Dental composite ceramic material and preparation method thereof

Abstract

The invention discloses a dental composite ceramic material and a preparation method thereof, and relates to the technical field of dental ceramic materials. The method comprises the following steps: preparing silicon-lithium-aluminum-based glass powder by adopting a melting method; sintering commercial zirconium oxide to obtain compact zirconium oxide; and spraying the glass powder on the surface of the compact zirconium oxide to prepare the dental composite ceramic material. According to the method, Li2CO3 serves as an active agent, P2O5 serves as a nucleating agent, silicon-lithium-aluminum-based glass is prepared, then the roasting process is controlled, and a glass glaze layer is successfully roasted on the surface of compactly sintered zirconia. The dental zirconia ceramic has the high-strength bonding performance of the glaze layer and zirconia and the excellent mechanical property of the glaze layer, and the problems that an existing dental zirconia ceramic glaze layer is prone to cracking and stripping and insufficient in glaze layer strength are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of dental ceramic materials, and in particular to a dental composite ceramic material and a preparation method thereof. Background Art

[0002] Dental zirconia ceramics possess excellent mechanical properties due to their phase transformation toughening mechanism. Due to their stable chemical properties and good biocompatibility, they can be safely used as dental restorative materials and are one of the most widely used materials for restoring dentition defects. For anterior high-translucent zirconia crowns or posterior zirconia crowns, if aesthetic requirements are not high, single-layer, fully anatomical crowns are routinely made to reduce the introduction of veneer. This can avoid clinical restoration failures due to porcelain breakage in double-layer porcelain crowns, extend clinical service life, and reduce restoration space requirements. However, fine polishing or glazing is required after blending to maintain the smoothness of the restoration and reduce wear on the opposing teeth and bacterial accumulation. Glazing can create a bright and lively surface, but the glazes used clinically have low strength and poor bonding with zirconia, making the glaze layer prone to cracking or flaking during use, resulting in reduced restoration performance.

[0003] The hardness and toughness of the glass layer are higher than those of traditional glaze. At the same time, glass infiltration forms a glass-zirconia gradient structure, and a mechanical interlocking is formed between the glass and zirconia, which can significantly improve the bonding strength between the glass layer and zirconia, so that it has better mechanical properties while also having higher bonding strength. Therefore, it is of great significance to bake a glass glaze layer on the surface of zirconia.

[0004] In summary, if glass glaze can be combined with zirconia ceramics, high bonding strength between the zirconia surface and the glaze layer can be achieved, while a glaze layer with higher mechanical properties can be obtained, thereby obtaining a glazed zirconia material with high strength and high bonding strength. However, due to the stable chemical properties of zirconia and the large differences in the preparation schemes and processes of the two, there are currently no reports on this ceramic material. Summary of the Invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a dental composite ceramic material and a preparation method thereof, so as to solve the problems of easy cracking and peeling of the existing dental zirconia ceramic glaze layer and insufficient glaze strength.

[0006] The present invention solves the above technical problems with the following technical solutions: a method for preparing a dental composite ceramic material is provided, comprising: (1) The glass powder raw material and ethanol are mixed uniformly to a slurry, dried, melted and then water quenched, the melting and then water quenching process is repeated, ball milled and sieved to obtain glass powder; (2) Sintering the commercial zirconia and cooling it to room temperature to obtain dense zirconia; (3) The glass powder obtained in step (1) is mixed evenly with deionized water to obtain a slurry, which is sprayed on the surface of the dense zirconia obtained in step (2), dried, sintered, and cooled to room temperature to obtain a dental composite ceramic material.

[0007] On the basis of the above technical solution, the present invention can also be improved as follows: Furthermore, in step (1), the glass powder raw material includes the following components in parts by weight: 58-67 parts of SiO2, 20-30 parts of Li2CO3, 1-10 parts of Al2O3, 1-2 parts of K2CO3, 1-2 parts of ZrO2 and 3-4 parts of P2O5.

