Method for high-precision ink direct writing 3D printing of ceramic teeth and application

Abstract

The application belongs to the technical field of biological oral manufacturing, and discloses a method for high-precision ink direct-writing 3D printing of ceramic teeth and application, which is suitable for preparing ink for ink direct-writing 3D printing; three-dimensional structure modeling software is used to design the shape of the ceramic tooth; an ink direct-writing 3D printer is used to print ceramic teeth with different shapes; the 3D printed ceramic tooth is placed in an oven for solidification; and the 3D printed ceramic tooth is placed in a sintering furnace for sintering. The 3D printed ceramic tooth prepared by the application has high precision and controllable structure shape, can overcome the problem of brittle material fracture caused by traditional processing technology, and realizes the processing of special ceramic materials. The application can also control the porosity of the ceramic tooth, meet the dynamic balance of mechanical properties and cell growth, and implant fixation. The raw material loss is small in the 3D printing process of the application, which is conducive to environmental protection and can reduce production cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biological oral manufacturing, and particularly relates to a method for high-precision ink direct writing 3D printing of ceramic teeth and application. BACKGROUND

[0002] In the traditional dental manufacturing field, there are mainly two processing methods. For "hard processing", the restoration is milled from a sintered whole, while for "soft processing", the tooth shape is first milled from a soft whole, and then sintered. The disadvantage of these two methods is that the amount of raw material waste is large, because the unused part of the material must be discarded after milling, and it is difficult to recycle the excess ceramic material. The advantage of the restoration produced by "hard processing" is the accurate shape and accurate size. However, the mold for sintering high-strength ceramics is high in cost and time-consuming. These tools are severely worn, so they can only withstand a short running period. In addition, due to the processing process of brittle materials, there is a considerable risk of micro-cracks on the ceramic surface. During "soft processing", no surface damage occurs because the shaping is performed before sintering. In addition, the milling of the tooth whole can shorten the processing time and prolong the service life of the tool. However, the contour and shape accuracy of "soft processing" restorations is more critical compared to "hard processing" parts, because the shrinkage rate during the subsequent sintering process must be considered and controlled.

[0003] Therefore, in order to overcome the above-mentioned defects, the method of ink direct writing 3D printing can effectively achieve the maintenance of tooth accuracy while solving the problem of cracking in the processing process of brittle materials. Ink direct writing printing provides the ability to generate dense green bodies with high resolution and complex shapes.

[0004] The amount of raw material waste is large, and it is difficult to recycle the excess ceramic material.

[0005] The closest prior art to the embodiments of the present application is the use of traditional 3D printing technology to manufacture ceramic teeth, which generally includes the following steps:

[0006] 1. Use three-dimensional modeling software to design a tooth model.

[0007] 2. Use 3D printing technology based on powder sintering or photocuring to manufacture teeth.

[0008] 3. Post-processing of the printed teeth, such as cleaning, grinding and sintering, etc.

[0009] Technical problems of the prior art:

[0010] 1) Precision problem: traditional 3D printing technology, especially powder sintering technology, has precision problems during the printing process. This results in the need for additional finishing work on the printed teeth, increasing the manufacturing complexity and cost.

[0011] 2) Material limitations: Existing 3D printing technologies have limitations in the types of materials they can use. Especially when printing high-strength, high-hardness ceramic materials, there are technical difficulties, which affect the quality and performance of the final product.

[0012] 3) Surface finish: The teeth printed by traditional 3D printing technology are not smooth enough, and additional post-processing steps such as grinding and polishing are needed. This not only increases the manufacturing time and cost, but also affects the appearance and texture of the final product.

[0013] 4) Printing efficiency and speed: Using traditional 3D printing technology, especially in applications requiring high precision and detailed structure, the printing speed is slow, affecting production efficiency.

[0014] 5) Post-processing complexity: Teeth printed by traditional 3D printing often require multiple post-processing steps such as cleaning, grinding and sintering. These steps not only increase the production time, but also introduce additional technical challenges such as maintaining the accuracy and strength of the product.

