A method for preparing a high-adhesion antibacterial film for oral invisible orthodontic appliances

Abstract

The present invention provides a method for preparing a high-adhesion antibacterial film for an oral invisible brace appliance, which belongs to the technical field of high-adhesion antibacterial films. The method is formed by sputtering a target material onto a substrate, wherein the target material includes an antibacterial material and a dopant, and the substrate is a glass substrate; the antibacterial material uses zinc oxide as the main antibacterial material, and the dopant uses gallium trioxide. The preparation method includes: preparing a glass substrate according to a basic ratio range, and mixing zinc oxide and gallium trioxide to prepare a target material; using magnetron sputtering technology, sputtering the target material with adaptive timing power, using pure Ar gas as the sputtering gas, and maintaining the whole sputtering process at room temperature, and depositing a GZO film on the substrate; a black and white checkered image is attached to the non-sputtering surface of the substrate; and applying the prepared high-adhesion antibacterial film to the surface of the oral invisible brace appliance as an antibacterial protective layer. The present invention solves the problem that the existing antibacterial protective film has low adhesion.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-adhesion antibacterial films, and in particular, relates to a method for preparing a high-adhesion antibacterial film for an oral invisible orthodontic appliance. Background Art

[0002] As an advanced orthodontic solution, oral invisible braces are widely popular for their beauty and comfort. However, long-term wearing of invisible braces can easily lead to bacterial growth on their surface, causing oral health problems such as gingivitis and tooth decay. To solve this problem, researchers have proposed a variety of technical solutions, but each solution has certain limitations. In the prior art, a common solution is to coat the surface of the invisible braces with an antibacterial coating, such as a silver ion antibacterial coating or a metal oxide antibacterial coating. Although this method can inhibit bacterial attachment to a certain extent, it faces the problem of easy detachment or inactivation of the coating, resulting in a significant decrease in antibacterial performance with increasing use time. Another method is to add antibacterial agents, such as chlorhexidine or tetracycline, to the brace material. However, this method may lead to excessive release of antibacterial agents, irritation to the patient's oral tissue, and the antibacterial agent itself is also easily inactivated or resistant to bacteria.

[0003] To overcome the above problems, researchers began to explore the use of antibacterial protective films. However, the existing antibacterial protective films still have the problem of low adhesion. In the complex oral environment, under long-term exposure to factors such as saliva and food residues, the antibacterial protective film is easy to fall off or be damaged, resulting in a significant reduction in the antibacterial effect. In addition, the existing technology faces the following technical difficulties when preparing high-performance antibacterial films:

[0004] 1. Balance between antibacterial properties and light transmittance: Improving antibacterial properties usually requires increasing the film thickness or changing its composition, but this may reduce light transmittance and affect the aesthetics of the invisible braces.

[0005] 2. Film uniformity and stability control: Traditional preparation methods make it difficult to accurately control the thickness and surface properties of the film, which affects the consistency and durability of the antibacterial effect.

[0006] 3. Controllability and repeatability of the preparation process: The lack of real-time monitoring and adaptive adjustment mechanisms makes it difficult to ensure consistency in product quality in large-scale production.

[0007] 4. Multi-objective performance optimization: It is difficult to simultaneously take into account multiple performance indicators such as high adhesion, high antibacterial property, high light transmittance and low surface roughness.

[0008] In response to these problems, it is urgent to develop a new method for preparing high-adhesion antibacterial films, which can not only solve the problem of low adhesion, but also ensure high light transmittance and have good controllability of the preparation process. Summary of the invention

[0009] In view of this, the present invention provides a method for preparing a high-adhesion antibacterial film for an oral invisible orthodontic appliance, which can solve the problem that it is difficult to simultaneously ensure the adhesion and light transmittance of the antibacterial film in the prior art.

[0010] The present invention is achieved in that:

[0011] The present invention provides a method for preparing a high-adhesion antibacterial film for an oral invisible appliance, comprising the following steps:

[0012] S10, using 70-80wt% of silicon dioxide, 10-20wt% of calcium oxide and 5-10wt% of sodium oxide to make a glass substrate, and mixing 80-90wt% of zinc oxide and 3wt% of gallium trioxide to make a target material;

[0013] S20, using magnetron sputtering technology to sputter the target material with adaptive timing power, using pure Ar gas as the sputtering gas, maintaining room temperature throughout the sputtering process, and depositing a GZO thin film on the substrate; a black and white checkered image is attached to the non-sputtering surface of the substrate;

[0014] S30. Apply the prepared high-adhesion antibacterial film to the surface of the oral invisible braces as an antibacterial protective layer.

[0015] On the basis of the above technical solution, the method for preparing a high-adhesion antibacterial film for an oral invisible appliance of the present invention can also be improved as follows:

[0016] Furthermore, the step of determining the adaptive timing power is specifically:

[0017] S21, acquiring surface images of the substrate at multiple angles in real time during magnetron sputtering;

[0018] S22, preprocessing the surface images at the multiple angles respectively to obtain preprocessed surface images at the multiple angles;

[0019] S23, selecting a surface image at an orthogonal shooting angle from among the pre-processed surface images at multiple angles, and performing background segmentation using an image segmentation technique to obtain a foreground image and a background image;

[0020] S24, performing alignment and registration according to the background image and the checkered image, and calculating the grayscale difference between the background image and the checkered image by using image processing technology as the transmittance of the GZO film;

[0021] S25, extracting texture features, contour center moment features, surface undulation features, and color features from the foreground image, and calculating the roughness of the GZO film;

[0022] S26, establishing a transmittance equation and a roughness equation taking into account magnetron sputtering process parameters, and fitting the transmittance equation and the roughness equation respectively using the real-time magnetron sputtering process parameters during the magnetron sputtering process and the calculated transmittance and roughness to obtain a transmittance fitting equation and a roughness fitting equation;

[0023] S27, establishing a game model using the transmittance fitting equation and the roughness fitting equation, where the constraints include a low transmittance of 80%, a GZO film thickness of 80-120 nm, and a preset maximum sputtering time and maximum power;

[0024] S28, solving the game model to obtain the optimal magnetron sputtering process parameters as the magnetron sputtering process parameters for the next period of time to perform magnetron sputtering;

[0025] S29, repeat steps S21 to S28 until a GZO film with a thickness of 80-120 nm is obtained.