[0008] The beneficial effects of adopting the above further technical solution are: Li2CO3 is used as an active agent, P2O5 is used as a nucleating agent, and the thermal expansion coefficient of the glass is regulated by Al2O3.

[0009] Furthermore, in step (1), the glass powder raw material includes the following components in parts by weight: 58-67 parts of SiO2, 25 parts of Li2CO3, 1-10 parts of Al2O3, 1.8 parts of K2CO3, 1.5 parts of ZrO2 and 3.2 parts of P2O5.

[0010] Furthermore, in step (1), the mass volume ratio of the glass powder raw material and ethanol is 1 g:1.8-2.2 mL.

[0011] Furthermore, in step (1), the mass volume ratio of the glass powder raw material and ethanol is 1 g:2 mL.

[0012] Furthermore, in step (1), ball milling is used to mix uniformly to a slurry state, and the ball milling parameters are 350-450 r / min and run for 1.5-2.5 hours.

[0013] Furthermore, in step (1), ball milling is used to mix uniformly to a slurry state, and the ball milling parameter is 400 r / min and the operation is carried out for 2 hours.

[0014] Furthermore, in step (1), the product is dried at 80° C. for 12 h.

[0015] Furthermore, in step (1), the temperature is heated to 1400-1600°C at a heating rate of 8-12°C / min and then kept at this temperature for 1.5-2.5 hours to complete the melting process.

[0016] The beneficial effect of adopting the above further technical solution is that the purpose of high-temperature melting is to allow the components to diffuse and mix in the liquid state to form a melt with uniform chemical composition.

[0017] Furthermore, in step (1), the temperature is raised to 1500°C at a heating rate of 10°C / min and then kept at this temperature for 2 hours to complete the melting process.

[0018] Furthermore, a resistance furnace is used for melting.

[0019] Furthermore, in step (1), the post-melting water quenching process is repeated 2-3 times.

[0020] Furthermore, in step (1), ball milling is performed at 380-420 r / min for 20-25 h.

[0021] Furthermore, in step (1), ball milling is performed at 400 r / min for 24 h.

[0022] Furthermore, in step (1), the product is passed through a 400-mesh sieve.

[0023] Furthermore, in step (1), the average particle size of the glass powder is 0.18-0.7 μm.

[0024] Furthermore, in step (1), the average particle size of 80% of the glass powder is 0.2-0.6 μm.

[0025] Furthermore, in step (2), the commercial zirconia is pretreated and then sintered. The pretreatment process is: cutting the commercial zirconia and then blowing away surface debris with oil-free air.

[0026] Furthermore, in step (2), the commercial zirconium oxide is 3Y-TZP.

[0027] Furthermore, cutting is performed according to a thickness of 1.2-1.7 mm and a diameter of 14.5-19.5 mm.

[0028] Furthermore, it is cut into a thickness of 1.2 mm and a diameter of 17 mm.

[0029] Furthermore, in step (2), the temperature is increased to 850-950°C at a heating rate of 8-12°C / min, and then kept at this temperature for 25-35 minutes. Then, the temperature is increased to 1400-1600°C at a heating rate of 0.3-0.4°C / min, and then kept at this temperature for 1.5-2.5 hours to complete the sintering process.

[0030] Furthermore, in step (2), the temperature is heated to 900°C at a heating rate of 10°C / min and kept at that temperature for 30 minutes, and then heated to 1450°C at a heating rate of 0.33°C / min and kept at that temperature for 2 hours to complete the sintering process.

[0031] Furthermore, in step (2), the thickness of the dense zirconia is 1 mm and the diameter is 14 mm.

[0032] Furthermore, in step (3), the mass ratio of the glass powder to deionized water is 1:4-8. Furthermore, in step (3), the glass powder is heated to 0.003-0.025 g / cm2 Sprayed on the surface of the dense zirconia prepared in step (2).

[0033] Furthermore, in step (3), the temperature is heated to 900-1500°C at a heating rate of 8-12°C / min and kept at this temperature for 0-2h to complete the sintering process.