[0015] In summary, the existing method of manufacturing ceramic teeth using traditional 3D printing technology has problems in precision, material selection, surface treatment, printing efficiency and post-processing complexity. These problems limit the application of traditional 3D printing technology in high-precision, high-performance ceramic tooth manufacturing. SUMMARY

[0016] To solve the problems of the prior art, the present application provides a method for high-precision ink direct writing 3D printing of ceramic teeth and its application.

[0017] The present application is implemented as follows: a method for high-precision ink direct writing 3D printing of ceramic teeth, comprising the following steps:

[0018] Step 1: Prepare ink suitable for ink direct writing 3D printing;

[0019] Step 2: Use three-dimensional modeling software to design the shape of the ceramic tooth;

[0020] Step 3: Use an ink direct writing 3D printer to print ceramic teeth with different shapes;

[0021] Step 4: Put the 3D printed ceramic tooth into the oven for solidification;

[0022] Step 5: Put the 3D printed ceramic tooth into the sintering furnace for sintering.

[0023] Preferably, the raw materials of the 3D printing ink include 30-40% inorganic ceramic functional filler, 40-50% main phase liquid, 2-10% second phase solvent immiscible with the main phase, and 3-5% additives, by volume fraction.

[0024] Preferably, the inorganic ceramic functional filler comprises any one or a combination of at least two of zirconium dioxide, aluminum oxide, mica, lead-free ore, lithium disilicate, silicon dioxide, aluminum oxide potassium silicate, brilliant stone, hydroxyapatite, calcium phosphate or fluorapatite.

[0025] Preferably, the main phase liquid comprises any one or a combination of at least two of water, acrylate, paraffin, beeswax, acrylamide, N, N'-methylene bisacrylamide and the like materials.

[0026] Preferably, the second phase solvent immiscible with the main phase comprises any one or a combination of at least two of methanol, water, ethanol, ammonium citrate, polysaccharide, DMF, ethylene glycol or glycerol.

[0027] Preferably, the additive comprises any one or a combination of at least two of paraffin ester, hard wax ester and beeswax.

[0028] The tooth is modeled using a spatial three-dimensional design software, including any one or a combination of at least two of incisors, canines, premolars and molars, and the size of the ceramic tooth is 0.1-30mm.

[0029] Preferably, the 3D printer air pump pressure is 5-100MPa; the 3D printer printing rate is 100-1000mm / s; and the nozzle size of the 3D printer is 50-1000μm.

[0030] Preferably, the curing temperature is 100-800℃, and the time is 0.5-2h; and the sintering temperature is 100-2000℃, and the time is 2-12h.

[0031] Another object of the present application is to provide an application of the method for directly writing 3D printing ceramic tooth with high precision ink in the field of biological oral tooth.

[0032] In combination with the above technical solutions and the technical problems solved, the technical solutions protected by the present application have the following advantages and positive effects:

[0033] First, the present application prepares ink suitable for directly writing 3D printing; uses three-dimensional modeling software to design the shape of the ceramic tooth; uses the ink directly writing 3D printer to print the ceramic tooth with different shapes; and puts the 3D printed ceramic tooth into the furnace for curing and sintering.

[0034] In the present application, the 3D printed ceramic tooth has high precision and controllable structure shape, and the shape of incisors, canines, premolars and molars can be designed according to actual needs.

[0035] In the present application, the raw material loss is small during the 3D printing process, which is conducive to environmental protection and can reduce production cost.

[0036] Second, the 3D printed ceramic tooth prepared by the present application can overcome the problem of brittle material fracture caused by traditional processing technology, and realize the processing of special ceramic materials, fully exerting the characteristics of ceramic materials such as biological inertia, high compatibility with the human body, and difficulty in causing inflammation or allergic reaction.

[0037] The present application can also control the porosity of the ceramic tooth, meet the dynamic balance of mechanical properties and cell growth, and implant fixation.

[0038] Third, the expected income and commercial value of the technical solution of the present application after transformation are: the present application has high commercial value and great development prospect, and creatively invents a new method for manufacturing controllable ceramic tooth porosity, which meets the mechanical properties and can also regulate the structure to allow cell growth, overcoming the defects of traditional processing technology.