[0026] The method for measuring the roughness of the GZO film is as follows: combining texture features, contour center moment features, surface undulation features and color features into a feature vector, normalizing each element of the feature vector, and calculating the modulus of the feature vector as the roughness of the GZO film.

[0027] The transmittance equation: ;

[0028] In the formula, is the transmittance of GZO film, is the power curve, is the sputtering time, is the distance between the target and the substrate, is the substrate rotation speed, is the unknown coefficient. It can be obtained by fitting the experimental data.

[0029] Roughness equation: ;

[0030] In the formula, is the roughness of the GZO film, is the power curve, is the sputtering time, is the distance between the target and the substrate, is the substrate rotation speed, is the unknown coefficient. It can be obtained by fitting the experimental data.

[0031] Variable Description:

[0032] : The transmittance of GZO film is calculated by image processing technology;

[0033] : The roughness of the GZO film is calculated by extracting texture features, contour center moment features, surface relief features and color features;

[0034] : Power curve is one of the magnetron sputtering process parameters;

[0035] : Sputtering time is one of the process parameters of magnetron sputtering;

[0036] : The distance between the target and the substrate is one of the process parameters of magnetron sputtering;

[0037] : Substrate rotation speed is one of the magnetron sputtering process parameters;

[0038] : Undetermined coefficients, obtained by fitting the experimental data.

[0039] The specific game model can be expressed as:

[0040] ;

[0041] st ;

[0042] ;

[0043] ;

[0044] ;

[0045] In the formula, represents the magnetron sputtering process parameter vector, and are functions of transmittance and roughness, respectively. is the weight coefficient used to balance the importance of transmittance and roughness.

[0046] Furthermore, the multiple angles include at least 15°, 45°, 90°, 135°, and 165°; the surface image at the orthogonal shooting angle is the surface image of the substrate captured when the plane where the camera lens is located is parallel to the substrate.

[0047] Furthermore, the magnetron sputtering process parameters include power curve, sputtering time, sputtering temperature, substrate rotation speed and the distance between the target and the substrate.

[0048] Furthermore, in the black and white checkered image, the side length of each square is 2-5 mm.

[0049] Compared with the prior art, the method for preparing a high-adhesion antibacterial film for an oral invisible appliance provided by the present invention has the following beneficial effects:

[0050] 1. High adhesion: By using 80-90wt% zinc oxide and 3wt% gallium trioxide to make a target material, combined with magnetron sputtering technology, a GZO film with high adhesion was successfully prepared. This unique material combination and preparation method significantly improves the bonding strength between the antibacterial film and the invisible brace substrate, effectively solving the problem of easy detachment of the antibacterial coating in the prior art. High adhesion ensures that the antibacterial film remains stable during long-term use, providing a basis for sustained antibacterial effects.

[0051] 2. Excellent optical performance: Through adaptive timing power control and real-time image analysis technology, this method achieves precise control of the light transmittance of the GZO film. In particular, by controlling the thickness of the GZO film within the range of 80-120nm, a high light transmittance of more than 80% was successfully achieved. This technical effect perfectly solves the balance between antibacterial performance and light transmittance, ensuring that the aesthetics of the invisible braces are not affected.

[0052] 3. Accurate control of film properties: This method introduces an innovative real-time monitoring and adaptive adjustment mechanism. By acquiring the substrate surface image in real time and using image processing technology to analyze the transmittance and roughness of the film, the transmittance equation and roughness equation considering the magnetron sputtering process parameters are established. This method significantly improves the controllability and repeatability of the film preparation process and ensures the uniformity and stability of the film.

[0053] 4. Multi-objective performance optimization: By establishing a game model, the multi-objective optimization of the antibacterial film performance is achieved by comprehensively considering multiple factors such as transmittance, film thickness, sputtering time and power. This optimization method not only ensures high transmittance, but also effectively controls the surface roughness, further enhancing the antibacterial effect. The low-roughness surface property is not conducive to bacterial attachment and reproduction, thereby improving the antibacterial durability.

[0054] 5. Safe and reliable antibacterial mechanism: The GZO film prepared by this method has inherent antibacterial properties and does not require the addition of traditional antibacterial agents. This additive-free antibacterial method avoids the risk of excessive release of antibacterial agents to irritate oral tissues, while greatly reducing the possibility of bacterial resistance. This safe and reliable antibacterial mechanism is particularly suitable for long-term use of oral appliances.

[0055] 6. Durability of antibacterial effect: Through high adhesion design and precise film property control, the antibacterial film prepared by this method can maintain a stable antibacterial effect throughout the entire correction cycle. This significantly reduces the risk of bacterial growth, effectively prevents oral health problems such as gingivitis and tooth decay, and improves the safety and comfort of invisible braces.

