Zirconia ceramic block, preparation method and application thereof
By employing a multi-layered zirconia structure in the denture, combining inner and outer zirconia blocks, the problem of insufficient cushioning structure in existing materials is solved, improving the lifespan and aesthetics of the denture and simulating the structural characteristics of natural teeth.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHENZHEN YURUCHENG DENTAL MATERIALS CO LTD
- Filing Date
- 2024-11-01
- Publication Date
- 2026-07-24
AI Technical Summary
Existing mid-to-low-end dental zirconia all-ceramic restorative materials lack a buffer structure, resulting in short denture lifespans and an inability to simulate the aesthetic and mechanical effects of gradual tooth transitions.
An inner zirconia block made of a micron-sized zirconia mixture and an outer zirconia block made of a nano-sized zirconia mixture are used. Multiple zirconia layers are laid on the outer zirconia block in order of permeability. The height of the inner zirconia block is not less than 2/3 of the height of the outer zirconia block, forming a multi-layer structure to simulate the structure of a real tooth.
It improves the lifespan and aesthetics of dentures, and through a multi-layered structure, it simulates the hardness and color translucency of natural teeth, thus enhancing the comfort and appearance of dentures.
Smart Images
Figure CN119409499B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of dental materials, and in particular to a zirconia ceramic block, its preparation method, and its application. Background Technology
[0002] Human teeth consist of multiple layers, including the pulp, dentin, and enamel. The dentin and enamel have different strengths, which buffers the wear and tear of the enamel during normal chewing, preventing the tooth from fracturing due to sudden, excessive force. However, the zirconia all-ceramic restorations currently used in mid-to-low-end dental clinics use a single, homogeneous material with uniform strength from the inside out. Lacking the buffering effect of dentin, the lifespan of the denture is reduced. Furthermore, its appearance is limited to a single color and translucency, failing to accurately simulate the gradual changes in tooth texture and the varying mechanical hardness between the inner and outer layers. Summary of the Invention
[0003] To address the shortcomings of existing methods, this invention provides a zirconia ceramic block, its preparation method, and its applications.
[0004] The technical solution adopted by the present invention to solve its technical problem is: a zirconia ceramic block, comprising an inner zirconia block made of a micron-sized zirconia mixture and an outer zirconia block made of a nano-sized zirconia mixture surrounding the inner zirconia block. The outer zirconia block comprises multiple zirconia layers laid vertically in order of transparency, wherein the thickness of the zirconia layer with the highest transparency and the thickness of the zirconia layer with the lowest transparency are both greater than the thickness of the zirconia layer between the highest and lowest transparency. The transparency of the inner zirconia block is the same as the highest transparency among the multiple zirconia layers, and the bottom end of the inner zirconia block is located in the zirconia layer with the lowest transparency. 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 and 0.5 μm, and the outer zirconia block is made of a zirconia mixture with a particle size between 10 and 80 nm.
[0007] Preferably, the zirconium oxide mixture of the outer zirconium oxide block includes a high-transmittance powder with a transmittance of 57% and a 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 ZrO2, 5-8 parts Y2O3, 0.01-0.3 parts Fe2O3, 0.01-0.3 parts Er2O3, 0-0.2 parts Mn2O3, and 0-0.5 parts Al2O3.
[0009] Preferably, the thickness of the zirconium oxide layer with the highest transparency and the thickness of the zirconium oxide layer with the lowest transparency are the same among the plurality of zirconium oxide layers.
[0010] A method for preparing a zirconia ceramic block, comprising:
[0011] Obtain the inner zirconia powder of the inner zirconia block with the same maximum transparency as the outer zirconia powder and pre-press it to form an inner zirconia blank;
[0012] Multiple outer zirconia powders with different permeability are obtained to prepare zirconia layers. Multiple zirconia layers are laid from bottom to top along the axial direction of the inner zirconia blank in order of increasing permeability of the outer zirconia powder. The inner zirconia blank and multiple zirconia layers are then dry-pressed as a whole to form a zirconia ceramic block blank.