[0034] The beneficial effect of adopting the above-mentioned further technical solution is that at high temperature, the glass is converted into a liquid phase, the viscosity decreases, and it is more conducive to reacting (penetrating) with zirconium oxide.

[0035] Furthermore, in step (3), the temperature is heated to 900-1500°C at a heating rate of 10°C / min and kept at this temperature for 0-2h to complete the sintering process.

[0036] The present invention also provides a dental composite ceramic material prepared by the method.

[0037] The present invention has the following beneficial effects: 1. In order to enhance the strength of the glaze layer on the surface of zirconium oxide and its bonding ability with the underlying zirconium oxide, the present invention uses Li2CO3 as an active agent and P2O5 as a nucleating agent to prepare a silicon-lithium-aluminum-based glass, and then controls the firing process to successfully fire the glass glaze layer on the surface of densely sintered zirconium oxide. The structure formed by the method for glazing the surface of zirconium oxide of the present invention has both high-strength bonding performance between the glaze layer and zirconium oxide and excellent mechanical properties of the glaze layer. Compared with the poor mechanical properties of the glaze layer of traditional zirconium oxide glazing and weak bonding force at the interface, the glaze layer has better mechanical properties due to the formation of crystals in the glaze layer. At the same time, penetration is formed between the silicon-lithium glass glaze layer and the zirconium oxide in this material, which is similar to the mechanical interlocking formed between the adhesive and dentin during bonding, making its bonding force higher. It is a new type of zirconium oxide surface glazing method with huge application potential.

[0038] 2. Strength: The glass glaze layer has mechanical properties far superior to those of the glaze layer used clinically, which can effectively avoid glaze cracking caused by insufficient glaze strength.

[0039] 3. Bonding strength: A transition layer of a certain range is formed between the zirconium oxide layer and the glass glaze layer. The interface between the glaze layer and the dense sintered zirconium oxide includes the zirconium oxide layer, the glass glaze layer, and a composite layer with a gradual change in composition between the zirconium oxide layer and the glaze layer. Figure 1 There is no interface and it has higher bonding strength, which can effectively avoid the glaze peeling caused by insufficient bonding strength between zirconium oxide and glaze layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic cross-sectional view of the finished product of the dental composite ceramic material of this application; Figure 2This is an SEM image of lithium silicate crystals visible on the surface of the material prepared in Example 1 after acid etching; Figure 3 This is an SEM image of zirconium silicate crystals visible on the surface of the material prepared in Example 2; Figure 4 This is an EDS surface scan image of the longitudinal section of the material prepared in Example 3; Figure 5 Schematic diagram of indentation testing. DETAILED DESCRIPTION

[0041] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples are only used to explain the present invention and are not intended to limit the scope of the invention. In the embodiments, if specific conditions are not specified, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0042] The manufacturer of the commercial zirconia in the following examples is Wieland Dental, Germany; The commercial zirconium oxide is Zenostar T1 (3Y-TZP).

[0043] Example 1: A dental composite ceramic material comprises the following steps: (1) Glass powder raw materials and ethanol were mixed at a mass volume ratio of 1 g:2 mL, and the mixture was uniformly mixed by ball milling until it became slurry. The ball milling parameters were run at 400 r / min for 2 h, dried at 80 °C for 12 h, melted in a resistance furnace, heated to 1500 °C at a heating rate of 10 °C / min, and kept warm for 2 h to complete the melting process. After melting, the mixture was water quenched. The melting and water quenching process was repeated twice, and the mixture was ball milled at 400 r / min for 24 h. The mixture was sieved through a 400 mesh sieve to obtain glass powder (average particle size of 0.18-0.7 μm). The glass powder raw material includes the following components in parts by weight: 60 parts of SiO2, 25 parts of Li2CO3, 8 parts of Al2O3, 1.8 parts of K2CO3, 1.5 parts of ZrO2 and 3.2 parts of P2O5; (2) 3Y-TZP was cut into pieces with a thickness of 1.2 mm and a diameter of 17 mm to obtain zirconia green discs. The surface debris was blown off with oil-free air. The pieces were heated to 900 °C in a high-temperature resistance furnace at a heating rate of 10 °C / min and kept at that temperature for 30 min. The pieces were then heated to 1450 °C at a heating rate of 0.33 °C / min and kept at that temperature for 2 h to complete the sintering process. The pieces were then cooled to room temperature in the furnace to obtain dense zirconia (1 mm thick and 14 mm in diameter). (3) The glass powder prepared in step (1) was mixed with deionized water in a mass ratio of 1:6 to obtain a homogenate. The homogenate was taken up with a pipette and the glass powder was concentrated to 0.003 g / cm 2 The zirconia was sprayed on the surface of the dense zirconia obtained in step (2), dried in a drying oven, heated to 1050°C in a high-temperature resistance furnace at a heating rate of 10°C / min, kept warm for 2 hours to complete the sintering process, and cooled to room temperature in the furnace to obtain a dental composite ceramic material.

