Femtosecond laser for implant processing and control method thereof

Abstract

The invention relates to the technical field of implant processing, in particular to a femtosecond laser for implant processing and a control method thereof.The method comprises the steps that the bone density of alveolar bone is obtained to determine the processing mode of the femtosecond laser; determining whether the processing process of a single stage is qualified or not based on the micropore distribution density of the implant surface in the corresponding processing mode; the vibration frequency of the implant in the rotating process is determined based on the judgment result that the machining process of the single stage is unqualified, so that the weight of the balancing weight is adjusted; obtaining the edge smoothness of the micropore based on the adjusted implant to determine whether the dispersion compensation of the femtosecond laser is qualified or not, and adjusting the spacing of the diffraction grating pair based on the judgment result that the dispersion compensation is unqualified; and determining the standard deviation of the thread pitch to determine the qualification of the moving trajectory of the femtosecond laser, and optimizing the preset frequency or optimizing the pitch adjustment mode for the unqualified moving trajectory. According to the embodiment of the invention, the bone combination rate of the implant is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of implant processing, and particularly to a femtosecond laser for implant processing and a control method thereof. Background Art

[0002] In the field of oral implant manufacturing, femtosecond laser has become the core technology for high-precision micro-structure processing due to its ultra-short pulse characteristics and low thermal damage advantages. However, implant processing faces multiple challenges: the bone density difference directly affects the laser energy absorption efficiency, and the processing mode needs to be dynamically adjusted; the accuracy of the thread pitch and micropore distribution directly affects the bone-bonding stability, but the traditional single-parameter control is difficult to cope with the cumulative error in multi-stage processing; in addition, the pulse broadening caused by group velocity dispersion and third-order dispersion during the transmission of femtosecond laser pulses will cause burrs on the micropore edges and the expansion of the heat-affected zone, seriously reducing the surface quality.

[0003] In the prior art, implant processing mostly relies on the fixed-parameter mode and lacks the adaptability to the dynamic feedback of bone density. For example, high bone density (above D2) requires high-energy density processing to form self-tapping threads, while low bone density (D3 / D4) requires reducing the power to avoid bone fractures, but the traditional system cannot match the bone density and dispersion compensation parameters in real time. At the same time, the vibration during the processing will cause the deviation of the thread pitch, and the existing counterweight adjustment mechanism is only based on static balance and does not combine the vibration frequency spectrum characteristics for dynamic optimization. In addition, the spacing adjustment of the dispersion compensation device depends on experience and cannot be corrected in real time, resulting in dispersion compensation lag or overcompensation, further exacerbating the pulse distortion.

[0004] Chinese Patent Application Publication No.: CN117353143A discloses a femtosecond laser and a mode-locking method of the femtosecond laser. The femtosecond laser includes a gain crystal, a pump source, and a resonator. The femtosecond laser further includes: at least one optical control switch disposed in the optical path of the laser optical path of the femtosecond laser; a driver for loading a preset driving signal to the optical control switch to enable the femtosecond laser to start the femtosecond pulse operation mode and maintain the operation of the femtosecond pulse operation mode. By loading a driving signal with a specific frequency to the optical control switch by the driver, the femtosecond laser can be excited to change from the DC operation mode to the femtosecond pulse operation mode, thereby realizing the start of the femtosecond pulse operation mode without mechanical movement and avoiding problems such as resonator detuning and inconsistent starting states caused by the mechanical movement method for starting the femtosecond pulse operation mode; and by continuously loading the driving signal to the optical control switch, the femtosecond laser can continuously maintain the femtosecond pulse operation mode without being interfered by other factors.

[0005] The following problems also exist in the prior art: In the prior art, the processing of implants mostly relies on a fixed parameter mode, and the processing process lacks real-time monitoring and adjustment, resulting in the lack of uniformity and regularity of the surface topography of the implants, low processing accuracy of the implants, and low bone bonding rate. Summary of the Invention

[0006] To this end, the present invention provides a femtosecond laser for implant processing and its control method to overcome the problems in the prior art that the processing process lacks real-time monitoring and adjustment, resulting in the lack of uniformity and regularity of the surface topography of the implants, low processing accuracy of the implants, and low bone bonding rate.

[0007] To achieve the above object, on the one hand, the present invention provides a femtosecond laser for implant processing and its control method, including: Obtain the bone density of the alveolar bone to determine the parameter configuration of the femtosecond laser for implant processing based on the bone density; Divide the processing process into several stages according to the implant diameter in the corresponding processing mode, and determine whether the processing process of a single stage is qualified based on the micropore distribution density on the implant surface; Determine the vibration frequency of the rotation process of the implant based on the determination result that the processing process of a single stage is unqualified, and change the weight of the traction counterweight of the implant according to the comparison result between the vibration frequency and the preset frequency; Obtain the edge smoothness of the micropores of the implant after the weight of the counterweight is adjusted to determine whether the dispersion compensation of the femtosecond laser is qualified, and adjust the distance between the diffraction grating pairs with a corresponding distance adjustment coefficient based on the determination result of unqualified dispersion compensation; Obtain the surface image of the implant to determine the standard deviation of the thread pitch to determine the qualification of the operation trajectory of the femtosecond laser, and optimize the preset frequency or the distance adjustment coefficient for the unqualified operation trajectory.

