Zirconium oxide porcelain block as well as preparation method and application thereof

Abstract

The invention relates to a zirconium oxide ceramic block and a preparation method and application thereof, the zirconium oxide ceramic block comprises an inner zirconium oxide block and an outer zirconium oxide block wrapping the inner zirconium oxide block, and the outer zirconium oxide block comprises a plurality of zirconium oxide layers which are sequentially laid in the vertical direction according to the order of transparency; the thickness of the zirconium oxide layer with the maximum transparency and the thickness of the zirconium oxide layer with the minimum transparency are both greater than the thickness of the zirconium oxide layer between the maximum transparency and the minimum transparency; the transparency of the inner zirconium oxide block is the same as the maximum transparency of the multiple zirconium oxide layers, the bottom end of the inner zirconium oxide block is located in the zirconium oxide layer with the minimum transparency, and the height of the inner zirconium oxide block is not smaller than 2 / 3 of the height of the outer zirconium oxide block; meanwhile, the invention discloses a preparation method and application of the ceramic block. According to the invention, the structure, color and light transmittance of the tooth can be more truly close to those of a real tooth, the service life of the tooth is prolonged, and the use comfort is improved.

Description

Technical Field

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

[0002] Human teeth consist of multiple layers of structures, including pulp, dentin and enamel, from the inside out. The strength of dentin and enamel are different, so during normal chewing and abrasion, dentin can buffer the wear of enamel and prevent teeth from being broken by sudden huge forces. However, the material currently used for low-end dental zirconia all-ceramic restorations is a single homogeneous material, which has the same strength from the inside out. Without the buffering dentin, the service life of the denture is reduced; in appearance, it also shows a color and transparency, which cannot well simulate the aesthetics of the gradient of teeth and the mechanical effects of different hardness inside and outside teeth. Summary of the invention

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

[0004] The technical solution adopted by the present invention to solve its technical problem is: a zirconia ceramic block, including an inner zirconia block made of a micron zirconia mixture and an outer zirconia block made of a nano zirconia mixture that wraps the inner zirconia block, the outer zirconia block including a plurality of zirconia layers laid in sequence in the order of transparency and in the vertical direction, and the thickness of the zirconia layer with the maximum transparency and the thickness of the zirconia layer with the minimum transparency are both greater than the thickness of the zirconia layer between the maximum transparency and the minimum transparency; the transparency of the inner zirconia block is the same as the maximum transparency of the plurality of zirconia layers, and the bottom end of the inner zirconia block is in the zirconia layer with the minimum transparency, and the height of the inner zirconia block is not less than 2 / 3 of the height of the outer zirconia block.

[0005] Preferably, the inner zirconia block is a zirconia block with an arched cross section.

[0006] Preferably, the inner zirconia block is made of a zirconia mixture with a particle size between 0.2-0.5 μm, and the outer zirconia block is made of a zirconia mixture with a particle size between 10-80 nm.

[0007] Preferably, the zirconium oxide mixture of the outer zirconium oxide block includes high-transmittance powder with a transmittance of 57% and low-transmittance powder with a transmittance of 43%, and the high-transmittance powder and the low-transmittance powder in each zirconium oxide layer are mixed in a certain proportion.

[0008] Preferably, the zirconium oxide mixture comprises the following components in parts by weight: 90-95 parts of ZrO2, 5-8 parts of Y2O3, 0.01-0.3 parts of Fe2O3, 0.01-0.3 parts of Er2O3, 0-0.2 parts of Mn2O3, and 0-0.5 parts of Al2O3.

[0009] Preferably, the thickness of the zirconium oxide layer with the greatest transparency among the plurality of zirconium oxide layers is the same as the thickness of the zirconium oxide layer with the least transparency.

[0010] A method for preparing a zirconium oxide ceramic block, comprising:

[0011] Obtaining inner zirconium oxide powder of an inner zirconium oxide block having the same maximum transparency as that of the outer zirconium oxide powder and pre-pressing the powder to form an inner zirconium oxide blank;

[0012] Obtaining a plurality of outer zirconium oxide powders with different transparencies for preparing a zirconium oxide layer, laying a plurality of zirconium oxide layers covering the inner zirconium oxide blank in order from bottom to top in the axial direction of the inner zirconium oxide blank in the order of the transparencies of the outer zirconium oxide powders from small to large outside the inner zirconium oxide blank, and dry-pressing the inner zirconium oxide blank and the plurality of zirconium oxide layers as a whole to form a zirconium oxide ceramic block blank;

[0013] Cold isostatically pressed zirconia ceramic block body;

[0014] The zirconia ceramic block is obtained by sintering the cold isostatically pressed zirconia ceramic block green body.

