SURFACE-TREATED IMPLANT STRUCTURE

Abstract

Provided is a surface-treated implant structure. The implant structure according to an aspect includes a fixture acting as an artificial tooth root, and the nano-protrusions included in the outer peripheral surface of the fixture exhibit a certain level of height, depth, and aspect ratio.

Claims

1. An implant structure comprising a fixture that acts as an artificial tooth root, wherein the fixture includes a cylindrical bone contact portion having a first outer peripheral surface on which a thread is formed and a gingival contact portion having a second outer peripheral surface and disposed on the bone contact portion, and the first outer peripheral surface or the second outer peripheral surface includes a plurality of nano-protrusions having a width of 10 nm to 1000 nm and an aspect ratio of 1000:1 to 1:50.

2. The implant structure of claim 1, wherein the aspect ratio of the nano-protrusions included in the first outer peripheral surface is different from the aspect ratio of the nano-protrusions included in the second outer peripheral surface.

3. The implant structure of claim 1, wherein the shape of the nano-protrusions of the second outer peripheral surface promotes the killing of bacteria present on the surface of the implant structure, and the nano-protrusions have a width of 10 to 1000 nm and an aspect ratio of 1:1 to 1:50.

4. The implant structure of claim 3, wherein the nano-protrusions have blunt ends.

5. The implant structure of claim 3, wherein an arithmetic mean roughness (Ra) value of the second outer peripheral surface is in a range of 1.0 μm to 5.0 μm.

6. The implant structure of claim 1, wherein the shape of the nano-protrusion of the first outer peripheral surface is to promote osseointegration with the implant, and the nano-protrusions have a width of 10 nm to 1000 nm and an aspect ratio of 1000:1 to 1:1.

7. The implant structure of claim 6, wherein an arithmetic mean roughness (Ra) value of the first outer peripheral surface is in a range of 0.5 μm to 3.0 μm.

8. The implant structure of claim 1, wherein the implant structure includes at least one material selected from titanium, or titanium alloy.

9. The implant structure of claim 1, wherein the implant structure is surface-treated with a femtosecond laser.

10. The implant structure of claim 9, wherein the surface treatment is irradiating of a femtosecond laser beam having a laser intensity of 1 W to 5 W on the surface of the first outer peripheral surface or the second outer peripheral surface in a linear-type and grid-type one or more times.

11. The implant structure of claim 10, wherein the first outer peripheral surface or the second outer peripheral surface is surface-treated by using a femtosecond laser, wherein (i) the height of a to-be-processed surface of the first outer peripheral surface or the second outer peripheral surface is 0.001 mm to 10 mm greater than a surface thereof which has not been subjected to the treatment using the femtosecond laser, or (ii) the depth of a to-be-processed surface of the first outer peripheral surface or the second outer peripheral surface is 0.001 mm to 10 mm greater than a surface thereof which has not been subjected to the treatment using the femtosecond laser.

12. An antibacterial composition comprising a metal material having a surface including a plurality of nano-protrusions having the aspect ratio of 1:1 to 1:50, wherein the metal material includes titanium, or a titanium alloy, and is surface-treated by using a femtosecond laser.

13. The antibacterial composition of claim 12, wherein the nano-protrusions have blunt ends.

14. An implant structure comprising a fixture that acts as an artificial tooth root, wherein the fixture includes a cylindrical bone contact portion including an outer peripheral surface on which a thread is formed, the outer peripheral surface is a bone formation facilitation region including a plurality of nano-protrusions having a width of 10 to 1000 nm and an aspect ratio of 1000:1 to 1:1, and an antibacterial activity facilitation region 114 that is located on the bone formation facilitation region and includes a plurality of nano-protrusions having a width of 10 to 1000 nm and an aspect ratio of 1:1 to 1:50.

15. The implant structure of claim 14, wherein the antibacterial activity facilitation region is formed in the range of 0.1 mm to 3.0 mm in a direction from a top end of the bone contact portion to the bone formation facilitation region.

16. The implant structure of claim 14, wherein the nano-protrusions of the antibacterial activity facilitation region have blunt ends.

17. The implant structure of claim 14, wherein the implant structure includes at least one material selected from titanium, or titanium alloy.

18. The implant structure of claim 14, wherein the implant structure is surface-treated with a femtosecond laser.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0080] FIG. 1 is a perspective view of an implant structure including an abutment-integrated fixture according to an embodiment of the present disclosure.

[0081] FIG. 2 illustrates an implant structure including a fixture according to an embodiment of the present disclosure, which is inserted into an alveolar bone.

[0082] FIG. 3 is a perspective view of an implant structure including an abutment-detachable fixture according to an embodiment of the present disclosure.

[0083] FIG. 4 illustrates a fixture according to an embodiment of the present disclosure, which is inserted into an alveolar bone.

[0084] FIG. 5 illustrates a system for manufacturing an implant structure according to the present disclosure.