[0013] Cold isostatic pressing of zirconia ceramic blanks;
[0014] Zirconia ceramic blocks are obtained by sintering and cold isostatic pressing of zirconia ceramic blanks.
[0015] Preferably, the pre-pressing pressure of the inner zirconia blank is no greater than 5 MPa; the overall dry pressing pressure is 60-70 MPa, and the holding time is 10-40 seconds; the cold isostatic pressing pressure is 100-300 MPa, and the holding time is 10-15 minutes; the sintering temperature is 1000-1100℃.
[0016] Preferably, the thickness of the zirconium oxide layer with the highest transparency and the thickness of the zirconium oxide layer with the lowest transparency are both greater than the thickness of the zirconium oxide layer between the highest and lowest 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 made from a zirconia ceramic block as described in any of the preceding items.
[0018] The beneficial effects of this invention are as follows: the outer zirconia block and the inner zirconia block are made of zirconia mixtures with different particle sizes to form two structures with different hardness, which improves the service life and comfort of the denture and better simulates the structural characteristics of natural teeth. The multi-layered structure of the outer zirconia block can better realize the changes in color and translucency of natural teeth, thus improving the aesthetics of the denture. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the cross-sectional structure of a zirconia ceramic block according to an embodiment of the present invention;
[0020] The component names and serial numbers in the figure are as follows: 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 Implementation
[0021] To more clearly illustrate the objectives, technical solutions, and advantages of the embodiments of the present invention, the present invention will be further described below in conjunction with the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.
[0022] A zirconia ceramic block, as shown in Figure 1, comprises an inner zirconia block 1 made of a micron-sized zirconia mixture and an outer zirconia block 2 made of a nano-sized zirconia mixture enclosing the inner zirconia block 1. Specifically, the inner zirconia block 1 is prepared using a micron-sized zirconia mixture with a particle size between 0.2 and 0.5 μm, while the outer zirconia block 2 is prepared using a nano-sized zirconia mixture. Therefore, the hardness of the outer zirconia block 2 is greater than that of the inner zirconia block 1, which is prepared using a zirconia mixture with a particle size between 10 and 80 nm. The zirconia mixture comprises the following components in parts by weight: 90-95 parts ZrO2, 5-8 parts Y2O3, and 0.01-0. A zirconium oxide mixture containing 0.3 parts Fe₂O₃, 0.01-0.3 parts Er₂O₃, 0-0.2 parts Mn₂O₃, and 0-0.5 parts Al₂O₃ is used. By adjusting the content of each component, a zirconium oxide mixture capable of preparing ceramic blocks with different transparency levels is formed. Compared with the high-transparency zirconium oxide mixture, the low-transparency zirconium oxide mixture has a higher content of ZrO₂ and a lower content of Y₂O₃. The amounts of Fe₂O₃, Er₂O₃, Al₂O₃, and Mn₂O₃ are basically the same in zirconium oxide mixtures with different transparency levels. At this point, a high-transparency powder with a transparency of 57% and a low-transparency powder with a transparency of 43% are first mixed together. Then, the high-transparency powder and the low-transparency powder are mixed in a certain proportion to prepare zirconium oxide layers with different transparency levels. For the outer zirconia powder, if four zirconia layers are set, the mass percentages of high-transmittance powder and low-transmittance powder in each zirconia layer are mixed in order of increasing transmittance, such as 20% and 80%, 40% and 60%, 60% and 40%, and 80% and 20%, respectively. The same principle applies when five, six, seven, and eight zirconia layers are used. The outer zirconia block 2 comprises multiple zirconia layers laid vertically in order of transmittance. The thickness of the zirconia layer with the highest transmittance and the thickness of the zirconia layer with the lowest transmittance are both greater than the thickness of the zirconia layer between the highest and lowest transmittance. In other words, the outer zirconia block 2 contains multiple zirconia layers. Each zirconia layer has a different permeability. For example, the bottom zirconia layer can be set as the zirconia layer with the lowest permeability, and the top zirconia layer can be set as the zirconia layer with the highest permeability. The thickness of the top and bottom zirconia layers is greater than the thickness of the zirconia layers in the middle. Preferably, the thickness of the zirconia layer with the highest permeability and the thickness of the zirconia layer with the lowest permeability are the same, that is, the thickness of the top and bottom zirconia layers. The permeability of the inner zirconia block 1 is the same as the highest permeability among the multiple zirconia layers, and the bottom end of the inner zirconia block 1 is located in the zirconia layer with the lowest permeability. The height of the inner zirconia block 1 is not less than 2 / 3 of the height of the outer zirconia block 2, which more realistically simulates the structure of a real tooth.
