Dry ice cryogenic hydrophilic activation method for additive manufacturing dental implants and implants thereof

Abstract

The application provides a dry ice low-temperature hydrophilic activation method for additive manufacturing of dental implants and the implant, and belongs to the technical field of surface treatment of oral medical instruments. The method comprises the following steps: providing a titanium alloy dental implant formed by additive manufacturing, pre-blowing the titanium alloy dental implant with compressed air, clamping the titanium alloy dental implant on an anti-collision tool, fixing the anti-collision tool on a rotating shaft, setting forward and reverse rotation and running time on a rotating device, setting a spraying pressure on a dry ice spraying device, simultaneously starting a rotating control device and a dry ice device, generating a dry ice particle spraying flow by using the dry ice low-temperature spraying device, spraying dry ice particles on the surface of the dental implant, and obtaining a dry ice low-temperature hydrophilic activated dental implant. The application can reduce the introduction of exogenous residues and improve the hydrophilic activation state of the surface of the dental implant.

Description

Technical Field

[0001] This application belongs to the field of surface treatment technology for oral medical devices, and particularly relates to a dry ice low-temperature hydrophilic activation method for additive manufacturing of dental implants, and the dental implants obtained by the method. Background Technology

[0002] Dental implants are essential oral medical devices used for the restoration of missing or damaged teeth. Titanium and titanium alloys, due to their good biocompatibility, corrosion resistance, and mechanical properties, have been widely used in the fabrication of dental implants. In recent years, with the development of metal additive manufacturing technology, selective laser melting (SLM) has gradually become a feasible manufacturing method for titanium alloy dental implants. This process can melt metal powder layer by layer according to a pre-set three-dimensional model to prepare dental implants with complex shapes, which improves the flexibility of implant structure design and can create a surface morphology suitable for bone tissue attachment on the implantation segment.

[0003] After dental implantation, its surface condition directly affects blood wetting, protein adsorption, cell adhesion, and subsequent osseointegration. It is generally believed that implant surfaces with better hydrophilicity are more conducive to fluid spread and the establishment of a biological interface in the initial stages of implantation. Therefore, hydrophilicating the surface of dental implants after preparation has become a crucial process for improving their bioactivity.

[0004] Current methods for hydrophilicating or surface-activating dental implants mainly include sandblasting and acid etching, as well as hydrophilic coating. Sandblasting and acid etching can improve the surface roughness and wettability of implants to some extent, but the sandblasting media and acid etching solutions can easily leave residues in complex surface structures. This is especially true for additively manufactured dental implants, where localized depressions and orifice areas are more prone to trapping particles, acid, or cleaning residues, making subsequent removal difficult. While hydrophilic coatings can improve surface wettability, there are issues with the bonding stability between the coating and the titanium alloy substrate. Under implantation screwing and long-term stress conditions, wear, peeling, or localized failure may occur.

[0005] Therefore, the key technical problem that needs to be solved in the existing technology is: how to improve the hydrophilicity of the surface of additively manufactured dental implants while avoiding the residue of exogenous substances such as sandblasting particles, acid etching solutions and coating materials on the implant surface or complex structural areas, so as to obtain a cleaner implant surface condition. Summary of the Invention

[0006] To address the technical problem in existing additive manufacturing dental implants where external substances such as sandblasting particles, acid etching solutions, or coating materials can easily remain on the implant surface or in complex structural areas during surface hydrophilication treatment, thus affecting the cleanliness of the implant surface, this application provides a dry ice low-temperature hydrophilic activation method for additive manufacturing dental implants and the implant thereof.

[0007] In a first aspect, this application provides a dry ice low-temperature hydrophilic activation method for additive manufacturing of dental implants, comprising the following steps: S1. Provides additively manufactured titanium alloy dental implants; S2. Pre-clean the dental implant and clamp the pre-cleaned dental implant into the anti-collision fixture, so that the anti-collision fixture holds the neck of the dental implant. S3. Fix the anti-collision fixture holding the dental implant onto the rotating shaft, and use a dry ice low-temperature spraying device to generate a dry ice particle jet. During the rotation, dry ice particles are sprayed onto the surface of the dental implant to obtain a dental implant that has been activated by dry ice low-temperature hydrophilicity.