[0008] Further, the process of determining the configuration parameters of the femtosecond laser based on the bone density includes: Compare the bone density with a preset bone density; Determine that the femtosecond laser processes the implant with the first configuration parameter based on the comparison result that the bone density is greater than the preset bone density; Determine that the femtosecond laser processes the implant with the second configuration parameter based on the comparison result that the bone density is less than or equal to the preset bone density.

[0009] Further, the process of determining whether the processing process of a single stage is qualified based on the micropore distribution density on the implant surface includes: Compare the micropore distribution density with a preset distribution density respectively; Determine that the processing process of a single stage is unqualified based on the comparison result that the micropore distribution density is less than the first preset density or greater than the second preset density.

[0010] Further, the process of determining the adjustment of the counterweight according to the vibration frequency during the rotation process of the implant includes: Real-time collect the vibration amplitude during the rotation process of the implant and compare it with the preset amplitude respectively; Determine the adjustment of the weight of the counterweight based on the comparison result that the vibration amplitude is greater than or equal to the first preset amplitude; Based on the comparison result that the vibration amplitude is less than the first preset amplitude and greater than the second preset amplitude, record the primary vibration corresponding to the vibration amplitude as a single vibration, and compare the number of times of the single vibration with the preset number of times; Determine the adjustment of the weight of the counterweight based on the comparison result that the number of times of the single vibration is greater than the preset number of times.

[0011] Further, the process of adjusting the weight of the counterweight includes: Determine the eccentricity of the implant processing process and compare the eccentricity with the preset eccentricity; Based on the comparison result that the eccentricity is greater than the preset eccentricity, subtract the preset eccentricity from the eccentricity to obtain an eccentricity difference; Set several weight adjustment methods corresponding to the eccentricity difference to adjust the weight of the counterweight.

[0012] Further, the process of determining the edge smoothness of the micropore includes: Compare the micropore with a standard micropore and coincide with the centers of the micropore and the standard micropore as reference points; Determine the ratio of the sum of the lengths of the standard micropore corresponding to all non-coincident positions of the micropore and the standard micropore to the circumference of the standard micropore as the edge smoothness.

[0013] Further, the process of determining whether the dispersion compensation of the femtosecond laser is qualified according to the edge smoothness includes: Compare the edge smoothness with the preset smoothness; Based on the comparison result that the edge smoothness is less than the preset smoothness, determine that the dispersion compensation of the femtosecond laser is unqualified and adjust the spacing of the diffraction grating pair; Among them, several spacing adjustment coefficients corresponding to the smoothness difference are set to increase the spacing based on the spacing adjustment coefficient, and the smoothness difference is the difference between the preset smoothness and the edge smoothness.

[0014] Further, after the implant is processed, the standard deviation of the thread pitch of the implant is obtained. The process of determining the adjustment parameter according to the standard deviation includes: Comparing the standard deviation with a preset standard deviation respectively; Based on the comparison result that the standard deviation is greater than the first preset standard deviation, determining to adjust the preset frequency; Wherein, a plurality of frequency optimization coefficients corresponding to the first standard deviation are set to reduce the preset frequency based on the frequency optimization coefficients. The first standard deviation is the difference between the standard deviation and the first preset standard deviation.

[0015] Further, after the implant is processed, the standard deviation of the thread pitch of the implant is obtained. The process of determining the adjustment parameter according to the standard deviation includes: Comparing the standard deviation with a preset standard deviation respectively; Based on the comparison result that the standard deviation is less than or equal to the first preset standard deviation and greater than the second preset standard deviation, determining to adjust the pitch adjustment coefficient; Wherein, a plurality of pitch correction coefficients corresponding to the second standard deviation are set to increase the pitch adjustment coefficient based on the pitch correction coefficients. The second standard deviation is the difference between the standard deviation and the second preset standard deviation.

