electron micrograph of the lithium disilicate glass-ceramic that embodiment 1 prepares;

Fig. 2 is the dental crown photo that is made of lithium disilicate glass-ceramic prepared by embodiment 1;

Fig. 3 is the photo of the cutting surface after cutting the lithium disilicate glass-ceramic prepared in Comparative Example 1;

Fig. 4 is the photo of the cutting surface after cutting the lithium disilicate glass-ceramic prepared in Comparative Example 2;

Fig. 5 is a comparison photo of the cutting surface after cutting the lithium disilicate glass ceramics prepared in Comparative Example 1 (A) and Example 1 (B).

Detailed ways

The lithium disilicate glass-ceramic of the present application, its preparation method and dental restoration will be further described in detail below in conjunction with specific examples. This application can be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of this application more thorough and comprehensive.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of the application are only for the purpose of describing specific embodiments, and are not intended to limit the application.

Herein, "one or more" refers to any one, any two or any two or more of the listed items.

In this application, "the first aspect", "the second aspect", and "the third aspect" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implying that the indicated The importance or number of technical features. Moreover, "first", "second", "third" and so on are only for the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on the quantity.

In this application, the technical features described in open form include closed technical solutions consisting of the listed features, and open technical solutions including the listed features.

In this application, when referring to a numerical range, unless otherwise specified, the above numerical range is considered continuous, and includes the minimum and maximum values of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum of the range is included. Furthermore, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise indicated, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein.

The percentage content involved in this application, unless otherwise specified, refers to mass percentage for solid-liquid mixing and solid-solid phase mixing, and refers to volume percentage for liquid-liquid phase mixing.

The percentage concentration involved in this application, unless otherwise specified, refers to the final concentration. The final concentration refers to the proportion of the added component in the system after the component is added.

The temperature parameters in this application, unless otherwise specified, are allowed to be treated at a constant temperature, and also allowed to be treated within a certain temperature range. The isothermal treatment allows the temperature to fluctuate within the precision of the instrument control.

Some examples of the present application provide a lithium disilicate glass-ceramic, by weight percentage, comprising the following components:

58%~68% SiO ₂ , 3%~6% K ₂ O, 14%~18% Li ₂ O, 0.6%~3% Al ₂ O ₃ , 2.5%~5% P ₂ O ₅ , 8.1% to 14% of ZrO ₂ , 0.5% to 2.5% of Na ₂ O, 0.5% to 3.5% of CeO ₂ , 0.5% to 3% of MgO and 0.2% to 2.5% of ZnO.

Specifically, the weight percentage of _SiO2 includes but not limited to: 58%, 59%, 60%, 60.5%, 61%, 61.5%, 62%, 62.5%, 63.2%, 64%, 64.5%, 65%, 65.5% %, 66%, 66.5%, 67.2%, 67.5%, 68%.

Specifically, the weight percentage of K ₂ O includes but not limited to: 3%, 3.04%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.74%, 3.8%, 4%, 4.2%, 4.5%, 5%, 5.5%, 6%.

Specifically, the weight percentage of Li ₂ O includes but not limited to: 14%, 14.2%, 14.5%, 14.6%, 14.8%, 15.1%, 15.3%, 15.5%, 16%, 16.5%, 17%, 17.5%, 18%.

Specifically, the weight percentage of Al ₂ O ₃ includes but not limited to: 0.6%, 0.8%, 1%, 1.06%, 1.2%, 1.5%, 2%, 2.5%, 3%.

Specifically, the weight percentage of P ₂ O ₅ includes but not limited to: 2.5%, 2.6%, 2.7%, 2.9%, 3%, 3.2%, 3.5%, 4%, 4.5%, 5%.

Specifically, the weight percentage of _ZrO2 includes but not limited to: 8.1%, 8.2%, 8.5%, 9%, 9.5%, 9.7%, 10%, 10.5%, 11%, 11.3%, 11.5%, 12%, 12.5% %, 13%, 13.5%, 14%.

Specifically, the weight percentage of Na ₂ O includes but not limited to: 0.5%, 0.8%, 1%, 1.1%, 1.2%, 1.23%, 1.25%, 1.4%, 1.5%, 2%, 2.2%, 2.5%.