[0008] In one optional implementation, the pre-purging in step S2 uses dust-free compressed air with a purging pressure of 0.2 to 0.5 MPa, a purging distance of 10 to 30 mm, and a purging time of 20 to 90 s.

[0009] In one alternative implementation, the anti-collision fixture is a precision three-jaw chuck or a spring chuck.

[0010] In one optional embodiment, in step S3, block dry ice is used as raw material, and the block dry ice is cut into powdered dry ice particles using a dry ice cryogenic jetting device, with a dry ice purity ≥99.9%; the dry ice cryogenic jetting device adopts a conical converging nozzle, which is circular or rectangular in shape, and the jetting velocity of the dry ice particles is 0.2-0.6 kg / min, with a pressure of 0.1-0.6 MPa; before generating the dry ice particle jetting flow, the dry ice cryogenic jetting device is vented to ensure stable air pressure, and the venting time is 3-5 seconds.

[0011] In one optional implementation, in step S3, the rotational speed of the rotating shaft is 25 r / min; the dry ice spraying time on the dental implant surface depends on the implant length. For dental implants with a length of 7-18 mm, the reciprocating spraying time of the dry ice particles is 20-45 s, and the spraying distance is 40 mm.

[0012] In one alternative implementation, the titanium alloy dental implant provided in step S1 is obtained in the following manner: TC4 titanium alloy powder with a particle size of 15-53 μm was selected as the molding material, and the TC4 titanium alloy powder was heated and dried at 110-160℃ for 2-2.5 h in a vacuum environment. Selective laser melting additive manufacturing (SLM) is used to melt and shape dried TC4 titanium alloy powder layer by layer according to a preset three-dimensional model of the dental implant. The laser power of the SLM is 50-250W, the scanning speed is 800-1200mm / s, the scanning interval is 0.1-0.2mm, the layer thickness is 20-40μm, and argon gas is introduced as a protective gas to obtain the titanium alloy dental implant formed by additive manufacturing.

[0013] In one alternative embodiment, the titanium alloy dental implant includes, along the axial direction, an implantation segment for implantation into the alveolar bone and an abutment connection segment for connection to an abutment or healing cap. The outer surface of the implant segment is provided with an external thread structure, and in the area where the external thread structure is located, there is a surface hole structure formed by selective laser melting additive manufacturing process, the surface hole structure including multiple surface holes that do not penetrate the implant.

[0014] On the other hand, this application also provides an additive manufacturing dental implant, which is obtained by the dry ice low-temperature hydrophilic activation method for additive manufacturing dental implants provided in this application.

[0015] Compared with the prior art, this application has the following beneficial effects: First, before dry ice cryogenic blasting of the titanium alloy dental implant, which has been additively manufactured and has had its abutment connection machined, the dental implant is pre-purified, and the implant neck is clamped using anti-collision fixtures. This ensures that some loose particles, cutting debris, and attached impurities are removed from the implant surface before dry ice blasting, while also preventing additional impact damage to the implant surface during clamping. Compared to direct sandblasting, acid etching, or coating treatments, this pretreatment method does not introduce sand particles, acid etching solutions, or coating materials into the implant surface, providing a cleaner and more stable treatment basis for subsequent low-residue hydrophilic activation treatment. This helps reduce the risk of exogenous substances remaining on the surface of the additively manufactured dental implant or in complex structural areas.

