Preparation method of dental zirconia ceramic restoration

Abstract

The invention discloses a dental zirconia ceramic restoration preparation method, and relates to the technical field of ceramic restoration, and the dental zirconia ceramic restoration preparation method specifically comprises the following preparation steps: 1, sequentially adding yttrium nitrate and an aqueous solution of zinc nitrate hexahydrate and zinc nitrate into a 0.5 mol / L zirconium oxychloride octahydrate solution, stirring and uniformly mixing, slowly dropwise adding ammonia water, and stirring for 30-60 minutes; and adjusting the pH value of the solution system to 9.6-10.2, standing and precipitating at room temperature for 12-16 hours, washing the precipitate with absolute ethyl alcohol and deionized water for 3-5 times, drying in a drying oven at 90-110 DEG C, and calcining at 690-710 DEG C for 1.8-2 hours to obtain the zirconium oxide composite powder. According to the preparation method of the dental zirconia ceramic restoration, yttrium ions and zinc ions are subjected to solid solution in zirconia crystal lattices to generate a solid solution strengthening effect, so that the restoration is endowed with antibacterial performance and acid corrosion resistance, and meanwhile, the strength of the restoration is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic restorations, and specifically to a preparation method of a zirconia ceramic restoration for dental use. Background Art

[0002] Referring to a Chinese patent "A preparation method of a zirconia ceramic restoration" (Publication No.: CN109734446A), it includes the following steps: mixing zirconia sol, a solvent, and a dispersant, and successively performing shaping, pre-sintering, and CAM processing to obtain a shaped restoration; sintering the shaped restoration to obtain a zirconia ceramic restoration; the dispersed phase of the zirconia sol is zirconia and a stabilizer. The present invention stabilizes the tetragonal phase of zirconia by using a stabilizer, and through pre-sintering and sintering, the density of the zirconia restoration reaches more than 99.3%, making it have a lower porosity and better surface finish; at the same time, the flexural strength of the zirconia ceramic restoration ≥ 800 MPa. However, the acid corrosion resistance of the prepared zirconia ceramic restoration needs to be improved; for this reason, the present invention proposes a preparation method of a zirconia ceramic restoration for dental use to solve the above-mentioned problems. Summary of the Invention

[0003] (I) Technical Problems to be Solved

[0004] Aiming at the deficiencies of the prior art, the present invention provides a preparation method of a zirconia ceramic restoration for dental use, solving the problems mentioned in the above background art.

[0005] (II) Technical Solutions

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions: A preparation method of a zirconia ceramic restoration for dental use specifically includes the following preparation steps:

[0007] Step 1: Sequentially add an aqueous solution of yttrium nitrate and zinc nitrate hexahydrate to a 0.5 mo1 / L zirconium oxychloride octahydrate solution, stir and mix evenly, then slowly add ammonia water to adjust the pH value of the solution system to 9.6 - 10.2, then place it at room temperature and let it stand for precipitation for 12 - 16 h, then wash the precipitate with anhydrous ethanol and deionized water 3 - 5 times, then put it into a drying oven at 90 - 110 °C for drying, and calcine it at a temperature of 690 - 710 °C for 1.8 - 2 h to obtain a zirconia composite powder;

[0008] Step 2: Pretreat the zirconia composite powder;

[0009] Step 3: Mix the pretreated zirconia powder, a solvent, and polyethylene glycol, and successively perform shaping, pre-sintering, and CAM processing to obtain a shaped restoration;

[0010] Step 4: Sinter the formed restoration;

[0011] Step 5: After sintering is completed, immerse it in a 100 mL Tris-HCl solution containing 180 - 200 mg of dopamine. After standing at 25°C for 20 - 24 h, take it out, wash it, and dry it; then, under anaerobic conditions, immerse it in a mixed solution of 5 mmol / L pentaerythritol tetrakis(mercaptoacetate) and dichloromethane, and add triethylamine until the solution concentration is 10 mmol / L. After immersing for 24 - 28 h, take it out, wash it, and dry it to obtain a zirconia ceramic restoration for dentistry.