[0016] On the other hand, the present invention also provides a femtosecond laser for implant processing, including: A core laser generation module, which includes an oscillator for generating an initial femtosecond laser pulse and a pump source for providing energy excitation to the gain medium; A pulse processing module, which is connected to the core laser generation module and includes a pair of diffraction gratings for broadening the pulse of the initial femtosecond laser and compensating for chromatic dispersion; A control mechanism, which is connected to the pulse processing module and is used to adjust the pitch according to the determination result of adjusting the pitch of the pair of diffraction gratings with corresponding adjustment parameters.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows. The present invention specifically determines the processing mode of the femtosecond laser according to the bone density of the planter. Different bone densities correspond to different requirements for implants. Specific processing is beneficial to improving the bone-bonding force. According to the implant diameter, the processing process is divided into several stages under the determined processing mode, and any processing stage is monitored in real time to determine the micropore distribution density. A short micropore distribution density indicates a dense micropore distribution, which can increase the adhesion sites of bone cells, promote the differentiation of osteoblasts, and enhance chemical bonding. Excessively dense micropores will hinder the diffusion of nutrients, resulting in hypoxia and necrosis of bone cells. Sparse micropores lead to insufficient mechanical interlocking, bone stress concentration, and difficulty for bone tissue to grow into the micropores. According to the micropore distribution density, the processing process of a single processing stage is accurately determined. Thus, when a single processing stage is determined to be unqualified, the vibration frequency during the rotation process of the implant is determined. The bone-bonding speed of the implant is correlated with the specific form of the processing technology. Compared with the forms of laser scanning microgrooves and implant rotation for processing threads, the processing form of combining laser scanning and implant rotation has a faster bone-bonding speed. However, during the rotation process of the implant, centrifugal force, mechanical vibration, and even air flow will affect the rotational stability of the implant. Insufficient stability will cause the implant to be eccentric. According to the eccentricity of the implant, the weight of the counterweight is adjusted to offset the vibration frequency caused by objective reasons, thereby improving the stability of the implant during the rotation process; based on the adjusted processing stage, the edge smoothness of the micropores is obtained to determine whether the chromatic dispersion compensation is qualified. The initial laser generated by the femtosecond laser will undergo chromatic dispersion. Through chromatic dispersion compensation, the width of the pulsed laser is restored from the picosecond level to the femtosecond level. When the chromatic aberration compensation is insufficient, the pulse energy density of the femtosecond laser will be insufficient, resulting in an extended interaction time between the laser and the material, and features such as melting and burrs appear at the micropore edges, resulting in insufficient edge smoothness of the micropores. Therefore, according to the edge smoothness of the micropores, the chromatic dispersion compensation amount is adjusted, thereby improving the processing accuracy of the implant and increasing the bone-bonding rate.

[0018] Further, after all the processing stages are completed, the thread pitch of the entire implant is determined to determine whether the overall running trajectory of the femtosecond laser is qualified, and for the unqualified running trajectory, the value of the preset frequency is reduced or the value of the pitch adjustment coefficient is increased to improve the judgment criterion and the chromatic dispersion compensation amount, thereby further improving the processing accuracy of the implant and increasing the bone-bonding rate.

[0019] Furthermore, the present invention determines the qualification of the operation trajectory of the femtosecond laser by determining the overall thread pitch. Insufficient dispersion compensation will cause phase distortion of the pulse and deviation of the focal position. By observing the change in the thread pitch, it can be determined whether the operation trajectory of the femtosecond laser is qualified. At the same time, insufficient rotational stability of the implant will also result in an unqualified operation trajectory of the femtosecond laser. The degrees of deviation of the operation trajectory caused by the two methods are different. The adjustment parameters can be determined based on the deviation degree between the thread pitch and the preset pitch, thereby further improving the machining accuracy of the implant and increasing the bone bonding rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flowchart of the control method of the femtosecond laser for implant machining according to an embodiment of the present invention; Figure 2 is a flowchart of determining the configuration parameters of the femtosecond laser according to an embodiment of the present invention; Figure 3 is a flowchart of determining whether the machining process of a single stage is qualified according to an embodiment of the present invention; Figure 4 is a schematic structural diagram of the femtosecond laser for implant machining according to an embodiment of the present invention; In the figure: 1, core laser generation module; 2, diffraction grating pair; 3, mirror; 4, first linear guide; 5, first motor; 6, second linear guide; 7, second motor; 8, output mirror; 9, initial femtosecond laser pulse; 10, refracted pulsed laser; 11, femtosecond pulsed laser. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to make the objectives and advantages of the present invention clearer, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0023] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0024] In addition, it should be noted that in the description of the present invention, unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0025] Please refer to Figure 1 as shown in Figure 1 which is a flowchart of the control method of the femtosecond laser for implant processing according to an embodiment of the present invention; Figure 2 which is a flowchart of determining the configuration parameters of the femtosecond laser according to an embodiment of the present invention; Figure 3 which is a flowchart of determining whether the processing process of a single stage is qualified according to an embodiment of the present invention.

[0026] An embodiment of the present invention provides a control method for a femtosecond laser for implant processing, including: Step S1, obtaining the bone density of the alveolar bone to determine the parameter configuration of the femtosecond laser for implant processing based on the bone density; Step S2, dividing the processing process into several stages according to the implant diameter in the corresponding processing mode, and determining whether the processing process of a single stage is qualified based on the micropore distribution density on the implant surface; Step S3, determining the vibration frequency of the rotation process of the implant based on the determination result that the processing process of a single stage is unqualified, and changing the weight of the traction counterweight of the implant according to the comparison result between the vibration frequency and the preset frequency; Step S4, obtaining the edge smoothness of the micropores of the implant after the weight of the counterweight is adjusted to determine whether the dispersion compensation of the femtosecond laser is qualified, and adjusting the distance between the pair of diffraction gratings with a corresponding distance adjustment coefficient based on the determination result that the dispersion compensation is unqualified; Step S5, obtaining the surface image of the implant to determine the standard deviation of the thread pitch to determine the qualification of the operating trajectory of the femtosecond laser, and optimizing the preset frequency or the distance adjustment coefficient for the unqualified operating trajectory.