[0056] In summary, the present invention solves the technical problem that it is difficult to simultaneously ensure adhesion and light transmittance in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 A flow chart of the preparation method provided by the present invention;

[0058] Figure 2 Flowchart of the steps for adaptive sequential power determination. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0060] like Figure 1 FIG. 1 is a flow chart of a method for preparing a high-adhesion antibacterial film for an oral invisible appliance provided by the present invention. The method comprises the following steps:

[0061] S10, using 70-80wt% of silicon dioxide, 10-20wt% of calcium oxide and 5-10wt% of sodium oxide to make a glass substrate, and mixing 80-90wt% of zinc oxide and 3wt% of gallium trioxide to make a target material;

[0062] S20, using magnetron sputtering technology to sputter the target material with adaptive timing power, using pure Ar gas as the sputtering gas, maintaining room temperature throughout the sputtering process, and depositing a GZO thin film on the substrate; a black and white checkered image is attached to the non-sputtering surface of the substrate;

[0063] S30. Apply the prepared high-adhesion antibacterial film to the surface of the oral invisible braces as an antibacterial protective layer.

[0064] like Figure 2 As shown, the steps of determining the adaptive timing power are specifically:

[0065] S21, acquiring surface images of the substrate at multiple angles in real time during magnetron sputtering;

[0066] S22, preprocessing the surface images at the multiple angles respectively to obtain preprocessed surface images at the multiple angles;

[0067] S23, selecting a surface image at an orthogonal shooting angle from among the pre-processed surface images at multiple angles, and performing background segmentation using an image segmentation technique to obtain a foreground image and a background image;

[0068] S24, performing alignment and registration according to the background image and the checkered image, and calculating the grayscale difference between the background image and the checkered image by using image processing technology as the transmittance of the GZO film;

[0069] S25, extracting texture features, contour center moment features, surface undulation features, and color features from the foreground image, and calculating the roughness of the GZO film;

[0070] S26, establishing a transmittance equation and a roughness equation taking into account magnetron sputtering process parameters, and fitting the transmittance equation and the roughness equation respectively using the real-time magnetron sputtering process parameters during the magnetron sputtering process and the calculated transmittance and roughness to obtain a transmittance fitting equation and a roughness fitting equation;

[0071] S27, establishing a game model using the transmittance fitting equation and the roughness fitting equation, where the constraints include a low transmittance of 80%, a GZO film thickness of 80-120 nm, and a preset maximum sputtering time and maximum power;

[0072] S28, solving the game model to obtain the optimal magnetron sputtering process parameters as the magnetron sputtering process parameters for the next period of time to perform magnetron sputtering;

[0073] S29, repeat steps S21 to S28 until a GZO film with a thickness of 80-120 nm is obtained.

[0074] Below is a detailed description of the above steps:

[0075] First, the specific implementation method of step S10 is to make a glass substrate according to the basic ratio range. Specifically, the glass substrate is composed of 70-80wt% silicon dioxide, 10-20wt% calcium oxide and 5-10wt% sodium oxide. The method for making the glass substrate can adopt conventional glass manufacturing processes, such as melting, float method and the like. In this process, it is necessary to strictly control the ratio range of each component to ensure that the glass substrate has good mechanical properties, corrosion resistance and light transmittance. At the same time, it is also necessary to mix 80-90wt% zinc oxide and 3wt% gallium trioxide to make a target material. The role of gallium trioxide as a dopant is to improve the antibacterial property of zinc oxide. In the specific operation, it is necessary to weigh the calculated mass fractions of zinc oxide and gallium trioxide, and fully mix them by mechanical stirring or ball milling to make a target material.

[0076] Then, the specific implementation method of step S20 is to use magnetron sputtering technology to sputter the above-mentioned target material with adaptive timing power to obtain a GZO film. In this process, pure Ar gas is used as the sputtering gas, and the entire sputtering process is kept at room temperature. Specifically, the prepared glass substrate is first placed in a vacuum chamber and evacuated to the required pressure through a vacuum system. Then, the magnetron sputtering device is started to sputter the target material with adaptive timing power. The so-called adaptive timing power refers to dynamically adjusting the sputtering power according to the surface characteristics of the substrate monitored in real time during the sputtering process, such as transmittance and roughness, to ensure that a GZO film with a thickness of 80-120nm and a visible light transmittance greater than 80% is finally obtained. In this process, a black and white checkered image is attached to the non-sputtering surface of the substrate to assist in monitoring the surface characteristics of the substrate.

[0077] Next, steps S21-S29 describe the specific implementation process of adaptive timing power. First, during the magnetron sputtering process, surface images of the substrate at multiple angles (such as 15°, 45°, 90°, 135° and 165°) are acquired in real time. These images contain important features of the substrate surface such as texture, contour, and ups and downs. Then, these images are preprocessed, such as filtering and normalization, to remove noise interference and obtain high-quality surface images.

[0078] Secondly, from the preprocessed multiple angle images, the surface image of the orthogonal shooting angle (that is, the image taken when the plane where the camera lens is located is parallel to the substrate) is selected. The image is divided into foreground and background using image segmentation technology. The foreground contains the surface features of the GZO film, while the background is the black and white checkered image attached to the substrate.

[0079] Then, using image processing technology, the background image and the grid image are compared, and the grayscale difference between the two is calculated to obtain the transmittance of the GZO film. At the same time, the texture features, contour center moment features, surface undulation features and color features of the foreground image are extracted, and these features are combined into a feature vector. After normalization, the modulus of the feature vector is calculated as the roughness of the GZO film.

[0080] Then, the transmittance equation and roughness equation considering the magnetron sputtering process parameters are established. Among them, the transmittance equation is , the roughness equation is The undetermined coefficients in these two equations are It needs to be obtained by fitting experimental data.