[0085] FIG. 6 shows images of the surface of a titanium implant structure: (A) of FIG. 6 shows an image of the titanium which is not surface-treated; (B) of FIG. 6 shows an image of the surface of the titanium metal implant which is treated with SLA (Sandblasted, Large grit, Acid-etched); (C) of FIG. 6 shows an image of the surface of titanium which is surface-treated with a femtosecond laser, and (D) of FIG. 6 shows images of the surface of the titanium that is surface-treated and the surface of the titanium that is surface-treated with a femtosecond laser.

[0086] FIG. 7 shows enlarged images of the surface of a titanium metal implant and the surface of a zirconia implant structure according to the surface-treatment: (A) of FIG. 7 shows the image of the zirconia surface that is not surface-treated; (B) of FIG. 7 shows the image of the zirconia surface that is surface-treated with Laser 1; (C) of FIG. 7 shows the image of the titanium surface that is not surface-treated; (D) of FIG. 7 shows the image of the titanium surface that is surface-treated with Laser 1; (E) of FIG. 7 shows the image of the titanium surface that is surface-treated with Laser 2; and (F) of FIG. 7 shows the image of the titanium surface that is surface-treated with Laser 3.

[0087] FIG. 8 shows enlarged images of the surface of the titanium metal implant structure that is treated linearly using a femtosecond laser while the number of processing varies: (A), (B), and (C) of FIG. 8 show images of the surface of the metal implant structure that is linearly processed once; (D), (E), and (F) of FIG. 8 show images of the surface of the metal implant structure that is linearly processed 10 times; (G) and (H) of FIG. 8 show images of the surface of the metal implant structure that is processed 100 times; and (1) of FIG. 8 shows the graph of the depth of the metal implant structure processed 100 times.

[0088] FIG. 9 shows images of the implant structure which is surface-treated with different femtosecond laser surface treatment conditions, indicating that even when the portion to be surface treated is a certain distance away from the laser focus area during the surface treatment using a femtosecond laser, the surface treatment is able to be performed.

[0089] FIG. 10 shows images of the metal implant structure which is surface-treated with a femtosecond laser: (A) of FIG. 10 shows the surface of the first outer peripheral surface including a thread upper surface 310, a thread lower surface 320, and a thread groove side surface 330; (B) of FIG. 10 shows the image of the thread upper surface 310 after the surface treatment; (C) of FIG. 10 shows the image of the thread lower surface 320 after the surface treatment; and (D) of FIG. 10 shows the image of the thread groove side surface 330 after the surface treatment.

[0090] FIG. 11 shows a top view of the surface of the implant structure which is treated with a femtosecond laser while the processing type and the number of processing vary: (A) of FIG. 11 shows the case of a linear surface treatment once; (B) of FIG. 11 shows the case of a linear surface treatment 10 times; (C) of FIG. 11 shows the case of a linear surface treatment 100 times; (D) of FIG. 11 shows the case of a grid surface treatment once; (E) of FIG. 11 shows the case of a grid surface treatment 20 times; and (F) of FIG. 11 shows the case of a grid surface treatment 100 times.

[0091] FIG. 12 shows images of the tilted surface of the implant structure which is treated with a femtosecond laser while the processing type and the number of processing vary: (A) of FIG. 12 shows the case of a linear surface treatment once; (B) of FIG. 12 shows the case of a linear surface treatment 10 times; (C) of FIG. 12 shows the case of a linear surface treatment 100 times; (D) of FIG. 12 shows the case of a grid surface treatment once; (E) of FIG. 12 shows the case of a grid surface treatment 20 times; and (F) of FIG. 12 shows the case of a grid surface treatment 100 times.

[0092] FIG. 13 shows images of nano-protrusions formed on the surface of the implant structure while the processing condition is changed by using a femtosecond laser: (A) of FIG. 13 shows the image of nano-protrusions having the aspect ratio of 100:1; (B) of FIG. 13 shows the image of nano-protrusions having the aspect ratio of 1:1; and (C) of FIG. 13 shows the image of nano-protrusions having the aspect ratio of 1:20.

[0093] FIG. 14 shows the effect of killing bacteria according to the shape of the surface of the implant structure: (A) of FIG. 14 shows the effect of killing bacteria in Control; (B) of FIG. 14 shows the effect of killing bacteria in Example 1; (C) of FIG. 14 shows the effect of killing bacteria in Example 2; and (D) of FIG. 14 shows the effect of killing bacteria in Example 3.

[0094] FIG. 15 shows the bacterial killing effect according to the surface shape of Example 2 according to the incubation time.

[0095] FIG. 16 shows images of a surface-treated implant structure implanted in an animal model and a computerised tomography (CT) scan result thereof: (A) of FIG. 16 shows a surface-treated implant structure implanted in an animal model; and (B) of FIG. 16 shows CT scan results of an implant structure which is surface-treated by simple machining, an implant structure which is surface-treated by a femtosecond laser, and an implant structure which is treated with a SLA (Sandblasted, Large grit, Acid-etched) surface treatment.

[0096] FIG. 17 shows the diagram with which the osseointegration effect of a surface-treated implant structure implanted in an animal model was confirmed: (A) of FIG. 17 shows the graph of the cortical BIC ratio; and (B) of FIG. 17 shows the graph of the cortical bone area ratio.