[0027] Specifically, bone density is determined based on cone beam computed tomography (CBCT). The oral region is scanned by a cone X-ray beam, and three-dimensional data is captured using a flat panel detector to reconstruct high-resolution tomographic images. In CBCT images, bone density is positively correlated with gray values. For example, the gray value of cortical bone is approximately 800 - 1500, and that of cancellous bone is approximately 200 - 800. The average gray value of the trabecular bone region can be extracted as a bone density index through software such as Mimics or OsiriX. The alveolar bone region is segmented by software to calculate topological parameters such as bone volume fraction (BV / TV) and trabecular thickness (Tb.Th) to quantitatively evaluate the bone density distribution.

[0028] Specifically, a personalized implant guide is generated based on the detection results of oral scanning and CBCT, and the thread angle is planned. Then, according to the planning results, through an adaptive hierarchical algorithm, the scanning density is dynamically adjusted according to the curvature change to plan the processing path of the femtosecond laser.

[0029] It can be understood that the diameter of the implant usually shows a tapered design from the abutment to the bottom end, specifically manifested as: 1. Abutment section: The diameter is the largest, usually 3.5 mm - 5.0 mm, to provide sufficient mechanical support area and adapt to the occlusal load of the crown or bridge.

[0030] 2. Body transition section: When extending from the abutment to the bottom end, the diameter gradually decreases, with a gradient of approximately 0.1 mm - 0.3 mm, forming a taper, such as 2° - 6°, to facilitate implantation into the bone and enhance the initial stability.

[0031] 3. Bottom end section: The diameter is the smallest, usually 2.0 mm - 3.5 mm, to reduce the risk of cortical bone penetration and increase the bone bonding area through threads or self-tapping structures.

[0032] In this embodiment, the processing process is divided into an abutment section, a body transition section, and a bottom end section according to the diameter of the implant.

[0033] Specifically, the process of determining the parameter configuration of the femtosecond laser based on the bone density includes: Comparing the bone density with a preset bone density; Based on the comparison result that the bone density is greater than the preset bone density, it is determined that the femtosecond laser processes the implant with the first configuration parameters; Based on the comparison result that the bone density is less than or equal to the preset bone density, it is determined that the femtosecond laser processes the implant with the second configuration parameters.

[0034] Specifically, the value range of the preset bone density is set to [1100, 1300], and 1200 is preferred in the embodiments of the present invention.

[0035] Specifically, the goal of implant processing with the first configuration parameters is to form a thread root acute angle of 30°-40°, enhance self-tapping, and reduce bone extrusion. The specific processing parameters are as follows: Pulse energy: 50 μJ - 100 μJ; Repetition frequency: 100 kHz - 200 kHz; Scanning speed: 1000 mm / s - 2000 mm / s; Focus position: -50 μm.

[0036] The goal of implant processing with the second configuration parameters is to form a microporous structure with a diameter of 200 - 400 μm. The specific processing parameters are as follows: Pulse energy: 10 μJ - 30 μJ; Repetition frequency: 50 kHz - 100 kHz; Scanning speed: 500 mm / s - 1000 mm / s; Focus position: +100 μm.

[0037] It can be understood that when implant processing is carried out with the above configuration parameters, for different processing positions, the specific pulse energy, repetition frequency, and scanning speed are all different. The specific corresponding relationship is prior art and will not be elaborated here.

[0038] Specifically, the process of determining whether the processing process of a single stage is qualified based on the micropore distribution density on the implant surface includes: Comparing the micropore distribution density with the preset distribution density respectively; Determining that the processing process of a single stage is unqualified based on the comparison result that the micropore distribution density is less than the first preset density or greater than the second preset density; Determining that the processing process of a single stage is qualified based on the comparison result that the micropore distribution density is greater than or equal to the first preset density and less than or equal to the second preset density; Among them, the first preset density is less than the second preset density.

[0039] Specifically, the process of determining the micropore distribution density includes: Obtaining the surface image of the implant, and dividing a number of concentric circles with a preset length gradient as the radius centered on any micropore; Determining the number of micropores within any concentric circular ring, and calculating the ratio of the number of micropores to the area of the corresponding concentric circular ring, and determining the ratio as the micropore distribution density.

[0040] Specifically, the values of the first preset density and the second preset density are determined according to clinical data. For example, for the abutment segment, the value of the first preset density is 1×10⁵ pores / mm², and the value of the second preset density is 5×10⁵ pores / mm²; for the body transition segment, the value of the first preset density is 0.5×10⁵ pores / mm², and the value of the second preset density is 3×10⁵ pores / mm²; for the bottom segment, the value of the first preset density is 2×10⁴ pores / mm², and the value of the second preset density is 3×10⁴ pores / mm². The values of the first preset density and the second preset density are determined according to clinical data. For example, for the abutment segment, the value of the first preset density is that the values of the first preset density and the second preset density are determined according to clinical data. For example, for the abutment segment, the value of the first preset density is Specifically, the values of the first preset density and the second preset density are determined according to clinical data. For example, for the abutment segment, the value of the first preset density is 1×10 5 pores / mm², and the value of the second preset density is 5×10 5 pores / mm 2 ; for the body transition segment, the value of the first preset density is 0.5×10 5 pores / mm 2 , and the value of the second preset density is 3×10 5 pores / mm 2 ; for the bottom segment, the value of the first preset density is 2×10 4 pores / mm 2 , and the value of the second preset density is 3×10 4 pores / mm 2 .

