Ceramic dental implant and preparation method and application thereof

Abstract

This invention relates to the field of dental implant technology, and in particular to a ceramic dental implant, its preparation method, and its application. The preparation method includes the following steps: mixing hafnium tetrachloride and zirconium tetrachloride in benzyl alcohol and reacting to obtain HZO piezoelectric ceramic powder; mixing the HZO piezoelectric ceramic powder with a sintering aid to obtain a mixture; using injection molding to prepare the implant body and abutment separately; sintering the implant body and abutment separately, and assembling them to obtain the ceramic dental implant. This invention, through synergistic optimization of material selection, structural design, interface connection, and surface modification, provides a ceramic dental implant with high safety, excellent mechanical properties, reliable interface connection, and piezoelectric activity, showing promising application prospects.

Description

Technical Field

[0001] This invention relates to the field of dental implant technology, and in particular to a ceramic dental implant, its preparation method, and its application. Background Technology

[0002] Dental implants are currently an important means of restoring missing or damaged teeth, and their long-term success rate is closely related to the implant materials and structural design. At present, titanium alloy implants are widely used in clinical practice. These implants have good mechanical strength and biocompatibility, but they still have the following drawbacks: First, the elastic modulus of titanium alloy is much higher than that of human bone tissue, which can easily produce a stress shielding effect and affect the normal metabolism of bone tissue; second, metallic materials are prone to producing artifacts in imaging examinations, interfering with postoperative evaluation; third, there may be a risk of metal ion release after long-term implantation, and some patients may also experience metal allergic reactions, affecting the restorative effect and safety.

[0003] In recent years, ceramic materials have gradually become an important alternative to metal implants due to their excellent biocompatibility, aesthetics, and corrosion resistance. Among them, piezoelectric ceramic materials can generate surface charges under mechanical loads. While some lead-containing piezoelectric ceramics (such as lead zirconate titanate, PZT) exhibit outstanding piezoelectric properties, their lead content poses potential biosafety risks, limiting their application in implantable medical devices. Research on the application of lead-free piezoelectric ceramic materials in dental implants is still in its early stages, and the compatibility of their material preparation processes with implant structural design requires further exploration.

[0004] Regarding the structure of ceramic implants, two-piece implants consist of a separate implant body and an abutment. This design helps maintain implant stability during the intraosseous healing phase, reduces the risk of infection, and allows for flexible adjustment of the superstructure according to different repair needs. However, most existing two-piece ceramic implants are made of alumina non-piezoelectric ceramic materials. Furthermore, their interface design between the implant and abutment generally suffers from insufficient connection strength and poor sealing, which can easily lead to microbial leakage and loosening of the connection, affecting long-term stability. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by providing a ceramic dental implant, its preparation method, and its application. Through the synergistic optimization of material selection, structural design, interface connection, and surface modification, a ceramic dental implant with high safety, excellent mechanical properties, reliable interface connection, and piezoelectric activity is provided.

[0006] To achieve the above objectives, the present invention provides a method for preparing a ceramic dental implant, comprising the following steps: S1. Hafnium tetrachloride and zirconium tetrachloride are mixed in benzyl alcohol and reacted to obtain HZO piezoelectric ceramic powder; S2. Mix HZO piezoelectric ceramic powder and sintering aid to obtain a mixture; S3. The mixture is used to prepare the implant body and abutment separately through injection molding; S4. The implant body and abutment are sintered separately and then assembled to obtain the ceramic dental implant.

[0007] In an optional embodiment, in S1, the molar ratio of hafnium tetrachloride to zirconium tetrachloride is (0.8-1.2):(0.8-1.2); the reaction temperature is 200-250℃, and the reaction time is 47-49 h. After the reaction is completed, the mixture is naturally cooled to room temperature, washed with anhydrous ethanol or n-hexane, and finally dried to obtain HZO piezoelectric ceramic powder.

[0008] In an optional embodiment, in S2, the sintering aid is selected from yttrium oxide (Y2O3); the mass ratio of the HZO piezoelectric ceramic powder to the sintering aid is 100:(0.5-1).

[0009] In an optional embodiment, in S2, the mixing method is ball milling, the ball milling medium is zirconia balls, the ball-to-material mass ratio is (4-6):1, the rotation speed is 300-400 r / min, and the time is 12-16 h; after the mixing is completed, the mixture is dried at 80-100℃ for 8-10 h and passed through a 150-250 mesh sieve to obtain the mixed material.