[0097] FIG. 18 shows diagrams related to the expression and cell differentiation of bone formation-related genes according to the surface treatment of an implant structure in a stem cell differentiation experiment: (A) of FIG. 18 shows the graph of the expression of Col1 gene; (B) of FIG. 18 shows the graph of the expression of the ALP gene; (C) of FIG. 18 shows the graph of the expression of the OCN gene; (D) of FIG. 18 shows a quantitative comparison of the cell differentiation level by ARS staining; and (E) of FIG. 18 shows the result obtained visually confirming the ARS staining level.

[0098] FIG. 19 shows a result of confirming the cell adsorption capacity of the surface-treated implant structure through fluorescence staining.

[0099] FIG. 20 shows a diagram to quantitatively compare the cell adsorption capacity of the surface-treated implant structure: (A) of FIG. 20 shows the diagram of the cell adsorption capacity at 4 hours of culture; and (B) of FIG. 20 shows the results of comparing the cell the diagram of the cell adsorption capacity at 24 hours of culture.

MODE OF DISCLOSURE

[0100] Hereinafter, the configuration and operation of the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0101] The following examples are provided to more completely explain the disclosure to those of ordinary skill in the art, and the following examples may be modified in various other forms, and the scope of the disclosure is not limited to the following examples.

[0102] The terminology used herein is used to describe specific embodiments, not to limit the disclosure. As used herein, the singular form may include the plural form unless the context clearly dictates otherwise. Also, the terms “comprise, include” and/or “comprising, including” are used to specify the presence of the referenced shapes, numbers, processes, actions, members, elements, and/or groups thereof, and do not exclude the presence or addition of one or more other shapes, numbers, actions, members, elements, and/or groups.

[0103] In the present specification, although an “implant fixture” is described as an example of the implant structure, the present disclosure is not limited thereto, and includes all implants that are able to be subjected to the surface treatment. In an embodiment, in this specification, “beam angle adjusting unit” is used as a generic term for the two-dimensional scan mirror unit and the single-axis scan mirror unit, and “rotating unit” is used as a general term for the stepping rotating unit and the continuous rotating unit.

[0104] 1. Implant Structure

[0105] The present disclosure provides an implant structure including a fixture that acts as an artificial tooth root, wherein the fixture includes a bone contact portion 111 having a first outer peripheral surface in which a thread is formed and a gingival contact portion 112 having a second outer peripheral surface, disposed above the second outer peripheral surface, wherein the first outer peripheral surface or the second outer peripheral surface includes nano-protrusions having a width of 10 nm to 1000 nm and an aspect ratio of 1000:1 to 1:50.

[0106] The present disclosure provides an implant structure including a fixture that acts as an artificial tooth root, wherein the fixture includes a bone contact portion 111 including an outer peripheral surface having a thread formed thereon, and the outer peripheral surface includes a bone formation facilitation region 113 including a plurality of nano-protrusions having a width of 10 nm to 1000 nm and an aspect ratio of 1000:1 to 1:1, and an antimicrobial activity facilitation region 114 located on the bone formation facilitation region and including a plurality of nano-protrusions having a width of 10 nm to 1000 nm and an aspect ratio of 1:1 to 1:50.

[0107] FIGS. 1 to 4 illustrate an example structure and shape of an implant structure according to an embodiment, and an image of the implant structure being inserted into an alveolar bone.

[0108] The fixture 110 of the implant structure 100 according to the present disclosure is implanted in a missing alveolar bone to form a tooth root, and may include a bone contact portion 111, a gingival contact portion 112, and an upper portion 130.

[0109] The fixture 110 of the implant structure 100 according to the present disclosure may be implanted in the missing alveolar bone to form a tooth root, and may include the bone contact portion 111 including a bone formation facilitation region 113 and an antimicrobial activity facilitation region 114.

[0110] The fixture 110 of the implant structure 100 may include a material which is harmless to the human body, for example, titanium, and the surface of the fixture 110 may be subjected to a certain surface treatment. The fixture 110 of the implant structure is generally called an abutment (not shown) and may be classified into various types depending on whether the abutment to which the artificial teeth are coupled is integrally formed. In an embodiment, the abutment 140 may be provided as an integral implant fixture in which the abutment 140 is integrally formed with the fixture. In an embodiment, the abutment 140 may be manufactured as being separated from the fixture, and may be coupled when the implant structure is inserted.

[0111] The fixture 110 of the implant structure 100 described in an embodiment may be the fixture for the abutment-integrated implant of FIG. 1 or the fixture for the abutment-separated implant of FIG. 3.

[0112] For example, the bone contact portion 111 is a portion of the fixture 110 of the implant structure 100 which is inserted into an alveolar bone 151, and may include a first outer peripheral surface in which a thread wound in a spiral shape is formed on the outer peripheral surface of a cylindrical shape thereof as a whole. The cylindrical shape may be a cylindrical pillar shape or a truncated cone shape, and the truncated cone shape may have a wider upper portion and a narrower lower portion, and vice versa. The thread may be a single-lead screw or a double-lead screw, and in other cases, may be a multi-lead screw. At this time, the pitch of each screw may be the same. The diameter of the thread may be gradually increased and, after a certain section, the diameter may be maintained constant. In an embodiment, a cutting blade (not shown) for self-tapping may be formed at the lower end thereof, and the cutting blade may allow the fixture 110 to be easily inserted while cutting the peripheral bone of the alveolar bone during the initial insertion process.

