Raw material mixture of zirconium oxide porcelain block and application of raw material mixture

Abstract

The invention relates to a raw material mixture of a zirconia porcelain block and application of the raw material mixture. The raw material mixture comprises the following components in percentage by weight: 89 to 91 percent of ZrO2, 5 to 10 percent of Y2O3, 0.03 to 0.3 percent of Er2O3, 0.01 to 0.3 percent of ZnO and 1 to 2 percent of SiC. Meanwhile, the invention discloses a zirconia ceramic block prepared from the raw material mixture and a false tooth. The auxiliary agent used in the method is higher in biological safety, due characteristics of the zirconium oxide ceramic block are ensured, the risk that harmful elements are dissolved out in the using process is avoided, and the using safety of the zirconium oxide ceramic block is ensured.

Description

Technical Field

[0001] The invention relates to the field of denture materials, in particular to a raw material mixture of a zirconium oxide ceramic block and application thereof. Background Art

[0002] With the progress and development of society, the application of oral materials has become more and more diversified. Zirconia ceramic blocks have become more and more important in the dental industry because of their jade-like appearance and good mechanical properties. As people's living standards improve, the requirements for dentures made of zirconia ceramic blocks are getting higher and higher, not only requiring excellent comprehensive mechanical properties, but also requiring good appearance properties. The light transmittance, moistness, bending strength, fracture toughness, etc. of dental zirconia ceramic blocks are all affected by the formula of zirconia ceramic blocks and the high-temperature sintering process at the same time, and the influence of these factors is mostly nonlinear. In addition, dentures will be affected by the acid-base environment in the mouth, food ingredients, etc. during use, and harmful elements will be dissolved to cause damage to the human body. For example, the conventionally used manganese oxide will be affected by the oral environment, denture wear, aging, etc., and there will be trace dissolution. Excessive intake of manganese elements will have adverse effects on the nervous system, and at the same time affect the strength and toughness of dentures, which are easy to break during use, thereby shortening the service life of dentures. This requires raw materials with higher biosafety to prepare zirconia ceramic blocks. Summary of the invention

[0003] In view of the existing deficiencies, the present invention provides a raw material mixture of a zirconium oxide ceramic block and application thereof.

[0004] The technical solution adopted by the present invention to solve the technical problem is: a raw material mixture of a zirconium oxide ceramic block includes the following components in weight percentage: 89-91% ZrO2, 5-10% Y2O3, 0.03-0.3% Er2O3, 0.01-0.3% ZnO, and 1-2% SiC.

[0005] Preferably, the ZrO2, Y2O3, Er2O3, ZnO and SiC are all powdered raw materials with a particle size of 20-300nm.

[0006] A zirconia ceramic block is prepared using a raw material mixture of any one of the above zirconia ceramic blocks.

[0007] As preferably, it is prepared by the following steps:

[0008] Powdered ZrO2, Y2O3, Er2O3, ZnO, and SiC powders with nanometer particle sizes are weighed in proportion and then mixed evenly to obtain a zirconium oxide mixture;

[0009] Pre-pressing the zirconium oxide mixture into a zirconium oxide blank;

[0010] The zirconia blank is cold isostatically pressed and then sintered to obtain a zirconia ceramic block.

[0011] Preferably, the pre-pressing pressure is 4-70 MPa, and the holding time is 20-50S.

[0012] Preferably, the cold isostatic pressing pressure is 100-300 MPa, and the holding time is 5-15 min.

[0013] The sintering comprises the following steps:

[0014] 1) Heating to 180°C at a rate of 2-7°C / min and keeping warm for 10-20 minutes;

[0015] 2), then heating to 1100°C at a heating rate of 10-30°C / min, and keeping at this temperature for 30-60min;

[0016] 3), then heat up to 1480°C at a heating rate of 2-7°C / min, and keep warm for 1-3h;

[0017] 4), then cool down the temperature from 1480 to 900±100℃ at a cooling rate of 3-10℃ / min;

[0018] 5), and naturally cool to room temperature.