Specifically, the weight percentages of _CeO include but are not limited to: 0.5%, 0.6%, 0.7%, 0.75%, 0.8%, 0.85%, 0.91%, 0.98%, 1.1%, 1.3%, 1.5%, 1.8%, 2 %, 2.5%, 3.5%.

Specifically, the weight percentage of MgO includes but not limited to: 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.55%, 1.6%, 1.65%, 1.69%, 1.7%, 1.75%, 1.8%, 2% , 2.5%, 3%.

Specifically, the weight percentage of ZnO includes but not limited to: 0.2%, 0.5%, 0.8%, 0.9%, 0.94%, 0.96%, 0.98%, 1%, 1.2%, 1.5%, 2%, 2.5%.

It can be understood that the sum of weight percentages of all components in the lithium disilicate glass-ceramic should satisfy 100%.

In some examples, the lithium disilicate glass-ceramic includes the following components by weight percentage:

60%~67.5% SiO ₂ , 3.4%~4.5% K ₂ O, 14%~15.5% Li ₂ O, 0.6%~1.5% Al ₂ O ₃ , 2.5%~3.5% P ₂ O ₅ , 8.1% to 13.5% of ZrO ₂ , 1% to 1.5% of Na ₂ O, 0.5% to 2.5% of CeO ₂ , 1% to 2% of MgO and 0.2% to 1.5% of ZnO.

In some examples, the lithium disilicate glass ceramic further includes 0.01%-3% of B ₂ O ₃ by weight percentage. By adding a certain range of B ₂ O ₃ , it is beneficial to improve the network structure of the glass and increase its fracture toughness. Specifically, the weight percentage of _B2O3 includes but not limited to: 0.01%, 0.1%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 1%, 1.32% _, 1.36%, 1.38%, 1.5% , 1.8%, 2%, 2.5%, 3%.

In some examples, the lithium disilicate glass-ceramic further includes 0.01% to 3% of coloring material by weight percentage. By adding a certain range of pigments, the color of the material can be adjusted to obtain a color similar to that of natural teeth. Specifically, the weight percentage of the colorant includes but is not limited to: 0.01%, 0.04%, 0.06%, 0.08%, 0.1%, 0.15%, 0.19%, 2.5%, 3%. It can be understood that the type of coloring material is not particularly limited, and can be reasonably selected according to the desired color. Without limitation, _the colorant may include _one of _{V2O5 , Tb4O7 , Er2O3 , Fe2O3} , _{Eu2O3 , Pr6O11} , _MnO2 and _TiO2 or Various.

In some examples, the crystal phase in the lithium disilicate glass-ceramic includes lithium disilicate and lithium metasilicate. A glassy phase is also included.

As mentioned above, the lithium disilicate glass-ceramic has relatively fine crystal grains, suitable hardness, high fracture toughness, and appropriate light transmittance. Without limitation, the lithium disilicate glass-ceramic satisfies one or more of the following properties:

(1) The average value of the three-point bending strength of the lithium disilicate glass-ceramic is 200MPa～240MPa;

(2) The diameter of the crystal grains in the lithium disilicate glass-ceramic is 200nm～900nm;

(3) the fracture toughness of the lithium disilicate glass-ceramic is 2.5～3.2MPa·m ^1/2 ;

(4) The hardness of the lithium disilicate glass-ceramic is 6200MPa～7300MPa;

(5) The light transmittance of the lithium disilicate glass ceramic is 30%-55%.

Other examples of the present application also provide the preparation method of lithium disilicate glass-ceramics as described above, including the following steps:

Weighing raw materials according to the components of the lithium disilicate glass-ceramic;

mixing, melting and shaping the raw materials to produce glass blocks;

performing annealing, nucleation treatment, first heat treatment and second heat treatment on the glass block to prepare the lithium disilicate glass-ceramic;

Wherein, the temperature of the first heat treatment is 610°C-700°C, and the temperature of the second heat treatment is 800°C-850°C.

Specifically, the temperature of the first heat treatment includes but is not limited to: 610°C, 620°C, 630°C, 640°C, 650°C, 660°C, 670°C, 680°C, 690°C, 700°C.

In some examples, the time for the first heat treatment is 1 min-120 min. Specifically, the time for the first heat treatment includes but is not limited to: 1min, 10min, 20min, 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min, 120min.

