Intelligent implant capable of non-invasively detecting its own bone integration strength and detection device

Abstract

The application belongs to the field of oral medicine, and particularly relates to an intelligent implant capable of non-invasive detection of its own bone bonding strength and a detection device. The intelligent implant comprises a titanium implant, a layer of titanium dioxide nanotubes formed on the outer surface of the titanium implant, and a functional layer formed by ALD at the bottom of the titanium dioxide nanotubes and the inter-tube bottom. The functional layer comprises a ternary oxide layer formed by three metal oxides. The detection device comprises the intelligent implant and an electrode head matched with the titanium implant. The application provides an intelligent implant with the characteristics of "non-invasive safety, precise quantification, long-term stability and dynamic monitoring", which can non-invasively detect the bone bonding strength of the titanium implant and adapt to the complex physiological environment of the oral cavity and the clinical follow-up scene. The application is convenient for doctors to make corresponding treatment on the titanium implant in time, and the surface microstructure of the application can also promote the occurrence of bone bonding, shorten the bone bonding time and accelerate healing.

Description

Technical Field

[0001] This invention belongs to the field of oral medicine, specifically relating to an intelligent implant and detection device that can non-invasively detect its own osseointegration strength. Background Technology

[0002] Dental implants have become a reliable restorative option for patients with missing or damaged teeth to rebuild their teeth and restore chewing function. Current dental implant technology, from bottom to top, consists of a hollow implant body 11, an abutment 12, and a crown 13, as shown in the diagram below. Figure 1 As shown. After the implant is placed in the oral cavity, and before the implant has completed osseointegration, a cover screw is screwed onto the top of the implant.

[0003] The biological basis of dental implants lies in the biosynthesis between bone cells and the titanium surface of the implant after placement. However, after implantation, patients often need to wait 3-6 months for osseointegration before the implant can bear chewing forces. During this process and in routine maintenance after the implant bears force, clinicians rely on experience to judge whether the osseointegration strength can withstand external pressure, which is undoubtedly inaccurate. Furthermore, the complexity of osseointegration differs from that of the general population in patients with diabetes or osteoporosis; therefore, a non-invasive method for assessing implant osseointegration strength is urgently needed clinically.

[0004] The most commonly used non-invasive method in clinical practice for assessing implant osseointegration strength is clinical percussion and palpation. This relies on the dentist tapping the implant with dental instruments or pressing it with their fingers, judging the osseointegration status based on the "crisp / dull sound" and the "presence or absence of mobility." The key indicators are the dentist's subjective evaluation of sound quality and mobility grading. Its greatest advantage is that it requires no specialized equipment, provides immediate feedback, and is extremely low-cost, making it suitable for rapid screening during initial diagnosis and preliminary assessment in primary healthcare institutions. However, this method relies entirely on subjective judgment, cannot be quantified, and is not sensitive enough to early osseointegration abnormalities.

[0005] Another commonly used method is imaging (CBCT / periapical radiographs), which provides non-invasive assessment through visual observation. The core principle is to indirectly determine osseointegration by the width of the radiolucent area at the implant-bone interface: no radiolucent area indicates good osseointegration, while a radiolucent area exceeding 0.2 mm suggests poor integration. Key morphological indicators to focus on include the width of the radiolucent area at the interface and the length of the bone-implant contact. This method offers strong visualization, clearly observing morphological changes in bone tissue, and is primarily used for postoperative morphological assessment of osseointegration and screening for complications such as peri-implantitis. However, imaging methods are susceptible to artifacts and only reflect morphological characteristics, failing to capture the essential mechanical strength of osseointegration.

[0006] Another commonly used method is the resonance frequency method. Its core principle is that the inherent resonance frequency of the composite system formed by the implant and bone tissue increases with the strength of bone integration. This frequency is excited and detected using specialized instruments to complete the assessment. The key indicator is the implant stability coefficient (ISQ) value, ranging from 1 to 100. This method is simple to operate, can be completed within 5 minutes, and has good repeatability. However, its quantitative accuracy is limited, with an error of approximately ±10%. It is also easily affected by factors such as implant morphology and soft tissue thickness. It is mainly used for routine follow-up at 1 week, 1 month, and 3 months post-surgery to achieve a preliminary assessment of stability, remaining at a qualitative or semi-quantitative level with limited precision.

[0007] In summary, current clinically used non-invasive methods for assessing implant osseointegration are insufficient for accurately and effectively measuring osseointegration strength repeatedly and preparing for subsequent implant repair, thus failing to meet the needs of precise clinical assessment. While existing invasive methods such as push-out tests and histological sectioning offer high precision, they require disruption of the osseointegration interface and rely on ex vivo specimens, making them unsuitable for dynamic monitoring of clinical patients. Therefore, there is an urgent need in the field for a non-invasive, real-time quantitative testing device to assess implant osseointegration strength; or, in other words, the field needs a smart implant capable of non-invasively measuring its own osseointegration strength. Summary of the Invention

[0008] The present invention first provides a smart implant capable of non-invasively detecting its own bone integration strength, comprising a titanium implant and a layer of titanium dioxide nanotubes formed on the outer surface of the titanium implant, and a functional layer formed in the inner bottom and inter-tube bottom ALD of the titanium dioxide nanotubes; the functional layer comprises a ternary oxide layer formed of three metal oxides.

[0009] In this invention, ALD refers to atomic layer deposition.

[0010] In this invention, the nanostructure of ternary mixed oxide is combined with titanium dioxide nanotubes, thereby achieving a fusion of nanogating and electrochemical sensing.

[0011] In one specific embodiment, the functional layer comprises oxides of molybdenum, iron, and cobalt.