[0019] Preferably, the zirconium oxide mixture comprises a high-transparency mixture and a low-transparency mixture, wherein the low-transparency mixture and the high-transparency mixture are mixed in a certain proportion to form a plurality of zirconium oxide mixtures with different transparencies, and the plurality of zirconium oxide mixtures with different transparencies are laid in sequence in the vertical direction in the order of the transparencies and then pre-pressed to obtain a zirconium oxide blank.

[0020] Preferably, the low-transparency mixture and the high-transparency mixture are mixed in a mass ratio of 2:1, 3:2, 1:1, 2:3, or 1:2.

[0021] A denture is made using the zirconium oxide ceramic block as described in any one of the above items.

[0022] The beneficial effects of the present invention are as follows: the present invention takes zirconium oxide as the main body, and the others are used as auxiliary agents. Among these auxiliary agents, silicon carbide has higher biological safety and will not dissolve harmful elements. At the same time, it also enhances the hardness of the zirconium oxide ceramic block, thereby enhancing the wear resistance of the device; zinc oxide plays an antibacterial role and also causes a decrease in surface tension during the sintering process, thereby lowering the sintering temperature, saving energy and time, reducing the lattice gap in the ceramic block, and improving the toughness and hardness of the ceramic block. DETAILED DESCRIPTION

[0023] In order to more clearly illustrate the purpose, technical solutions and advantages of the embodiments of the present invention, the present invention will be further described in conjunction with the embodiments below, and a clear and complete description will be given. Obviously, the embodiments described are partial embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0024] A raw material mixture for a zirconia ceramic block comprises the following components in weight percentage: 89-91% ZrO2, 5-10% Y2O3, 0.03-0.3% Er2O3, 0.01-0.3% ZnO, and 1-2% SiC. A zirconia mixture capable of preparing ceramic blocks of different transparencies is formed by adjusting the content of each component, and then the zirconia ceramic block is obtained by sintering the mixture. The low-transparency zirconia mixture has a higher content of ZrO2 and a lower content of Y2O3, while the amounts of Er2O3, ZnO, and SiC in the zirconia mixtures of different transparencies are substantially the same. ZrO2, Y2O3, Er2O3, ZnO, and SiC are all powdered raw materials with a particle size of 20-300nm.

[0025] A zirconium oxide ceramic block is prepared by the following steps:

[0026] The powdered ZrO2, Y2O3, Er2O3, ZnO and SiC powders with nanometer particle sizes are weighed in proportion and then mixed evenly to obtain a zirconium oxide mixture. The particle size of each component is 20-300nm. The components are weighed according to the following weight percentages: 89-91% of ZrO2, 5-10% of Y2O3, 0.03-0.3% of Er2O3, 0.01-0.3% of ZnO and 1-2% of SiC. After weighing, they are mixed evenly to obtain a zirconium oxide mixture. At this time, when preparing a multi-layered zirconium oxide ceramic block, the zirconium oxide mixture is first mixed into a high-transparency mixture and a low-transparency mixture, and then the low-transparency mixture and the high-transparency mixture are mixed in a certain proportion to form a plurality of zirconium oxide mixtures with different transparencies. The transparency of the zirconium oxide mixture is adjusted according to the changes in the contents of ZrO2 and Y2O3. The higher the transparency, the lower the content of ZrO2 and the higher the content of Y2O3.

[0027] The zirconia mixture is pre-pressed to obtain a zirconia blank. When preparing a non-multi-layered zirconia ceramic block, the mixed zirconia mixture is pre-pressed into a zirconia blank in a mold under a pressure of 40-70MPa and a holding time of 20-50S; when preparing a multi-layered zirconia ceramic block, a plurality of zirconia mixtures with different transparencies are laid in sequence in the vertical direction in the order of transparencies and then pre-pressed to obtain a zirconia blank, that is, they are laid in layers from bottom to top in the order of transparencies from small to large, and after each layer is laid, the first pre-pressing is performed under a pressure of 4-6MPa, and then the next layer is laid on it. After all layers are laid, they are pressed again under a pressure of 40-70MPa and a holding time of 20-50S to obtain a multi-layered zirconia blank. For example, when preparing a five-layered zirconia ceramic block, the low-transparency mixture and the high-transparency mixture are mixed in a mass ratio of 2:1, 3:2, 1:1, 2:3, and 1:2 to obtain each layer of zirconia powder mixture.