[0023] Further improvements, such as Figure 1 As shown, the inner zirconia block 1 is a zirconia block with an arched cross section. That is to say, the inner zirconia block 1 is a structure similar to a spherical cap. Its bottom surface corresponds to the zirconia layer with the minimum permeability, while its arched top corresponds to any other zirconia layer, depending on the situation. In this way, there will be no protruding edges and sharp corners that generate stress, which can better buffer the stress on the outer zirconia block.
[0024] A method for preparing a zirconia ceramic block, comprising:
[0025] To obtain the inner zirconia powder of inner zirconia block 1 with the same maximum permeability as the outer zirconia powder, and to pre-press it to form an inner zirconia blank, the raw materials used include the following components in parts by weight: 90-95 parts ZrO2, 5-8 parts Y2O3, 0.01-0.3 parts Fe2O3, 0.01-0.3 parts Er2O3, 0-0.2 parts Mn2O3, and 0-0.5 parts Al2O3. The particle size of all components is between 0.2-0.5 μm, and the pre-pressing pressure is not greater than 5 MPa. Since the particle size of all components is larger than that of the outer zirconia powder, and its permeability needs to be the same as the maximum permeability in the outer zirconia powder, the amount of ZrO2 is reduced, while the amount of Y2O3 is increased.
[0026] Multiple outer zirconia powders with different translucency are obtained to prepare the zirconia layers. These outer zirconia powders are then sequentially layered from bottom to top along the axial direction of the inner zirconia blank, in order of increasing translucency. The inner zirconia blank and the multiple zirconia layers are then dry-pressed as a whole to form a zirconia ceramic block. The translucency of the outer zirconia powder is determined by the translucency of the zirconia layers it forms. At this point, the multiple zirconia layers are stacked vertically, and each zirconia layer has a different translucency. Meanwhile, the inner zirconia... The zirconium blank is encased in multiple zirconium oxide layers; when the inner zirconium oxide block 1 is an arched zirconium oxide block, its bottom surface corresponds to the zirconium oxide layer with the lowest transmittance; first, the amounts of each component in the raw material are weighed according to the proportion, and then the raw materials are mixed to produce a high-transmittance powder with a transmittance of 57% and a low-transmittance powder with a transmittance of 43% for the zirconium oxide layer. Then, the high-transmittance powder and the low-transmittance powder are mixed in a certain proportion to prepare the outer zirconium oxide powder for preparing zirconium oxide layers with different transmittances. The raw materials used include the following components in parts by weight: 90-95 parts Z The raw material contains 5-8 parts ZrO2, 0.01-0.3 parts Y2O3, 0.01-0.3 parts Fe2O3, 0.01-0.3 parts Er2O3, 0-0.2 parts Mn2O3, and 0-0.5 parts Al2O3. The principle behind this adjustment is that a low-transparency zirconium oxide mixture, compared to a high-transparency mixture, has a higher ZrO2 content and a lower Y2O3 content. The amounts of Fe2O3, Er2O3, Al2O3, and Mn2O3 are roughly equivalent in zirconium oxide mixtures of different transparency levels. The particle size distribution of all components in this raw material is... The diameters are all between 10-80 nm; the overall dry pressing pressure is 60-70 MPa, and the holding time is 10-40 seconds; furthermore, the thickness of the zirconia layer with the highest permeability and the thickness of the zirconia layer with the lowest permeability are both set to be greater than the thickness of the zirconia layer between the highest and lowest permeability, 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, so that the inner zirconia block 1 can better play a buffering role.