[0012] Preferably, in Step 1, the yttrium content in yttrium nitrate is 3 - 5 mol%; the zinc content in the aqueous solution of zinc nitrate hexahydrate is 1 - 2 wt%.

[0013] Preferably, the pretreatment step in Step 2 is specifically as follows: Add stearic acid to absolute ethanol, heat it to 70 - 80°C, stir for 20 - 30 min to obtain a mixed solution; place the zirconia powder in a blast dryer at 70 - 80°C for drying for 18 - 24 h, then pour it into the mixed solution, heat it to 65 - 75°C in a water bath, continuously stir for 1.5 - 2 h, and then place it in a blast drying oven at 55 - 65°C for drying for 18 - 24 h, and then crush it through a 90 - 100 mesh sieve.

[0014] Preferably, the volume ratio of the absolute ethanol to the stearic acid is 1:(0.5 - 0.8); the mass ratio of the zirconia powder to the stearic acid is 1:(0.6 - 0.75).

[0015] Preferably, in Step 3, the molding pressure is 15 - 30 MPa, and the molding time is 10 - 30 min.

[0016] Preferably, in Step 4, the sintering temperature is 1200 - 1450°C, and the sintering time is 2 - 3 h.

[0017] Preferably, in Step 5, the pH value of the Tris-HCl solution is 8.5.

[0018] Preferably, in Step 5, ultrasonic cleaning is performed with absolute ethanol for 30 - 40 min; nitrogen drying is used.

[0019] (III) Beneficial effects

[0020] The present invention provides a preparation method for a zirconia ceramic restoration for dentistry. Compared with the prior art, it has the following beneficial effects:

[0021] (1) The preparation method of the dental zirconia ceramic restoration. By dissolving yttrium ions and zinc ions into the zirconia lattice, a solid solution strengthening effect is produced, endowing the restoration with antibacterial properties and acid corrosion resistance. At the same time, the strength of the restoration is improved, enabling it to better withstand the chewing pressure in the oral cavity, reducing the risk of cracking or breaking of the restoration during use. In the oral environment, it can resist the erosion of substances such as saliva and food, is not prone to discoloration and damage, maintains good performance and appearance for a long time, and extends the service life of the restoration.

[0022] (2) The preparation method of the dental zirconia ceramic restoration. By pre-treating the zirconia composite powder, the hydrophilic carboxyl group and hydrophobic hydrocarbon group in the stearic acid are adsorbed on the surface of the zirconia composite powder, changing the surface of the zirconia composite powder from hydrophilic to hydrophobic, reducing the surface energy between the zirconia composite powder particles, and reducing the agglomeration phenomenon between the particles, thereby improving the mechanical properties of the restoration. At the same time, it helps to improve the densification of the zirconia composite powder during the sintering process, reduce pores and defects, and thus improve the hardness and wear resistance of the restoration.

[0023] (3) The preparation method of the dental zirconia ceramic restoration. Through impregnation treatment, a polydopamine coating is formed on the surface of the zirconia ceramic and grafted with pentaerythritol tetrakis(mercaptoacetate), which can serve as a physical barrier to improve the wear resistance and acid corrosion resistance of the restoration. At the same time, the introduced functional groups such as mercapto groups have strong reactivity and can be coupled with bioactive substances such as antibacterial drugs and growth factors, endowing the restoration with special functions such as antibacterial and tissue healing promotion. Detailed implementation mode

[0024] The technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, 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.