[0028] The zirconia blank is cold isostatically pressed and then sintered to obtain a zirconia ceramic block. The cold isostatic pressing pressure is 100-300 MPa and the pressure holding time is 5-15 minutes.

[0029] Sintering includes the following steps:

[0030] 1) Heating to 180°C at a rate of 2-7°C / min and keeping warm for 10-20 minutes;

[0031] 2), then heating to 1100°C at a heating rate of 10-30°C / min, and keeping at this temperature for 30-60min;

[0032] 3), then heat up to 1480°C at a heating rate of 2-7°C / min, and keep warm for 1-3h;

[0033] 4), then cool down the temperature from 1480 to 900±100℃ at a cooling rate of 3-10℃ / min;

[0034] 5) Allow to cool naturally to room temperature.

[0035] A denture is formed by carving a zirconium oxide ceramic block as described in any one of the above items.

[0036] Example 1

[0037] 90.14% ZrO2, 8% Y2O3, 0.21% Er2O3, 0.15% ZnO, and 1.5% SiC are weighed according to the following weight percentages, and each component is a powder with a particle size of 200nm. After weighing, the components are evenly mixed to obtain a high-transparency mixture for preparing a high-transparency zirconia ceramic block;

[0038] 92.5% ZrO2, 6% Y2O3, 0.18% Er2O3, 0.12% ZnO, and 1.2% SiC are weighed according to the following weight percentages, and each component is a powder with a particle size of 200nm. After weighing, the components are evenly mixed to obtain a low-transparency mixture for preparing a low-transparency zirconia ceramic block;

[0039] The low-transparency mixture and the high-transparency mixture are mixed evenly in mass ratios of 2:1, 3:2, 1:1, 2:3, and 1:2 to form five raw material mixtures, namely a first-layer raw material mixture with a mass ratio of 2:1, a second-layer raw material mixture with a mass ratio of 3:2, a third-layer raw material mixture with a mass ratio of 1:1, a fourth-layer raw material mixture with a mass ratio of 2:3, and a fifth-layer raw material mixture with a mass ratio of 1:2; at this time, in the total weight of each raw material mixture, the first-layer raw material mixture and the first-layer raw material mixture each account for 23% of the total weight, and the second-layer raw material mixture, the third-layer raw material mixture, and the fourth-layer raw material mixture each account for 18% of the total weight.

[0040] A zirconia ceramic block body is prepared by using a dry pressing mold, and a first layer of raw material mixture, a second layer of raw material mixture, a third layer of raw material mixture, a fourth layer of raw material mixture and a fifth layer of raw material mixture are laid in the mold from bottom to top in sequence, and after each layer of raw material mixture is laid, it is pre-pressed under a pressure of 5MPa before laying the next layer, and when all five layers of raw material mixture are laid, it is dry pressed as a whole under the conditions of a pressure of 70MPa and a holding time of 40S to obtain a zirconia blank with a multi-layer structure;

[0041] The zirconia ceramic block body is formed by cold isostatic pressing, the cold isostatic pressing pressure is 270 MPa, and the holding time is 15 minutes;

[0042] The zirconia ceramic block is sintered by cold isostatic pressing to obtain a zirconia ceramic block. The sintering temperature is 1050° C. and the heating rate is no more than 2° C. / min.

[0043] The zirconia blank was cold isostatically pressed and then sintered to obtain a zirconia ceramic block, the cold isostatic pressing pressure was 200 MPa, and the holding time was 12 minutes;

[0044] At this time, sintering is carried out according to the following steps:

[0045] 1) Heating to 180°C at a heating rate of 6°C / min and keeping at this temperature for 10 min;

[0046] 2), then heating to 1100°C at a heating rate of 26°C / min and keeping at this temperature for 45 min;

[0047] 3), then heat up to 1480°C at a heating rate of 3°C / min and keep at this temperature for 2h;

[0048] 4), then cool down the temperature from 1480 to 900°C at a cooling rate of 8°C / min;

[0049] 5), and finally, naturally cooled to room temperature in the furnace to obtain a zirconia ceramic block with a five-layer structure, the transmittance of each layer is 43%, 45%, 48%, 50%, and 52%, respectively, and the corresponding bending strength is 1102MPa, 1086MPa, 1021MPa, 993MP, and 986MPa.