[0081] Next, a game model is established with the obtained transmittance and roughness fitting equations as constraints, and considering the constraints such as low transmittance of 80%, GZO film thickness of 80-120nm, and the preset maximum sputtering time and maximum power. The game model is solved to obtain the optimal magnetron sputtering process parameters, including power curve, sputtering time, sputtering temperature, substrate rotation speed, and the distance between the target and the substrate.

[0082] Finally, the obtained optimal magnetron sputtering process parameters are applied to the actual magnetron sputtering process, and steps S21-S28 are repeated until a GZO film that meets the requirements is obtained. The GZO film has a thickness of 80-120 nm and a visible light transmittance greater than 80%.

[0083] Step S30 is to apply the prepared high-adhesion antibacterial film to the surface of the oral invisible braces as an antibacterial protective layer. Since the GZO film has excellent antibacterial properties and good adhesion, it can effectively prevent bacteria from growing on the surface of the invisible braces, providing patients with better oral hygiene protection.

[0084] In general, this method for preparing high-adhesion antibacterial film for oral invisible braces fully utilizes the advantages of magnetron sputtering technology. Through real-time monitoring and adaptive adjustment of process parameters, the optical and surface properties of the GZO film can be accurately controlled to meet the stringent requirements of invisible braces.

[0085] Specifically, the principle of the present invention is:

[0086] First, glass is selected as the substrate material, which is composed of 70-80 weight percent silicon dioxide, 10-20 weight percent calcium oxide and 5-10 weight percent sodium oxide. This glass substrate not only has good optical transmittance, but also forms a stable chemical bond with the GZO film, ensuring the high adhesion of the antibacterial film.

[0087] Secondly, 80-90 weight percent zinc oxide and 3 weight percent gallium trioxide are mixed to form a sputtering target. Zinc oxide, as the main antibacterial component, exerts a strong bactericidal activity by producing active oxygen species or interrupting bacterial cell membranes. The doping of gallium trioxide can further improve the antibacterial properties of the GZO film.

[0088] Then, the target material is sputtered and deposited by magnetron sputtering technology to form a GZO film on a glass substrate. Different from the traditional fixed process parameters, the present invention adopts an adaptive sequential power control strategy. Specifically, the surface images of the substrate at multiple angles are acquired in real time, and the key parameters such as the transmittance and roughness of the GZO film are calculated through image segmentation and feature extraction. Then, the transmittance and roughness equations considering the magnetron sputtering process parameters are established, and a game model is solved to dynamically adjust the power curve, sputtering time, substrate rotation speed and other parameters, and finally a high-quality GZO film with a thickness of 80-120nm and a visible light transmittance greater than 80% is obtained.

[0089] This intelligent preparation method based on real-time monitoring and adaptive adjustment fully utilizes the flexibility of magnetron sputtering technology, and can accurately control the optical and surface properties of GZO films to meet the stringent requirements of invisible braces. Compared with the existing fixed process parameters, this method not only improves the consistency and stability of product quality, but also greatly shortens the debugging cycle and greatly improves production efficiency.

[0090] The following are the detailed steps and explanations of the preparation of GZO thin films using magnetron sputtering technology, including the magnetron sputtering principle, process control, and adaptive power control method:

[0091] 1. The following is an explanation of the principle of magnetron sputtering technology. Magnetron sputtering is a physical vapor deposition (PVD) technology that uses magnetic field to confine plasma to improve sputtering efficiency. Its basic principles are as follows:

[0092] (1) An inert gas such as argon is filled into a vacuum chamber, and a high voltage is applied between the target (cathode) and the substrate (anode).

[0093] (2) The electric field ionizes the argon gas to form plasma, producing a large number of positive ions and electrons.

[0094] (3) Positive ions are accelerated by the electric field to bombard the target surface, sputtering out target atoms.

[0095] (4) The magnetic field behind the target causes the electrons to spiral near the target surface, increasing the ionization probability and improving the sputtering efficiency.

[0096] (5) The sputtered target atoms are deposited on the substrate surface to form a thin film.

[0097] 2. The following is an explanation of the precise control of the GZO film preparation process: In order to accurately control the thickness, transmittance and roughness of the GZO film, it is necessary to monitor and adjust the following parameters in real time during the sputtering process:

[0098] (1) Sputtering power: affects the sputtering rate and film growth rate.

[0099] (2) Sputtering time: directly determines the film thickness.

[0100] (3) Working air pressure: affects the mean free path, which in turn affects the density and roughness of the film.

[0101] (4) Substrate temperature: affects the crystallinity and surface mobility of the film.

[0102] (5) Target-substrate distance: affects deposition rate and uniformity.

[0103] Specific control methods include:

[0104] a) Thickness control: Use a quartz crystal monitor to monitor the deposition rate and thickness in real time; dynamically adjust the sputtering time according to the target thickness (80-120nm).

[0105] b) Transmittance control: Use an optical monitoring system to measure the film transmittance in real time; control the film stoichiometry by adjusting the oxygen partial pressure and sputtering power.

[0106] c) Roughness control: Use in-situ ellipsometer to monitor the surface morphology of the film; adjust the working gas pressure and substrate temperature to optimize the film growth mode.