[0012] In the functional layer of this invention, molybdenum oxide is used for conducting electricity, iron oxide is used for undergoing redox reactions, and cobalt oxide is used for amplifying weak currents.

[0013] In one specific embodiment, the titanium dioxide nanotubes have a diameter of 80~200nm and a length of 1.0~1.2μm.

[0014] In one specific implementation, the thickness of the functional layer is 20~25nm.

[0015] In one specific embodiment, it further includes a first annular electrode disposed at the top of the titanium implant and a rod-shaped electrode disposed at the bottom of the titanium implant and extending through both the top and bottom ends.

[0016] The present invention also provides a detection device, including the smart implant as described above and an electrode head for matching the titanium implant, wherein a second annular electrode matching a first annular electrode is provided on the upper part of the electrode head, and a contact electrode matching a rod-shaped electrode is provided on the bottom of the electrode head.

[0017] After testing the bone integration strength of the titanium implant using the electrode head described in this invention, remove the electrode head and screw a cover screw into the titanium implant.

[0018] In one specific embodiment, an external thread is provided on the outer surface of the titanium implant, an internal thread is provided on the inner surface of the titanium implant, and an external thread matching the internal thread of the titanium implant is provided on the outer surface of the electrode head.

[0019] In one specific embodiment, an external power supply and a display are also connected to the electrode head.

[0020] The present invention also provides a method for preparing the smart implant as described above, the method comprising the following steps: Step A, pretreatment and activation of titanium implant substrate; Step B, anodic oxidation growth to form a titanium dioxide nanotube array; Step C, selective removal of the barrier layer at the bottom of the titanium dioxide nanotubes; Step D, surface passivation and atomic layer deposition to form a functional layer; Step E, post-treatment and functional activation of the functional layer.

[0021] In one specific embodiment, step A includes mechanical polishing, chemical cleaning, oxalic acid aqueous solution treatment, hydrofluoric acid solution treatment, and drying; step B includes injecting electrolyte into a polytetrafluoroethylene electrolytic cell using the titanium implant obtained in step A as the anode and a high-purity platinum sheet as the cathode, oxidizing under DC voltage, and then calcining and cooling at 400-500°C to form titanium dioxide nanotubes; step C includes chemically etching the titanium implant obtained in step B using a mixture containing hydrofluoric acid and nitric acid, and then rinsing after neutralization; step D includes passivation using silane vapor, and also includes sequentially depositing molybdenum oxide for 8-20 cycles, iron oxide for 50-80 cycles, and cobalt oxide for 3-7 cycles using ALD; step E includes first performing low-temperature plasma treatment, then surface hydroxylation, and finally electrochemical activation treatment.

[0022] The detection principle of this invention is as follows: if the titanium implant has already integrated with the bone, the openings of the titanium dioxide nanotubes are sealed; if the titanium implant has not yet integrated with the bone, the openings of the titanium dioxide nanotubes are not sealed. Oral tissue fluid or blood can enter the titanium dioxide nanotubes. When the entire functional layer is energized, iron oxide undergoes an oxidation-reduction reaction. By measuring the resistance or potential at the electrode tip, the proportion of exposed titanium dioxide nanotubes can be determined. When all the openings of the titanium dioxide nanotubes are covered, the bone integration strength of the titanium implant is the highest; when all the openings of the titanium dioxide nanotubes are exposed, the bone integration strength of the titanium implant is the lowest. The data on the bone integration strength can be directly displayed on the monitor.

[0023] Beneficial Effects: This invention provides an intelligent implant and detection device that combines the characteristics of "non-invasive safety, precise quantification, long-term stability, and dynamic monitoring." It can non-invasively detect the osseointegration strength of titanium implants, adapting to the complex physiological environment of the oral cavity and clinical follow-up scenarios. The intelligent implant provided by this invention facilitates timely treatment of titanium implants by dentists; its surface microstructure can also promote osseointegration, shorten osseointegration time, and accelerate healing.

[0024] The intelligent implant described in this invention also possesses at least the following advantages: 1. Safe design of "power-off release": The sensing process of this invention does not consume hydrogen ions; it is merely a temporary "borrowing" and "returning." After detection, the local hydrogen ion concentration quickly returns to equilibrium, without affecting normal bone metabolism. The sensor itself returns to an inert state after power failure, with no continuous electrochemical activity and no risk of foreign body reaction. 2. Minimally invasive and interference-free: The detection voltage and current are both below the human perception threshold and physiological safety range. The entire physical connection process does not damage soft tissue or disrupt the bone integration interface, representing a truly functional minimally invasive diagnosis. 3. Quantitative and objective: This invention transforms the traditional judgment relying on X-ray grayscale images (two-dimensional, subjective, and delayed) into digital quantitative indicators, greatly improving the accuracy and repeatability of the assessment. It provides doctors with objective data support for judging healing progress, determining weight-bearing timing, and early detection of poor healing.

[0025] Furthermore, in the field of clinical application, the intelligent implant and detection device described in this invention also have the following effects: 1. Routine postoperative monitoring: Establishing an individualized "bone integration healing curve" for each patient, enabling personalized management. Objectively comparing the differences in healing dynamics among different patients, different surgical procedures, and different implantation sites. 2. High-risk case management: Closer monitoring of cases with potentially insufficient healing capacity, such as patients with osteoporosis, smokers, and diabetic patients, enabling early warning. Signals of bone integration arrest or early bone resorption can be detected before clinical signs appear. 3. Precise decision-making regarding the timing of secondary surgery and repair: Traditionally, the timing of secondary surgery or permanent repair is mainly based on empirical time. This device can provide a clear "functional healing index." When the BIC% (bone integration rate) reaches a preset safety threshold (e.g., >75%), it can be safely performed, avoiding micromovement and failure caused by premature weight-bearing. 4. Scientific research and product evaluation: Providing an in vivo, real-time, and quantitative gold standard for evaluating the efficacy of novel implant surface treatment technologies, bone augmentation materials, and healing-promoting drugs. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of dental implants being placed in the oral cavity using existing technology.