[0027] Cold isostatic pressing of zirconia ceramic blocks, with a cold isostatic pressing pressure of 100-300MPa and a holding time of 10-15min;
[0028] Zirconia ceramic blocks are obtained by sintering and cold isostatic pressing of zirconia ceramic blanks. The sintering temperature is 1000-1100℃ and the heating rate is no more than 2℃ / min.
[0029] A denture made from a zirconia ceramic block as described in any of the preceding claims.
[0030] Example 1
[0031] Weigh out 90 parts ZrO2, 8 parts Y2O3, 0.15 parts Fe2O3, 0.3 parts Er2O3, 0.015 parts Mn2O3, and 0.1 parts Al2O3 with a particle size of 0.3μm, and mix them to prepare an inner layer of zirconia powder with a transparency of 55% for the produced zirconia layer;
[0032] Weigh out 94 parts ZrO2, 5 parts Y2O3, 0.09 parts Fe2O3, 0.3 parts Er2O3, 0.02 parts Mn2O3, and 0.05 parts Al2O3 with a particle size of 50nm, and mix them to prepare a low-transmittance powder with a transmittance of 43% for the produced zirconium oxide layer;
[0033] Weigh out 91 parts ZrO2, 7 parts Y2O3, 0.1 parts Fe2O3, 0.4 parts Er2O3, and 0.1 parts Al2O3 with a particle size of 50nm, and mix them to prepare a high-transmittance powder with a transmittance of 57% for the produced zirconia layer;
[0034] The outer layer zirconia powder for preparing each zirconia layer is prepared by mixing high-transmittance powder (57% transmittance) and low-transmittance powder (43% transmittance) in the following mass percentages: 20% and 80%, 30% and 70%, 40% and 60%, 60% and 40%, 70% and 30%, and 80% and 20%, respectively. Figure 1 As shown, a first zirconia layer 20, a second zirconia layer 21, a third zirconia layer 22, a fourth zirconia layer 23, a fifth zirconia layer 24, and a sixth zirconia layer 25 are formed accordingly. At this time, the first zirconia layer 20 and the sixth zirconia layer 25 each account for 20% of the total weight of the multiple zirconia layers, while the other zirconia layers each account for 15% of the total weight.
[0035] Zirconia ceramic blanks are prepared using a dry pressing mold. First, an inner zirconia blank is formed by pre-pressing inner zirconia powder under a pressure of 5 MPa using one mold. Then, in another mold, a portion of the outer zirconia powder of the first zirconia layer 20 is laid. Next, the inner zirconia blank is placed in the center of the laid first zirconia layer 20. The remaining outer zirconia powder of the first zirconia layer 20 is then laid around the circumference of the inner zirconia blank. Finally, a second zirconia layer is sequentially laid on top of the first zirconia layer 20. The inner zirconia blank is wrapped by layers 21 (zirconia), 22 (zirconia), 23 (zirconia), 24 (zirconia), and 25 (zirconia). After each outer zirconia powder layer is laid, it is pre-compressed. The pre-compressing pressure is no more than 5 MPa. If a pre-compressing pressure of 5 MPa is selected, each outer zirconia powder layer forms a zirconia layer. After the laying is completed, the inner zirconia blank and each zirconia layer are dry-compressed as a whole to form a zirconia ceramic block blank. The pressure is 70 MPa and the holding time is 30 seconds.