[0016] Secondly, this application fixes the anti-collision fixture holding the dental implant to a rotating shaft, and uses a dry ice cryogenic spraying device to generate a jet of dry ice particles to spray the surface of the dental implant during the rotation of the implant. The dry ice particles, driven by compressed air, act at high speed on the implant surface, physically removing dust, trace amounts of loose powder, and weakly bound impurities. Simultaneously, the dry ice particles sublimate upon contact with the implant surface, unlike sandblasting media which leaves solid particle residues in surface depressions, orifices, or complex local structures, and eliminates the need for acid etching solutions or hydrophilic coating materials. Therefore, this application can improve the hydrophilic activation level of the dental implant surface while avoiding the adverse effects of residual exogenous substances such as sandblasting particles, acid etching solutions, and coating materials. Furthermore, the dry ice cryogenic spraying method achieves a relatively clean hydrophilic activated surface, enabling additively manufactured dental implants to form a surface state conducive to liquid spread and the establishment of a bio-interface without relying on sandblasting, acid etching, or coating materials. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart of a dry ice low-temperature hydrophilic activation method for additive manufacturing of dental implants provided in an embodiment of this application; Figure 2 This is a photograph of a dental implant obtained through processing according to an embodiment of this application; Figure 3 This is a diagram illustrating the hydrophilicity testing process for a dental implant according to an embodiment of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0020] like Figure 1 As shown in the figure, this application provides a dry ice low-temperature hydrophilic activation method for additive manufacturing dental implants, including the following steps: S1. Provides additively manufactured titanium alloy dental implants; S2. Pre-clean the dental implant and clamp the pre-cleaned dental implant into the anti-collision fixture so that the anti-collision fixture holds the neck of the dental implant. S3. Fix the anti-collision fixture holding the dental implant onto the rotating shaft, and use a dry ice low-temperature spraying device to generate a dry ice particle jet. During the rotation, dry ice particles are sprayed onto the surface of the dental implant to obtain a dental implant that has been activated by dry ice low-temperature hydrophilicity.

[0021] The dry ice cryogenic hydrophilic activation method for additively manufactured dental implants provided in this application involves pre-purifying the implant before dry ice cryogenic blasting. The implant neck is held in place using anti-collision fixtures. This process removes loose particles, cutting debris, and adhering impurities from the implant surface before dry ice blasting, preventing additional impact damage during clamping. Compared to direct sandblasting, acid etching, or coating treatments, this pretreatment method does not introduce sand particles, acid etching solutions, or coating materials onto the implant surface. This provides a cleaner and more stable foundation for subsequent low-residue hydrophilic activation treatment, reducing the risk of exogenous substances remaining on the surface of the additively manufactured dental implant or in complex structural areas.

[0022] Furthermore, in this embodiment, the anti-collision fixture holding the dental implant is fixed to the rotating shaft, and a dry ice cryogenic spraying device is used to generate a jet of dry ice particles to spray the surface of the dental implant during the rotation of the dental implant. The dry ice particles, driven by compressed air, act at high speed on the surface of the dental implant, physically removing dust, trace amounts of loose powder, and weakly bound impurities. Simultaneously, the dry ice particles sublimate upon contact with the implant surface, unlike sandblasting media which leaves solid particle residues in surface depressions, openings, or complex local structures, and eliminates the need for acid etching solutions or hydrophilic coating materials. Therefore, this embodiment can improve the hydrophilic activation level of the dental implant surface while avoiding the adverse effects of residual exogenous substances such as sandblasting particles, acid etching solutions, and coating materials. Moreover, the dry ice cryogenic spraying method achieves a relatively clean hydrophilic activated surface, enabling the additively manufactured dental implant to form a surface state conducive to liquid spread and the establishment of a bio-interface without relying on sandblasting, acid etching, or coating materials.

[0023] In some embodiments, the pre-purging in step S2 uses dust-free compressed air, with a purging pressure of 0.2–0.5 MPa, a purging distance of 10–30 mm, and a purging time of 20–90 s. During pre-purging, the purging airflow can be moved along the axial direction of the dental implant and the purging direction can be adjusted around the circumference of the dental implant so that the airflow covers the external thread sidewalls, thread grooves, and the area near the surface hole opening.

[0024] Furthermore, the anti-collision tooling is a precision three-jaw chuck or spring chuck.

[0025] Pre-purging is used to remove loose powder, dust, and impurities with weak adhesion from the dental implant surface, as well as impurities that can be directly carried away by the airflow. If the purging pressure is too low, it will be insufficient for loose particles near the orifice and in the thread grooves; if the purging pressure is too high or the purging distance is too short, the local airflow impact can become too concentrated. Controlling the purging pressure, purging distance, and purging time within the above ranges helps to complete the initial cleaning while maintaining processing efficiency. Pre-purging does not replace subsequent dry ice particle spraying; rather, it allows the subsequent dry ice particles to primarily target the loose powder and weakly bound deposits remaining after pre-purging.