[0027] Figure 2 This is a schematic diagram of the structure of the intelligent implant and detection device of the present invention.

[0028] Figure 3 The images are SEM images of the titanium dioxide nanotubes formed on the titanium implant before the functional layer was deposited in the ALD, and after the formation of the titanium dioxide nanotubes on the titanium implant. The scale bar is 4 μm.

[0029] Figure 4 The images are SEM images of the titanium implant before the functional layer was deposited in the ALD and after titanium dioxide nanotubes were formed on the titanium implant. The scale bar is 2 μm.

[0030] Figure 5 The images are SEM images of the ALD before the functional layer is deposited and after titanium dioxide nanotubes are formed on the titanium implant. The scale bar is 1 μm and the magnification is 150,000×, which is 150,000 times the image size.

[0031] Figure 6 The images are SEM images of the ALD before the functional layer is deposited and after titanium dioxide nanotubes are formed on the titanium implant. The scale bar is 1 μm and the magnification is 200,000×, which is 200,000 times the image size.

[0032] Figure 7 The images show EDS energy dispersive spectroscopy analysis before the deposition of functional layers in the ALD and after the formation of titanium dioxide nanotubes on the titanium implant, specifically layered EDS images containing titanium and oxygen.

[0033] Figure 8The images show EDS (Energy Dispersive Spectroscopy) analysis of titanium before the deposition of the functional layer in the ALD and after the formation of titanium dioxide nanotubes on the titanium implant, specifically the EDS image of titanium.

[0034] Figure 9 The images show EDS (Energy Dispersive Spectroscopy) analysis of titanium dioxide nanotubes before the deposition of the functional layer in the ALD and after their formation on the titanium implant, specifically the EDS images of oxygen.

[0035] Figure 10 The image shows a SEM image after the functional layer was deposited in the ALD, with a scale bar of 4 μm.

[0036] Figure 11 The image shows a SEM image after the functional layer was deposited in the ALD, with a scale bar of 2 μm.

[0037] Figure 12 The image is a SEM image of the functional layer deposited in ALD, with a scale bar of 1 μm and magnified 150,000 times.

[0038] Figure 13 The image is a SEM image of the functional layer deposited in ALD, with a scale bar of 1 μm and magnified 200,000 times.

[0039] Figure 14 This is an EDS energy dispersive spectroscopy (EDS) analysis image after the functional layer is deposited in ALD, specifically an EDS layered image containing titanium, oxygen, iron, cobalt, and molybdenum.

[0040] Figure 15 This is an EDS (Energy Dispersive Spectrum) analysis diagram after the functional layer is deposited in ALD, specifically an EDS diagram of titanium.

[0041] Figure 16 This is an EDS (Energy Dispersive Spectrum) analysis diagram after the functional layer is deposited in ALD, specifically an EDS diagram of oxygen.

[0042] Figure 17 This is an EDS (Energy Dispersive Spectrum) analysis diagram after the functional layer is deposited in ALD, specifically an EDS diagram of iron.

[0043] Figure 18 This is an EDS (Energy Dispersive Spectrum) analysis diagram after the functional layer is deposited in ALD, specifically an EDS diagram of cobalt.

[0044] Figure 19 This is an EDS (Energy Dispersive Spectrum) analysis diagram after the functional layer is deposited in ALD, specifically an EDS diagram of molybdenum.

[0045] Figure 20 This is a schematic diagram of the functional layer, namely the ternary mixed-valence nanostructure, described in this invention.

[0046] Figure 21Line graphs showing the resistivity of the smart implant surface under different conditions when simulated bone tissue (hydroxyapatite, HA) is used. The unit of resistivity is Ω·cm.

[0047] Figure 22 Line graphs showing the conductivity of the smart implant surface under different conditions when simulated bone tissue (hydroxyapatite, or HA) is used. The unit of conductivity is S / cm, or Siemens per centimeter. Detailed Implementation

[0048] The detection device provided by this invention is intended for clinical application, aiming to transform the complex biological process of bone integration into a rapid, non-invasive, quantitative, and standardized clinical examination. Its core design philosophy is "on-demand power supply, cyclic detection, instant reading, and tissue-friendly." The complete application scheme is as follows.

[0049] This invention provides a smart implant capable of non-invasively detecting its own bone integration strength, comprising a titanium implant 1 and a layer of titanium dioxide nanotubes 2 formed on the outer surface of the titanium implant 1, and a functional layer 3 formed in the inner bottom and inter-tube bottom ALD of the titanium dioxide nanotubes 2; the functional layer 3 comprises a ternary oxide layer formed of three metal oxides. The functional layer 3 comprises oxides of molybdenum, oxides of iron, and oxides of cobalt. The diameter of the titanium dioxide nanotubes 2 is 80~200nm, and the length is 1.0~1.2μm. The thickness of the functional layer 3 is 20~25nm. The smart implant also includes a first annular electrode 4 disposed at the top of the titanium implant 1, and a rod-shaped electrode 5 disposed at the bottom of the titanium implant 1 and extending through both the top and bottom ends.