Specifically, the temperature of the second heat treatment includes but is not limited to: 800°C, 810°C, 820°C, 830°C, 840°C, 850°C.

In some examples, the time for the second heat treatment is 1 min-20 min. Specifically, the time for the second heat treatment includes but is not limited to: 1 min, 2 min, 4 min, 6 min, 8 min, 10 min, 15 min, and 20 min.

In addition, understandably, the mixing method is ball milling.

In some examples, the melting conditions include: a temperature of 1400° C. to 1600° C. and a time of 60 minutes to 300 minutes.

Specifically, the melting temperature includes but not limited to: 1400°C, 1450°C, 1500°C, 1550°C, 1600°C.

Specifically, the melting time includes but is not limited to: 60 min, 80 min, 100 min, 120 min, 140 min, 200 min, 300 min.

In some examples, the annealing conditions include: a temperature of 400° C. to 500° C. and a time of 30 minutes to 90 minutes.

Specifically, the annealing temperature includes but is not limited to: 400°C, 420°C, 440°C, 460°C, 480°C, 500°C.

Specifically, the annealing time includes but is not limited to: 30 min, 40 min, 50 min, 70 min, 90 min.

In some examples, the nucleation conditions include: a temperature of 500° C. to 600° C. and a time of 60 minutes to 360 minutes.

Specifically, the nucleation temperature includes but not limited to: 500°C, 520°C, 540°C, 560°C, 580°C, 600°C.

Specifically, the nucleation time includes but is not limited to: 60 min, 80 min, 100 min, 150 min, 200 min, 250 min, 300 min, and 360 min.

Other examples of the present application also provide a dental restoration, including the above-mentioned lithium disilicate glass-ceramic. Further, the dental restoration is an embedded restoration material, such as an intracoronal restoration, an inlay, an onlay, a veneer, and the like.

The following are specific examples, and unless otherwise specified, the raw materials used in the examples are commercially available products.

Example 1

This embodiment is a lithium disilicate glass-ceramic, its components are shown in Table 1 (mass percentage %), and the preparation method is as follows:

(1) Take each raw material (analytically pure) according to the components in Table 1, wherein potassium oxide and lithium oxide are introduced by potassium carbonate and lithium carbonate respectively, phosphorus pentoxide is introduced by ammonium dihydrogen phosphate, boron oxide is introduced by boric acid, Sodium oxide is introduced from sodium carbonate, and the remaining raw materials are silicon dioxide, aluminum oxide, zirconium oxide, cerium oxide, magnesium oxide and zinc oxide;

(2) each raw material of step (1) is ball milled for 8h and mixed evenly, and degassed in a muffle furnace;

(3) Put the material in step (2) into a high-temperature furnace melting furnace and melt it at a temperature of 1500° C. for 2 hours;

(4) pouring and demolding the melt of step (3);

(5) annealing the glass block demolded in step (4) at a temperature of 420°C for 0.5h;

(6) Nucleating the material after step (5) annealed at a temperature of 520° C. for 3 hours;

(7) heat-treating the material nucleated in step (6) at a temperature of 630° C. for 1 hour;

(8) heat-treating the material after the heat treatment in step (7) at a temperature of 820° C. for 4 minutes to prepare the lithium disilicate glass-ceramic.

The preparation method of the lithium disilicate glass ceramics of Examples 2-5 and Comparative Examples 1-4 is the same as that of Example 1, the main difference is that the mass percentages of each component are different, as shown in Table 1 (mass percentage %).

Table 1

SiO ₂ K ₂ O Li ₂ O Al ₂ O ₃ P ₂ O _{5 ZrO2} Na ₂ O B ₂ O _{3 CeO2} MgO ZnO colorant Example 1 61 3.74 15.1 1.06 2.9 9.7 1.25 1.38 0.98 1.7 1 0.19 Example 2 63.2 3.6 14.6 1 3 8.2 1.2 1.36 1.1 1.7 0.98 0.06 Example 3 60.0 3.7 14.8 1 2.9 11.3 1.23 1.36 0.91 1.69 0.96 0.15 Example 4 58.0 3.04 14.5 1 2.7 13.5 1.2 1.32 2 1.65 0.94 0.15 Example 5 66.2 3.3 14 1 2.55 8.1 1.08 0.5 0.8 1.45 0.88 0.14 Comparative example 1 65.2 3.8 15.4 1.07 2.9 5.1 1.27 1.39 0.98 1.7 1 0.19 Comparative example 2 64.9 3.78 15.3 1.1 3.9 4.5 1.26 1.4 0.98 1.7 1 0.18

Example 6

This embodiment is a lithium disilicate glass-ceramic, the preparation method of which is the same as that of Example 1, the main difference being that the heat treatment temperature in steps (7) and (8) is different, specifically, the heat treatment temperature in step (7) is 610 ℃, the heat treatment temperature in step (8) is 840 ℃.