[0015] Preferably, the pre-pressing pressure of the inner zirconia blank is not greater than 5MPa; the pressure of the overall dry pressing is 60-70MPa, and the holding time is 10-40S; the pressure of the cold isostatic pressing is 100-300MPa, and the holding time is 10-15min; and the sintering temperature is 1000-1100°C.

[0016] Preferably, the thickness of the zirconium oxide layer with the maximum transparency and the thickness of the zirconium oxide layer with the minimum transparency among the multiple zirconium oxide layers are both greater than the thickness of the zirconium oxide layer between the maximum transparency and the minimum transparency; the height of the inner zirconium oxide block is not less than 2 / 3 of the sum of the heights of the multiple zirconium oxide layers.

[0017] A denture is made using the zirconium oxide ceramic block as described in any one of the above items.

[0018] The beneficial effects of the present invention are as follows: the outer zirconium oxide block and the inner zirconium oxide of the present invention adopt a mixture of zirconium oxides of different particle sizes to form two structures with different hardnesses, thereby improving the service life and comfort of use of the denture and better simulating the structural characteristics of real teeth. The multi-layer structure of the outer zirconium oxide block can better realize the changes in the color and transparency of real teeth, thereby improving the aesthetics of the denture. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the cross-sectional structure of a zirconia ceramic block according to an embodiment of the present invention;

[0020] Names and serial numbers of components in the figure: 1 - inner zirconia block 2 - outer zirconia block 20 - first zirconia layer 21 - second zirconia layer 22 - third zirconia layer 23 - fourth zirconia layer 24 - fifth zirconia layer 25 - sixth zirconia layer. DETAILED DESCRIPTION

[0021] 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.

[0022] A zirconia ceramic block, as shown in 1, comprises an inner zirconia block 1 made of a micron zirconia mixture and an outer zirconia block 2 made of a nano zirconia mixture and wrapping the inner zirconia block 1, that is, the inner zirconia block 1 is prepared by using a micron-grade zirconia mixture, and the zirconia mixture with a particle size between 0.2-0.5 μm is used to prepare it, and the outer zirconia block 2 is prepared by using a nano-grade zirconia mixture. The hardness of the outer zirconia block 2 prepared in this way is greater than that of the inner zirconia block 1, and the zirconia mixture with a particle size between 10-80 nm is used to prepare it. At this time, the zirconia mixture includes the following components in parts by weight: 90-95 parts of ZrO2, 5-8 parts of Y2O3, 0.01-0 .3 parts of Fe2O3, 0.01-0.3 parts of Er2O3, 0-0.2 parts of Mn2O3, and 0-0.5 parts of Al2O3. By adjusting the content of each component, a zirconium oxide mixture that can be used to prepare porcelain blocks with different translucency is formed. Compared with the high-translucency zirconium oxide mixture, the low-translucency zirconium oxide mixture has a higher content of ZrO2 and a lower content of Y2O3. The amounts of Fe2O3, Er2O3, Al2O3 and Mn2O3 in the zirconium oxide mixtures with different translucency are basically the same. At this time, a high-translucency powder with a transparency of 57% and a low-translucency powder with a transparency of 43% are first mixed to obtain a high-translucency powder with a transparency of 57% and a low-translucency powder with a transparency of 43%. Then, the high-translucency powder and the low-translucency powder are mixed in a certain proportion to prepare zirconium oxide layers with different translucency. The outer layer of zirconium oxide powder, when the zirconium oxide layer is set to four layers, the mass percentages of high-transmittance powder and low-transmittance powder in each zirconium oxide layer are mixed and prepared in the order of transmittance from small to large, such as 20% and 80%, 40% and 60%, 60% and 40%, 80% and 20%, respectively. When the zirconium oxide layer is set to five, six, seven and eight layers, the mixing and preparation can be carried out according to the same principle; the outer zirconium oxide block 2 includes a plurality of zirconium oxide layers laid in sequence in the vertical direction in the order of transmittance, and the thickness of the zirconium oxide layer with the maximum transmittance and the thickness of the zirconium oxide layer with the minimum transmittance are both greater than the thickness of the zirconium oxide layer between the maximum transmittance and the minimum transmittance, that is, the outer zirconium oxide block 2 includes a plurality of zirconium oxide layers. Layers, the transparency of each zirconia layer is different, such as setting the bottom zirconia layer as the zirconia layer with the smallest transparency, and setting the top zirconia layer as the zirconia layer with the largest transparency, the thickness of the top and bottom zirconia layers are both greater than the thickness of the middle zirconia layer, preferably, the thickness of the zirconia layer with the largest transparency among the multiple zirconia layers is the same as the thickness of the zirconia layer with the smallest transparency, that is, the thickness of the top and bottom zirconia layers; the transparency of the inner zirconia block 1 is the same as the largest transparency among the multiple zirconia layers, and the bottom end of the inner zirconia block 1 is in the zirconia layer with the smallest transparency, and the height of the inner zirconia block 1 is not less than 2 / 3 of the height of the outer zirconia block 2, which can more realistically simulate the structure of real teeth.