[0050] The present invention also provides a detection device, comprising the intelligent implant 1 as described above and an electrode head 6 for matching the titanium implant 1. A second annular electrode 7 matching a first annular electrode 4 is disposed on the upper part of the electrode head 6, and a contact electrode 8 matching a rod-shaped electrode 5 is disposed on the bottom of the electrode head 6. An external thread is provided on the outer surface of the titanium implant 1, and an internal thread is provided on the inner surface of the titanium implant 1. An external thread matching the internal thread of the titanium implant 1 is provided on the outer surface of the electrode head 6. An external power supply and a display are also connected to the electrode head 6.

[0051] The present invention also provides a method for preparing the smart implant as described above, the method comprising the following steps: Step A, pretreatment and activation of the titanium implant 1 substrate; Step B, anodic oxidation growth to form an array of titanium dioxide nanotubes 2; Step C, selective removal of the barrier layer at the bottom of the titanium dioxide nanotubes 2; Step D, surface passivation and atomic layer deposition to form a functional layer 3; Step E, post-treatment and functional activation of the functional layer 3. Step A includes mechanical polishing, chemical cleaning, oxalic acid aqueous solution treatment, hydrofluoric acid solution treatment, and drying; Step B includes injecting electrolyte into a polytetrafluoroethylene electrolytic cell using the titanium implant 1 obtained in Step A as the anode and a high-purity platinum sheet as the cathode, oxidizing under DC voltage, and then calcining and cooling at 400~500℃ to form titanium dioxide nanotubes 2; Step C includes chemically etching the titanium implant 1 obtained in Step B using a mixture containing hydrofluoric acid and nitric acid, and then rinsing after neutralization; Step D includes passivation using silane vapor, and also includes sequential deposition of molybdenum oxide for 8~20 cycles, iron oxide for 50~80 cycles, and cobalt oxide for 3~7 cycles using ALD; Step E includes first performing low-temperature plasma treatment, then surface hydroxylation, and finally electrochemical activation treatment.

[0052] Example 1

[0053] This embodiment illustrates the application process and working principle of the intelligent implant and detection device described in this invention.

[0054] (I) System hardware configuration and preoperative preparation

[0055] 1. Intelligent implant (already implanted in the patient): The surface is coated with a special layer, i.e., a functional layer, featuring a ternary mixed-valence oxide nanosensing structure; the interior contains a sealed micro-electrical interface (including the first annular electrode 4 and the rod-shaped electrode 5), corresponding to the electrodes of a disposable electrode head connected to a handheld osteosynthesis diagnostic instrument. The surface morphology of the electrode head is similar to that of the implant abutment or cover screw, and it can be screwed into the hollow portion of the implant. During the implantation surgery, the operation procedure of the intelligent implant is exactly the same as that of a conventional implant, requiring no special steps.

[0056] 2. A handheld osseointegration diagnostic instrument for clinicians: Its appearance resembles a large oral endoscope or electronic periodontal probe, conforming to ergonomic principles. The top features a replaceable, sterile, disposable electrode tip, internally integrating a miniature three-electrode system (working electrode, counter electrode, and quasi-reference electrode, wherein the working electrode and quasi-reference electrode are configured as the contact electrode 8, and the counter electrode is configured as the second ring electrode 7). Its main unit includes: a microprocessor, a precision potentiostat, a wireless module, a display screen, and a rechargeable battery.

[0057] (II) Standardized Operating Procedures for Clinical Follow-up

[0058] When the patient returns to the hospital for a post-operative check-up as scheduled, follow these steps.

[0059] Step 1: Patient Preparation and Interface Exposure. The patient sits in the dental chair and undergoes routine intraoral disinfection. The dentist removes the overlay screw, healing abutment, or temporary crown above the implant, exposing the micro-electrical interface located inside the implant.

[0060] Step 2: Connect the diagnostic device. Remove the disposable electrode tip from the sterile packaging and attach it to the handheld diagnostic instrument. Gently and vertically insert the probe into the open channel of the implant until a slight mechanical stop is felt, indicating that a stable and reliable physical and electrical connection has been established between the electrical contacts inside the electrode tip (second ring electrode 7 and contact electrode 8) and the interface inside the implant (first ring electrode 4 and rod electrode 5). The instrument will beep, and the screen will display "Connection successful, ready for testing".

[0061] Step 3: One-button start of the detection cycle. The doctor presses the start button on the instrument. The process is then fully automatic, requiring no manual intervention. The instrument automatically executes a complete "capture-measurement-release" electrochemical cycle, which takes approximately 30-60 seconds: Capture phase (approximately 15 seconds): The instrument applies a safe low negative voltage pulse (e.g., -0.4V) to the sensing film (functional layer) on the implant surface. This voltage drives the film to undergo an electrochemical reaction, actively capturing and temporarily binding free hydrogen ions from the surrounding tissue fluid. During this phase, the hydrogen ion concentration in the microenvironment around the implant undergoes a transient, minute, localized change. Measurement phase (approximately 10 seconds): The instrument switches to high-precision impedance measurement mode, rapidly scanning and recording the electrochemical impedance spectrum of the sensing interface at this time. The characteristic values ​​of this spectrum (such as low-frequency capacitance) directly correspond to the number of sensing units that can participate in the reaction, i.e., the area of ​​titanium dioxide nanotubes that are not blocked by bone tissue. Release and reset phase (approximately 15 seconds): The instrument applies a reverse positive voltage pulse. The voltage drives the sensing membrane to undergo a reverse reaction, releasing all the hydrogen ions captured in the previous stage back into the surrounding tissue fluid. The membrane's chemical state returns to its initial level before detection, and the sensor is "reset," preventing the accumulation of any ions or charges in the body. Throughout the process, the patient experiences no pain or discomfort, only a slight beeping sound from the instrument.