[0039] The technical solution of the present application fills the technical gap at home and abroad: the present application fills the technical gap of uncontrollable porosity of traditional ceramic tooth manufacturing, and successfully realizes the high-precision 3D printing of ceramic tooth with adjustable porosity and designable shape by preparing ink for 3D printing.

[0040] The technical solution of the present application solves the technical problems that people have been eager to solve but have failed to succeed: the present application solves the technical problem that the mechanical properties and cell growth of the currently manufactured ceramic tooth cannot be dynamically balanced.

[0041] The technical solution of the present application overcomes technical bias: the present application overcomes the technical bias that traditional processing of ceramic tooth cannot use ink direct writing 3D printing method.

[0042] Fourth, the method for high-precision ink direct writing 3D printing of ceramic tooth provided by the embodiment of the present application embodies the significant technical progress in the field of 3D printing of ceramic tooth, mainly embodied in the following aspects:

[0043] 1) Highly customized tooth design: using three-dimensional structure modeling software to design the shape of the ceramic tooth allows highly customized and accurate matching of the specific tooth needs of the patient, improving the adaptability and comfort of tooth repair and replacement.

[0044] 2) High-precision 3D printing technology: through ink direct writing 3D printing technology, the shape and size of the tooth can be accurately controlled, ensuring the accuracy and realism of the tooth, which is particularly critical for complex tooth structures.

[0045] 3) Optimized 3D printing ink formula: through specific ink formula (including main phase liquid, inorganic non-metallic particles, second phase liquid and additives), the flowability and stability of the printing material are optimized, thereby improving the accuracy of the printing process and the quality of the printed product.

[0046] 4) Strong material selection: A variety of inorganic non-metallic material combinations are provided, such as the combination of zirconium dioxide and aluminum oxide, which have good biocompatibility and durability, suitable for long-term use of teeth.

[0047] 5) Improvement of sintering process: Through the sintering process in a specific sintering furnace, the hardness and durability of the ceramic teeth can be further improved, ensuring the long-term use performance of the product.

[0048] 6) Environmental adaptability: The selection of the second phase liquid provides better printing process environmental adaptability, ensuring the stability of the ink in different printing environments.

[0049] In summary, this high-precision ink direct writing 3D printing ceramic tooth method improves the precision, realism and durability of tooth repair and replacement through its innovative printing technology, optimized ink formula and material selection, while ensuring high customization and adaptability, reflecting significant technological progress. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0051] Figure 1 is the flow chart of the high-precision ink direct writing 3D printing ceramic tooth method provided by the embodiments of the present application;

[0052] Figure 2 is the flow chart of the 3D printing ceramic tooth provided by the embodiments 1-5 of the present application. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the present application more clear, the following will further describe the present application in combination with embodiments. It should be understood that the specific embodiments described here are only used to explain the present application, and are not used to limit the present application.

[0054] In view of the problems existing in the prior art, the present application provides a high-precision ink direct writing 3D printing ceramic tooth method and application.

[0055] As shown in Figure 1 The embodiments of the present application provide a high-precision ink direct writing 3D printing ceramic tooth method, which comprises the following steps:

[0056] Step one, preparing ink suitable for ink direct writing 3D printing;

[0057] Step two, designing the shape of the ceramic tooth using three-dimensional modeling software;

[0058] Step three, printing the ceramic tooth with different shapes using ink direct writing 3D printer;

[0059] Step four, placing the 3D printed ceramic tooth into the furnace for solidification;

[0060] Step five, placing the 3D printed ceramic tooth into the sintering furnace for sintering.

[0061] Preferably, the raw materials of the 3D printing ink include 45-75% main phase liquid, 20-40% inorganic non-metallic particles, 2-10% second phase liquid and 3-5% additives by volume fraction.