[0023] Further improvements such as Figure 1 As shown in the figure, the inner zirconia block 1 is a zirconia block with an arched cross-section, that is, the inner zirconia block 1 is a spherical segment-like structure, the bottom surface of which corresponds to the zirconia layer with the smallest transparency, and the arch top corresponds to any other zirconia layer according to the situation, so that there are no protruding edges and sharp corners that generate stress, and the force on the outer zirconia block can be better buffered.

[0024] A method for preparing a zirconium oxide ceramic block, comprising:

[0025] The inner layer zirconium oxide powder of the inner zirconium oxide block 1 having the same maximum transparency as the outer layer zirconium oxide powder is obtained and pre-pressed to form an inner zirconium oxide blank, the raw materials used include the following components in parts by weight: 90-95 parts of ZrO2, 5-8 parts of Y2O3, 0.01-0.3 parts of Fe2O3, 0.01-0.3 parts of Er2O3, 0-0.2 parts of Mn2O3, 0-0.5 parts of Al2O3, the particle sizes of all components are between 0.2-0.5 μm, the pre-pressing pressure is not greater than 5 MPa, and at this time, since the particle sizes of all its components are larger than the particle sizes of the outer layer zirconium oxide powder, the transparency is required to be the same as the maximum transparency of the outer layer zirconium oxide powder, the amount of ZrO2 is reduced, and the amount of Y2O3 is increased;

[0026] A plurality of outer zirconium oxide powders with different transparencies for preparing zirconium oxide layers are obtained, and a plurality of zirconium oxide layers for wrapping the inner zirconium oxide blank are sequentially laid from bottom to top in the axial direction of the inner zirconium oxide blank in the order of the transparencies of the outer zirconium oxide powders from small to large, and the inner zirconium oxide blank and the plurality of zirconium oxide layers are dry-pressed as a whole to form a zirconium oxide ceramic block blank; the transparencies of the outer zirconium oxide powders are the same as the transparencies of the zirconium oxide layers formed thereby, and at this time, the plurality of zirconium oxide layers are stacked in the vertical direction, and the transparencies of each zirconium oxide layer are different, and the inner zirconium oxide blank is The zirconium blank is wrapped by multiple zirconium oxide layers; when the inner zirconium oxide block 1 is a zirconium oxide block with an arched cross section, its bottom surface corresponds to the zirconium oxide layer with the smallest transparency; firstly, the amount of each component in the raw material is weighed in proportion, and then the raw materials are mixed to produce a high-transmittance powder with a transparency of 57% and a low-transmittance powder with a transparency of 43% for the produced zirconium oxide layer, and then the high-transmittance powder and the low-transmittance powder are mixed in a certain proportion to prepare an outer layer of zirconium oxide powder for preparing zirconium oxide layers with different transparencies. The raw materials used include the following components in parts by weight: 90-95 parts of Z rO2, 5-8 parts Y2O3, 0.01-0.3 parts Fe2O3, 0.01-0.3 parts Er2O3, 0-0.2 parts Mn2O3, 0-0.5 parts Al2O3. The adjustment principle is that the low-transparency zirconium oxide mixture has a higher content of ZrO2 and a lower content of Y2O3 than the high-transparency zirconium oxide mixture, and the amounts of Fe2O3, Er2O3, Al2O3 and Mn2O3 in the zirconium oxide mixtures of different transparencies are basically the same. The particle size of all components in the raw material is The diameters are all between 10-80nm; the overall dry pressing pressure is 60-70Mpa, and the holding time is 10-40S; further, the thickness of the zirconium oxide layer with the maximum transparency and the thickness of the zirconium oxide layer with the minimum transparency in the multiple zirconium oxide layers are both set to be greater than the thickness of the zirconium oxide layer between the maximum transparency and the minimum transparency, so that the structural strength of the denture can be ensured when the ceramic block is processed into a denture; the height of the inner zirconia block 1 is not less than 2 / 3 of the sum of the heights of the multiple zirconia layers, and the inner zirconia block 1 can better play a buffering role.