[0026] After pre-purging, the dental implant is clamped in an anti-impact fixture. The anti-impact fixture uses a precision three-jaw or spring-loaded chuck to hold the neck of the dental implant. During clamping, the axis of the dental implant is aligned with the subsequent axis of rotation, and the clamping force is controlled to keep the dental implant stable during rotation and spraying, while reducing the possibility of the fixture causing indentations, scratches, or impacts to the neck.

[0027] Positioning the clamping device at the neck of the dental implant reduces the obstruction of the implant's external thread structure and surface bore structure by the anti-collision fixture, keeping the implant as the primary surface to be treated exposed. The precision three-jaw chuck achieves centered positioning through synchronous jaws, while the spring chuck disperses local clamping pressure through circumferential elastic clamping.

[0028] In this embodiment, the pre-purging in step S2 is performed using dust-free compressed air. Specifically, the additively manufactured titanium alloy dental implant can be clamped in an anti-collision fixture, allowing the implant to be fully exposed to the purging airflow. During the pre-purging process, the purging pressure of the dust-free compressed air is controlled at 0.2–0.5 MPa, the purging distance at 10–30 mm, and the purging time at 20–90 seconds. The operator can adjust the nozzle direction according to the shape and structure of the dental implant, allowing the airflow to move axially along the implant or circumferentially around it, thus ensuring the airflow covers the external thread sidewalls, thread grooves, and the area containing the surface hole structure.

[0029] The above parameter range is mainly used for preliminary cleaning of the dental implant surface. A blowing pressure of 0.2–0.5 MPa effectively removes weakly adhered powder particles, processing debris, and loose dust, while avoiding repeated collisions of particles on the surface due to excessive airflow impact. A blowing distance of 10–30 mm ensures good coverage and stability of the airflow after reaching the implant surface, facilitating effective cleaning of different areas. Too close a distance may result in concentrated impact in certain areas, while too far a distance may reduce the ability to remove loose impurities. A blowing time of 20–90 seconds allows for sufficient coverage of the implant surface while maintaining good process efficiency.

[0030] After pre-purging, loosely attached metal powder and environmental dust on the surface of the dental implant can be removed in advance. This step is not intended to replace the subsequent dry ice cryogenic blasting treatment, but rather serves as a pretreatment step before entering the dry ice blasting process. For dental implants formed by additive manufacturing, small amounts of loose particles can easily accumulate in the external thread area, surface hole structure, and local depressions. If these particles directly enter the subsequent dry ice blasting stage, they are prone to movement, tumbling, or local collisions under the impact of high-speed airflow and particles. In this embodiment, by pre-purging to remove easily detachable impurities, the subsequent dry ice particles can act more effectively on the surface attachment layer, weakly bound contaminants, and residual dust, thereby helping to improve the stability of the subsequent processing.

[0031] Furthermore, the clean air itself does not introduce liquid cleaning media, nor does it add a new source of solid particles to the dental implant surface. Therefore, after pre-purging, the dental implant can maintain a relatively clean surface condition for subsequent processes. For additively manufactured dental implants with surface pore structures, this pretreatment method can initially clean loose impurities near the pores and in the thread grooves, reducing the possibility of impurities remaining or re-attaching during subsequent processing, and providing more suitable surface conditions for subsequent dry ice low-temperature hydrophilic activation treatment.

[0032] In some embodiments, in step S3, block dry ice is used as raw material, and the block dry ice is cut into powdered dry ice particles by a dry ice cryogenic jetting device, with a dry ice purity ≥99.9%; the dry ice cryogenic jetting device adopts a conical converging nozzle, which is circular or rectangular in shape, and the jetting velocity of the dry ice particle jet is 0.2-0.6 kg / min, and the pressure is 0.1-0.6 MPa; before generating the dry ice particle jetting flow, the dry ice cryogenic jetting device is vented to ensure stable air pressure, and the venting time is 3-5 seconds.