[0010] In an optional embodiment, in S3, the injection molding process includes the following steps: mixing the mixture and binder at a mass ratio of (8-10):1, heating to 80-100℃ and stirring until homogeneous; then injecting the mixture into a pre-made mold under a pressure of 130-170MPa, and then holding it under pressure at 180-220MPa. After naturally cooling to room temperature, a degreasing treatment is performed to obtain the implant body and abutment. The binder includes paraffin wax and polyvinyl alcohol, and the mass ratio of paraffin wax to polyvinyl alcohol is (2-4):1; the degreasing treatment is performed at a temperature of 400-500℃ for 2-3 hours.

[0011] In an optional embodiment, in S3, the implant body is a columnar structure with a diameter of 3.5-5 mm and a length of 8-14 mm; the surface of the implant body is provided with a threaded structure, which is a trapezoidal fine thread with a pitch of 0.5-0.8 mm and a tooth crest width of 0.1-0.2 mm to avoid stress concentration; the top of the implant body is provided with an internal connection structure.

[0012] In an optional embodiment, in S2, the abutment is a columnar stepped structure with a diameter of 4-6 mm and a total height of 5-9 mm; one end of the abutment is provided with an external connection end adapted to the internal connection structure, and the other end is provided with a prosthesis connection end.

[0013] In one optional embodiment, the inner connection structure and the outer connection end are connected in a staggered pattern to ensure connection stability; the mating gap between the outer connection end of the abutment and the inner connection end of the implant body is controlled within ±0.01mm.

[0014] In an optional embodiment, in step S4, before sintering, the connection end between the implant body and the abutment is precision ground using a diamond grinding wheel until the surface roughness Ra ≤ 0.2 μm. Then, a ceramic slurry is applied to the surfaces of both the implant body and the abutment. The ceramic slurry is formulated from the HZO piezoelectric ceramic powder, has a solid content of 60-70%, and a coating thickness of 0.05-0.1 mm. After coating, the implant body and the abutment are sintered separately. After sintering, they are cooled to room temperature, and their shape is trimmed to remove surface burrs and excess sintered layer. The assembled implant is then the ceramic dental implant.

[0015] In an optional embodiment, in S4, the heating rate of the sintering treatment is 4-6℃ / min, the target temperature is 1400-1500℃, the holding time is 2-3h, and the cooling rate is 2-4℃ / min.

[0016] In an optional embodiment, S4 further includes a surface modification treatment step after assembly; the surface modification treatment is plasma etching, the plasma etching power is 150-200W, the time is 10-15min, and the gas is a mixture of oxygen and argon, the volume ratio of oxygen to argon is 1:(2.5-3.5).

[0017] Plasma etching is used to form a composite structure of micron-scale trenches and nano-scale pores on the implant surface to improve surface roughness and specific surface area, thereby enhancing bone tissue adhesion. The trenches have a width of 1-2 μm and a depth of 0.5-1 μm; the pores have a size of <200 nm.

[0018] The present invention also provides a ceramic dental implant, which is prepared according to the method for preparing the ceramic dental implant.

[0019] The present invention also provides the application of the ceramic dental implant in the preparation of dental restorative instruments.

[0020] The present invention has achieved the following beneficial effects: (1) This invention applies HZO piezoelectric ceramic powder to the field of dental implants. This material does not contain toxic and harmful elements such as lead, avoiding the biosafety hazards of traditional lead-containing piezoelectric ceramics, and simultaneously solving the problems of metal ion precipitation and allergic reactions that may occur with titanium alloy implants. This material has excellent piezoelectric properties, with a piezoelectric constant d. 33 With a strength of ≥200pC / N and a bending strength of ≥350MPa, it not only meets the mechanical performance requirements but also simulates the electrophysiological characteristics of human bone tissue through the piezoelectric effect, providing electroactive functions for the implant.