[0027] Cold isostatic pressing of zirconia ceramic block body, the cold isostatic pressing pressure is 100-300MPa, and the holding time is 10-15min;

[0028] The zirconia ceramic block is obtained by sintering the cold isostatically pressed zirconia ceramic block green body, the sintering temperature is 1000-1100° C., and the heating rate is not greater than 2° C. / min.

[0029] A denture is made using the zirconium oxide ceramic block as described in any one of the above items.

[0030] Example 1

[0031] Weigh 90 parts of ZrO2, 8 parts of Y2O3, 0.15 parts of Fe2O3, 0.3 parts of Er2O3, 0.015 parts of Mn2O3, and 0.1 parts of Al2O3 with a particle size of 0.3 μm, and mix them to produce an inner layer of zirconium oxide powder with a transparency of 55%;

[0032] Weigh 94 parts of ZrO2, 5 parts of Y2O3, 0.09 parts of Fe2O3, 0.3 parts of Er2O3, 0.02 parts of Mn2O3, and 0.05 parts of Al2O3 with a particle size of 50 nm, and mix them to produce a low-transmittance powder with a transmittance of 43% for the produced zirconium oxide layer;

[0033] Weigh 91 parts of ZrO2, 7 parts of Y2O3, 0.1 parts of Fe2O3, 0.4 parts of Er2O3, and 0.1 parts of Al2O3 with a particle size of 50 nm, and mix them to produce a high-transmittance powder with a transmittance of 57% for the produced zirconium oxide layer;

[0034] The outer layer zirconium oxide powder for preparing each zirconium oxide layer is prepared by mixing the high-transmittance powder with a transmittance of 57% and the low-transmittance powder with a transmittance of 43% in each zirconium oxide layer in the following manner: 20% and 80%, 30% and 70%, 40% and 60%, 60% and 40%, 70% and 30%, 80% and 20% by mass. Figure 1 As shown in the figure, a first zirconium oxide layer 20, a second zirconium oxide layer 21, a third zirconium oxide layer 22, a fourth zirconium oxide layer 23, a fifth zirconium oxide layer 24, and a sixth zirconium oxide layer 25 are formed accordingly; at this time, in the total weight of the multiple zirconium oxide layers, the first zirconium oxide layer 20 and the sixth zirconium oxide layer 25 each account for 20% of the total weight, and the other zirconium oxide layers each account for 15% of the total weight.

[0035] The zirconia ceramic block body is prepared by using a dry pressing mold. First, a mold is used to pre-press the inner layer of zirconia powder at a pressure of 5MPa to form an inner zirconia body. Then, a portion of the outer layer of zirconia powder of the first zirconia layer 20 is laid in another mold. Then, the inner zirconia body is placed in the middle of the laid first zirconia layer 20. Then, the remaining outer layer of zirconia powder of the first zirconia layer 20 is laid around the circumference of the inner zirconia body. Finally, the second zirconia powder is laid on the first zirconia layer 20 in sequence. The zirconium oxide layer 21, the third zirconium oxide layer 22, the fourth zirconium oxide layer 23, the fifth zirconium oxide layer 24, and the sixth zirconium oxide layer 25 wrap the inner zirconium oxide blank. After each outer layer of zirconium oxide powder is laid, it is pre-pressed. The pre-pressing pressure is not more than 5MPa. If the pre-pressing pressure of 5MPa is selected, each outer layer of zirconium oxide powder forms a zirconium oxide layer. After laying, the inner zirconium oxide blank and each zirconium oxide layer are dry-pressed as a whole to form a zirconium oxide ceramic block blank. The pressure is 70Mpa and the pressure holding time is 30S.

[0036] 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;

[0037] 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.