[0033] In the above embodiments, block dry ice is cut into powdered dry ice particles by the equipment, and then concentrated into a jet stream through a conical converging nozzle under the action of compressed gas. A circular outlet can form a relatively concentrated jet area, while a rectangular outlet can form a jet area that spreads out in one direction. The specific selection can be made according to the length of the dental implant and the area to be treated. The jet mass flow rate and jet pressure jointly affect the number of dry ice particles reaching the surface of the dental implant per unit time and the impact state. Adjusting within the above range can enable the dry ice particles to act on floating powder and weakly bound impurities in thread grooves, surface orifices, and local depressions.

[0034] Before generating the dry ice particle jet, the dry ice cryogenic jetting equipment is vented for 3-5 seconds to stabilize the airflow and jet pressure in the jetting pipeline before the nozzle is aimed at the surface of the dental implant to be treated. This venting process reduces the discontinuous particle supply caused by air pressure fluctuations at the beginning of the jetting process, ensuring a more stable jetting effect on each area of ​​the dental implant after the jetting begins.

[0035] In some embodiments, in step S3, the rotational speed of the rotating shaft is 25 r / min; the dry ice spraying time on the dental implant surface depends on the implant length. For dental implants with a length of 7-18 mm, the reciprocating spraying time of the dry ice particles is 20-45 s, and the spraying distance is 40 mm.

[0036] In this embodiment, the reciprocating jetting refers to the nozzle moving back and forth along the axial direction of the dental implant within the corresponding range of the implant segment while the implant rotates, allowing the jet stream to move from one end of the implant segment to the other and then back. The dental implant rotates at 25 r / min, allowing the external threads, thread grooves, and surface orifices in different circumferential orientations to sequentially enter the jet stream's effective range; the nozzle's axial reciprocating movement ensures that different axial positions are sequentially treated by the jet stream. For shorter dental implants, a relatively shorter jetting time can be selected within the range of 20–45 s; for longer dental implants or implants with a larger surface structure coverage area, a relatively longer jetting time can be selected.

[0037] Maintaining a spray distance of 40mm ensures a stable working space between the nozzle outlet and the dental implant surface. Upon reaching the implant surface, dry ice particles impact and peel away loose particles, residual powder, and weakly bound impurities. The dry ice then sublimates, thus preventing the formation of solid particle residues similar to sandblasting media in threaded grooves, surface orifices, or other local depressions.

[0038] Dry ice cryogenic spraying does not achieve hydrophilic activation by forming an external coating on the dental implant surface. Instead, it reduces loose particles and adhering impurities covering the titanium alloy surface through a continuous process of pre-purging, dry ice particle impaction, and dry ice sublimation. This allows for more thorough exposure of the external threads, surface holes, and micro-undulations formed by additive manufacturing. When the test liquid comes into contact with the treated implant segment, the liquid more easily adheres to and spreads between the external thread grooves, surface hole openings, and adjacent micro-undulations, thereby creating a surface state that has been hydrophilically activated by dry ice cryogenic spraying.

[0039] After dry ice particle spraying is complete, stop the dry ice cryogenic spraying equipment and rotating shaft. Allow the remaining dry ice on and around the dental implant to fully sublimate before releasing the anti-collision fixture and removing the dental implant. During the removal and placement process, use clean clamps to contact the abutment connection section or other non-primary activated areas of the dental implant, avoiding direct contact with the implant surface. Figure 2 A dental implant obtained using the method described in this embodiment is shown.

[0040] In the above embodiments, the titanium alloy dental implant provided in step S1 has been formed into a predetermined integral shape through additive manufacturing, enabling neck clamping and surface spraying treatment. The dry ice low-temperature hydrophilic activation treatment mainly acts on the outer surface of the dental implant to remove floating powder and weakly bound impurities still attached to the surface after pre-blowing, and to fully expose the original surface morphology of the titanium alloy.