The preparation method is as follows:

(1) Take each raw material (analytically pure) according to the components in Table 1, wherein potassium oxide and lithium oxide are introduced by potassium carbonate and lithium carbonate respectively, phosphorus pentoxide is introduced by ammonium dihydrogen phosphate, boron oxide is introduced by boric acid, Sodium oxide is introduced from sodium carbonate, and the remaining raw materials are silicon dioxide, aluminum oxide, zirconium oxide, cerium oxide, magnesium oxide and zinc oxide;

(2) each raw material of step (1) is ball milled for 8h and mixed evenly, and degassed in a muffle furnace;

(3) Put the material in step (2) into a high-temperature furnace melting furnace and melt it at a temperature of 1500° C. for 2 hours;

(4) pouring and demolding the melt of step (3);

(5) annealing the glass block demolded in step (4) at a temperature of 420°C for 0.5h;

(6) Nucleating the material after step (5) annealed at a temperature of 520° C. for 3 hours;

(7) heat-treating the material nucleated in step (6) at a temperature of 610° C. for 1 hour;

(8) heat-treating the material after the heat treatment in step (7) at a temperature of 840° C. for 4 minutes to prepare the lithium disilicate glass-ceramic.

Example 7

This embodiment is a lithium disilicate glass-ceramic, the preparation method of which is the same as that of Example 1, the main difference being that the heat treatment temperature in steps (7) and (8) is different, specifically, the heat treatment temperature in step (7) is 670 ℃, the heat treatment temperature in step (8) is 800 ℃.

The preparation method is as follows:

(1) Take each raw material (analytically pure) according to the components in Table 1, wherein potassium oxide and lithium oxide are introduced by potassium carbonate and lithium carbonate respectively, phosphorus pentoxide is introduced by ammonium dihydrogen phosphate, boron oxide is introduced by boric acid, Sodium oxide is introduced from sodium carbonate, and the remaining raw materials are silicon dioxide, aluminum oxide, zirconium oxide, cerium oxide, magnesium oxide and zinc oxide;

(2) each raw material of step (1) is ball milled for 8h and mixed evenly, and degassed in a muffle furnace;

(3) Put the material in step (2) into a high-temperature furnace melting furnace and melt it at a temperature of 1500° C. for 2 hours;

(4) pouring and demolding the melt of step (3);

(5) annealing the glass block demolded in step (4) at a temperature of 420°C for 0.5h;

(6) Nucleating the material after step (5) annealed at a temperature of 520° C. for 3 hours;

(7) heat-treating the material nucleated in step (6) at a temperature of 670° C. for 1 hour;

(8) heat-treating the material after the heat treatment in step (7) at a temperature of 800° C. for 4 minutes to prepare the lithium disilicate glass-ceramic.

Test case:

(1) Average value of three-point bending strength: tested according to GB30367-2013;

(2) Fracture toughness: tested according to the single-edge V-notch beam (SEVNB) method;

(3) Hardness: Test according to GB/T 16534-2009 Fine Ceramics Hardness Test Method at Room Temperature (Vickers Hardness Tester);

(4) Transmittance: Tested with a haze meter;

(5) The diameter of crystal grain: test by SEM scanning electron microscope;

(6) Machining performance: The lithium disilicate glass-ceramics prepared in Examples and Comparative Examples were cut and polished (without sintering) according to existing processing methods to make dental crowns, and the roughness of the crown surface was observed.

The test results are shown in Table 2 below:

Table 2

In addition, the SEM scanning electron microscope image of Example 1 is shown in FIG. 1 , and it can be seen from FIG. 1 that the crystal grains of the glass-ceramics are fine, and the diameter of the crystal grains is 250 nm to 700 nm.