[0044] Example 2: A dental composite ceramic material comprises the following steps: In step (3), the amount of glass powder is 0.008 g / cm 2 , heated to 1250°C and kept warm for 2 hours, with the rest being the same as in Example 1.

[0045] Example 3: A dental composite ceramic material comprises the following steps: In step (3), the amount of glass powder is 0.025g / cm 2 , heated to 1500℃, kept warm for 0h, and the rest is the same as Example 1.

[0046] Example 4: A dental composite ceramic material comprises the following steps: (1) Glass powder raw materials and ethanol were mixed at a mass volume ratio of 1 g:1.8 mL, and the mixture was uniformly mixed by ball milling until it became slurry. The ball milling parameters were run at 350 r / min for 2.5 h, dried at 80 °C for 12 h, melted in a resistance furnace, heated to 1600 °C at a heating rate of 8 °C / min, and kept warm for 1.5 h to complete the melting process. After melting, the mixture was quenched with water. The melting and water quenching process was repeated twice, and the mixture was ball milled at 380 r / min for 25 h. The mixture was sieved through a 400 mesh sieve to obtain glass powder (average particle size of 0.18-0.7 μm). The glass powder raw material includes the following components in parts by weight: 58 parts of SiO2, 20 parts of Li2CO3, 1 part of Al2O3, 1 part of K2CO3, 1 part of ZrO2 and 53 parts of P2O; (2) 3Y-TZP was cut into pieces with a thickness of 12 mm and a diameter of 17 mm to obtain zirconia green discs. The surface debris was blown off with oil-free air. The pieces were heated to 850°C in a high-temperature resistance furnace at a heating rate of 8°C / min and kept at that temperature for 35 min. The pieces were then heated to 1400°C at a heating rate of 0.3°C / min and kept at that temperature for 2.5 h to complete the sintering process. The pieces were then cooled to room temperature in the furnace to obtain dense zirconia (1 mm thick and 14 mm in diameter). (3) The glass powder prepared in step (1) was mixed with deionized water in a mass ratio of 1:4 to obtain a homogenate. The homogenate was taken up with a pipette and the glass powder was mixed at a mass ratio of 0.003 / cm 2 The zirconia was sprayed on the surface of the dense zirconia obtained in step (2), dried in a drying oven, heated to 900°C in a high-temperature resistance furnace at a heating rate of 8°C / min, kept warm for 2 hours to complete the sintering process, and cooled to room temperature in the furnace to obtain a dental composite ceramic material.