[0062] The volume fraction of the main phase liquid can be 45%, 46%, 47%, 48%, 49%, 50%, 55%, 60%, 65%, 70% or 75%, etc., the volume fraction of the inorganic non-metallic particles can be 20%, 21%, 22%, 23%, 24%, 25%, 30%, 35%, 36% or 40%, etc., the volume fraction of the second phase liquid can be 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 3%, 3.5%, 4%, 5%, 6%, 7%, 8%, 9% or 10%, etc., and the volume fraction of the additive can be 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 4% or 5%, etc., but not limited to the listed values, other values not listed within the above ranges are also applicable.

[0063] Preferably, the main phase liquid includes water, acrylate, paraffin wax, beeswax, acrylamide, boehmite sol, N,N'-methylenebisacrylamide, any one of them or a combination of at least two of them, wherein the combination typically but not limited to examples include: a combination of paraffin wax and acrylamide, a combination of paraffin wax and water, a combination of paraffin wax and acrylate, a combination of paraffin wax and N,N'-methylenebisacrylamide, a combination of N,N'-methylenebisacrylamide and water, or a combination of N,N'-methylenebisacrylamide and boehmite sol, etc.

[0064] Preferably, the inorganic non-metallic material comprises any one or a combination of at least two of zirconium dioxide, silicon dioxide, aluminum oxide, mica, lepidolite, lithium disilicate, potassium alumino-silicate, barylite, hydroxyapatite, calcium phosphate or fluorapatite, wherein typical but non-limiting examples of the combination are a combination of zirconium dioxide and aluminum oxide, a combination of mica and lepidolite, a combination of lithium disilicate and potassium alumino-silicate, a combination of barylite and hydroxyapatite, a combination of calcium phosphate and fluorapatite, or a combination of zirconium oxide and silicon dioxide, etc.

[0065] Preferably, the second phase liquid comprises any one or a combination of at least two of methanol, water, ethanol, ammonium citrate, polysaccharide, DMF, ethylene glycol or glycerol, wherein typical but non-limiting examples of the combination are a combination of methanol and ethanol, a combination of methanol and water, a combination of methanol and ammonium citrate, a combination of ammonium citrate and DMF, a combination of ammonium citrate and polysaccharide, a combination of methanol and ethylene glycol, a combination of ammonium citrate and ethylene glycol, a combination of water and glycerol, or a combination of ammonium citrate and glycerol, etc.

[0066] Preferably, the additive comprises any one or a combination of at least two of paraffin wax ester, hard wax ester and beeswax, wherein typical but non-limiting examples of the combination are a combination of beeswax and paraffin wax ester, a combination of beeswax and hard wax ester, or a combination of paraffin wax ester and hard wax ester, etc.

[0067] The method for inkjet direct writing (DIW) 3D printing of oral teeth specifically comprises: selecting inorganic non-metallic materials such as silicon dioxide, aluminum oxide, zirconium oxide, lepidolite, lithium disilicate, etc. as the main material of the ceramic tooth, selecting an appropriate resin as the main phase liquid to mix with the inorganic particles to form a suspension, and creatively adding a second phase liquid that is insoluble in the resin main phase solution to make the suspension system form a capillary suspension. The content of the second phase liquid is adjusted to further adjust the rheological properties of the printing ink, and finally the ink is suitable for inkjet direct writing (DIW) 3D printing. A nozzle with a precision of 50-1000 μm is used for inkjet direct writing printing to obtain a ceramic tooth with high precision.

[0068] As a preferred technical solution of the present application, the size of the printed ceramic tooth is 0.1-30 mm, wherein the length can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 20 mm, 22 mm, 24 mm, 26 mm, 28 mm or 30 mm, etc., but not limited to the listed values, and other unlisted values within the range are also applicable.

[0069] Preferably, the size of the printed ceramic tooth is 0.1-30mm, wherein the width can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 20mm, 22mm, 24mm, 26m, 28mm or 30mm, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0070] Preferably, the size of the printed ceramic tooth is 0.1-30mm, wherein the height can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 20mm, 22mm, 24mm, 26m, 28mm or 30mm, etc., but not limited to the listed values, other values not listed in the range of values are also applicable.

[0071] As a preferred technical solution of the present application, the tooth shape includes incisor, canine, premolar, molar, etc.