[0025] Example 1

[0026] Step 1: Add an aqueous solution of yttrium nitrate with a yttrium content of 3 mol% and zinc nitrate hexahydrate with a zinc content of 1 wt% to a 0.5 mol / L solution of zirconium oxychloride octahydrate in sequence. After stirring and mixing evenly, slowly add ammonia water to adjust the pH value of the solution system to 9.6, then let it stand at room temperature for precipitation for 12 h. Then, the precipitate is washed 3 times with anhydrous ethanol and deionized water, and then placed in a drying oven at 90 °C for drying and calcined at 690 °C for 1.8 h to obtain the zirconia composite powder.

[0027] Step 2. Pretreat the zirconia composite powder: Mix absolute ethanol and stearic acid with a volume ratio of 1:0.5, heat up to 70 °C, and stir for 20 min to obtain a mixed solution; Place the zirconia powder in a blast dryer at 70 °C and dry for 18 h. Then, according to a mass ratio of 1:0.6 of zirconia powder to stearic acid, pour it into the mixed solution, heat up to 65 °C in a water bath, continuously stir for 1.5 h, and then place it in a blast drying oven at 55 °C and dry for 18 h, and then pulverize and pass through a 90-mesh sieve;

[0028] Step 3. Mix the pretreated zirconia powder, solvent and polyethylene glycol, and carry out molding, pre-sintering and CAM processing in sequence. Among them, the molding pressure is 15 MPa and the molding time is 10 min to obtain a molded restoration;

[0029] Step 4. Sinter the molded restoration, the sintering temperature is 1200 °C and the sintering time is 2 h;

[0030] Step 5. After sintering is completed, immerse it in a 100 mL solution of 180 mg dopamine with a pH value of 8.5 Tris-HCl, let it stand at 25 °C for 20 h, take it out, ultrasonically clean it with absolute ethanol for 30 min, and then blow it dry with nitrogen; Then, under anaerobic conditions, immerse it in a mixed solution of 5 mmol / L pentaerythritol tetrakis(mercaptoacetate) and dichloromethane, and add triethylamine until the solution concentration is 10 mmol / L. After immersing for 24 h, take it out, ultrasonically clean it with absolute ethanol for 30 min, and then blow it dry with nitrogen to obtain a zirconia ceramic restoration for dentistry.

[0031] Example 2

[0032] Step 1. Sequentially add yttrium nitrate with a yttrium content of 4 mol% and an aqueous solution of zinc nitrate hexahydrate with a zinc content of 1.5 wt% to a 0.5 mol / L zirconium oxychloride octahydrate solution, stir and mix evenly, then slowly drip ammonia water to adjust the pH value of the solution system to 10, and then place it at room temperature and let it stand and precipitate for 14 h. Then, wash the precipitate 4 times with absolute ethanol and deionized water, then put it in a drying oven at 100 °C and dry it, and calcine it at 700 °C for 1.9 h to obtain a zirconia composite powder;

[0033] Step 2. Pretreat the zirconia composite powder: Mix absolute ethanol and stearic acid with a volume ratio of 1:0.6, heat up to 75 °C, and stir for 25 min to obtain a mixed solution; Place the zirconia powder in a blast dryer at 75 °C and dry for 22 h. Then, according to a mass ratio of 1:0.7 of zirconia powder to stearic acid, pour it into the mixed solution, heat up to 70 °C in a water bath, continuously stir for 1.8 h, and then place it in a blast drying oven at 60 °C and dry for 22 h, and then pulverize and pass through a 95-mesh sieve;

[0034] Step 3: Mix the pretreated zirconia powder, solvent and polyethylene glycol, and successively carry out molding, pre-sintering and CAM processing. Among them, the molding pressure is 25 MPa and the molding time is 20 min to obtain a molded restoration;

[0035] Step 4: Sinter the molded restoration, the sintering temperature is 1350 °C and the sintering time is 2 h;

[0036] Step 5: After sintering is completed, immerse it in a 100 mL solution of 190 mg dopamine with a pH value of 8.5 Tris-HCl. After standing at 25 °C for 22 h, take it out, ultrasonically clean it with absolute ethanol for 35 min, and then dry it with nitrogen; then, under anaerobic conditions, immerse it in a mixed solution of 5 mmol / L pentaerythritol tetrakis(mercaptoacetate) and dichloromethane, and add triethylamine until the solution concentration is 10 mmol / L. After immersing for 26 h, take it out, ultrasonically clean it with absolute ethanol for 35 min, and then dry it with nitrogen to obtain a zirconia ceramic restoration for dentistry.