[0113] The thread may include a thread upper surface 310, a thread lower surface 320, and a thread groove side surface 330.

[0114] The first outer peripheral surface of the bone contact portion 111 has nano-protrusions having a specific aspect ratio formed on the surface. For example, a specific pattern by nano-protrusions may be prepared by a laser surface treatment. The surface treatment may be performed by simultaneously performing a blasting process, in which sand fine particles are sprayed to increase the surface roughness, and an etching process, in which an etching solution is used to corrode the surface to increase the surface roughness.

[0115] The bone contact portion 111 may be exposed to bacteria, etc. However, the bone contact portion 111 may be mainly inserted into the alveolar bone 151 and requires bone fusion, and may be surface-treated to promote bone fusion.

[0116] The bone contact portion 111 may include the bone formation facilitation region 113 corresponding to the first outer peripheral surface and the antibacterial activity facilitation region 114 corresponding to the second outer peripheral surface. In this case, the risk of exposure to bacteria is reduced and at the same time, and risks caused by the exposure to bacteria, etc., which may occur at the upper part of the bone contact portion 111, may be reduced.

[0117] Due to the laser surface treatment, the surface pattern of each of the thread upper surface 310, the thread lower surface 320, and the thread groove side surface 330 of the bone contact portion 111 may be treated differently.

[0118] The bone contact portion 111 may be processed to form an osseointegration facilitation structure on the thread lower surface 320 and a blunt structure on the thread upper surface 310. In an embodiment, the osseointegration facilitation structure and the blunt structure may all be formed in the thread groove side surface 330.

[0119] The gingival contact portion 112 may include a second outer peripheral surface which is disposed above the bone contact portion 111 and has an outer peripheral surface on which the thread is not formed. The gingival contact portion 112 may contact a gingiva 150.

[0120] The gingival contact portion 112 may have a cylindrical, conical, or layered shape, and for example, may be cylindrical (for example, a cylindrical pillar shape, a truncated shape), and the truncated cone shape may have a wider upper portion and a narrower lower portion, and vice versa.

[0121] The second outer peripheral surface of the gingival contact portion 112 has nano-protrusions having a specific aspect ratio formed on the surface. For example, a specific pattern by nano-protrusions may be prepared by a laser surface treatment. The surface treatment may be performed by simultaneously performing a blasting process, in which sand fine particles are sprayed to increase the surface roughness, and an etching process, in which an etching solution is used to corrode the surface to increase the surface roughness.

[0122] However, although the gingival contact portion 112 needs bone fusion when being inserted into the alveolar bone 151, the gingival contact portion 112 is highly likely to have a contact with the gingiva 150 and to be exposed to, for example, bacteria. Accordingly, the gingival contact portion 112 needs to be surface-treated to facilitate the depth of bacteria existing on the surface.

[0123] The upper portion 130 may be disposed above the gingival contact portion 112, and may be coupled to an abutment or a crown depending on the type of implant. For example, in the case of an integrated implant fixture, a crown may be coupled to the upper portion thereof, and in the case of an implant structure in which the fixture and the abutment are separated from each other, the abutment may be coupled to the upper portion thereof.

[0124] The upper portion 130 may have a substantially truncated cone shape. The upper portion 130 may have a smooth surface formed by simply cutting, without the surface treatment.

[0125] 2. Implant Structure Manufacturing System

[0126] 2.1. Case in which an Object is a Rotating Body

[0127] FIG. 5 illustrates a system for manufacturing an implant structure according to the present disclosure.

[0128] Referring to FIG. 5, a laser surface treatment apparatus 200 according to an embodiment of the present disclosure may include a laser generating unit 210, a beam expanding unit 220, a beam angle adjusting unit 230, and a beam focusing unit 240, a rotating unit 250, and a control unit 260. The components shown in FIG. 3 are not essential in implementing the implant structure manufacturing system, so the implant structure manufacturing system described herein may have more or fewer components than those listed above.

[0129] The laser generating unit 210 may generate a laser beam for the surface-treatment of the object 270. To this end, the laser generating unit 210 may use a pulsed laser source. The laser beam generated in pulse units by the laser generating unit 210 may be irradiated onto the object 270 sequentially through the beam expanding unit 220, the beam angle adjusting unit 230, and the beam focusing unit 240.

[0130] The laser generating unit 210 may generate a laser beam of any one of nanoseconds, picoseconds, and femtoseconds. In an embodiment, the laser generating unit 210 may generate a femtosecond laser beam. Here, the femtosecond laser beam is an ultrashort laser beam having a pulse duration time of 1 femtosecond to 1000 femtoseconds. Accordingly, the laser generating unit 210 according to an embodiment of the present invention may generate a pulsed laser beam having a pulse duration time of the femtoseconds range. Here, the pulse repetition rate may be in the range of several to several hundreds kHz or in the MHz range. As the wavelength of the laser beam, all laser wavelengths located within the range from the infrared region to the ultraviolet region may be used. For example, the wavelength of the laser beam may include an infrared wavelength, a visible light wavelength, and an ultraviolet wavelength.