[0047] Example 5: A dental composite ceramic material comprises the following steps: (1) Glass powder raw materials and ethanol were mixed at a mass volume ratio of 1 g:2.2 mL, and ball milled to a uniform slurry. The ball milling parameters were run at 450 r / min for 1.5 h, dried at 80 °C for 12 h, melted in a resistance furnace, heated to 1400 °C at a heating rate of 12 °C / min, and kept warm for 2.5 h to complete the melting process. After melting, the raw materials were water quenched. The melting and water quenching process was repeated three times, and the raw materials were ball milled at 3420 r / min for 20 h. The raw materials were sieved through a 400-mesh sieve to obtain glass powder (average particle size of 0.18-0.7 μm). The glass powder raw material includes the following components by weight: 67 parts of SiO2, 30 parts of Li2CO3, 10 parts of Al2O3, 2 parts of K2CO3, 2 parts of ZrO2 and 54 parts of P2O; (2) 3Y-TZP was cut into pieces with a thickness of 1.2 mm and a diameter of 17 mm to obtain zirconia green discs. The surface debris was blown off with oil-free air. The pieces were heated to 950°C in a high-temperature resistance furnace at a heating rate of 12°C / min and kept at that temperature for 25 min. The pieces were then heated to 1600°C at a heating rate of 0.4°C / min and kept at that temperature for 1.5 h to complete the sintering process. The pieces were then cooled to room temperature in the furnace to obtain dense zirconia (1 mm thick and 14 mm in diameter). (3) The glass powder prepared in step (1) was mixed with deionized water in a mass ratio of 1:8 to obtain a homogenate. The homogenate was taken up with a pipette and the glass powder was concentrated to 0.025 g / cm 2 The zirconia was sprayed on the surface of the dense zirconia obtained in step (2), dried in a drying oven, heated to 1400°C in a high-temperature resistance furnace at a heating rate of 12°C / min, kept warm for 0.5h to complete the sintering process, and cooled to room temperature in the furnace to obtain a dental composite ceramic material.

[0048] Comparative Example 1: A zirconia-glaze layer structure with a thickness of 1.02 mm was prepared using a traditional manual glazing method, wherein the thickness of the dense zirconia was 1 mm and the thickness of the surface glaze layer was 0.02 mm.

[0049] First, dense zirconia was prepared using the method of Example 1. The zirconia was then glazed manually: the surface was cleaned and impurities were removed using an ultrasonic cleaner or alcohol wipes to prevent loss of glaze adhesion. Glazing was applied using a glaze brush. Glaze slurry (IPS e.max ceram glaze pastes, Ivoclar Vivadent, Schaan, Liechtenstein, and IPS e.max ceram building liquids allround, Ivoclar Vivadent, Schaan, Liechtenstein) was applied evenly and thinly (approximately 20 μm) to the zirconia surface. Repeated application, which could result in uneven thickness, was avoided. Edges could be gently brushed for transition. Sintering was then performed using the following parameters: 403°C for 6 min, then heated at 60°C / min to 1000°C, held for 15 min, vacuum-treated between 450°C and 999°C, and then cooled at 450°C.

[0050] Test example 1. The dental composite ceramic materials prepared in Examples 1-3 were etched with 10 wt% hydrofluoric acid for 15 min to perform surface etching. Scanning electron microscopy and energy dispersive spectrometer were used to detect the surface. Figure 2-4 .

[0051] Depend on Figure 2-3 It can be seen that the formation of crystals improves the hardness and toughness of the glass glaze layer Depend on Figure 4 It can be seen that there is a silicon penetration area, and below the penetration area is a dense zirconia area, which shows that glass has penetrated into the zirconia, forming a mechanical interlocking similar to that formed between the adhesive and dentin during bonding, making its bonding strength higher.

[0052] 2. Characterization tests were performed on the dental composite ceramic materials prepared in Examples 1-3. The test results are as follows: 1. Strength performance testing A dental composite ceramic material with a thickness of 1.02 mm was prepared according to the method described in Examples 1-3, wherein the thickness of the dense zirconia and composite layer was 1 mm, and the thickness of the glass glaze layer was 0.02 mm.

[0053] A microhardness tester was used to test the hardness and toughness of the glaze surface. After loading a force of 9.807 N and holding it for 15 s, a square indentation was obtained. The diagonal length was measured to calculate the hardness of the glaze layer. The crack length was measured to calculate the fracture toughness.