[0041] Specifically, when the distribution density of the micropores is greater than the second preset density, the micropores are too densely distributed, resulting in restricted migration of osteocytes, prone to hypoxia necrosis, and a decrease in the bone bonding rate; when the distribution density of the micropores is less than the first preset density, the micropores are too sparsely distributed, resulting in insufficient mechanical interlocking, and it is difficult for bone tissue to grow into the micropores.

[0042] Specifically, the process of adjusting the counterweight according to the vibration frequency during the rotation process of the implant includes: Real-time collect the vibration amplitude during the rotation process of the implant and compare it with the preset amplitude respectively; Based on the comparison result that the vibration amplitude is greater than or equal to the first preset amplitude, determine the weight of the counterweight to be adjusted; Based on the comparison result that the vibration amplitude is less than the first preset amplitude and greater than the second preset amplitude, record the vibration corresponding to the vibration amplitude as a single vibration, and compare the number of times of the single vibration with the preset number of times; Based on the comparison result that the number of times of the single vibration is greater than the preset number of times, determine the weight of the counterweight to be adjusted.

[0043] Specifically, the acquisition of the single vibration is based on a single processing stage, and the setting of the preset number of times is based on a single processing stage.

[0044] It can be understood that during the femtosecond laser processing of the implant, the counterweight refers to a dynamic balance counterweight used to balance the rotation system (such as the implant clamping device or the spindle drive system), and its function is to offset the rotational vibration caused by the centrifugal force deviation of the implant.

[0045] Specifically, during the rotation of the implant, the vibration amplitude can be measured by, for example, a piezoelectric acceleration sensor that converts mechanical vibration into an electrical signal through the piezoelectric effect, directly measures the vibration acceleration, and calculates the vibration velocity or displacement amplitude through integration. This is the prior art and will not be elaborated here. The measurement method of the vibration amplitude is not specifically limited as long as it meets the measurement requirements.

[0046] Specifically, the value range of the first preset amplitude is set to [45μm, 55μm], and 50μm is preferably selected in the embodiment of the present invention; the value range of the second preset amplitude is set to [25μm, 35μm], and 30μm is preferably selected in the embodiment of the present invention; the value range of the preset number of times is set to [3 times, 5 times], and 4 times is preferably selected in the embodiment of the present invention.

[0047] It can be understood that in the embodiment of the present invention, the values of the preset amplitude and the preset number of times are both determined according to clinical trial data. When the vibration is greater than the first preset amplitude, high-frequency vibration will occur and visible vibration marks will appear on the implant surface. When the vibration is less than or equal to the first preset amplitude and greater than the second preset vibration amplitude, there will be a risk of microcracks.

[0048] Specifically, the process of adjusting the weight of the counterweight includes: Determine the eccentricity during the implant processing process and compare the eccentricity with the preset eccentricity; Based on the comparison result that the eccentricity is greater than the preset eccentricity, subtract the preset eccentricity from the eccentricity to obtain an eccentricity difference; Set several weight adjustment methods corresponding to the eccentricity difference to adjust the weight of the counterweight.

[0049] Specifically, the value range of the preset eccentricity is set to [12μm, 25μm], and 20μm is preferably selected in the embodiment of the present invention. The preset eccentricity is determined according to the ISO1940 dynamic balance grade standard to ensure that the surface roughness of the processed surface is less than 20μm and avoid periodic vibration marks caused by imbalance.

[0050] Specifically, based on the comparison result that the eccentricity difference is greater than or equal to the preset eccentricity difference, it is determined to increase the counterweight in the opposite direction of the eccentricity; Determine to reduce the counterweight in the positive eccentricity direction based on the comparison result that the eccentricity difference is less than the preset eccentricity difference.

[0051] Specifically, the offset direction of the eccentricity is determined by a laser vibrometer to obtain the vector direction of the eccentricity. For example, the offset along the X, Y, or Z axis. Suppose the measured eccentricity is offset by 30 μm in the positive X-axis direction. Then, it is necessary to increase the counterweight in the negative X-axis direction or reduce the counterweight in the positive X-axis direction.

[0052] Specifically, the value range of the preset eccentricity difference is set to [5 μm, 10 μm]. In the embodiment of the present invention, 8 μm is preferably used. The amplitude of the weight reduction or increase of the specific counterweight block is equal to the ratio of the eccentricity difference to the system sensitivity coefficient.

[0053] Specifically, the determination process of the edge smoothness of the microhole includes: Compare the microhole with a standard microhole and align the centers of the microhole and the standard microhole as the reference points; Determine the ratio of the sum of the lengths of the standard microholes corresponding to all non-coincident positions between the microhole and the standard microhole to the perimeter of the standard microhole as the edge smoothness.

[0054] Specifically, the standard microhole refers to a microhole with roughness and edge angles meeting the requirements. For example, the roughness Ra ≤ 0.1 μm, and the edge angle range is: 8° - 15° is the standard microhole. It can be understood that the standard microhole is not a single hole, and there is a corresponding standard microhole for any microhole on the implant.