[0041] In some embodiments, the titanium alloy dental implant provided in step S1 is obtained in the following manner: TC4 titanium alloy powder with a particle size of 15-53 μm was selected as the molding material, and the TC4 titanium alloy powder was heated and dried at 110-160℃ for 2-2.5 h in a vacuum environment. Selective laser melting additive manufacturing (SLM) is used to melt and shape dried TC4 titanium alloy powder layer by layer according to a preset three-dimensional model of the dental implant. The laser power of the SLM is 50-250W, the scanning speed is 800-1200mm / s, the scanning interval is 0.1-0.2mm, the layer thickness is 20-40μm, and argon gas is introduced as a protective gas to obtain the titanium alloy dental implant formed by additive manufacturing.

[0042] Vacuum heating and drying of TC4 titanium alloy powder can reduce the impact of moisture adsorbed during storage and transfer on the powder spreading and melting processes. Powder with a particle size of 15–53 μm can meet the requirements for layer-by-layer powder spreading and laser melting molding. Laser power, scanning speed, scanning spacing, and layer thickness jointly determine the energy input and interlayer overlap within a unit area. Combining and selecting parameters within the above ranges can form the predetermined three-dimensional structure of the dental implant. Argon gas protection is used to reduce the degree of contact between the titanium alloy powder and the molten pool and air during the molding process.

[0043] In some embodiments, the titanium alloy dental implant includes, along the axial direction, an implant segment for implantation into the alveolar bone and an abutment connection segment for connection to an abutment or healing cap; the outer surface of the implant segment is provided with an external thread structure, and in the region where the external thread structure is located, there is a surface hole structure formed by selective laser melting additive manufacturing process, the surface hole structure including a plurality of surface holes that do not penetrate the implant.

[0044] The external thread structure is used to fit the dental implant with the alveolar bone during implantation, and multiple non-penetrating surface holes form orifices and local depressions on the implant segment surface. This structure gives the implant segment surface more threaded grooves and orifice areas compared to a normal smooth metal surface; therefore, in subsequent surface treatment, different circumferential orientations and different axial positions need to be sequentially subjected to the jet flow.

[0045] This application also provides an additively manufactured dental implant, which is obtained by processing using the dry ice low-temperature hydrophilic activation method for additively manufactured dental implants provided in the above-described embodiments of this application. Figure 2 A photograph of a dental implant obtained by the dry ice low-temperature hydrophilic activation method described in this application is shown. This dental implant was obtained using the aforementioned dry ice low-temperature hydrophilic activation method. The treated dental implant retains its external thread structure of the implantation segment and multiple non-penetrating surface holes, eliminating the need for an additional hydrophilic coating on the surface; the dry ice sublimation leaves no sprayed medium on the implant surface, which helps reduce the residue of exogenous solid particles.

[0046] The dental implants obtained were processed using the aforementioned dry ice low-temperature hydrophilic activation method. After processing, loose powder, loose powder, processing debris, and trace impurities on the implant surface were effectively removed. The surface pore structure and threaded area of ​​the implant segment could undergo relatively uniform physical activation, while the abutment connection segment remained smooth and maintained dimensional accuracy. Since this dental implant process does not require sandblasting, acid etching, or coating materials, the risk of foreign residue retention and coating peeling is reduced, resulting in a cleaner and more uniform hydrophilic state on the implant surface. Dental implants treated in this way can directly proceed to subsequent cleaning, sterilization, and packaging processes. In clinical use, this helps maintain stable surface wettability and bio-interface conditions, while also facilitating initial fluid spread and cell attachment in the alveolar bone.

[0047] Meanwhile, the implantation segment of the additively manufactured dental implant has an external thread structure and a surface hole structure that does not penetrate the implant. The surface itself has certain geometric undulations. Since the dry ice cryogenic blasting in this embodiment does not achieve the hydrophilic effect by coating an external hydrophilic layer, but rather through a continuous process of low-temperature physical impact, particle sublimation, and vacuum impurity removal, it reduces impurities that obscure the surface orifices and thread gaps, allowing the original surface hole structure and micro-undulations to participate more fully in liquid spreading. For titanium alloy surfaces with high surface cleanliness, the liquid spreads more easily among the external threads, surface orifices, and micro-undulations. This embodiment can thus improve the hydrophilic activation degree of the additively manufactured dental implant surface without introducing sandblasting particles, acid etching solutions, or coating materials, and provide a more stable surface foundation for subsequent cleaning, sterilization, and encapsulation.

