Manufacturing method of zirconia ceramic false tooth green body

Abstract

The invention discloses a preparation method of a zirconia ceramic false tooth green body, which belongs to the field of dentistry and comprises the following steps: raw material preparation: selecting high-purity zirconia powder as a basic raw material, and preparing a proper amount of flexibilizer at the same time; mixing and ball milling: uniformly mixing zirconium oxide powder and a toughening agent according to a ratio, and putting the mixture into a ball mill for ball milling; molding: preparing the mixed raw materials into a prototype of a false tooth blank; degreasing: putting the formed green body into a degreasing furnace for degreasing treatment; sintering: sintering the degreased green body in a high-temperature sintering furnace; and finish machining: carrying out finish machining on the sintered false tooth green body, so that the surface of the false tooth green body is smooth and meets the wearing requirement of the false tooth. According to the manufacturing method of the zirconia ceramic false tooth green body, zirconia ceramic is natural in color, free of black edge phenomenon, capable of meeting the requirement of a patient for attractiveness, free of anaphylactic reaction on a human body, free of gingival inflammation or body discomfort and high in safety.

Description

Technical Field

[0001] The present invention relates to the field of dental technology, and particularly to a method for manufacturing a zirconia ceramic denture blank. Background Art

[0002] In the field of oral rehabilitation, dentures are important devices for replacing missing teeth. Dentures, also known as false teeth, are artificial tooth devices designed to replace natural teeth missing due to various reasons (such as age, disease, accident, etc.). Through different materials and manufacturing methods, dentures can completely imitate the shape and function of natural teeth to achieve the effects of chewing, biting, and aesthetics. It is mainly used to improve chewing and pronunciation difficulties caused by tooth loss and to improve the quality of life of patients.

[0003] Traditional dentures are made of nickel-chromium alloy. Long-term contact between nickel-chromium alloy and the gums will produce slight rust stains, resulting in a black edge phenomenon at the gum margin, which greatly affects the aesthetics. More seriously, a small number of people are allergic to metals, and wearing nickel-chromium alloy dentures is likely to cause adverse reactions such as gum inflammation or physical discomfort, bringing pain to patients. Currently, the ceramic materials commonly used to make dentures are mainly alumina or zirconia. Although alumina has good wear resistance, its brittleness is relatively large, and it is easy to break during use, resulting in a shortened service life of the dentures and unable to meet the long-term use needs of patients. Summary of the Invention

[0004] The purpose of the present invention is to propose a method for manufacturing a zirconia ceramic denture blank to solve the problem that the existing zirconia ceramic dentures are relatively brittle, easy to break during use, resulting in a shortened service life of the dentures and unable to meet the long-term use needs of patients.

[0005] To achieve the above purpose, the present invention adopts the following technology: A method for manufacturing a zirconia ceramic denture blank, comprising the following steps:

[0006] S1. Raw material preparation: Select high-purity zirconia powder as the basic raw material. At the same time, prepare an appropriate amount of toughening agent;

[0007] S2. Mixing and ball milling: Mix the zirconia powder and the toughening agent evenly according to a ratio, and put them into a ball mill for ball milling;

[0008] S3. Forming: Make the mixed raw materials into the prototype of the denture blank;

[0009] S4. Debinding: Put the formed blank into a debinding furnace for debinding treatment;

[0010] S5. Sintering: Put the debound blank into a high-temperature sintering furnace for sintering;

[0011] S6. Finishing: The sintered denture blank is subjected to finishing to make its surface smooth and meet the wearing requirements of the denture.

[0012] As a further description of the above technical solution: In step S1, the purity of the selected zirconia powder is above 99%, and the selected toughening agent is yttrium oxide, and its addition amount is 3%-5% of the mass of the zirconia powder.

[0013] As a further description of the above technical solution: In step S2, the ball milling time is controlled within 10 - 15 hours, and the ball milling speed is 200 - 300 revolutions per minute.

[0014] As a further description of the above technical solution: In step S3, injection molding is used for molding. During the injection molding process, the injection temperature is controlled at 150 - 180°C, and the injection pressure is 10 - 15 MPa.

[0015] As a further description of the above technical solution: In step S3, dry pressing molding is used for molding. During dry pressing molding, the pressure is controlled at 50 - 80 MPa, and the pressure holding time is 2 - 3 minutes.

[0016] As a further description of the above technical solution: In step S4, the debinding process is divided into two stages: low-temperature debinding and high-temperature debinding. The low-temperature debinding temperature is 300 - 400°C, and the heat preservation time is 2 - 3 hours. The high-temperature debinding temperature is 600 - 700°C, and the heat preservation time is 1 - 2 hours.

[0017] As a further description of the above technical solution: In step S5, the sintering temperature is controlled at 1400 - 1500°C, the sintering time is 3 - 5 hours, and the sintered denture blank needs to be cooled, and the cooling rate is controlled at 5 - 10°C per minute.

[0018] As a further description of the above technical solution: In step S6, the finishing includes grinding and polishing processes.

[0019] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0020] The zirconia ceramic has a natural color, is similar to natural teeth, does not show a black edge phenomenon, can meet the aesthetic needs of patients. The zirconia ceramic has no allergic reaction to the human body, will not cause problems such as gingivitis or physical discomfort, and has high safety. By adding an appropriate amount of toughening agent and optimizing the sintering process, the strength and toughness of the zirconia ceramic are effectively improved, the brittleness is reduced, and the service life of the denture is extended. Specific Embodiments

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0022] A method for manufacturing a zirconia ceramic denture blank provided in this embodiment includes the following steps:

[0023] S1. Raw material preparation: Select high-purity zirconia powder as the basic raw material. At the same time, prepare an appropriate amount of toughening agent.