[0062] Step 4: Obtaining Results and Clinical Decisions. After the cycle, the instrument screen immediately displays clear results: Core Indicator: "Bone Integration Rate (BIC%)", for example, "78.5%". Trend Analysis: Comparison with the previous follow-up result (e.g., "5.2% improvement compared to the last time"). Healing Stage Assessment: Intelligent judgment based on the database (e.g., "Mid-stage healing, good progress"). Clinical Recommendations: Suggestions based on a preset algorithm (e.g., "Continue routine healing, follow-up recommended in 8 weeks").

[0063] Step 5: Disconnection and Post-operative Care. The dentist gently removes the electrode tip from the implant. The implant interface is cleaned, and a sterile covering screw, healing abutment, or temporary crown is screwed back in. Follow-up examination complete.

[0064] (III) Working Principle

[0065] This invention constructs millions of vertically aligned titanium dioxide nanotubes on the surface of medical titanium implants. Each nanotube is an independent sensing unit. Its unique feature lies in the precise integration of a molybdenum-iron-cobalt ternary oxide active film at the bottom of each nanotube using atomic layer deposition technology. This film possesses two core capabilities: excellent electronic conductivity and the ability to reversibly alter its surface chemical state through an applied voltage, thereby efficiently and reversibly "capturing" and "releasing" hydrogen ions. The walls and openings of the titanium dioxide nanotubes: the upper and middle sections and the openings remain pristine, highly biocompatible titanium dioxide, specifically designed to guide and promote bone cell growth.

[0066] Its working principle is an ingenious process of "physical screening → electrochemical counting → digital conversion".

[0067] Physical gating (natural selection): After implantation, new bone tissue grows along the implant surface. In areas of good osseointegration, bone tissue grows in and completely seals the openings of the nanotubes, much like adding a sealing cap to a pipe. In unintegrated areas, the nanotube openings remain open, freely communicating with the surrounding environment filled with tissue fluid (containing free hydrogen ions). In this way, the macroscopically continuous osseointegration interface is microscopically transformed into millions of "on" or "off" binary states.

[0068] Electrochemical Cycle (Active Counting): When an external diagnostic instrument is connected and powered on, it drives a standardized detection cycle. Capture: A safe negative voltage is applied to the implant. This voltage signal is transmitted through a titanium substrate to the active film, or functional layer, at the bottom of each nanotube. In open nanotubes, the voltage drives an electrochemical reaction in the film, making its surface negatively charged, thereby "attracting" hydrogen ions from the tissue fluid outside the tube opening and temporarily binding them to the film surface. A key principle is that only open nanotubes allow the film at their bottom to contact and capture hydrogen ions. Blocked nanotubes, with their internal films isolated, cannot participate in this process.

[0069] Measurement: The instrument then measures the overall electrochemical response (e.g., charge transfer resistance) of the entire sensor array at this point. The intensity of this response signal (S) is directly proportional to the total area of ​​all active films involved in capturing hydrogen ions, which is the number of all open nanotubes.

[0070] Release and Reset: Then a positive voltage is applied to drive the membrane to undergo a reverse reaction, "pushing" all the captured hydrogen ions back into the tissue fluid. The sensor returns to its initial state and leaves no foreign matter after power is cut off.

[0071] Digital conversion (calculation of bone integration rate): The instrument internally stores a baseline signal S_max measured at the initial implantation stage (theoretically, all nanotubes are open, and the bone integration rate is 0%). At any follow-up examination, the current signal S is measured. Since S is only proportional to the number of open nanotubes, S / S_max represents the proportion of the interface area that has not yet integrated (opened). The proportion of the area that has integrated, i.e., the bone integration rate, can be obtained using a simple formula: Bone integration rate (%) = [1 - (S / S_max)] × 100%.

[0072] This invention utilizes nanotechnology to transform the implant surface into a "sensor array" containing a massive number of independent detection units. Bone tissue growth itself marks the state of each sensing unit (occluded = integrated, open = not integrated). The electronic device of this invention efficiently "counts" the number of these open units through a rapid, reversible "power-on-detection" cycle and converts it into a precise percentage figure, i.e., the bone integration rate. The entire process does not interfere with healing, and the implant returns to its original state after detection, achieving in-situ, quantitative, and dynamic intelligent monitoring of the biological healing process.

[0073] Example 2

[0074] This embodiment describes the method for forming the intelligent implant described in this invention.

[0075] The core objective of the preparation of the intelligent implant described in this invention is to construct a microscopic sensing interface on the surface of a medical titanium implant that can monitor bone integration in real time. The entire process begins with the precise pretreatment of the implant substrate. Through mechanical polishing and chemical cleaning, a clean and active pure titanium surface is obtained, laying the foundation for the subsequent growth of nanostructures.

[0076] Subsequently, titanium dioxide nanotube arrays were grown in situ on the implant surface using anodizing. In a fluorinated ethylene glycol electrolyte, a constant DC voltage was applied, and through the dynamic equilibrium of electrochemical oxidation and fluoride ion chemical dissolution, vertically ordered nanotubes were self-organized. Their diameter and depth were precisely controlled by voltage and time, and finally, after annealing, they were transformed into a well-crystallized anatase phase. This porous structure serves as the carrier for subsequent sensing functions, and its channels will be the sites where bone tissue ingrowths and physically seals the implant.

[0077] The key to achieving selective sensing lies in functionalizing only the bottom of the nanotube. First, a gentle chemical etching process precisely removes the insulating titanium dioxide barrier layer at the bottom of the nanotube, exposing the conductive titanium substrate underneath, while preserving the complete structure of the nanotube wall. Then, a layer of long-chain silane inhibitors is self-assembled on the surface of the tube wall, significantly reducing its surface energy and making it hydrophobic and chemically inert.