[0107] 3. To realize adaptive sequential power control, it is necessary to use a high-speed response programmable DC power supply to realize power control according to the adaptive sequential power determination step in the present invention. The specific implementation steps of adaptive sequential power control are as follows:

[0108] a) System initialization: set target film parameters (thickness, transmittance, roughness); initialize sputtering parameters (power, gas pressure, substrate temperature, etc.);

[0109] b) Real-time monitoring: continuously collect thickness, transmittance and roughness data during the film growth process; calculate the deviation between the current film performance and the target parameters;

[0110] c) Parameter optimization: According to the deviation value, the steps of determining the adaptive sequential power are programmed to form a software module for calculating the optimal sputtering parameters; focusing on optimizing the sequential change of the sputtering power;

[0111] d) Power regulation: Send the optimized power curve to the power regulation module; realize dynamic adjustment of sputtering power, such as pulse modulation or ramp change;

[0112] e) Closed-loop control: Continuously repeat steps b to d until the target film parameters are reached; achieve precise control of film performance and process stability.

[0113] 4. Based on the above principles and control methods, the magnetron sputtering process of GZO thin film can be refined into the following steps:

[0114] (1) Pretreatment of vacuum chamber: evacuate to the background pressure <5×10^-6Pa; introduce high-purity argon gas to the working pressure (0.5-1Pa);

[0115] (2) Target pre-sputtering: Start the magnetron sputtering source and pre-sputter at low power for 5-10 minutes; clean the target surface and stabilize the sputtering conditions;

[0116] (3) Substrate pretreatment: heating the substrate to a set temperature (room temperature ~ 200°C); plasma cleaning to remove surface contamination;

[0117] (4) Start the adaptive control system: activate the real-time monitoring system; initialize the control algorithm and power regulation module;

[0118] (5) Start film deposition: set the initial sputtering power (e.g., 200 W); open the baffle and start film growth;

[0119] (6) Real-time control process: the system continuously monitors the film thickness, transmittance and roughness; the control algorithm dynamically optimizes the sputtering parameters; the power regulation module adjusts the sputtering power in real time;

[0120] (7) Termination of deposition: After reaching the target film parameters, the shutter is automatically closed; the sputtering power supply is stopped and the gas supply is turned off;

[0121] (8) Cooling annealing: cooling to room temperature in an argon atmosphere; performing subsequent heat treatment to optimize film properties if necessary;

[0122] 5. During the entire sputtering process, special attention should be paid to the following technical points:

[0123] (1) Gas pressure control: Accurately control the argon flow rate to maintain a stable working pressure.

[0124] (2) Temperature management: Precise temperature regulation through substrate heater and cooling system.

[0125] (3) Uniformity control: Optimize the target-substrate distance and substrate rotation speed.

[0126] (4) Interface engineering: Consider the introduction of a buffer layer to improve the bonding between the GZO film and the substrate.

[0127] (5) Impurity control: Select high-purity target materials and working gases to reduce the risk of contamination.

[0128] (6) Energy regulation: The ion bombardment energy can be adjusted by bias voltage to optimize the film structure.

[0129] Through the above steps and technical points, the GZO film can be accurately and controllably prepared, and a high-quality antibacterial film with a thickness of 80-120nm, a transmittance of >80%, and good adhesion can be obtained. The introduction of adaptive sequential power control further improves the consistency of film performance and the repeatability of the process, laying a technical foundation for the large-scale production of antibacterial films for oral invisible braces.

[0130] The high-adhesion antibacterial film produced in the solution of the present invention is used for oral invisible orthodontic appliances, and the positive effects brought about include:

[0131] First of all, the key to this high-adhesion antibacterial film is its strong adhesion. This film is formed by sputtering a target containing 80-90% zinc oxide and 2-6% gallium trioxide onto a glass substrate using magnetron sputtering technology. The main components of the glass substrate include 70-80% silicon dioxide, 10-20% calcium oxide and 5-10% sodium oxide.

[0132] During the sputtering process, the zinc oxide in the target material and the silicon dioxide, calcium oxide and other components in the glass substrate will react chemically to form stable covalent bonds or ionic bonds. This chemical bonding allows the GZO film to be firmly attached to the surface of the glass substrate and is not easy to fall off during long-term wear. This is very important because invisible braces need to be worn for a long time. If the antibacterial film layer falls off during use, it will not only affect the appearance, but also lose its protective effect on the patient's oral health. The chemical bonding mechanism formed in the preparation method provided by the present invention effectively solves this problem and ensures the reliable adhesion of the antibacterial film.

[0133] Secondly, this GZO antibacterial film itself has excellent antibacterial properties. Zinc oxide, as the main antibacterial material, can produce active oxygen free radicals after dissolution, destroy bacterial cell membranes, and inhibit bacterial metabolism and reproduction. At the same time, zinc oxide can also play an antibacterial role by changing the pH value in bacterial cells and interfering with enzyme activity. Gallium trioxide, as a dopant, can enhance the antibacterial properties of the GZO film. Gallium ions have broad-spectrum antibacterial activity, can interfere with the permeability of bacterial cell membranes, and inhibit bacterial growth. At the same time, gallium can also compete with metal ions required for bacterial metabolism to further inhibit bacterial growth. This composite antibacterial mechanism enables the GZO film to effectively inhibit various oral bacteria, including highly pathogenic Staphylococcus aureus and Enterococcus. This is very important for preventing various oral infections caused by wearing invisible braces.

[0134] In addition to good adhesion and excellent antibacterial properties, this GZO antibacterial film also has excellent optical properties, with a visible light transmittance of more than 80%. This means that even under the coverage of the GZO film, the transparent and beautiful characteristics of the invisible braces themselves will not be greatly affected. This is very critical to the user experience of invisible braces. Many patients choose invisible braces in the hope of hiding the correction process to achieve better aesthetic effects. If the transparency and aesthetic feeling of the invisible braces are greatly reduced after the antibacterial film is coated, this will undoubtedly affect the patient's wearing experience. However, the antibacterial film produced by the preparation method of a high-adhesion antibacterial film for oral invisible braces of the present invention perfectly solves this problem with its excellent optical properties. When wearing invisible braces, patients can still enjoy good transparency and aesthetic feeling, and at the same time, they can also obtain effective oral hygiene protection.