[0131] The beam expanding unit 220 may adjust the size of the laser beam generated by the laser generating unit 210 in units of pulses. More specifically, the beam expanding unit 220 may expand the size of the laser beam. In an embodiment, the beam expanding unit 220 may generate a laser beam as a collimated beam with less dispersion or focusing. Accordingly, the laser beam generated by the laser generating unit 210 may be converted into a collimated beam while being enlarged in size, through the beam expanding unit 220.

[0132] The beam expanding unit 220 may change a diameter of the laser beam generated by the laser generating unit 210 and output the changed laser beam toward the beam angle adjusting unit 230. In this case, the beam expanding unit 220 may manually or automatically adjust the size of the laser beam.

[0133] The beam angle adjusting unit 230 may adjust the focal position of the laser beam output by the beam expanding unit 220. The beam angle adjusting unit may be a two-dimensional scan mirror unit or a single-axis scan mirror unit.

[0134] The two-dimensional scan mirror unit (or XY scan mirror unit) is a beam angle adjusting unit configured to have two axes, that is, the two-dimensional scan mirror unit, a laser beam irradiated to the object 270 may adjust the focal position of the laser beam irradiated to the object 270, that is, the focal position on the X-axis and Y-axis, according to a control signal from the control unit 260. The single-axis scan mirror unit is a beam angle adjusting unit configured to have one axis, may adjust the focal position of a laser beam output from the beam expanding unit 220. That is, the single-axis scan mirror unit may adjust the focal position of the laser beam irradiated to the object 270, that is, the focal position on the X-axis or the Y-axis, according to a control signal from the control unit 260.

[0135] The beam angle adjusting unit 230 may include an X-axis scan mirror and a Y-axis scan mirror to perform a one-dimensional or two-dimensional scanning operation. Here, each of the X-axis scan mirror and the Y-axis scan mirror is configured to include a pair of scan mirrors having a galvanometer method, and each of the pair of scan mirrors may deflect the laser beam in one of directions of axes which transverse on the X-Y plane.

[0136] The beam angle adjusting unit 230 may reflect the laser beam in a direction for laser surface treatment through the X-axis scan mirror and the Y-axis scan mirror to irradiate the laser beam to a target position on the object 270. In an embodiment, the beam angle adjusting unit 230 may finely control the laser beam in the direction of X-axis or Y-axis along the upper surface of the object 270, through the X-axis scan mirror and the Y-axis scan mirror.

[0137] For example, in an embodiment, the beam angle adjusting unit 230 may irradiate the laser beam on the first outer peripheral surface or the second outer peripheral surface of the implant structure 100, which corresponds to an object, in a horizontal direction (that is, the longitudinal direction of implant structure), along a predetermined scanning path, according to a control signal from the control unit 260.

[0138] Here, nano-protrusions may be formed on the first outer peripheral surface or the second outer peripheral surface of the implant structure 100. In an embodiment, the predetermined scanning path may be determined based on two-dimensional focal position data provided from the control unit 260 to the beam angle adjusting unit 230.

[0139] Meanwhile, in an embodiment, the surface of the first outer peripheral surface or the second outer peripheral surface of the implant structure 100 which is treated with a laser beam may be at the higher or lower levels than a portion which is not surface-treated. In an embodiment, the predetermined scanning path may be determined based on two-dimensional focal position data provided from the control unit 260 to the beam angle adjusting unit 230.

[0140] The beam focusing unit 240 may be disposed under the beam angle adjusting unit 230 to focus, to the object 270, the laser beam which has passed through the beam angle adjusting unit 230.

[0141] Also, the beam focusing unit 240 may change a laser beam incident from the beam angle adjusting unit 230 at a certain angle into a direction perpendicular to the longitudinal direction of the object 270.

[0142] The beam focusing unit 240 may include a telecentric F-theta lens or an F-theta lens. Accordingly, the beam focusing unit 240 may perform a micro- or nano-scale laser surface treatment on the surface of the object 270 (for example, the first outer peripheral surface or the second outer peripheral surface).

[0143] The rotating unit 250 may fix the object 270 such that the object 270 is positioned in a direction in which the laser beam travels, that is, under the beam focusing unit 240. In an embodiment, the rotating unit 250 may rotate, according to a control signal from the control unit 260, the object 270 by a predetermined angle (for example, 120 degrees) for each surface treatment process.

[0144] The control unit 260 may control the overall operation of the laser surface treatment apparatus 200. In an embodiment, the control unit 260 may control at least some of the components 210 to 250 in order to drive an application program stored in a memory. Furthermore, the control unit 260 may, to drive the application program, combine at least two or more of the components included in the laser surface treatment apparatus 200 and operate the same.