[0055] Specifically, the sum of the lengths of the standard microholes refers to the sum of the edge lengths of the standard microholes corresponding to the non-coincident positions.

[0056] Specifically, the process of determining whether the dispersion compensation of the femtosecond laser is qualified according to the edge smoothness includes: Compare the edge smoothness with a preset smoothness; Determine that the dispersion compensation of the femtosecond laser is qualified based on the comparison result that the edge smoothness is greater than or equal to the preset smoothness; Determine that the dispersion compensation of the femtosecond laser is unqualified based on the comparison result that the edge smoothness is less than the preset smoothness and adjust the spacing of the diffraction grating pair; Among them, several spacing adjustment coefficients corresponding to the smoothness difference are set to increase the spacing based on the spacing adjustment coefficients. The smoothness difference is the difference between the preset smoothness and the edge smoothness.

[0057] Specifically, the value range of the preset smoothness is set to [0.8, 0.95]. In the embodiment of the present invention, 0.85 is preferably used.

[0058] Specifically, under the condition that the dispersion compensation is determined to be unqualified, the smoothness difference is compared with a preset smoothness difference; Based on the comparison result that the smoothness difference is greater than the preset smoothness difference, it is determined to increase the pitch with a first pitch adjustment coefficient; Based on the comparison result that the smoothness difference is less than or equal to the preset smoothness difference, it is determined to increase the pitch with a second pitch adjustment coefficient.

[0059] Specifically, the value range of the preset smoothness difference is set to [0.05, 0.15], and preferably 0.1 in the embodiments of the present invention; the value range of the first pitch adjustment coefficient is set to [1.004, 1.008], and preferably 1.005 in the embodiments of the present invention; the value range of the second pitch adjustment coefficient is set to [1.001, 1.003], and preferably 1.002 in the embodiments of the present invention.

[0060] Specifically, the larger the smoothness difference is, the greater the degree of unqualified dispersion compensation amount is, and it is necessary to increase the pitch of the diffraction grating pair to increase the dispersion compensation amount. It can be understood that the compensation degree of the dispersion compensation amount is positively correlated with the pitch of the diffraction grating pair.

[0061] Specifically, after the implant is processed, the standard deviation of the thread pitch of the implant is obtained. The process of determining the adjustment parameter according to the standard deviation includes: The standard deviation is respectively compared with a preset standard deviation; Based on the comparison result that the standard deviation is greater than a first preset standard deviation, it is determined to adjust the preset frequency; Wherein, a plurality of frequency optimization coefficients corresponding to the first standard deviation are set to reduce the preset frequency based on the frequency optimization coefficient, and the first standard deviation is the difference between the standard deviation and the first preset standard deviation.

[0062] Specifically, the process of determining the standard deviation includes: The distances between individual threads of the implant are respectively compared with a preset distance; Based on the comparison result that the distance is less than or equal to a first preset distance and greater than or equal to a second preset distance, it is determined that the thread pitch is qualified; Based on the comparison result that the distance is greater than the first preset distance or less than the second preset distance, it is determined that the thread pitch is unqualified; Based on the determination result of unqualified thread pitch, the absolute difference between the distance and the preset distance is determined; The standard deviation of the absolute difference is calculated.

[0063] Specifically, the first preset distance and the second preset distance are the maximum and minimum values of the thread pitch allowed according to the design requirements. For example, according to the ISO standard requirements, the pitch error ≤ ±0.02mm and the pitch requirement is 2mm, then the first preset distance is 2.02mm and the second preset distance is 1.98mm.

[0064] Specifically, the value range of the first preset standard deviation is set to [0.3mm, 0.5mm], and 0.3mm is preferred in the embodiments of the present invention.

[0065] Specifically, the first standard deviation is compared with a preset difference value; Based on the comparison result that the first standard deviation is greater than the preset difference value, it is determined to reduce the preset frequency with a first frequency optimization coefficient; Based on the comparison result that the first standard deviation is less than or equal to the preset difference value, it is determined to reduce the preset frequency with a second frequency optimization coefficient.

[0066] Specifically, the value range of the preset difference value is set to [0.02mm, 0.06mm], and 0.04mm is preferred in the embodiments of the present invention; the value range of the first frequency optimization coefficient is set to [0.92, 0.95], and 0.94 is preferred in the embodiments of the present invention; the value range of the second frequency optimization coefficient is set to [0.96, 0.98], and 0.97 is preferred in the embodiments of the present invention.

[0067] Specifically, after the implant is processed, the standard deviation of the thread pitch of the implant is obtained. The process of determining the adjustment parameter according to the standard deviation includes: The standard deviation is respectively compared with a preset standard deviation; Based on the comparison result that the standard deviation is less than or equal to the first preset standard deviation and greater than the second preset standard deviation, it is determined to adjust the pitch adjustment coefficient; Wherein, a plurality of pitch correction coefficients corresponding to the second standard deviation are set to increase the pitch adjustment coefficient based on the pitch correction coefficients, and the second standard deviation is the difference between the standard deviation and the second preset standard deviation.