[0037] Example 2

[0038] Step 1: Sequentially add yttrium nitrate with a yttrium content of 5 mol% and zinc nitrate hexahydrate aqueous solution with a zinc content of 2 wt% to a 0.5 mol / L zirconium oxychloride octahydrate solution. After stirring and mixing evenly, slowly add ammonia water to adjust the pH value of the solution system to 0.2, and then place it at room temperature for static precipitation for 16 h. Then, wash the precipitate 5 times with absolute ethanol and deionized water, then put it into a drying oven at 110 °C to dry, and calcine it at 710 °C for 2 h to obtain a zirconia composite powder;

[0039] Step 2: Pretreat the zirconia composite powder: Mix anhydrous ethanol and stearic acid with a volume ratio of 1:0.8, heat it to 80 °C, and stir for 30 min to obtain a mixed solution; Place the zirconia powder in a blast dryer at 80 °C for drying for 24 h. Among them, the zirconia powder and stearic acid are in a mass ratio of 1:0.75, pour it into the mixed solution, heat it to 75 °C in a water bath, continuously stir for 2 h, and then place it in a blast drying oven at 65 °C for drying for 24 h, and then crush it through a 100-mesh sieve;

[0040] Step 3: Mix the pretreated zirconia powder, solvent and polyethylene glycol, and successively carry out molding, pre-sintering and CAM processing. Among them, the molding pressure is 30 MPa and the molding time is 30 min to obtain a molded restoration;

[0041] Step 4: Sinter the molded restoration, the sintering temperature is 1450 °C and the sintering time is 3 h;

[0042] Step 5: After sintering, immerse it in a 100 mL Tris-HCl solution containing 200 mg of dopamine with a pH value of 8.5. After standing at 25 °C for 24 h, take it out, ultrasonically clean it with absolute ethanol for 40 min, and then dry it with nitrogen; then, under anaerobic conditions, immerse it in a mixed solution of 5 mmol / L pentaerythritol tetrakis(mercaptoacetate) and dichloromethane, add triethylamine until the solution concentration is 10 mmol / L, immerse it for 28 h, take it out, ultrasonically clean it with absolute ethanol for 40 min, and then dry it with nitrogen to obtain a dental zirconia ceramic restoration.

[0043] Comparative Example 1

[0044] Compared with Example 1, the difference is that the zirconia composite powder is replaced with zirconia and yttrium oxide; the rest remains unchanged.

[0045] Comparative Example 2

[0046] Compared with Example 1, the difference is that the zirconia composite powder is not pretreated; the rest remains unchanged.

[0047] Comparative Example 3

[0048] Compared with Example 1, the difference is that the sintered restoration is not impregnated; the rest remains unchanged.

[0049] Antibacterial performance test: Refer to GB / T 21866-2008 to test the antibacterial rate (using Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus as the bacterial strains); the results are shown in Table 1.

[0050] Wear resistance test: Test using a friction and wear testing machine with a loading load of 5 N and a cyclic friction number of 500,000 times; the results are shown in Table 1.

[0051] Etching treatment of the specimen: Prepare a 1 mmol / L citric acid solution (pH = 3.20) with deionized water; measure 50 mL of the citric acid aqueous solution with a beaker, keep it at a constant temperature of 37 °C, place the specimen with the occlusal surface facing up into it, and slowly stir it with a constant-temperature magnetic stirrer to simulate the oral saliva flow environment; after reaching the set etching treatment time, take out the specimen, wash it repeatedly with deionized water, and naturally dry it at room temperature.