The lithium disilicate glass-ceramic prepared in Example 1 was cut and polished (without sintering) to make a dental crown. The photo is shown in Figure 2. It can be seen that the cutting surface is smooth and the cutting edge is complete. Figures 3 to 5 are comparative photos of the cutting surfaces of Comparative Examples 1 and 2 and Comparative Example 2 and Example 1. It can be seen that Comparative Examples 1 and 2 adopt different _ZrO2 contents on the basis of Example 1, which not only improves the fracture toughness Descending, cutting is difficult at the same time, and the cutting surface after cutting is rough.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present application, which is convenient for a specific and detailed understanding of the technical solution of the present application, but should not be construed as limiting the protection scope of the patent application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all belong to the protection scope of the present application. It should be understood that technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in this application are within the protection scope of the appended claims of this application. Therefore, the scope of protection of the patent application should be based on the content of the appended claims, and the description and drawings can be used to interpret the content of the claims.

Claims (11)

1. The lithium disilicate glass ceramic is characterized by comprising the following components in percentage by weight:

58% -68% of SiO ₂ 3 to 6 percent of K ₂ O, 14-18% Li ₂ O, 0.6-3% Al ₂ O ₃ 2.5 to 5 percent of P ₂ O ₅ ZrO in 8.1-14 wt% ₂ Na 0.5-2.5% ₂ O, 0.5-3.5% CeO ₂ 0.5 to 3 percent of MgO and 0.2 to 2.5 percent of ZnO.

2. The lithium disilicate glass ceramic according to claim 1, comprising, in weight percent:

60% -67.5% of SiO ₂ 3.4 to 4.5 percent of K ₂ O, 14-15.5% Li ₂ O, 0.6-1.5% Al ₂ O ₃ 2.5 to 3.5 percent of P ₂ O ₅ ZrO 8.1-13.5% ₂ 1 to 1.5 percent of Na ₂ O, 0.5-2.5% CeO ₂ 1 to 2 percent of MgO and 0.2 to 1.5 percent of ZnO.

3. Root of Chinese characterThe lithium disilicate glass ceramic according to claim 1, wherein the composition further comprises, in weight percent, 0.01% to 3% B ₂ O ₃ 。

4. The lithium disilicate glass ceramic according to claim 1, wherein the composition further comprises, in weight percent, 0.01% to 3% colorant.

5. The lithium disilicate glass ceramic according to any of claims 1 to 4, wherein the lithium disilicate glass ceramic has one or more of the following characteristics:

(1) The average value of the three-point bending strength of the lithium disilicate glass ceramic is 200 MPa-240 MPa;

(2) The grain diameter of the lithium disilicate glass ceramic is 200 nm-900 nm;

(3) The fracture toughness of the lithium disilicate glass ceramic is 2.5-3.2 MPa.m ^1/2 ；

(4) The hardness of the lithium disilicate glass ceramic is 6200 MPa-7300 MPa;

(5) The transmittance of the lithium disilicate glass ceramic is 30% -55%.

6. The method for producing a lithium disilicate glass ceramic according to any of claims 1 to 5, comprising the steps of:

weighing raw materials according to the components of the lithium disilicate glass ceramic;

mixing, melting and forming the raw materials to prepare a glass block;

annealing, nucleation, first heat treatment and second heat treatment are carried out on the glass block to prepare the lithium disilicate glass ceramic;

wherein the temperature of the first heat treatment is 610-700 ℃, and the temperature of the second heat treatment is 800-850 ℃.

7. The method for preparing a lithium disilicate glass ceramic according to claim 6, wherein the conditions for melting comprise: the temperature is 1400-1600 ℃ and the time is 60-300 min.

8. The method for preparing a lithium disilicate glass ceramic according to claim 6, wherein the annealing conditions comprise: the temperature is 400-500 ℃ and the time is 30-90 min.

9. The method for preparing a lithium disilicate glass ceramic according to claim 6, wherein the nucleation conditions comprise: the temperature is 500-600 ℃ and the time is 60-360 min.

10. The method for producing a lithium disilicate glass ceramic according to any of claims 6 to 9, wherein the time of the first heat treatment is 1 to 120 minutes and the time of the second heat treatment is 1 to 20 minutes.

11. A dental restoration comprising a lithium disilicate glass ceramic according to any of claims 1 to 5.

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