[0054] The indentation method is used to test the hardness and fracture toughness of the glaze surface. The specific operation method is as follows: The HXD-1000TMC hardness tester was used to press out a hardness with an average diagonal length of 1.5 on the flat glaze surface with a load of 9.807 N for 15 s. a The indentation will extend outward along the diagonal direction of the square at the four vertices with a total length of c Microcracks (satisfying c / a>2.5), such as Figure 5 Measure the total length of the crack c Diagonal length of indentation a , and put it into the following formula to obtain the hardness and fracture toughness values ​​of the glaze layer.

[0055]

[0056]

[0057] Where: H Indicates microhardness / MPa; F Indicates loading load / N; a Indicates the diagonal length of the indentation / mm; K IC Indicates fracture toughness / MPam 1 / 2 ; E represents elastic modulus / GPa; c Indicates the total crack length / mm.

[0058] 2. Combined performance testing Using the scratch test, the normal force of the indenter is gradually increased along the scratch path until the glaze layer is separated from the underlying zirconia layer. At this time, the normal force is the bonding force between the glaze layer and the bonding layer.

[0059] The results are shown in Table 1.

[0060] Table 1 Performance test results

[0061] As shown in Table 1, the hardness and toughness of Examples 1-5 are higher than those of Comparative Example 1. The hardness is 1-2 times that of Comparative Example 1, and the bonding strength between the glaze layer and the base zirconia is also higher than that of Comparative Example 1.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a dental composite ceramic material, characterized in that: The following steps are involved: (1) The glass powder raw material and ethanol are mixed uniformly to a slurry, dried, melted and then water quenched, the melting and then water quenching process is repeated, ball milled and sieved to obtain glass powder; (2) Sintering the commercial zirconia and cooling it to room temperature to obtain dense zirconia; (3) The glass powder obtained in step (1) is mixed evenly with deionized water to obtain a slurry, which is sprayed on the surface of the dense zirconia obtained in step (2), dried, sintered, and cooled to room temperature to obtain a dental composite ceramic material.

2. The method for preparing a dental composite ceramic material according to claim 1, wherein: In step (1), the glass powder raw material includes the following components in parts by weight: 58-67 parts of SiO2, 20-30 parts of Li2CO3, 1-10 parts of Al2O3, 1-2 parts of K2CO3, 1-2 parts of ZrO2 and 3-4 parts of P2O5.

3. The method for preparing a dental composite ceramic material according to claim 1, wherein: In step (1), the mixture is evenly mixed into a slurry by ball milling, and the ball milling parameter is 350-450 r / min and the operation is carried out for 1.5-2.5 h.

4. The method for preparing a dental composite ceramic material according to claim 1, wherein: In step (1), the temperature is heated to 1400-1600°C at a heating rate of 8-12°C / min and then kept at this temperature for 1.5-2.5 hours to complete the melting process.

5. The method for preparing a dental composite ceramic material according to claim 1, wherein: In step (2), the commercial zirconia is pretreated and then sintered. The pretreatment process is: cutting the commercial zirconia and then blowing away surface debris with oil-free air.

6. The method for preparing a dental composite ceramic material according to claim 1, wherein: In step (2), the temperature is increased to 850-950°C at a heating rate of 8-12°C / min, and then kept at this temperature for 25-35 minutes. Then, the temperature is increased to 1400-1600°C at a heating rate of 0.3-0.4°C / min, and then kept at this temperature for 1.5-2.5 hours to complete the sintering process.

7. The method for preparing a dental composite ceramic material according to claim 1, wherein: In step (3), the mass ratio of glass powder to deionized water is 1:4-8.

8. The method for preparing a dental composite ceramic material according to claim 1, wherein: In step (3), the glass powder is heated at 0.003-0.025 g / cm 2 Sprayed on the surface of the dense zirconia prepared in step (2).

9. The method for preparing a dental composite ceramic material according to claim 1, wherein: In step (3), the temperature is heated to 900-1500°C at a heating rate of 8-12°C / min and kept at this temperature for 0-2h to complete the sintering process.

10. A dental composite ceramic material produced by the method for producing a dental composite ceramic material according to any one of claims 1 to 9.

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