[0036] The zirconia ceramic block blank was cold isostatically pressed at a pressure of 270 MPa for 15 minutes.
[0037] The sintered and cold isostatically pressed zirconia ceramic blanks are used to obtain zirconia ceramic blocks. The sintering temperature is 1050℃ and the heating rate is no more than 2℃ / min.
[0038] Zirconia ceramic blocks are sculpted to form dentures. The dentures have appropriately sized incisal edges, natural color transitions, and uniform translucency and strength. The flexural strength (MPa) of each of the six zirconia layers (20, 21, 22, 23, 24, and 25) is 960, 950, 945, 940, 930, and 920, respectively, and the corresponding translucency (%) is 46, 48, 50, 52, 53, and 55.
[0039] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. A zirconia ceramic block, characterized in that, The device comprises an inner zirconia block made of a micron-sized zirconia mixture and an outer zirconia block made of a nano-sized zirconia mixture enclosing the inner zirconia block. The outer zirconia block comprises multiple zirconia layers laid vertically in order of their transparency, with the thickness of the zirconia layer with the highest transparency and the thickness of the zirconia layer with the lowest transparency both being greater than the thickness of the zirconia layer between the highest and lowest transparency. The transparency of the inner zirconia block is the same as the highest transparency among the multiple zirconia layers, and the bottom of the inner zirconia block is located within the zirconia layer with the lowest transparency. 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 zirconia 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 and 0.5 µm, and the outer zirconia block is made of a zirconia mixture with a particle size between 10 and 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 a high-transmittance powder with a transmittance of 57% and a 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.
5. The zirconia ceramic block according to claim 4, characterized in that... The zirconium oxide mixture comprises the following components in parts by weight: 90-95 parts ZrO2, 5-8 parts Y2O3, 0.01-0.3 parts Fe2O3, 0.01-0.3 parts Er2O3, 0-0.2 parts Mn2O3, and 0-0.5 parts Al2O3.
6. The zirconia ceramic block according to claim 1, characterized in that... The thickness of the zirconium oxide layer with the highest transparency and the thickness of the zirconium oxide layer with the lowest transparency are the same among the plurality of zirconium oxide layers.
7. A method for preparing a zirconia ceramic block according to claim 1, characterized in that, include: Obtain the inner zirconia powder of the inner zirconia block with the same maximum transparency as the outer zirconia powder and pre-press it to form an inner zirconia blank; Multiple outer zirconia powders with different permeability are obtained to prepare zirconia layers. Multiple zirconia layers are laid from bottom to top along the axial direction of the inner zirconia blank in order of increasing permeability of the outer zirconia powder. The inner zirconia blank and multiple zirconia layers are then dry-pressed as a whole to form a zirconia ceramic block blank. Cold isostatic pressing of zirconia ceramic blanks; Zirconia ceramic blocks are obtained by sintering and cold isostatic pressing of zirconia ceramic blanks.
8. The method for preparing the zirconia ceramic block according to claim 7, characterized in that... The pre-pressing pressure of the inner zirconia blank is no more than 5 MPa; the overall dry pressing pressure is 60-70 MPa, and the holding time is 10-40 seconds; the cold isostatic pressing pressure is 100-300 MPa, and the holding time is 10-15 minutes; the sintering temperature is 1000-1100℃.
9. The method for preparing the zirconia ceramic block according to claim 7, characterized in that... The thickness of the zirconium oxide layer with the highest transparency and the thickness of the zirconium oxide layer with the lowest transparency among the plurality of zirconium oxide layers are both greater than the thickness of the zirconium oxide layer between the highest and lowest transparency; the height of the inner zirconium oxide block is not less than 2 / 3 of the sum of the heights of the plurality of zirconium oxide layers.
10. A denture, characterized in that... It is prepared using a zirconia ceramic block as described in any one of claims 1-6.