[0145] More specifically, the control unit 260 may control the laser generating unit 210 to adjust the wavelength, pulse duration time, and pulse repetition rate of the laser beam generated in units of pulses by the laser generating unit 210.

[0146] In an embodiment, the control unit 260 may generate a control signal including two-dimensional focal position data (that is, focal position data of X and Y axes) of a laser beam for treating the surface of the object 270, and may transmit the control signal to the beam angle adjusting unit 230. The beam angle adjusting unit 230 may irradiate the laser beam based on the two-dimensional focus position data included in the control signal transmitted by the control unit 260.

[0147] In an embodiment, the control unit 260 monitors the surface treatment process using a laser on one area of the object 270 in real time, and when the surface treatment for the one area is completed, the control unit 260 controls the rotating unit 250 to rotate the object 270 by a predetermined angle step by step, and then control the laser surface treatment for other areas of the object 270.

[0148] For example, the control unit 260 may control the laser generating unit 210 and the beam angle adjusting unit 230 to perform the laser surface treatment on the first outer peripheral surface of the fixture 110 of the implant structure 100. When the surface treatment of the first outer peripheral surface is completed, the control unit 260 controls the rotating unit 250 to rotate the fixture 110 of the implant structure 100 in a clockwise or counterclockwise direction by a predetermined angle (for example, 120 degrees), and then, controls the laser generating unit 210 and the beam angle adjusting unit 230 to perform the laser surface treatment on the second outer peripheral surface of the fixture 110 of the implant structure 100. When the surface treatment of the second outer peripheral surface is completed, the control unit 260 controls the rotating unit 250 to rotate the fixture 110 of the implant structure 100 in the same direction by a predetermined angle (for example, 120 degrees), and then, controls the laser generating unit 210 and the beam angle adjusting unit 230 to perform the laser surface treatment on the surface of an abutment of the implant structure 100. Through this step-by-step rotation process, the surface of the implant structure 100 may be surface-treated at a very high speed.

[0149] Meanwhile, as another example, depending on the shape of the object, the object may undergo more or less the surface treatment processes than the surface treatment process described above. In an embodiment, the rotating may be configured to be made by different angles step by step rather than the same angle step by step.

[0150] The control unit 260 may control such that the laser generating unit 210, the beam angle adjusting unit 230, and the rotating unit 250 are synchronized with each other. That is, the control unit 260 may control the beam angle adjusting unit 230 based on the generation period of the laser beam irradiated from the laser generating unit 210. In an embodiment, the control unit 260 may control the rotating unit 250 by synchronizing with the time for surface-treating the object 270 through the laser generating unit 210 and the beam angle adjusting unit 230.

[0151] In an embodiment, the laser surface treatment apparatus 200 may include an inhalation unit 280 for sucking fine particles generated while performing the surface treatment of the implant structure. The inhalation unit 280 may prevent the fine particles generated during processing from adhering to and accumulating on the base material.

[0152] As described above, the laser surface treatment apparatus according to an embodiment of the present disclosure may perform the laser surface treatment on an object at a very high speed by using a beam angle adjusting unit and a rotating unit. By treating the surface at such a high speed, the overall process time for laser surface treatment can be shortened.

[0153] 2.2. Case in which an Object is not a Rotating Body

[0154] When the implant structure is not a rotating body, the laser surface treatment apparatus (not shown) may include a laser generating unit, a beam expanding unit, a beam angle adjusting unit, a beam focusing unit, an object moving unit, and a control unit.

[0155] In this case, the implant structure may be fixed on an object moving unit and processed. The object moving unit may be synchronized with the surface treatment time of the laser beam by the control unit, and may move the object horizontally or vertically.

[0156] Due to the horizontal or vertical movement of the object, the surface of the object may be surface-treated by a laser beam.

[0157] Except for the object moving unit, the laser generating unit, the beam expanding unit, the beam angle adjusting unit, the beam focusing unit, and the control unit of the laser surface treatment apparatus are applied mutatis mutandis as described in connection with the case where the object is a rotating body.

Experimental Example 1. Confirmation of the Surface of the Implant Structure According to the Surface Treatment Method

[0158] FIG. 6 illustrates a titanium implant structure: an implant structure which is not surface-treated ((A) of FIG. 6); an implant structure which is surface-treated with SLA (Sandblasted, Large grit, Acid-etched) ((B) of FIG. 6); and an implant structure which is surface-treated with a femtosecond laser beam ((C) of FIG. 6).

[0159] As shown in (A) of FIG. 6, it was confirmed that no specific structure or pattern was formed on the surface of the titanium implant structure that was not subjected to the surface treatment.

[0160] As shown in (B) of FIG. 6, when the implant structure was surface-treated through SLA, it was confirmed that an irregular pattern was formed on the surface of the implant structure.

[0161] In an embodiment, the implant structure was surface-treated with a femtosecond laser beam and the surface thereof was confirmed. At this time, the energy of the femtosecond laser was 1.2 J/cm.sup.2, the pulse width was 230 fs, and the pulse repetition rate was 100 kHz. As a result, as shown in (C) of FIG. 6, it was confirmed that a certain pattern was formed on the surface of the implant structure.