[0068] Specifically, the value range of the second preset standard deviation is set to [0.1mm, 0.29mm], and 0.15mm is preferred in the embodiments of the present invention.

[0069] Specifically, the second standard deviation is compared with a preset difference value; Based on the comparison result that the second standard deviation is greater than the preset difference value, it is determined to reduce the pitch adjustment coefficient with a first pitch correction coefficient; Based on the comparison result that the second standard deviation is less than or equal to the preset difference value, it is determined to reduce the pitch adjustment coefficient with a second pitch correction coefficient.

[0070] Specifically, the value range of the first pitch correction coefficient is set to [0.955, 0.97], and preferably 0.96 in the embodiments of the present invention; the value range of the second pitch correction coefficient is set to [0.971, 0.99], and preferably 0.98 in the embodiments of the present invention.

[0071] Please refer to Figure 4 as shown, which is a schematic structural diagram of the femtosecond laser used for implant processing in the embodiments of the present invention.

[0072] The embodiments of the present invention further provide a femtosecond laser for implant processing, including: A core laser generation module 1, which includes an oscillator (not shown in the figure) for generating initial femtosecond laser pulses 9 and a pump source (not shown in the figure) for providing energy excitation for the gain medium; A pulse processing module, which is connected to the core laser generation module, includes a pair of diffraction gratings 2 for broadening the pulses of the initial femtosecond laser 9 and compensating for dispersion, a mirror 3 for reflecting pulsed laser light, a first motor 5, a second motor 7, a first linear guide 4 and a second linear guide 6 for moving the pair of diffraction gratings 2 along a specific direction, and an output mirror 8 for emitting femtosecond pulsed laser light 11; A control mechanism (not shown in the figure), which is connected to the pulse processing module, includes, A parameter determination module, which is used to determine the bone density of the alveolar bone, so as to determine the parameter configuration of the femtosecond laser for implant processing based on the bone density; A stage division module, which is used to divide the processing process into several stages according to the implant diameter, and determine whether the processing process of a single stage is qualified based on the micropore distribution density on the implant surface; A stability determination module, which is used to adjust the parameters according to the comparison result between the vibration frequency of the implant and a preset frequency to change the weight of the traction counterweight of the implant; A compensation determination module, which is used to determine whether the dispersion compensation of the femtosecond laser is qualified according to the edge smoothness of the micropores of the implant, and adjust the pitch of the pair of diffraction gratings based on the determination result of unqualified dispersion compensation; A trajectory determination module, which is used to determine the qualification of the operating trajectory of the femtosecond laser according to the standard deviation of the thread pitch of the implant, and optimize the preset frequency or the pitch adjustment coefficient for the unqualified operating trajectory.

[0073] Specifically, the specific process of the femtosecond laser generating femtosecond pulsed laser light includes: The initial femtosecond pulsed laser 9 generated by the core laser generation module 1 becomes a refracted pulsed laser 10 after being refracted by the output mirror 8 and enters the pulsed processing module. After being broadened by the diffraction grating pair 2, it returns through the reflector 3, and then after the dispersion compensation by the diffraction grating pair 2, it is output by the output mirror 8 to become a femtosecond pulsed laser 11.

[0074] Example 1: The implant is processed using the first set of configuration parameters, specifically: pulse energy: 70 μJ, repetition frequency: 150 kHz, scanning speed: 1500 mm / s, focal position: -50 μm.

[0075] The implant is processed using the second set of configuration parameters, specifically: pulse energy: 20 μJ, repetition frequency: 75 kHz, scanning speed: 750 mm / s, focal position: +100 μm.

[0076] For the implant processed by using the control method of the femtosecond laser for implant processing according to the embodiment of the present invention, the bone bonding rate and bone bonding ratio in actual application are significantly improved compared with the traditional processing method, as shown in Table 1 specifically.

[0077] Table 1 Comparison results of bone bonding rate and bone bonding rate

[0078] Data source: Clinical trials of the Stomatological Hospital Affiliated to XX University, sample size n = 200, with 100 samples for each of the first set of configuration parameters and the second set of configuration parameters.

[0079] As can be seen from the table, the bone bonding rate and bone bonding ratio of the implant produced by using the method according to the embodiment of the present invention are significantly improved compared with the traditional processing method.

[0080] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

Claims

1. A control method for a femtosecond laser used for implant processing, characterized in that: include: Acquiring the bone density of the alveolar bone to determine the parameter configuration of the femtosecond laser for implant processing based on the bone density; In the corresponding processing mode, the processing process is divided into several stages according to the implant diameter, and whether the processing process of a single stage is qualified is determined based on the micropore distribution density on the implant surface; Determine the vibration frequency of the implant during rotation based on the result of the determination that the processing of a single stage is unqualified, so as to change the weight of the traction weight block of the implant according to the comparison result between the vibration frequency and the preset frequency; Obtaining the edge smoothness of the implant micropore after the weight of the counterweight block is adjusted to determine whether the dispersion compensation of the femtosecond laser is qualified, and adjusting the spacing of the diffraction grating pair with the corresponding spacing adjustment coefficient based on the determination result that the dispersion compensation is unqualified; The surface image of the implant is obtained to determine the standard deviation of the thread pitch to determine the eligibility of the running trajectory of the femtosecond laser, and the preset frequency or the pitch adjustment coefficient is optimized for the unqualified running trajectory.