[0021] (2) This invention adopts a two-section implant structure, with the implant body and abutment designed separately. This facilitates the stability of the implant during the intraosseous healing stage and allows for flexible adjustment of the superstructure according to different repair needs. The implant body and abutment are connected by a quincunx joint, with the gap controlled within ±0.01mm. After connection, a sealing barrier is formed, effectively preventing bacterial infiltration and reducing the risk of peri-implantitis. This solves the problems of insufficient connection strength and poor interface sealing of existing two-section ceramic implants.

[0022] (3) The present invention uses plasma etching process to modify the micro-nano structure of the implant body surface, forming a composite structure of micron-level grooves and nano-level pores on the implant surface, which significantly improves the surface roughness and specific surface area, which is conducive to osteoblast adhesion, proliferation and differentiation, enhances the mechanical interlocking force and biological activity of the implant and bone tissue, and further promotes the stable integration of the implant and bone tissue.

[0023] (4) The ceramic dental implant prepared by the present invention has been tested and all mechanical properties, structural precision and biocompatibility indicators meet the YY / T 0520-2009 standard "General Requirements for Dental Implant Systems" and meet the requirements for clinical use.

[0024] In summary, this invention provides a ceramic dental implant with high safety, excellent mechanical properties, reliable interface connection, and piezoelectric activity through synergistic optimization of material selection, structural design, interface connection, and surface modification, which has good application prospects. Attached Figure Description

[0025] Figure 1 This is a TEM image of the HZO piezoelectric ceramic powder in Example 1 of the present invention at a scale bar of 50 nm; Figure 2 This is a TEM image of the HZO piezoelectric ceramic powder in Example 1 of the present invention at a scale bar of 5 nm; Figure 3 This is an external characterization diagram of the implant body in Embodiment 1 of the present invention; Figure 4 This is an external representation diagram of the base in Embodiment 1 of the present invention. Detailed Implementation

[0026] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0027] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0028] Example 1 This embodiment provides a method for preparing a ceramic dental implant, including the following steps: Hafnium tetrachloride and zirconium tetrachloride were mixed and dissolved in benzyl alcohol at a molar ratio of 1:1, with a mass ratio of hafnium tetrachloride to benzyl alcohol of 0.2:100. After reacting at 220°C for 48 hours, the mixture was naturally cooled to room temperature, washed with anhydrous ethanol, and dried to obtain HZO piezoelectric ceramic powder.

[0029] HZO piezoelectric ceramic powder and yttrium oxide were ball-milled at a mass ratio of 100:0.8, with zirconia balls as the milling medium and a ball-to-material mass ratio of 5:1. The milling speed was 350 r / min, and the time was 14 h. After mixing, the mixture was dried at 90℃ for 9 h and then passed through a 200-mesh sieve to obtain the final mixture.

[0030] The mixture of materials and binder was prepared at a mass ratio of 9:1. The binder was a mixture of paraffin wax and polyvinyl alcohol at a mass ratio of 3:1. The mixture was heated to 90°C and stirred until homogeneous. Then, it was injected into a precast mold under a pressure of 150 MPa and pressed under a pressure of 200 MPa. After naturally cooling to room temperature, it was degreased at 450°C for 2.5 hours to obtain the implant body and abutment.

[0031] The implant body is a cylindrical structure with a diameter of 4 mm and a length of 10 mm. The surface of the implant body has trapezoidal fine threads with a pitch of 0.6 mm and a crest width of 0.15 mm. The top of the implant body has an internal connecting structure.

[0032] The abutment has a columnar stepped structure with a diameter of 5mm and a total height of 6mm. One end of the abutment has an external connection end that matches the internal connection structure, and the other end has a prosthesis connection end. The internal connection structure and the external connection end are connected using a staggered joint. The fit gap between the external connection end of the abutment and the internal connection end of the implant body is controlled within ±0.01mm.

[0033] The connection point between the implant body and the abutment was precision ground using a diamond grinding wheel to a surface roughness of Ra=0.15μm. Subsequently, a ceramic slurry (formulated from HZO piezoelectric ceramic powder) with a solid content of 65% and a thickness of 0.075mm was applied to both the implant body and the abutment. After application, the implant body and abutment were sintered separately. The sintering process was set with a heating rate of 5℃ / min, a target temperature of 1450℃, and a holding time of 2 hours. After sintering, the implant was cooled to room temperature at a cooling rate of 3℃ / min. The shape was then refined, removing surface burrs and excess sintered layer. The assembled implant was the final ceramic dental implant.