Experimental Example 2. Surface Treatment Using a Femtosecond Laser

[0162] The surface of the implant structure was treated by controlling the size of the area to be processed, the processing speed and the processing direction, etc. by setting the processing conditions of the femtosecond laser differently. The processing speed was adjusted to be from 0.1 mm/s to 1000 mm/s, and the processing shape was treated as a point type, a linear type, or a grid type.

[0163] FIG. 7 shows enlarged images of the surface of a titanium metal implant and the surface of a zirconia implant structure according to the surface-treatment: As shown in FIG. 7(B), in the case of the zirconia implant structure, a uniform pattern was not formed during surface treatment. On the other hand, (D) to (F) of FIG. 7, in the case of the titanium metal implant, it was confirmed that a certain pattern was formed during the surface treatment. At this time, the femtosecond laser processing conditions are shown in Table 1 below.

TABLE-US-00001 TABLE 1 Laser 1 Laser 2 Laser 3 Laser power (W) 1.5 1.5 1.5 Processing speed 500 500 500 (mm/s) Processing shape Line Line Line Number of 1 10 100 processing (times)

[0164] FIG. 8 shows enlarged images of the surface of the titanium metal implant structure that is treated linearly using a femtosecond laser while the number of processing varies. As a result, it was confirmed that the pattern was formed in a certain shape on the surface of the implant structure as the number of processing is increased. When the surface treatment is performed linearly 100 times, it was confirmed that when the surface treatment was linearly performed 100 times, the depth was about 170 μm. Therefore, it was confirmed that the linear heat treatment is performed once using a femtosecond laser, the etching was performed to the depth of about 170 nm.

[0165] FIG. 9 shows images of the surface of the implant structure of which height and depth varies depending on the condition of the surface treatment of the femtosecond laser. As a result, it was confirmed that the etched surface was a height of 0 mm to 10 mm higher or a depth of 0 mm to 10 mm lower than the surface which is not surface-treated according to the set processing conditions. In an embodiment, in the case of the surface treatment using a femtosecond laser, even when being away from the laser focal region by a certain distance, the surface treatment can be performed. For example, the surface treatment can be performed even when the portion to be surface-treated is 8 mm to 12 mm away from the laser focal region (4 mm to 6 mm below or 4 mm to 6 mm above the portion which is not surface-treated). Since the surface treatment can be performed as described above, it was confirmed that the thread of the implant fixture having a difference in the height of less than 10 mm can be surface-treated once or several times.

[0166] FIG. 10 shows images of the metal implant structure which is surface-treated with a femtosecond laser: (A) of FIG. 10 shows the thread upper surface 310, the thread lower surface 320, and the thread groove side surface 330 of the surface of the first outer peripheral surface in the case where the surface treatment was performed simultaneously while the linear treatment condition using a femtosecond laser was set once; (B) of FIG. 10 shows an enlarged image of the surface of the thread upper surface 310; (C) of FIG. 10 shows an enlarged image of the surface of the thread lower surface 320; and (D) of FIG. 10 shows an enlarged image of the surface of the thread groove side surface 330. As shown in FIG. 8, it was confirmed that femtosecond laser treatment may embody a surface that exhibits an osseointegration facilitation effect even on the surface of a metal implant structure having the structure including a thread and a thread groove.

[0167] FIGS. 11 and 12 show images of the surface of the implant structure which is treated using a femtosecond laser while the processing shape and the number of processing are adjusted. For example, the surface of the implant structure was treated in a linear type and a grid type by a femtosecond laser. (A) of FIG. 11 and (A) of FIG. 12 show the results of the linear surface treatment which is performed once, (B) of FIG. 11 and (B) of FIG. 12 show the results of the linear surface treatment which is performed 10 times, (C) of FIG. 11 and (C) of FIG. 12 show the results of the linear surface treatment which is performed 100 times, (D) of FIG. 11 and (D) of FIG. 12 show the results of the grid surface treatment which is performed once, (E) of FIG. 11 and (E) of FIG. 12 show the results of the grid surface treatment which is performed 20 times, and (F) of FIG. 11 and (F) of FIG. 12 show the results of the grid surface treatment which is performed 100 times. As shown in FIGS. 11 and 12, it was confirmed that the surface could be processed into different shapes depending on the processing shape applied on the surface and the number of processing. Specifically, it was confirmed that, during the linear treatment, the lines formed by nano-protrusions on the surface of the implant structure (for example, arrangement in a row or mountain range) or valleys forming the width of nano-protrusions were treated clearly according to the number of processing, and during grid-type treatment, the aspect ratio of nano-protrusions of the surface of the implant structure was increased.

[0168] FIG. 13 shows images of nano-protrusions formed on the surface of the implant structure while the processing condition is changed by using a femtosecond laser: At this time, the processing conditions using the femtosecond laser are shown in Table 2 below.