[0050] Example 2

[0051] The zirconium oxide ceramic block (sample) prepared in the application and the zirconium oxide ceramic block (reference substance) prepared conventionally using manganese oxide were subjected to the following experiments and then tested for dissolution in simulated artificial saliva;

[0052] 1) Tested on an existing dental friction and wear testing machine for 30 hours;

[0053] 2) The samples after the friction and wear test and the control samples were subjected to aging test in an aging test chamber under the aging conditions of 75°C and 69 days (equivalent to 6 years at 37°C);

[0054] 3) After the aging test, the samples and the reference substance are tested for dissolution in artificial saliva;

[0055] The ingredients of artificial saliva are: NaCl 0.4g / L, KCl 0.4g / L, CaCl2·2H2O 0.795g / L, NaH2PO4·2H2O 0.78g / L, Na2S·2H2O 0.005g / L, urea 1g / L, and distilled water 1L; its pH value is adjusted to 5.0; after testing, no harmful metals were dissolved in the samples, while trace amounts of manganese were dissolved in the control.

[0056] It should be understood that those skilled in the art may make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A raw material mixture of a zirconium oxide ceramic block, characterized in that: The invention comprises the following components in weight percentage: 89-91% ZrO2, 5-10% Y2O3, 0.03-0.3% Er2O3, 0.01-0.3% ZnO, and 1-2% SiC.

2. The raw material mixture of the zirconium oxide ceramic block according to claim 1, characterized in that: The ZrO2, Y2O3, Er2O3, ZnO and SiC are all powdered raw materials with a particle size of 20-300nm.

3. A zirconium oxide ceramic block, characterized in that: The zirconium oxide ceramic block is prepared by using the raw material mixture described in any one of claims 1-2.

4. The zirconia ceramic block according to claim 3, characterized in that: Prepared by the following steps: Powdered ZrO2, Y2O3, Er2O3, ZnO, and SiC powders with nanometer particle sizes are weighed in proportion and then mixed evenly to obtain a zirconium oxide mixture; Pre-pressing the zirconium oxide mixture into a zirconium oxide blank; The zirconia blank is cold isostatically pressed and then sintered to obtain a zirconia ceramic block.

5. The zirconium oxide ceramic block according to claim 4, characterized in that The pre-pressing pressure is 4-70MPa, and the holding time is 20-50S.

6. The zirconium oxide ceramic block according to claim 4, characterized in that The cold isostatic pressing pressure is 100-300 MPa, and the holding time is 5-15 min.

7. The zirconia ceramic block according to claim 4, characterized in that: The sintering comprises the following steps: 1) Heating to 180°C at a rate of 2-7°C / min and keeping warm for 10-20 minutes; 2), then heating to 1100°C at a heating rate of 10-30°C / min, and keeping at this temperature for 30-60min; 3), then heat up to 1480°C at a heating rate of 2-7°C / min, and keep warm for 1-3h; 4), then cool down the temperature from 1480 to 900±100℃ at a cooling rate of 3-10℃ / min; 5) Cool naturally to room temperature.

8. The zirconium oxide ceramic block according to claim 4, characterized in that The zirconium oxide mixture includes a high-transparency mixture and a low-transparency mixture. The low-transparency mixture and the high-transparency mixture are mixed in a certain proportion to form a plurality of zirconium oxide mixtures with different transparencies. The plurality of zirconium oxide mixtures with different transparencies are laid in sequence in the vertical direction in the order of the transparencies and then pre-pressed to obtain a zirconium oxide blank.

9. The zirconium oxide ceramic block according to claim 8, characterized in that The low-transparency mixture and the high-transparency mixture are mixed in mass ratios of 2:1, 3:2, 1:1, 2:3, and 1:

2.

10. A denture characterized by : It is made by using the zirconium oxide ceramic block as described in any one of claims 3-9.