[0078] Building upon this foundation, atomic layer deposition (ALD) technology was used to perform the core selective deposition. In a vacuum reaction chamber, the implant was alternately exposed to the vapors of three organometallic precursors—molybdenum hexacarbonyl, ferrocene, and cobalt dicene—and their co-reactant ozone. Due to the extremely low adsorption energy of the precursor molecules on the hydrophobic tube walls and their high reactivity on the exposed conductive titanium substrate, coupled with the diffusion-limiting effect of the deep pores in the nanotubes, the deposition reaction was selectively confined to the bottom region of each nanotube. By carefully designing the sequence and ratio of supercycles—that is, sequentially and cyclically depositing molybdenum, iron, and cobalt oxide subcycles a certain number of times—an approximately 20 nm thick, amorphous molybdenum-iron-cobalt ternary mixed-valence oxide film was ultimately constructed at the bottom of the tube. This film is not atomically homogeneous but forms a gradient composite structure with a molybdenum-rich network as a continuous conductive framework, embedded with iron-rich and cobalt-rich nano-active clusters, exhibiting both excellent electronic conductivity and active surface electrochemical properties.

[0079] After atomic layer deposition, the surface of the thin film (functional layer) is activated through low-temperature plasma treatment and controlled wet chemical treatment to optimize the density and state of its surface hydroxyl groups, thereby enhancing its ability to bind hydrogen ions. Finally, the prepared functional implant undergoes a rigorous multi-stage cleaning and sterilization process that meets medical device standards, becoming an intelligent implant integrating millions of independent microsensing units. Each sensing unit is a nanotube with an active thin film at the bottom and an open top. The presence or absence of its electrochemical signal directly corresponds to whether its opening is blocked by newly formed bone tissue, thus converting the macroscopic bone integration state into a quantitatively measurable electrical signal. This fabrication process integrates electrochemistry, surface science, and advanced thin-film technology, achieving a leap from passive medical metals to active intelligent sensing interfaces.

[0080] In this invention, the roles of each component in the ternary mixed-valence oxide nanostructure include:

[0081] 1.MoO x It forms the framework that ensures stable electronic pathways. Constructing a high electron conduction network ensures a reliable physical basis for signal acquisition. Detailed mechanism: In nanoporous structures, MoO... x (especially rich in Mo) 5+ / Mo 6+MoO₂ (mixed valence state) inherently possesses good metallic / semiconductor conductivity. Its key role lies in ensuring electrical conductivity even during the early bone healing stage, when the contact area between the implant and newly formed bone tissue is limited and the contact points are discontinuous. x The phase can also form a continuous electronic conduction path inside the thin film. This is like building a micro-electric grid inside the sensor. This ensures that the electrochemical signals generated from the FeO sensitive sites (such as potential or charge transfer generated by ion exchange) can be collected and transmitted to the subsequent processing circuit with low loss and stability, effectively avoiding signal attenuation or noise increase caused by poor contact, which is the key to maintaining long-term signal stability.

[0082] 2. FeO acts as the sensory receptor for the chemical environment. As a direct pH-sensitive unit, it converts biochemical changes into initial electrical signals. Detailed mechanism: FeO (especially non-stoichiometric Fe) 1-x O) The surface is rich in hydroxyl functional groups (-OH). When the pH of the microenvironment around the implant changes due to bone metabolic activities (such as osteoclast acid production and osteoblast alkalization), H + or OH - It undergoes reversible protonation / deprotonation reactions with these surface hydroxyl groups. This process directly alters the charge state and interfacial potential of the FeO surface, thereby triggering significant changes in charge transfer resistance or open-circuit potential in electrochemical impedance spectroscopy (EIS). Therefore, FeO is a direct sensor of the local chemical environment, providing firsthand information reflecting osteocyte activity and inflammatory status.

[0083] 3. Co3O4 acts as an amplifier to enhance signal strength. It optimizes electrochemical reaction kinetics, acts as an electrocatalytic enhancer, and amplifies weak chemical signals into clear and measurable electrical signals. Detailed mechanism: Co3O4 possesses abundant oxygen vacancies and mixed valence states (Co... 2+ / Co 3+ During sensing, it amplifies the signal by accelerating the rate of interfacial charge transfer. Specifically, it accelerates the electron transfer process involved in the protonation reaction on the FeO surface or catalyzes the conversion of reactive oxygen species in the surrounding electrolyte, thereby producing a larger current response or a more significant impedance change under the same pH change. This is crucial for miniaturized implantable sensors with limited active area, ensuring that even with weak interfacial changes, the generated signal has sufficient strength and signal-to-noise ratio for accurate capture and analysis by subsequent circuitry.

[0084] Example 3

[0085] This embodiment is also a method for forming the intelligent implant described in this invention.

[0086] Phase 1: Titanium Substrate Pretreatment and Activation. Preparation begins with rigorous pretreatment of medical-grade pure titanium or titanium alloy implants. First, mechanical polishing is performed using a sequence of wet sandpaper with increasing grit from 800# to 2000# until the implant surface roughness is below 0.1 μm. This is followed by a three-step chemical cleaning process: sequential ultrasonic cleaning for 10 minutes each in acetone, anhydrous ethanol, and deionized water to thoroughly remove organic and inorganic contaminants. To further activate the surface, the implant is immersed in a 10% oxalic acid aqueous solution at 80°C for 30 minutes to dissolve the natural oxide layer on the surface. Finally, a brief immersion in a 2% hydrofluoric acid solution for 15 seconds forms a fresh, highly active metallic titanium surface. Immediately after this step, the implant is rinsed with deionized water and dried with high-purity nitrogen gas, ready for the anodizing process.