TABLE-US-00002 TABLE 2 Example 1 Example 2 Example 3 Laser power (W) 1.5 1.5 1.5 Processing speed 500 500 500 (mm/s) Processing shape Line Grid Grid Number of 1 10 100 processing (times)

[0169] As a result, it was confirmed that the laser surface-treated implants could have nano-protrusions with an aspect ratio of 1000:1 to 1:50 depending on the surface treatment conditions. For example, it was confirmed that, depending on the processing shape, the nano-protrusions has the aspect ratio of 1000:1 to 10:1 in the case of a linear type, and the aspect ratio of 1:1 to 1:50 in the case of a lattice type.

[0170] When the surface treatment conditions include the linear shape and 1 cycle (Example 1), it was confirmed that nano-protrusions with curved ends were formed, when the surface treatment conditions include the grid type and 10 cycles (Example 2), it was confirmed that the nano-protrusions with blunt ends were formed, and when the surface treatment conditions include the grid type and 100 cycles (Example 3), it was confirmed that the nano-protrusions with sharp ends were formed.

Experimental Example 3. Antibacterial Effect of Implant Structure in Animal Model

[0171] FIG. 14 shows the effect of killing bacteria according to the shape of the surface of the implant structure, and FIG. 15 shows the bacterial killing effect according to the surface shape of Example 2 according to the incubation time.

[0172] As a result, it was confirmed that the implant structure having the surface containing nano-protrusions with a specific aspect ratio exhibited an antibacterial effect. For example, in the implant structure of Example 1, the number of surviving bacteria was reduced along with some bacterial killing (see (B) of FIG. 14), and in the implant structure of Example 2, the bacterial killing effect was greatly increased and excellent antibacterial properties were obtained (see (C) of FIG. 14). On the other hand, the effect of killing bacteria was hardly confirmed in the implant structure of Example 3 (see (D) of FIG. 14). In an embodiment, it was confirmed that significant antibacterial activity was experimentally confirmed from the shape of the surface of Example 2 (see FIG. 15).

[0173] This result shows that while the existing technology prevents the deposition of bacteria such as bacteria on the surface of the implant structure by coating a separate coating layer with, for example, TCP on the surface of the implant structure, in the case of the implant structure according to the present disclosure, the surface thereof includes nano-protrusions having a specific aspect ratio, and thus, bacteria is directly killed and an antibacterial effect is obtained. Through the above results, it was confirmed that the implant structure which is surface-treated by the femtosecond laser can be processed to exhibit the bacteria killing effect on the implant structure surface when inserted into the human body.

Experimental Example 4. Effects of Osseointegration of Implant Structures in Animal Models

[0174] (A) of FIG. 16 shows an image of a surface-treated implant structure which is implanted in an animal model, and (B) of FIG. 16 shows CT scan results of an implant structure which is surface-treated by simple machining, an implant structure which is surface-treated by a femtosecond laser, and an implant structure which is treated with a SLA (Sandblasted, Large grit, Acid-etched) surface treatment.

[0175] FIG. 17 shows the diagram with which the osseointegration effect of a surface-treated implant structure implanted in an animal model was confirmed: (A) of FIG. 17 shows the graph of the cortical BIC ratio; and (B) of FIG. 17 shows the graph of the cortical bone area ratio. As a result, it was confirmed that the cortical BIC ratio and the cortical bone area ratio were the highest in the implant structure (M+L) which is surface-treated with a femtosecond laser. This means that the implant structure which is surface-treated with a femtosecond laser exhibits an equal or higher level of osseointegration effect than the implant structure which is surface-treated with SLA.

[0176] FIG. 18 shows diagrams related to the expression and cell differentiation of bone formation-related genes according to the surface treatment of an implant structure in a stem cell differentiation experiment: (A) of FIG. 18 shows the graph of the expression of Col1 gene; (B) of FIG. 18 shows the graph of the expression of the ALP gene; (C) of FIG. 18 shows the graph of the expression of the OCN gene; (D) of FIG. 18 shows a quantitative comparison of the cell differentiation level by ARS staining; and (E) of FIG. 18 shows the result obtained visually confirming the ARS staining level. As a result, on the 14th day of stem cell differentiation in the implant structure which is surface-treated with a femtosecond laser, the expression of Col1, ALP, and OCN genes, which are genes related to bone formation, was increased by about 20%-50%. Accordingly, it was confirmed that the expression of the genes was higher than that of other surface-treated structures (see (A) to (C) of FIG. 18). In an embodiment, as a result of confirming the degree of cell differentiation by the implant structure through ARS staining, it was confirmed that the implant structure (Ti+FsL) which is surface-treated with a femtosecond laser was higher than that of other surface-treated structures (see (D) and (E) of FIG. 18).

[0177] FIGS. 19 and 20 show images with which the cell adsorption capacity of the surface-treated implant structure was able to be confirmed. Referring to FIGS. 19 and 20, M denotes a simple machining, P denotes precision polishing after the simple machining, and L denotes a surface treatment using a femtosecond laser. As a result, it was confirmed that the initial adhesion ability of osteogenic stem cells was significantly improved on the femtosecond laser-treated surface (M+L, P+L).

[0178] Through the above results, it was confirmed that the implant structure which is surface-treated using the femtosecond laser can rapidly promote bone recovery, that is, osseointegration, occurring in the vicinity of the structure when inserted into the human body.