[0072] Preferably, the curing temperature of the printed structure in the sintering furnace is 100-800℃, wherein the wavelength can be 100℃, 200℃, 300℃, 400℃, 500℃, 600℃, 700℃ or 800℃, etc., but not limited to the listed values, other values not listed in the range of values are also applicable.

[0073] Preferably, the curing time of the printed structure in the sintering furnace is 10-300min, wherein the time can be 10min, 30min, 60min, 90min, 120min, 150min, 180min, 210min, 240min, 270min, 280min, 290min or 300min, etc., but not limited to the listed values, other values not listed in the range of values are also applicable.

[0074] Preferably, the sintering temperature of the printed structure in the sintering furnace is 100-2000℃, wherein the wavelength can be 500℃, 600℃, 700℃, 800℃, 900℃, 1000℃, 1100℃, 1200℃, 1300℃, 1400℃, 1500℃, 1600℃, 1700℃, 1800℃, 1900℃ or 2000℃, etc., but not limited to the listed values, other values not listed in the range of values are also applicable.

[0075] Preferably, the post-printed structure is sintered in a sintering furnace for a time period of 60-600 minutes, wherein the time period can be 60 minutes, 90 minutes, 120 minutes, 150 minutes, 180 minutes, 210 minutes, 240 minutes, 270 minutes, 300 minutes, 360 minutes, 420 minutes, 480 minutes, 540 minutes or 600 minutes, etc., but not limited to the listed values, other values not listed in this range are also applicable.

[0076] A flow chart of the 3D-printed ceramic tooth according to embodiments 1-5 of the present application is shown in FIG. 1. Figure 2

[0077] Embodiment 1

[0078] The present embodiment provides a method for preparing a high-precision ink direct writing 3D-printed zirconia ceramic tooth, comprising the following steps:

[0079] (1) 3D-printing ink preparation: zirconia particles with a volume fraction of 30% and a main phase solution acrylamide with a volume fraction of 60% are mixed in a planetary mixer to prepare a suspension. In a 100 mL cup, 50 mL of the sample is added, and mixed at a speed of 1000 rpm for 2 minutes. Subsequently, a second phase solution water with a volume fraction of 5% is added, and the suspension is mixed at a speed of 500 rpm for 5 minutes. Finally, a volume fraction of 5% of beeswax is added.

[0080] (2) Rheological property adjustment of ink: after adding the second phase liquid to the suspension, the rheological properties of the ink suspension are changed sharply, and the yield stress, storage modulus and elastic modulus of the ink are adjusted as much as possible by adjusting the volume content of the second phase liquid. The rheological properties of the ink, the yield stress, the storage modulus and the elastic modulus of the ink are further changed after adding water, and increase with the increase of the volume content of water.

[0081] (3) Ceramic tooth shape design: a three-dimensional structure modeling software is used to design the shape of the ceramic tooth, and the designed shape structure is converted into a g-code language that can be recognized by the ink direct writing 3D printer. Layer-by-layer 3D printing is carried out under the conditions of 8 MPa air pressure and 900 mm / s.

[0082] (4) Post-3D-printing ceramic tooth solidification: the 3D-printed ceramic tooth is placed in a furnace for solidification, and the temperature is raised at a rate of 2°C per minute. After 100 minutes of temperature rise, the solidification temperature reaches 200°C, and the solidification time lasts for 60 minutes. After debinding, the temperature is lowered at a rate of 10°C per minute, and the ceramic tooth is taken out after about 20 minutes of temperature lowering until room temperature is reached.

[0083] ​(5) 3D printing post ceramic tooth sintering: Put the 3D printed ceramic tooth into the sintering furnace for sintering, according to the temperature rise of 10°C per minute, after 150 minutes of temperature rise, reach the sintering temperature of 1500°C, continue sintering for 300 minutes, after sintering is completed, according to the temperature drop of 10°C per minute, drop temperature for about 150 minutes, until the ceramic tooth is taken out after reaching room temperature.