[0135] In addition to the above-mentioned key advantages, this GZO antibacterial film also embodies some innovations in the preparation process. During the sputtering process, by real-time monitoring of the optical properties of the substrate surface, establishing a predictive model for transmittance and roughness, and using adaptive sequential power control, a GZO film with a thickness of 80-120nm and a transmittance greater than 80% was finally obtained.

[0136] This preparation method based on real-time monitoring and adaptive optimization reflects the fine control of process parameters. By acquiring the substrate surface image in real time, analyzing its optical properties, and matching it with the preset performance targets, the sputtering power can be adjusted in time to ensure that the GZO film layer that meets the requirements is finally obtained. This adaptive control process not only improves production efficiency, but also ensures the stability of product quality.

[0137] In order to better understand and implement the preparation method of the present invention, a specific embodiment 1 of the preparation method is provided below. The specific implementation steps of this embodiment 1 are as follows:

[0138] First, in step S21, it is necessary to obtain surface images of the substrate at multiple angles (such as 15°, 45°, 90°, 135° and 165°) in real time during the magnetron sputtering process. These images contain important features of the substrate surface such as texture, contour, and ups and downs.

[0139] Then, in step S22, these images are preprocessed, such as filtering, normalization, etc., to remove noise interference and obtain high-quality surface images. The specific preprocessing method is as follows:

[0140] ;

[0141] In the formula, Represents the original image pixel The gray value of Represents the filter function, and the preprocessed image is obtained after filtering . Filter function Common image filtering methods such as Gaussian filtering and median filtering can be used.

[0142] ;

[0143] In the formula, Represents the normalized image pixel The gray value of the image is mapped to the interval [0, 1] through linear normalization.

[0144] Next, in step S23, a surface image of an orthogonal shooting angle (i.e., an image shot when the plane where the camera lens is located is parallel to the substrate) is selected from the preprocessed multiple angle images. The image is divided into two parts, the foreground and the background, using image segmentation technology. The specific segmentation method is as follows:

[0145]

[0146] In the formula, Represents the segmentation result, when the pixel The gray value is greater than the threshold When , it is classified as foreground, otherwise it is classified as background. The Otsu method or other adaptive threshold segmentation algorithms can be used to determine it.

[0147] Then, in step S24, the background image and the grid image are compared by using image processing technology to calculate the grayscale difference between the two, thereby obtaining the transmittance of the GZO film. The specific calculation method is as follows:

[0148] ;

[0149] In the formula, Represents the background image pixels The gray value of Represents the pixels of a grid image Gray value, sum symbol Represents the background area All pixels within are accumulated.

[0150] Next, in step S25, texture features, contour center moment features, surface relief features and color features are extracted from the foreground image, and these features are combined into a feature vector , after normalization, calculate the modulus of the eigenvector As the roughness of the GZO film. The specific calculation formula is as follows:

[0151]

[0152] ;

[0153] In the formula, Indicates the extracted Features, Represents the feature vector The second norm of , that is, the modulus of the eigenvector.

[0154] Then, in step S26, a transmittance equation and a roughness equation are established taking into account the magnetron sputtering process parameters. The transmittance equation is:

[0155] ;

[0156] In the formula, is the transmittance of GZO film, is the power curve, is the sputtering time, is the distance between the target and the substrate, is the substrate rotation speed, are unknown coefficients. These unknown coefficients can be obtained by fitting experimental data.

[0157] The roughness equation is:

[0158] ;

[0159] In the formula, is the roughness of the GZO film, is an undetermined coefficient and can also be obtained by fitting experimental data.

[0160] Next, in step S27, a game model is established, with the obtained transmittance and roughness fitting equations as constraints, and considering the low transmittance of 80%, the GZO film thickness of 80-120nm, and the preset maximum sputtering time and maximum power and other constraints, the game model is solved to obtain the optimal magnetron sputtering process parameters.

[0161] The specific game model can be expressed as:

[0162] ;

[0163] st ;

[0164] ;

[0165] ;

[0166] ;

[0167] In the formula, represents the magnetron sputtering process parameter vector, and are functions of transmittance and roughness, respectively. is the weight coefficient used to balance the importance of transmittance and roughness.

[0168] Finally, in step S28, the above game model is solved to obtain the optimal magnetron sputtering process parameters. , as the magnetron sputtering process parameters for the next period of time, magnetron sputtering is performed. Then steps S21 to S28 are repeated until a GZO film with a thickness of 80-120 nm is obtained.

[0169] In summary, in steps S21-S29, the real-time monitoring and adaptive adjustment of the magnetron sputtering process are achieved by using technologies such as image processing, mathematical modeling and optimization algorithms, so as to accurately control the optical and surface properties of the GZO film and meet the stringent requirements of the invisible braces. Specifically, in this embodiment 1:

[0170] 1. Through multi-angle image acquisition and preprocessing, high-quality substrate surface images were obtained, laying the foundation for subsequent feature extraction and parameter calculation.

[0171] 2. Using image segmentation and feature extraction technology, key parameters such as the transmittance and roughness of the GZO film were successfully calculated.

[0172] 3. Based on these parameters, the transmittance and roughness equations considering the magnetron sputtering process parameters were established, and the corresponding unknown coefficients were obtained by fitting the experimental data.

[0173] 4. Taking these two equations as constraints, a game model was constructed and the optimal magnetron sputtering process parameters were obtained.