[0048] To further observe the hydrophilic activation effect of dental implants after the above process, a hydrophilicity test can be performed on the treated dental implant samples, and the surface wetting state can be observed by droplet contact. Figure 3 This paper illustrates the hydrophilicity testing process for dental implants after dry ice low-temperature hydrophilic activation treatment. During the test, a dental implant sample treated with dry ice low-temperature hydrophilic activation was selected, and its abutment connection segment was held in a clean clamp with the implant segment facing the test droplet. A predetermined volume of test droplet was dropped onto a clean surface, and the implant segment was slowly brought close to the test droplet until the end of the implant segment contacted the test droplet. The wetting and spreading of the test liquid in the external thread structure and surface pore structure areas of the implant segment were then observed.

[0049] The aforementioned droplet contact observation test was used to visually verify the hydrophilic activation effect of the treated dental implant. According to the test observation, when the implant segment came into contact with the test droplet, the test liquid adhered to the outer surface of the implant segment and wetted upwards along the external thread structure. As the contact process continued, the coverage area of ​​the test liquid on the implant segment surface gradually increased, and liquid adhesion and spreading phenomena could be observed in the external thread grooves and adjacent surface pore areas. This demonstrates that the implant segment surface of the dental implant treated with dry ice low-temperature hydrophilic activation exhibits a good wetting response to the test liquid.

[0050] In some specific embodiments, the additively manufactured dental implants can be subjected to dry ice low-temperature hydrophilic activation treatment according to the following parameter combinations. Example 1

[0051] Selective laser melting additive manufacturing (SLM) was used to melt and shape dried TC4 titanium alloy powder layer by layer according to a pre-set three-dimensional model of the dental implant. The laser power of the SLM was 50-250W, the scanning speed was 800-1200mm / s, and the layer thickness was 15-30μm. Argon gas was introduced as a protective gas during the layer-by-layer melting and shaping process to print a φ4.5×10 dental implant blank.

[0052] The printed implant was removed from the substrate and mounted on the working shaft of a rotary motor. The motor was adjusted to rotate in both directions, with the rotation speed set to 25 r / min. The time for a 10 mm implant was set to 25 s. Simultaneously, the dry ice spraying equipment was set to a spray pressure of 0.2 MPa, a flow rate of 0.3 kg / min, and a spraying distance of 40 mm for dry ice low-temperature hydrophilic activation treatment. After spraying was completed and the residual dry ice had sublimated, the dental implant was removed. Example 2

[0053] Selective laser melting additive manufacturing (SLM) was used to melt and shape dried TC4 titanium alloy powder layer by layer according to a pre-set three-dimensional model of the dental implant. The laser power of the SLM was 50-250W, the scanning speed was 800-1200mm / s, and the layer thickness was 15-30μm. Argon gas was introduced as a protective gas during the layer-by-layer melting and shaping process to print a φ4.5×10 dental implant blank.

[0054] The printed implant was removed from the substrate and mounted on the working shaft of a rotary motor. The motor was adjusted to rotate in both directions, with the rotation speed set to 25 r / min. The time for a 10 mm implant was set to 25 s. Simultaneously, the dry ice spraying equipment was set to a spray pressure of 0.35 MPa, a flow rate of 0.4 kg / min, and a spraying distance of 40 mm for dry ice low-temperature hydrophilic activation treatment. After spraying was completed and the residual dry ice had sublimated, the dental implant was removed. Example 3

[0055] Selective laser melting additive manufacturing (SLM) was used to melt and shape dried TC4 titanium alloy powder layer by layer according to a pre-set three-dimensional model of the dental implant. The laser power of the SLM was 50-250W, the scanning speed was 800-1200mm / s, and the layer thickness was 15-30μm. Argon gas was introduced as a protective gas during the layer-by-layer melting and shaping process to print a φ4.5×10 dental implant blank.