[0024] S2. Mixing and ball milling: Mix the zirconia powder and the toughening agent evenly according to a ratio, and put them into a ball mill for ball milling.

[0025] S3. Forming: Make the mixed raw materials into the prototype of the denture blank.

[0026] S4. Debinding: Put the formed blank into a debinding furnace for debinding treatment.

[0027] S5. Sintering: Put the debound blank into a high-temperature sintering furnace for sintering.

[0028] S6. Finishing: Perform finishing on the sintered denture blank to make its surface smooth and meet the wearing requirements of the denture.

[0029] Specifically, in step S1, the purity of the selected zirconia powder is above 99%. The selected toughening agent is yttrium oxide, and its addition amount is 3%-5% of the mass of the zirconia powder. The addition of the toughening agent can effectively improve the toughness of the zirconia ceramic and reduce its brittleness.

[0030] Specifically, in step S2, the ball milling time is controlled within 10 - 15 hours, and the ball milling speed is 200 - 300 revolutions per minute. Through ball milling, the raw material particles are refined and evenly dispersed, which is beneficial to the subsequent forming and sintering of the blank.

[0031] Specifically, in step S3, injection molding or dry pressing is used for forming. During the injection molding process, the injection temperature is controlled at 150 - 180°C, and the injection pressure is 10 - 15 MPa. During dry pressing, the pressure is controlled at 50 - 80 MPa, and the pressure holding time is 2 - 3 minutes. The formed blank needs to be preliminarily trimmed to remove the excess part and make its shape close to the final denture shape.

[0032] Specifically, in step S4, the degreasing process is divided into two stages: low-temperature degreasing and high-temperature degreasing. The low-temperature degreasing temperature is 300-400 °C, and the heat preservation time is 2-3 hours. The low-temperature degreasing mainly removes the organic binder in the green body. The high-temperature degreasing temperature is 600-700 °C, and the heat preservation time is 1-2 hours, so as to further remove the residual impurities and ensure the purity of the green body.

[0033] Specifically, in step S5, the sintering temperature is controlled at 1400-1500 °C, and the sintering time is 3-5 hours. The sintered denture green body needs to be cooled, and the cooling rate is controlled at 5-10 °C / minute. During the sintering process, the zirconia particles will densify to form a ceramic structure with good strength and toughness. Cooling after sintering can avoid cracks in the green body due to thermal stress.

[0034] Specifically, in step S6, the finish machining includes grinding and polishing processes. Through finish machining, its surface is made smooth to meet the wearing requirements of the denture. At the same time, according to the patient's oral condition, the shape and size of the denture are finely adjusted to ensure good fit between the denture and the patient's oral cavity.

[0035] As described above, it is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. A method for manufacturing a zirconia ceramic denture blank, characterized in that: The following steps are involved: S1. Raw material preparation: Select high-purity zirconium oxide powder as the basic raw material, and prepare an appropriate amount of toughening agent; S2, mixing and ball milling: the zirconium oxide powder and the toughening agent are mixed evenly according to a certain proportion, and put into a ball mill for ball milling; S3, molding: the mixed raw materials are made into the prototype of the denture blank; S4, degreasing: putting the formed green body into a degreasing furnace for degreasing treatment; S5, sintering: placing the degreased green body into a high-temperature sintering furnace for sintering; S6. Finishing: The sintered denture blank is finished to make its surface smooth and meet the wearing requirements of the denture.

2. The method for manufacturing a zirconia ceramic denture blank according to claim 1, characterized in that: In step S1, the purity of the zirconium oxide powder is above 99%, the toughening agent is yttrium oxide, and the amount of the toughening agent added is 3%-5% of the mass of the zirconium oxide powder.

3. The method for manufacturing a zirconia ceramic denture blank according to claim 1, characterized in that: In step S2, the ball milling time is controlled at 10-15 hours, and the ball milling speed is 200-300 rpm.

4. The method for manufacturing a zirconia ceramic denture blank according to claim 1, characterized in that: In step S3, the molding is performed by injection molding. During the injection molding process, the injection temperature is controlled to be 150-180° C. and the injection pressure is controlled to be 10-15 MPa.

5. The method for manufacturing a zirconia ceramic denture blank according to claim 1, characterized in that: In step S3, the forming is performed by dry pressing. During dry pressing, the pressure is controlled at 50-80 MPa and the holding time is 2-3 minutes.

6. The method for manufacturing a zirconia ceramic denture blank according to claim 1, characterized in that: In step S4, the degreasing process is divided into two stages: low-temperature degreasing and high-temperature degreasing. The low-temperature degreasing temperature is 300-400°C, the insulation time is 2-3 hours, and the high-temperature degreasing temperature is 600-700°C, the insulation time is 1-2 hours.

7. The method for manufacturing a zirconia ceramic denture blank according to claim 1, characterized in that: In step S5, the sintering temperature is controlled at 1400-1500°C, the sintering time is 3-5 hours, and the denture blank needs to be cooled after sintering, and the cooling rate is controlled at 5-10°C / minute.

8. The method for manufacturing a zirconia ceramic denture blank according to claim 1, characterized in that: In step S6, finishing includes grinding and polishing.