[0084] Example 2

[0085] The embodiment provides a high-precision ink direct writing 3D printing alumina ceramic tooth preparation method, comprising the following steps:

[0086] (1) 3D printing ink preparation: 25% by volume fraction of alumina particles and 60% by volume fraction of main phase solution boehmite sol are mixed in a planetary mixer to prepare a suspension. 60 mL of the sample is added in a 100 mL cup, and mixed at a speed of 3000 rpm for 4 minutes. Subsequently, 7% by volume fraction of the second phase solution ethanol is added, and the suspension is mixed at a speed of 5000 rpm for 5 minutes. Finally, 8% by volume fraction of paraffin is added.

[0087] (2) Ink rheological property adjustment: after the second phase liquid is added to the suspension, the rheological properties of the ink suspension are sharply changed, and the yield stress, storage modulus and elastic modulus of the ink are adjusted as much as possible by adjusting the volume content of the second phase liquid. After the addition of paraffin, the rheological properties of the ink, the yield stress, the storage modulus and the elastic modulus of the ink are further changed, and increase with the increase of the volume content of paraffin.

[0088] (3) Ceramic tooth shape design: a three-dimensional structure modeling software is used to design the shape of the ceramic tooth, the designed shape structure is converted into a g-code language which can be recognized by the ink direct writing 3D printer, and layer-by-layer 3D printing is carried out under the conditions of 11 MPa air pressure and 800 mm / s.

[0089] (4) 3D printing post ceramic tooth sintering: Put the 3D printed ceramic tooth into the sintering furnace for sintering, according to the temperature rise of 10°C per minute, after 150 minutes of temperature rise, reach the sintering temperature of 1500°C, continue sintering for 300 minutes, after sintering is completed, according to the temperature drop of 10°C per minute, drop temperature for about 150 minutes, until the ceramic tooth is taken out after reaching room temperature.

[0090] (5) 3D printing post ceramic tooth sintering: Put the 3D printed ceramic tooth into the sintering furnace for sintering, according to the temperature rise of 10°C per minute, after 150 minutes of temperature rise, reach the sintering temperature of 1500°C, continue sintering for 300 minutes, after sintering is completed, according to the temperature drop of 10°C per minute, drop temperature for about 150 minutes, until the ceramic tooth is taken out after reaching room temperature.

[0091] Example 3

[0092] The embodiment provides a high-precision ink direct writing 3D printing silicon dioxide ceramic tooth preparation method, which comprises the following steps:

[0093] (1) 3D printing ink preparation: 27% by volume of silicon dioxide particles and 62% by volume of a main phase solution of acrylate are mixed in a planetary stirrer to prepare a suspension. 50 mL of the sample is added in a 100 mL cup, and mixing is performed at a speed of 2000 rpm for 5 minutes. Subsequently, 6% by volume of a second phase solution of ammonium citrate is added, and the suspension is mixed at a speed of 800 rpm for 3 minutes. Finally, 5% by volume of beeswax is added.

[0094] (2) Adjustment of rheological properties of ink: after the second phase liquid is added to the suspension, the rheological properties of the ink suspension are sharply changed, and the yield stress, storage modulus and elastic modulus of the ink are adjusted as much as possible by adjusting the volume content of the second phase liquid. After the addition of ammonium citrate, the rheological properties of the ink, the yield stress, the storage modulus and the elastic modulus of the ink are further changed, and increase with the increase of the volume content of ammonium citrate.

[0095] (3) Ceramic tooth shape design: a three-dimensional structure modeling software is used to design the shape of the ceramic tooth, the designed shape structure is converted into a g-code language that can be recognized by an ink direct writing 3D printer, and layer-by-layer 3D printing is performed under the conditions of 6 MPa air pressure and 1000 mm / s.

[0096] (4) Ceramic tooth solidification after 3D printing: the 3D printed ceramic tooth is placed in a furnace for solidification, the temperature is increased by 5°C per minute, the solidification temperature of 400°C is reached after 80 minutes of temperature increase, and the solidification time is 60 minutes. After debinding, the temperature is decreased by 10°C per minute, and the ceramic tooth is taken out after about 40 minutes of temperature decrease until room temperature is reached.