[0034] The TEM characterization image of the HZO piezoelectric ceramic powder in Example 1 at a scale bar of 50 nm is shown below. Figure 1 As shown; TEM characterization image of HZO piezoelectric ceramic powder in Example 1 at a scale bar of 5 nm, as shown. Figure 2 As shown. From Figure 1 and 2 The results show that the sample exhibits clear lattice fringes and the lattice distribution is uniform at different magnifications, indicating that 5nm HZO piezoelectric ceramic powder with uniform size has been successfully prepared.

[0035] An external characterization diagram of the implant body in Example 1, as shown below. Figure 3 As shown; an external characterization diagram of the base in Example 1, as shown. Figure 4 As shown.

[0036] Example 2 This embodiment provides a method for preparing a ceramic dental implant, which differs from Embodiment 1 in that: (1) Modify the degreasing treatment temperature to 500℃ and the time to 3h.

[0037] (2) Modify the implant body diameter to 5mm, length to 12mm, pitch to 0.8mm, and tooth crest width to 0.2mm; abutment diameter to 6mm and total height to 7mm.

[0038] (3) Modify the grinding to a surface roughness Ra=0.1μm; the solid content of the ceramic slurry is 70%; the target temperature for sintering is 1500℃ and the holding time is 3h.

[0039] Example 3 This embodiment provides a method for preparing a ceramic dental implant, which differs from Embodiment 1 in that: A plasma etching step was added after assembly. The etching power was set to 200W, the time to 15min, and the gas was a mixture of oxygen and argon with a volume ratio of 1:3.

[0040] Therefore, this invention provides a ceramic dental implant with high safety, excellent mechanical properties, reliable interface connection, and piezoelectric activity through synergistic optimization of material selection, structural design, interface connection, and surface modification, which has good application prospects.

[0041] Finally, it should be noted that the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a ceramic dental implant, characterized in that, Includes the following steps: S1. Hafnium tetrachloride and zirconium tetrachloride are mixed in benzyl alcohol and reacted to obtain HZO piezoelectric ceramic powder; S2. Mix HZO piezoelectric ceramic powder and sintering aid to obtain a mixture; S3. The mixture is used to prepare the implant body and abutment separately through injection molding; S4. The implant body and abutment are sintered separately and then assembled to obtain the ceramic dental implant.

2. The method for preparing a ceramic dental implant according to claim 1, characterized in that, In S1, the molar ratio of hafnium tetrachloride to zirconium tetrachloride is (0.8-1.2):(0.8-1.2); the reaction temperature is 200-250℃ and the reaction time is 47-49h.

3. The method for preparing a ceramic dental implant according to claim 1, characterized in that, In S2, the sintering aid is selected from yttrium oxide; the mass ratio of the HZO piezoelectric ceramic powder to the sintering aid is 100:(0.5-1).

4. The method for preparing a ceramic dental implant according to claim 1, characterized in that, In S3, the surface of the implant body is provided with a threaded structure, and the top of the implant body is provided with an internal connection structure; one end of the abutment is provided with an external connection end adapted to the internal connection structure.

5. The method for preparing a ceramic dental implant according to claim 4, characterized in that, The inner connection structure and the outer connection end are connected by a quincunx pattern.

6. The method for preparing a ceramic dental implant according to claim 1, characterized in that, In S4, before sintering, ceramic slurry is applied to the surfaces of the implant body and the abutment respectively. The ceramic slurry is prepared from the HZO piezoelectric ceramic powder, and the solid content of the ceramic slurry is 60-70%, with a coating thickness of 0.05-0.1 mm.

7. The method for preparing a ceramic dental implant according to claim 1, characterized in that, In S4, the heating rate of the sintering process is 4-6℃ / min, the target temperature is 1400-1500℃, and the holding time is 2-3h.

8. The method for preparing a ceramic dental implant according to claim 1, characterized in that, In S4, after assembly, a surface modification treatment step is also included; the surface modification treatment is plasma etching, the plasma etching power is 150-200W, the time is 10-15min, and the gas is a mixture of oxygen and argon.

9. A ceramic dental implant, characterized in that, The ceramic dental implant is prepared according to any one of claims 1-8.

10. The use of the ceramic dental implant of claim 9 in the preparation of dental restorative instruments.

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