2. The control method of a femtosecond laser for implant processing according to claim 1, characterized in that: The process of determining the configuration parameters of the femtosecond laser based on the bone density includes: comparing the bone density with a preset bone density; Determining that the femtosecond laser processes the implant with the first configuration parameter based on the comparison result that the bone density is greater than the preset bone density; Based on the comparison result that the bone density is less than or equal to the preset bone density, it is determined that the femtosecond laser processes the implant with the second configuration parameters.

3. The control method of a femtosecond laser for implant processing according to claim 2, characterized in that: The process of determining whether a single stage of processing is acceptable based on the micropore distribution density on the implant surface includes: Comparing the micropore distribution density with the preset distribution density respectively; The processing of a single stage is determined to be unqualified based on the comparison result that the micropore distribution density is less than the first preset density or greater than the second preset density.

4. The control method of a femtosecond laser for implant processing according to claim 3, characterized in that: The process of determining the adjustment of the counterweight according to the vibration frequency of the implant's rotation process includes: The vibration amplitude of the implant during rotation is collected in real time and compared with the preset amplitude; Determining to adjust the weight of the counterweight block based on a comparison result that the vibration amplitude is greater than or equal to a first preset amplitude; Based on the comparison result that the vibration amplitude is less than the first preset amplitude and greater than the second preset amplitude, one vibration corresponding to the vibration amplitude is recorded as a single vibration, and the number of the single vibration is compared with the preset number; The weight of the counterweight block is adjusted based on a comparison result that the number of the single vibration is greater than the preset number.

5. The control method of a femtosecond laser for implant processing according to claim 4, characterized in that: The process of adjusting the weight of the counterweight block includes: Determining an eccentricity during implant processing, and comparing the eccentricity with a preset eccentricity; Based on the comparison result that the eccentricity is greater than the preset eccentricity, subtracting the eccentricity from the preset eccentricity to obtain an eccentricity difference; Several weight adjustment methods corresponding to the eccentricity difference are provided to adjust the weight of the counterweight block.

6. The control method of a femtosecond laser for implant processing according to claim 5, characterized in that: The process of determining the edge smoothness of microholes includes: Comparing the micropore with a standard micropore, and aligning the micropore with the center of the standard micropore as a reference point; The ratio of the sum of the lengths of the standard microholes corresponding to all non-overlapping positions of the microhole and the standard microhole to the perimeter of the standard microhole is determined as the edge smoothness.

7. The control method of a femtosecond laser for implant processing according to claim 6, characterized in that: The process of determining whether the dispersion compensation of a femtosecond laser is qualified based on edge smoothness includes: comparing the edge smoothness with a preset smoothness; Based on the comparison result that the edge smoothness is less than the preset smoothness, determining that the dispersion compensation of the femtosecond laser is unqualified and adjusting the spacing of the diffraction grating pair; Among them, a number of spacing adjustment coefficients corresponding to the smoothness difference are set to increase the spacing based on the spacing adjustment coefficients, and the smoothness difference is the difference between the preset smoothness and the edge smoothness.

8. The control method of a femtosecond laser for implant processing according to claim 7, characterized in that: After the implant is processed, the standard deviation of the thread pitch of the implant is obtained, and the process of determining the adjustment parameter according to the standard deviation includes: comparing the standard deviations with preset standard deviations respectively; Determining to adjust the preset frequency based on a comparison result that the standard deviation is greater than a first preset standard deviation; Among them, a plurality of frequency optimization coefficients corresponding to a first standard deviation are provided to reduce the preset frequency based on the frequency optimization coefficients, and the first standard deviation is a difference between the standard deviation and the first preset standard deviation.

9. The control method of a femtosecond laser for implant processing according to claim 7, characterized in that: After the implant is processed, the standard deviation of the thread pitch of the implant is obtained, and the process of determining the adjustment parameter according to the standard deviation includes: comparing the standard deviations with preset standard deviations respectively; Determining to adjust the spacing adjustment coefficient based on a comparison result that the standard deviation is less than or equal to a first preset standard deviation and greater than a second preset standard deviation; Among them, a plurality of spacing correction coefficients corresponding to a second standard deviation are provided to increase the spacing adjustment coefficient based on the spacing correction coefficient, and the second standard deviation is a difference between the standard deviation and the second preset standard deviation.

10. A femtosecond laser using the control method of a femtosecond laser for implant processing according to any one of claims 1 to 9, characterized in that: include: A core laser generation module, which includes an oscillator for generating initial femtosecond laser pulses and a pump source for providing energy excitation to the gain medium; A pulse processing module connected to the core laser generating module, comprising a diffraction grating pair for broadening the pulse of the initial femtosecond laser and compensating for dispersion; A control mechanism is connected to the pulse processing module and is used to adjust the spacing of the diffraction grating pair according to the corresponding adjustment parameter according to the determination result of adjusting the spacing of the diffraction grating pair.

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