[0097] (5) Ceramic tooth sintering after 3D printing: the 3D printed ceramic tooth is placed in a sintering furnace for sintering, the temperature is increased by 10°C per minute, the debinding temperature of 1300°C is reached after 130 minutes of temperature increase, and the sintering time is 300 minutes. After sintering, the temperature is decreased by 10°C per minute, and the ceramic tooth is taken out after about 130 minutes of temperature decrease until room temperature is reached.

[0098] Embodiment 4

[0099] The embodiment provides a high-precision ink direct writing 3D printing hydroxyapatite ceramic tooth preparation method, which comprises the following steps:

[0100] (1) 3D printing ink preparation: hydroxyapatite particles with a volume fraction of 33% and the main phase solution N, N'-methylene bisacrylamide with a volume fraction of 57% are mixed in a planetary mixer to prepare a suspension. Add 50 mL of the sample in a 100 mL cup and mix at a speed of 600 rpm for 5 minutes. Then, add the second phase solution polysaccharide with a volume fraction of 5%, and mix the suspension at a speed of 900 rpm for 3 minutes. Finally, add the hard wax ester with a volume fraction of 5%.

[0101] (2) Rheological property adjustment of ink: after adding the second phase liquid to the suspension, the rheological properties of the ink suspension are changed sharply. The yield stress, storage modulus and elastic modulus of the ink are adjusted by adjusting the volume content of the second phase liquid. After adding polysaccharide, the rheological properties of the ink are further changed, and the yield stress, storage modulus and elastic modulus of the ink increase with the increase of the volume content of polysaccharide.

[0102] (3) Ceramic tooth shape design: use three-dimensional structure modeling software to design the shape of the ceramic tooth, convert the designed shape structure into g-code language which can be recognized by the ink direct writing 3D printer, and perform layer-by-layer 3D printing under the conditions of 20 MPa air pressure and 200 mm / s.

[0103] (4) Ceramic tooth solidification after 3D printing: place the 3D printed ceramic tooth into the oven for solidification, heat at a rate of 10°C per minute, reach the solidification temperature of 300°C after heating for 30 minutes, and continue the solidification time for 60 minutes. After debinding, cool at a rate of 20°C per minute, and take out the ceramic tooth after about 15 minutes until it reaches room temperature.

[0104] (5) Ceramic tooth sintering after 3D printing: place the 3D printed ceramic tooth into the sintering oven for sintering, heat at a rate of 10°C per minute, reach the debinding temperature of 1350°C after heating for 135 minutes, and continue the sintering time for 300 minutes. After sintering, cool at a rate of 15°C per minute, and take out the ceramic tooth after about 90 minutes until it reaches room temperature.

[0105] Example 5

[0106] The present embodiment provides a high-precision ink direct writing 3D printing mica porcelain tooth preparation method, which comprises the following steps:

[0107] (1) 3D printing ink preparation: mix mica particles with a volume fraction of 35% and the main phase solution acrylamide with a volume fraction of 55% in a planetary mixer to prepare a suspension. Add 50 mL of the sample in a 100 mL cup and mix at a speed of 700 rpm for 3 minutes. Then, add the second phase solution ammonium citrate with a volume fraction of 5%, and mix the suspension at a speed of 1100 rpm for 6 minutes. Finally, add the paraffin with a volume fraction of 5%.

[0108] (2) Rheological property adjustment of ink: After adding the second phase liquid into the suspension, the rheological property of the ink of the suspension is changed sharply, and the yield stress, storage modulus and elastic modulus of the ink are adjusted as much as possible by adjusting the volume content of the second phase liquid. The rheological property of the ink, the yield stress, the storage modulus and the elastic modulus of the ink are further changed after adding ammonium citrate, and increase with the increase of the volume content of ammonium citrate.

[0109] (3) Ceramic tooth shape design: The shape of the ceramic tooth is designed using three-dimensional structure modeling software, the designed shape structure is converted into g-code language which can be recognized by the ink direct writing 3D printer, and layer-by-layer 3D printing is carried out under the conditions of 16 MPa air pressure and 300 mm / s.