[0056] The printed implant was removed from the substrate and mounted on the working shaft of a rotary motor. The motor was adjusted to rotate in both directions, with the rotation speed set to 25 r / min. The time for a 10 mm implant was set to 25 s. Simultaneously, the dry ice spraying equipment was set to a spray pressure of 0.5 MPa, a flow rate of 0.5 kg / min, and a spraying distance of 40 mm for dry ice low-temperature hydrophilic activation treatment. After spraying was completed and the residual dry ice had sublimated, the dental implant was removed.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A dry ice low-temperature hydrophilic activation method for additive manufacturing of dental implants, characterized in that, Includes the following steps: S1. Provides additively manufactured titanium alloy dental implants; S2. Pre-clean the dental implant and clamp the pre-cleaned dental implant into the anti-collision fixture, so that the anti-collision fixture holds the neck of the dental implant. S3. Fix the anti-collision fixture holding the dental implant onto the rotating shaft, and use a dry ice low-temperature spraying device to generate a dry ice particle jet. During the rotation, dry ice particles are sprayed onto the surface of the dental implant to obtain a dental implant that has been activated by dry ice low-temperature hydrophilicity.

2. The dry ice low-temperature hydrophilic activation method for additive manufacturing dental implants according to claim 1, characterized in that, In step S2, the pre-purging uses dust-free compressed air with a purging pressure of 0.2–0.5 MPa, a purging distance of 10–30 mm, and a purging time of 20–90 s.

3. The dry ice low-temperature hydrophilic activation method for additive manufacturing dental implants according to claim 1, characterized in that, The anti-collision fixture is a precision three-jaw chuck or spring clamp.

4. The dry ice low-temperature hydrophilic activation method for additive manufacturing dental implants according to any one of claims 1-3, characterized in that, In step S3, block dry ice is used as raw material and is cut into powdered dry ice particles using a dry ice cryogenic blasting device. The dry ice purity is ≥99.9%. The dry ice cryogenic blasting device uses a conical converging nozzle, which can be circular or rectangular. The jet velocity of the dry ice particles is 0.2-0.6 kg / min, and the pressure is 0.1-0.6 MPa. Before generating the dry ice particles jet, the dry ice cryogenic blasting device is vented to ensure stable air pressure. The venting time is 3-5 seconds.

5. The dry ice low-temperature hydrophilic activation method for additive manufacturing dental implants according to claim 4, characterized in that, In step S3, the rotational speed of the rotating shaft is 25 r / min; the dry ice spraying time on the dental implant surface depends on the implant length. For dental implants with a length of 7-18 mm, the reciprocating spraying time of the dry ice particles is 20-45 s, and the spraying distance is 40 mm.

6. The dry ice low-temperature hydrophilic activation method for additive manufacturing dental implants according to claim 4, characterized in that, In step S1, the titanium alloy dental implant is obtained in the following manner: TC4 titanium alloy powder with a particle size of 15-53 μm was selected as the molding material, and the TC4 titanium alloy powder was heated and dried at 110-160℃ for 2-2.5 h in a vacuum environment. Selective laser melting additive manufacturing (SLM) is used to melt and shape dried TC4 titanium alloy powder layer by layer according to a preset three-dimensional model of the dental implant. The laser power of the SLM is 50-250W, the scanning speed is 800-1200mm / s, the scanning interval is 0.1-0.2mm, the layer thickness is 20-40μm, and argon gas is introduced as a protective gas to obtain the titanium alloy dental implant formed by additive manufacturing.

7. The dry ice low-temperature hydrophilic activation method for additive manufacturing dental implants according to claim 6, characterized in that, The titanium alloy dental implant includes, along its axial direction, an implantation segment for implantation into the alveolar bone and an abutment connection segment for connection to the abutment or healing cap. The outer surface of the implant segment is provided with an external thread structure, and in the area where the external thread structure is located, there is a surface hole structure formed by selective laser melting additive manufacturing process, the surface hole structure including multiple surface holes that do not penetrate the implant.

8. An additively manufactured dental implant, characterized in that, The dental implant was obtained by the dry ice low-temperature hydrophilic activation method according to any one of claims 1 to 7.

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