[0174] 5. The optimized parameters were applied to the actual magnetron sputtering process. After multiple iterations, a GZO film that met the requirements was finally produced.

[0175] In general, this adaptive adjustment method based on image monitoring, mathematical modeling and optimization algorithm makes full use of the flexibility of magnetron sputtering technology, can accurately control the optical and surface properties of GZO films, and provide a high-quality antibacterial protective layer for oral invisible braces.

[0176] In order to further better understand and implement the present invention, the following is an example 2 of an application scenario of the present invention: A dental hospital recently received a 25-year-old female patient who needed invisible braces due to tooth misalignment. The doctor customized a set of highly transparent invisible braces for the patient, aiming to provide the patient with a good aesthetic experience during the correction process. However, the doctor is also worried that long-term wearing of invisible braces may cause patients to suffer from gingivitis, tooth decay and other problems.

[0177] To solve this problem, the hospital decided to use the high-adhesion antibacterial film proposed by the present invention as the antibacterial protective layer of the invisible braces. The specific implementation steps are as follows:

[0178] 1. Preparation of glass substrate

[0179] First, the hospital prepared a glass substrate composed of 75 weight percent silicon dioxide, 15 weight percent calcium oxide and 10 weight percent sodium oxide according to the ratio requirements of the present invention. During the preparation process, the process personnel strictly controlled the ratio of each component to ensure that the glass substrate has good optical transmittance and chemical stability.

[0180] 2. Target preparation

[0181] Next, the process personnel mixed 85 weight percent zinc oxide and 3 weight percent gallium trioxide to prepare a target material for magnetron sputtering. To ensure a uniform mixture, they used mechanical stirring and stirred repeatedly for 30 minutes.

[0182] 3. Magnetron sputtering deposition

[0183] The prepared glass substrate is placed in a vacuum chamber and evacuated to 1×10^-4Pa through the vacuum system. Then, the magnetron sputtering equipment is started to sputter and deposit the above target material with adaptive timing power. During the entire sputtering process, the process personnel monitor the image characteristics of the substrate surface in real time, dynamically adjust the power curve, sputtering time and other process parameters to ensure that the final GZO film with a thickness of 100nm and a visible light transmittance of 85% is obtained.

[0184] Specifically, during the sputtering process, the process personnel collected images of the substrate surface in real time from five angles: 15°, 45°, 90°, 135° and 165°. Through image preprocessing, such as filtering and normalization, high-quality surface images were obtained. Among them, the orthogonal images taken at an angle of 90° were selected for subsequent analysis.

[0185] The image segmentation technology is used to divide the 90° angle image into two parts: the foreground (GZO film surface) and the background (checkered pattern). Then, the image processing algorithm is used to compare the background image with the black and white checkered pattern pre-attached to the substrate, and the transmittance of the GZO film is calculated to be 85%.

[0186] At the same time, texture features, contour center moment features, surface undulation features and color features are extracted from the foreground image, and these features are combined into a feature vector. After normalization, the modulus of the feature vector is calculated and the roughness of the GZO film is obtained to be 0.35nm.

[0187] Based on the above monitoring data, the process personnel established the transmittance and roughness equations considering the magnetron sputtering parameters. After fitting the experimental data, the transmittance equation is:

[0188] ;

[0189] The roughness equation is:

[0190] ;

[0191] in, is the transmittance of the GZO film, is the power curve, is the sputtering time, is the distance between the target and the substrate, is the substrate rotation speed.

[0192] Next, the process personnel established a game model with the above-mentioned transmittance and roughness equations as constraints, and considered the transmittance greater than 85%, GZO film thickness of 100±20nm, maximum sputtering time of 60 minutes, maximum power of 500W and other constraints. The model was solved and the optimal magnetron sputtering process parameters were obtained: the power curve was constant at 500W, the sputtering time was 50 minutes, the distance between the target and the substrate was 10cm, and the substrate rotation speed was 3rpm.

[0193] These optimized process parameters were applied to the actual magnetron sputtering process. After many iterations, a GZO film with a thickness of 100nm, a visible light transmittance of 85%, and a roughness of 0.35nm was successfully deposited on the glass substrate.

[0194] 4. Surface coating of invisible braces

[0195] The prepared GZO film, as a high-adhesion antibacterial film, is directly coated on the surface of the invisible braces. Since a strong chemical bond is formed between the GZO film and the glass substrate, it can be reliably attached to the invisible braces and will not fall off during long-term wear. At the same time, the excellent light transmittance of the GZO film also ensures that the aesthetics of the invisible braces is not affected.

[0196] 5. Antibacterial performance verification

[0197] To verify the performance of GZO antibacterial film, the hospital selected two common oral pathogenic bacteria, Escherichia coli and Staphylococcus aureus, and conducted bacterial culture experiments on invisible braces samples coated with GZO film and uncoated control samples.

[0198] The culture results showed that within 24 hours, the colony counts of Escherichia coli and Staphylococcus aureus in the GZO film samples were significantly lower than those in the control group, decreasing by 85% and 80% respectively. This shows that the GZO film can effectively inhibit the growth and reproduction of these two bacteria on the surface of invisible braces.

[0199] The experimental data are organized as shown in Table 1 below:

[0200] Table 1 Experimental data table

[0201]

[0202] Through this experiment, it was verified that the GZO antibacterial film prepared by the present invention can exert excellent antibacterial properties on the surface of invisible braces for a long time, providing effective oral health protection for patients.

[0203] 6. Clinical application effect

[0204] After verifying the performance of the GZO antibacterial film, the hospital coated the surface of the invisible braces of the 25-year-old female patient with the GZO film. During the one-year treatment, the patient did not experience any gingivitis or caries, and her oral health was good. At the same time, the patient was also satisfied with the transparent aesthetics of the invisible braces, and the overall wearing experience was significantly improved compared to before.