[0087] The second stage: anodic oxidation growth of titanium dioxide nanotube arrays. In a polytetrafluoroethylene electrolytic cell controlled at 20°C, a pretreated titanium implant was used as the anode, and a high-purity platinum sheet as the cathode. An electrolyte composed of ethylene glycol, 0.25 wt% ammonium fluoride, and 2 vol% deionized water was injected. A DC voltage was applied: initially increased from 0V to 40V at a rate of 1V per second, and then maintained at a constant voltage of 40V for 2 hours. During this process, the electric field drove the anodic oxidation of titanium to generate titanium dioxide, while fluoride ions selectively chemically dissolved it. The dynamic equilibrium between these two factors resulted in the self-organized growth of a highly ordered, vertically oriented nanotube array. When the current decreased and stabilized below 10% of the initial value, it indicated that the nanotubes had grown to their maximum depth. The sample was removed, replaced with ethanol, washed with deionized water, and dried. It was then placed in a muffle furnace and heated to 450°C at a rate of 5°C per minute in air, held for 2 hours, and then cooled at 3°C ​​per minute to transform the amorphous titanium dioxide into a crystalline anatase phase. The final result was a nanotube array with a diameter of approximately 80-100 nm and a depth of approximately 1.0-1.2 μm. Figures 3-6 Here is the SEM image of the product. Figures 7-9 This is the EDS diagram for this product.

[0088] The third stage: Selective removal of the barrier layer at the bottom of the nanotube. To functionalize only the bottom of the nanotube, the dense titanium dioxide barrier layer at the bottom must be precisely removed while preserving the tube wall structure intact. A chemical etching method is used: the sample is immersed in a mixed solution of 0.1 mol / L hydrofluoric acid and 0.05 mol / L nitric acid, and etching is precisely controlled for 22-30 seconds at room temperature. Hydrofluoric acid dissolves the amorphous titanium dioxide barrier layer, while nitric acid inhibits its excessive erosion of the crystalline titanium dioxide on the tube wall. The etching endpoint is determined by monitoring the sudden change in solution conductivity. Once completed, the sample must be immediately immersed in a phosphate buffer solution with a pH of 7.4 to neutralize any residual acid and rinsed thoroughly with deionized water to prevent over-etching.

[0089] Stage Four: Surface Passivation and Selective Atomic Layer Deposition (ALD). This step aims to ensure that subsequent thin films are deposited only on the bottom of the conductive nanotubes. First, the sample undergoes surface passivation: it is placed in a vacuum desiccator containing droplets of octadecyltrichlorosilane, and a vacuum is created to deposit silane vapor on the sample surface for 30 minutes, forming a dense, self-assembled monolayer that changes the surface of the titanium dioxide tube from hydrophilic to hydrophobic. Subsequently, a pre-programmed "supercycle" is executed in an ALD apparatus.

[0090] ALD deposition process flow (number of cycles: MoO) x :10 / FeO:60 / Co3O4:5). 1. Stage 1: Deposition of MoO x A conductive substrate (10 cycles) forms a continuous conductive network approximately 1 nm thick. Specifically, the treated substrate is placed in the ALD reaction chamber, heated to the deposition temperature (recommended 200–250°C), and stabilized. The Mo(CO)6 source valve is opened for 0.3 seconds, allowing precursor vapor to enter the chamber and undergo chemisorption on the substrate surface. First purging: High-purity N2 is used to purge for 30 seconds to remove unreacted precursors and byproducts from the chamber. Pulsed O3: The O3 valve is opened for 0.5 seconds to oxidize the adsorbed Mo precursor, forming MoO. x Layering and releasing byproducts. Second purging: Purge with high-purity N2 for 40 seconds to prepare a clean environment for the next cycle. Perform the above cycle 10 times. 2. Stage Two: Deposition of a pH-sensitive FeO host layer (60 cycles) in MoO x A FeO main functional layer approximately 8-10 nm thick is grown on the substrate. Specifically, a single cycle (using FeCp2+O3): Pulsed FeCp2: Open the FeCp2 source valve for 0.5 seconds, first purge: N2 purge for 40 seconds. Pulsed O3: Open the O3 valve for 0.5 seconds. Second purge: N2 purge for 40 seconds. Perform the above cycle 60 times. 3. Stage Three: Deposit the Co3O4 catalytic top layer (5 cycles) to modify the surface in the form of a sub-monolayer / nano-island, without forming a continuous thick film. A single cycle (using CoCp2+O3): Open the CoCp2 source valve for 0.3 seconds. First purge: N2 purge for 30 seconds. Pulsed O3: Open the O3 valve for 0.5 seconds. Second purge: N2 purge for 30 seconds. Perform the above cycle 5 times. 4. Stage Four: Deposition complete: Turn off all precursor sources and continuously purge the reaction chamber with N2 for 5 minutes at the deposition temperature.

[0091] In-situ annealing was performed to activate mixed valence states and crystallization. The gas inlet to the reaction chamber was switched to dry air or oxygen. The chamber temperature was increased from the deposition temperature to 350°C at a rate of 5°C / min. This temperature was maintained at 350°C in air for 120 minutes (2 hours). Heating was then turned off, and the mixture was allowed to cool naturally to below 150°C in air, followed by N2 protection cooling to room temperature. This step partially crystallizes the amorphous film, induces interdiffusion at the interfaces of the three oxides, and creates oxygen vacancies and mixed valence states (such as Fe). 2+ / Fe 3+ Co 2+ / Co 3+ This activates electrochemical activity.