[0110] (4) Ceramic tooth solidification after 3D printing: The 3D printed ceramic tooth is placed in a furnace for solidification, the temperature is raised at a rate of 10℃ per minute, the solidification temperature of 360℃ is reached after 36 minutes of heating, and the solidification time is 60 minutes. After debinding, the temperature is lowered at a rate of 20℃ per minute, and the ceramic tooth is taken out after about 18 minutes of cooling until room temperature is reached.

[0111] (5) Ceramic tooth sintering after 3D printing: The 3D printed ceramic tooth is placed in a sintering furnace for sintering, the temperature is raised at a rate of 10℃ per minute, the debinding temperature of 1000℃ is reached after 100 minutes of heating, and the sintering time is 300 minutes. After sintering, the temperature is lowered at a rate of 20℃ per minute, and the ceramic tooth is taken out after about 50 minutes of cooling until room temperature is reached.

[0112] The embodiments of the present application have achieved some positive effects in research and development or use, and indeed have great advantages compared with the prior art. The following content is described in combination with data, charts and the like in the test process.

[0113] Ink Solids content (%) Porosity (%) Shrinkage (%) Zirconium dioxide 87.4±1.7 12.6±0.2 7.0±1.0 Silicon dioxide 69.8±2.1 30.1±0.7 11.8±0.8 Aluminium oxide 51.9±1.6 47.5±0.5 16.2±0.7 Hydroxyapatite 76.5±1.5 23.5±0.3 13.2±0.6 Mica 44.9±1.3 55.5±0.8 19.2±0.9

[0114] The porosity shrinkage rate of the ceramic tooth is shown in the table.

[0115] In the table, the tooth porosity size can be adjusted by adjusting the ink formula.

[0116] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any modification, equivalent replacement and improvement made by any person skilled in the art within the technical range disclosed by the present application, as long as it is within the spirit and principles of the present application, should be covered within the protection scope of the present application.

Claims

1. A method for high-precision ink direct-write 3D printing of ceramic teeth, characterized in that, Includes the following steps: Step 1: Prepare ink suitable for ink-to-ink 3D printing; Step two: Design the shape of the ceramic teeth using 3D structural modeling software; Step 3: Use an ink-to-write 3D printer to print ceramic teeth of different shapes; Step four: Place the 3D-printed ceramic teeth into the furnace for curing; Step 5: Place the 3D-printed ceramic teeth into a sintering furnace for sintering; Use spatial 3D design software to model teeth, including any one or at least two of the following composite structures: incisors, canines, premolars, and molars; ceramic teeth are 5-20mm in size. The air pump pressure of the 3D printer is 5-100 MPa; the printing speed of the 3D printer is 100-1000 mm / s; the nozzle size of the 3D printer is 50-1000 μm. The raw materials of 3D printing ink, by volume fraction, include 30-40% inorganic ceramic functional filler, 40-50% main phase liquid, 2-10% second phase solvent that is immiscible with the main phase, and 3-5% additives; The main phase liquid includes any one or a combination of at least two of the following materials: acrylate, acrylamide, N,N′-methylenebisacrylamide; The second phase solvent that is immiscible with the main phase includes any one or a combination of at least two of methanol, water, ethanol, ammonium citrate, polysaccharide, DMF, ethylene glycol or glycerol; Additives include any one or a combination of at least two of paraffin esters, hard wax esters, and beeswax.

2. The method for high-precision ink direct writing 3D printing of ceramic teeth as described in claim 1, characterized in that, Inorganic ceramic functional fillers include any one or a combination of at least two of zirconium dioxide, alumina, mica, lead-free minerals, lithium disilicate, silicon dioxide, potassium aluminosilicate, spar, hydroxyapatite, calcium phosphate, or fluorapatite.

3. The method for high-precision ink direct-write 3D printing of ceramic teeth as described in claim 1, characterized in that, The curing temperature is 100–800℃ and the time is 0.5–2h; the sintering temperature is 100–2000℃ and the time is 2–12h.

4. The application of a method for high-precision ink direct writing 3D printing of ceramic teeth as described in any one of claims 1 to 3 in the field of bio-dental dentistry.

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