[0052] Hardness test: Refer to GB / T 16534-2009 for testing; the results are shown in Table 1.

[0053] Table 1

[0054]

[0055] As can be seen from Table 1, the antibacterial performance, corrosion resistance, and acid corrosion resistance of Examples 1-3 in this embodiment are all significantly improved compared to Comparative Examples 1-3.

[0056] Meanwhile, the content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0057] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device.

[0058] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of a zirconia ceramic restoration for dental use, characterized in that, Specifically, it includes the following preparation steps: Step 1: Sequentially add aqueous solutions of yttrium nitrate and zinc nitrate hexahydrate to a 0.5 mo1 / L zirconium oxychloride octahydrate solution. After stirring and mixing evenly, slowly add ammonia water to adjust the pH value of the solution system to 9.6 - 10.

2. Then place it at room temperature and let it stand for precipitation for 12 - 16 h. Then wash the precipitate 3 - 5 times with absolute ethanol and deionized water. Next, put it into a drying oven at 90 - 110°C to dry, and calcine it at 690 - 710°C for 1.8 - 2 h to obtain a zirconia composite powder; Step 2: Pretreat the zirconia composite powder; Step 3: Mix the pretreated zirconia powder, solvent, and polyethylene glycol, and carry out forming, pre-sintering, and CAM processing in sequence to obtain a formed restoration; Step 4: Sinter the formed restoration; Step 5: After sintering is completed, immerse it in a 100 mL Tris-HCI solution containing 180 - 200 mg of dopamine. After standing at 25°C for 20 - 24 h, take it out, wash it, and dry it with nitrogen; then under anaerobic conditions, immerse it in a mixed solution of pentaerythritol tetrakis(mercaptoacetate) and dichloromethane at 5 mmol / L, and add triethylamine until the solution concentration is 10 mmol / L. After immersing for 24 - 28 h, take it out, wash it, and dry it with nitrogen to obtain a zirconia ceramic restoration for dental use.

2. The preparation method of a zirconia ceramic restoration for dental use according to claim 1, characterized in that: In the said Step 1, the yttrium content in yttrium nitrate is 3 - 5 mol%; the zinc content in the aqueous solution of zinc nitrate hexahydrate is 1 - 2 wt%.

3. The preparation method of a zirconia ceramic restoration for dental use according to claim 1, characterized in that: The specific pretreatment steps in the said Step 2 are: Add stearic acid to absolute ethanol, heat it to 70 - 80°C, stir for 20 - 30 min to obtain a mixed solution; Place the zirconia powder in a blast dryer at 70 - 80°C for drying for 18 - 24 h, then pour it into the mixed solution, raise the temperature to 65 - 75°C in a water bath, continuously stir for 1.5 - 2 h, and then place it in a blast drying oven at 55 - 65°C for drying for 18 - 24 h, and then crush it through a 90 - 100 mesh sieve.

4. The preparation method of a dental zirconia ceramic restoration according to claim 3, characterized in that: The volume ratio of the said absolute ethanol to stearic acid is 1:(0.5 - 0.8); the mass ratio of the said zirconia powder to stearic acid is 1:(0.6 - 0.75).

5. The preparation method of a dental zirconia ceramic restoration according to claim 1, characterized in that: In the said Step 3, the forming pressure is 15 - 30 MPa, and the forming time is 10 - 30 min.

6. The preparation method of a zirconia ceramic restoration for dental use according to claim 1, characterized in that: In the said Step 4, the sintering temperature is 1200 - 1450°C, and the sintering time is 2 - 3 h.

7. A method for preparing a zirconia ceramic dental restoration according to claim 1, characterized in that: In the said Step 5, the pH value of the Tris-HCI solution is 8.

5.

8. The preparation method of a dental zirconia ceramic restoration according to claim 1, characterized in that: In the said Step 5, ultrasonic cleaning is carried out with absolute ethanol for 30 - 40 min; drying is carried out with nitrogen.

Images