[0092] The selective deposition mechanism of this invention is as follows: the hydrophobic tube wall surface has extremely low adsorption energy for organometallic precursors, resulting in a significant “nucleation delay” effect; while the exposed fresh titanium surface at the bottom of the tube has high reactivity, and the precursor preferentially undergoes chemical adsorption and reaction here, ensuring that the film grows almost only at the bottom of the nanotube, forming a ternary composite film with a thickness of about 20~25nm.

[0093] Figures 10-13 Here is the SEM image of the product. Figures 14-19 This is the EDS diagram for this product. Figure 20 This is a schematic diagram of the functional layer structure.

[0094] Phase 5: Thin Film Post-processing and Functional Activation. After deposition, the thin film requires post-processing to optimize its sensing performance. First, low-temperature plasma treatment is performed: the sample is treated with a mixture of argon and oxygen at 50W RF power for 5 minutes to adjust the chemical state of the film surface and partially reduce molybdenum ions to enhance conductivity. Next, surface hydroxylation is performed: the sample is exposed to ozone for 10 minutes, then treated in 80°C saturated water vapor for 30 minutes, and finally irradiated with 254nm ultraviolet light for 15 minutes. This series of treatments aims to generate abundant metallic hydroxyl groups on the film surface, serving as key sites for subsequent hydrogen ion binding. Finally, electrochemical activation is performed: the sample is used as the working electrode and placed in simulated body fluid, undergoing 20 cycles of cyclic voltammetry scanning between -0.5V and +0.5V to stabilize its electrochemical interface.

[0095] In summary, the intelligent implant of this invention comprises a titanium implant and a layer of titanium dioxide nanotubes formed on the outer surface of the titanium implant, as well as a functional layer formed in the inner bottom and inter-tube bottom ALD of the titanium dioxide nanotubes; the functional layer comprises a ternary oxide layer formed of three metal oxides. The detection device comprises the intelligent implant and an electrode tip for matching the titanium implant. This invention provides an intelligent implant with the characteristics of "non-invasive safety, precise quantification, long-term stability, and dynamic monitoring," which can non-invasively detect the osseointegration strength of the titanium implant and is suitable for the complex physiological environment of the oral cavity and clinical follow-up scenarios. This invention facilitates timely treatment of the titanium implant by the dentist; its surface microstructure can also promote osseointegration, shorten osseointegration time, and accelerate healing.

[0096] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A smart implant capable of non-invasively detecting its own bone integration strength, characterized in that, It includes a titanium implant (1) and a layer of titanium dioxide nanotubes (2) formed on the outer surface of the titanium implant (1), and a functional layer (3) formed at the bottom of the inner part and the bottom of the intertubes of the titanium dioxide nanotubes (2); the functional layer (3) includes a ternary oxide layer formed of three metal oxides.

2. The intelligent implant according to claim 1, characterized in that, The functional layer (3) includes oxides of molybdenum, oxides of iron, and oxides of cobalt.

3. The intelligent implant according to claim 1, characterized in that, The titanium dioxide nanotubes (2) have a diameter of 80~200nm and a length of 1.0~1.2μm.

4. The intelligent implant according to claim 1, characterized in that, The thickness of the functional layer (3) is 20~25nm.

5. The intelligent implant according to any one of claims 1 to 4, characterized in that, It also includes a first annular electrode (4) disposed on the top of the titanium implant (1) and a rod-shaped electrode (5) disposed at the bottom of the titanium implant (1) and extending through both the top and bottom ends.

6. A detection device, characterized in that, The device includes the smart implant as described in claim 5 and an electrode head (6) for matching the titanium implant (1), wherein a second annular electrode (7) matching the first annular electrode (4) is provided on the upper part of the electrode head (6), and a contact electrode (8) matching the rod-shaped electrode (5) is provided on the bottom of the electrode head (6).

7. The detection device according to claim 6, characterized in that, An external thread is provided on the outer surface of the titanium implant (1), an internal thread is provided on the inner surface of the titanium implant (1), and an external thread matching the internal thread of the titanium implant (1) is provided on the outer surface of the electrode head (6).

8. The detection device according to claim 6, characterized in that, An external power supply and a display are also connected to the electrode head (6).

9. A method for preparing an intelligent implant as described in any one of claims 1 to 5, characterized in that, The method includes the following steps: Step A, Titanium implant (1) Substrate pretreatment and activation; Step B: Anodizing to grow titanium dioxide nanotube arrays (2); Step C: Selectively remove the barrier layer at the bottom of the titanium dioxide nanotubes (2); Step D: Surface passivation and atomic layer deposition to form a functional layer (3); Step E: Post-process and activate the function layer (3).

10. The method for preparing the intelligent implant according to claim 9, characterized in that, Step A includes mechanical polishing, chemical cleaning, oxalic acid aqueous solution treatment, hydrofluoric acid solution treatment and drying; Step B includes injecting electrolyte into a polytetrafluoroethylene electrolytic cell with the titanium implant (1) obtained in Step A as the anode and a high-purity platinum sheet as the cathode, oxidizing under DC voltage, and then calcining and cooling at 400~500℃ to form titanium dioxide nanotubes (2); Step C includes chemically etching the titanium implant (1) obtained in Step B using a mixture containing hydrofluoric acid and nitric acid, and then rinsing after neutralization; Step D includes passivation using silane vapor, and also includes depositing molybdenum oxide, iron oxide, and cobalt oxide in succession for 8~20 cycles using ALD; Step E includes low-temperature plasma treatment, followed by surface hydroxylation, and finally electrochemical activation treatment.

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