[0205] By comparison, the patient did not have any oral infection problems when using the invisible braces with the GZO antibacterial film of the present invention, but had mild gingivitis when using ordinary invisible braces before. This fully demonstrates that the high-adhesion antibacterial film provided by the present invention can effectively prevent bacteria from growing on the surface of the invisible braces, bringing significant oral health benefits to patients.

[0206] In summary, this embodiment fully verifies the excellent performance of the high-adhesion antibacterial film of the present invention. By adopting an intelligent magnetron sputtering process, a GZO film with a thickness of 100nm, a transmittance of 85%, and a roughness of 0.35nm was successfully prepared and applied to the surface of the invisible braces. The GZO antibacterial film not only has excellent antibacterial activity, but also forms a strong bond with the base material, and can continue to play a role during long-term use, providing effective oral health protection for patients. At the same time, its excellent optical properties also ensure that the aesthetics of the invisible braces is not affected.

[0207] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a high-adhesion antibacterial film for an oral invisible appliance, characterized in that: The following steps are involved: S10, using 70-80wt% of silicon dioxide, 10-20wt% of calcium oxide and 5-10wt% of sodium oxide to make a glass substrate, and mixing 80-90wt% of zinc oxide and 3wt% of gallium trioxide to make a target material; S20, using magnetron sputtering technology to sputter the target material with adaptive timing power, using pure Ar gas as the sputtering gas, maintaining room temperature throughout the sputtering process, and depositing a GZO thin film on the substrate; a black and white checkered image is attached to the non-sputtering surface of the substrate; S30, applying the prepared high-adhesion antibacterial film to the surface of the oral invisible orthodontic appliance as an antibacterial protective layer; The step of determining the adaptive timing power is specifically: S21, acquiring surface images of the substrate at multiple angles in real time during magnetron sputtering; S22, preprocessing the surface images at the multiple angles respectively to obtain preprocessed surface images at the multiple angles; S23, selecting a surface image at an orthogonal shooting angle from among the pre-processed surface images at multiple angles, and performing background segmentation using an image segmentation technique to obtain a foreground image and a background image; S24, performing alignment and registration according to the background image and the checkered image, and calculating the grayscale difference between the background image and the checkered image by using image processing technology as the transmittance of the GZO film; S25, extracting texture features, contour center moment features, surface undulation features, and color features from the foreground image, and calculating the roughness of the GZO film; S26, establishing a transmittance equation and a roughness equation taking into account magnetron sputtering process parameters, and fitting the transmittance equation and the roughness equation respectively using the real-time magnetron sputtering process parameters during the magnetron sputtering process and the calculated transmittance and roughness to obtain a transmittance fitting equation and a roughness fitting equation; S27, establishing a game model using the transmittance fitting equation and the roughness fitting equation, where the constraints include a low transmittance of 80%, a GZO film thickness of 80-120 nm, and a preset maximum sputtering time and maximum power; S28, solving the game model to obtain the optimal magnetron sputtering process parameters as the magnetron sputtering process parameters for the next period of time to perform magnetron sputtering; S29, repeat steps S21 to S28 until a GZO film with a thickness of 80-120 nm is obtained.

2. The high-adhesion antibacterial film for oral invisible orthodontic appliances according to claim 1, characterized in that: The method for extracting texture features, contour center moment features, surface undulation features and color features from the foreground image and calculating the roughness of the GZO film is specifically as follows: combining these features into a feature vector, normalizing each element of the feature vector, and calculating the modulus of the feature vector as the roughness of the GZO film.

3. The method for preparing a high-adhesion antibacterial film for an oral invisible appliance according to claim 2, characterized in that: The transmittance equation: ； In the formula, is the transmittance of GZO film, is the power curve, is the sputtering time, is the distance between the target and the substrate, is the substrate rotation speed, , , , is the coefficient to be determined.

4. The method for preparing a high-adhesion antibacterial film for an oral invisible appliance according to claim 3, characterized in that: The roughness equation: ; In the formula, is the roughness of the GZO film, is the power curve, is the sputtering time, is the distance between the target and the substrate, is the substrate rotation speed, , , , , is the coefficient to be determined.

5. The method for preparing a high-adhesion antibacterial film for an oral invisible appliance according to claim 4, characterized in that: The multiple angles include at least 15°, 45°, 90°, 135° and 165°; the surface image at the orthogonal shooting angle is the surface image of the substrate taken when the plane where the camera lens is located is parallel to the substrate.

6. The method for preparing a high-adhesion antibacterial film for an oral invisible appliance according to claim 5, characterized in that: The magnetron sputtering process parameters include power curve, sputtering time, sputtering temperature, substrate rotation speed, and the distance between the target and the substrate.

7. The method for preparing a high-adhesion antibacterial film for an oral invisible appliance according to claim 6, characterized in that: In the black and white square image, the side length of each square is 2-5 mm.

8. The method for preparing a high-adhesion antibacterial film for an oral invisible appliance according to claim 7, characterized in that: The game model is expressed as: ; In the formula, represents the magnetron sputtering process parameter vector, and are functions of transmittance and roughness, respectively. is the weight coefficient used to balance the importance of transmittance and roughness.

9. The method for preparing a high-adhesion antibacterial film for an oral invisible appliance according to claim 8, characterized in that: The constraints of the game model are expressed as: ； ； ； ； In the formula, Indicates the duration of the splash. Indicates the maximum splashing time, represents the sputtering power, Indicates the maximum sputtering power.

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