[0038] The zirconia ceramic blocks are carved to form dentures. The denture has an appropriate cutting end size, a natural color transition, uniform light transmittance and strength. The bending strength (MPa) of each layer in the first zirconia layer 20, the second zirconia layer 21, the third zirconia layer 22, the fourth zirconia layer 23, the fifth zirconia layer 24, and the sixth zirconia layer 25 are 960, 950, 945, 940, 930, and 920 respectively, and the corresponding transmittance (%) is 46, 48, 50, 52, 53, and 55.

[0039] 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 zirconia ceramic block, characterized in that: It comprises an inner zirconia block made of a micron zirconia mixture and an outer zirconia block made of a nano zirconia mixture which wraps the inner zirconia block, wherein the outer zirconia block comprises a plurality of zirconia layers which are laid in sequence in the order of transparency and in the vertical direction, and the thickness of the zirconia layer with the maximum transparency and the thickness of the zirconia layer with the minimum transparency are both greater than the thickness of the zirconia layer between the maximum transparency and the minimum transparency; the transparency of the inner zirconia block is the same as the maximum transparency of the plurality of zirconia layers, and the bottom end of the inner zirconia block is in the zirconia layer with the minimum transparency, and the height of the inner zirconia block is not less than 2 / 3 of the height of the outer zirconia block.

2. The zirconia ceramic block according to claim 1, characterized in that: The inner zirconia block is a zirconia block with an arched cross section.

3. The zirconium oxide ceramic block according to claim 1, characterized in that The inner zirconia block is made of a zirconia mixture with a particle size between 0.2-0.5 μm, and the outer zirconia block is made of a zirconia mixture with a particle size between 10-80 nm.

4. The zirconia ceramic block according to claim 3, characterized in that: The zirconium oxide mixture of the outer zirconium oxide block includes high-transmittance powder with a transmittance of 57% and low-transmittance powder with a transmittance of 43%. The high-transmittance powder and the low-transmittance powder in each zirconium oxide layer are mixed in a certain proportion.

5. The zirconium oxide ceramic block according to claim 4, characterized in that The zirconium oxide mixture includes the following components in parts by weight: 90-95 parts of ZrO2, 5-8 parts of Y2O3, 0.01-0.3 parts of Fe2O3, 0.01-0.3 parts of Er2O3, 0-0.2 parts of Mn2O3, and 0-0.5 parts of Al2O3.

6. The zirconia ceramic block according to claim 1, characterized in that : The thickness of the zirconium oxide layer with the largest transparency among the multiple zirconium oxide layers is the same as the thickness of the zirconium oxide layer with the smallest transparency.

7. A method for preparing a zirconium oxide ceramic block, characterized in that: include: Obtaining inner layer zirconium oxide powder of an inner zirconium oxide block having the same maximum transparency as that of the outer layer zirconium oxide powder and pre-pressing the powder to form an inner zirconium oxide blank; Obtaining a plurality of outer zirconium oxide powders with different transparencies for preparing a zirconium oxide layer, laying a plurality of zirconium oxide layers covering the inner zirconium oxide blank in order from bottom to top in the axial direction of the inner zirconium oxide blank in the order of the transparencies of the outer zirconium oxide powders from small to large outside the inner zirconium oxide blank, and dry-pressing the inner zirconium oxide blank and the plurality of zirconium oxide layers as a whole to form a zirconium oxide ceramic block blank; Cold isostatically pressed zirconia ceramic block body; The zirconia ceramic block is obtained by sintering the cold isostatically pressed zirconia ceramic block green body.

8. The method for preparing the zirconium oxide ceramic block according to claim 7, characterized in that : The pre-pressing pressure of the inner zirconia blank is not more than 5MPa; the pressure of the overall dry pressing is 60-70Mpa, and the holding time is 10-40S; the pressure of the cold isostatic pressing is 100-300MPa, and the holding time is 10-15min; the sintering temperature is 1000-1100℃.

9. The method for preparing the zirconium oxide ceramic block according to claim 7, characterized in that : The thickness of the zirconium oxide layer with the maximum transparency and the thickness of the zirconium oxide layer with the minimum transparency among the multiple zirconium oxide layers are both greater than the thickness of the zirconium oxide layer between the maximum transparency and the minimum transparency; the height of the inner zirconium oxide block is not less than 2 / 3 of the sum of the heights of the multiple zirconium oxide layers.

10. A denture characterized by : It is made by using the zirconium oxide ceramic block as described in any one of claims 1-6.

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