KR20180106457A - Orthodontic screw - Google Patents

Abstract

The present invention relates to an orthodontic screw which comprises the following: a body unit having screw threads on the outer circumferential surface, formed of a titanium metal or a titanium alloy, and fixed to the alveolar bone through the gum; and a head unit formed at one end of the body unit, and exposed to the outside of the gum, in which one side of an orthodontic wire is hooked and supported. A plurality of grooves are formed on the outer circumferential surface of the body unit so that an adhesive material can be injected or the grooves can be filled with the bone tissue of teeth.

Description

Orthodontic screw

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a screw for orthodontic treatment, and more particularly, to a screw for orthodontic treatment for fixing a wire used for correcting a tooth.

In order to calibrate the crooked teeth, a bracket is attached to the surface or the back of the tooth, and the screw is inserted into the alveolar bone and substantially perpendicular to the height direction of the tooth. Then, by pulling the wire connected to one side of the bracket and fixing the other side of the wire to the screw, the tooth is calibrated.

At this time, when the other end of the wire is fixed to the screw when the screw is firmly coupled to the alveolar bone, the thread does not come out of the alveolar bone due to the tension of the wire.

The anchor screw used for fixing the wire for orthodontic treatment disclosed in Korean Patent Registration No. 10-0759470 filed and filed by the present applicant will be described.

The anchor screw includes a head portion 110 exposed to the outside of the gum and a threaded portion 120 engaged with the alveolar bone. The hollow portion communicating with the inside of the head portion 110 and the threaded portion 120 has a longitudinal direction . A plurality of transverse holes 123.1 to 123.N are formed in the outer circumferential surface of the threaded portion 120 to communicate with the hollow portion.

Thus, when an adhesive material harmless to the living body is injected through the hollow portion while the threaded portion 120 is inserted into the alveolar bone, the adhesive material flows into the lateral holes 123.1 to 123.N and is adhesively bonded to the alveolar bone, The anchor screw is firmly coupled to the alveolar bone.

Alternatively, when the threaded portion 120 is inserted into the alveolar bone, the bone tissue of the tooth is introduced into and filled in the lateral holes 123.1 to 123.N and the hollow portion, so that the anchor screw is firmly coupled to the alveolar bone.

The conventional anchor screw as described above is firmly coupled to the alveolar bone but has a disadvantage in that it is easily broken during insertion into the alveolar bone because the hollow is formed inside the alveolar bone.

In addition, such previously used implants have used pure titanium (Ti) or an alloy such as Ti-6Al-4V.

In recent years, in order to improve the bone-bonding properties in bone scaffolds, it is desired to form micrometer (㎛) sized pores in an implant using a manufacturing process such as sand blaster, wet etching, and anodizing There is an attempt to do. However, the mechanisms related to titanium anodization have not yet been elucidated. Recently, several research teams have been studying the mechanism. However, a long reaction time is required for the interaction between the bone tissue and the implant It is reported that, for example, tooth implants take a period of more than 12 weeks.

Korean Patent Publication No. 10-0856031

It is an object of the present invention to provide a screw for orthodontic treatment which can be firmly coupled to an alveolar bone without deteriorating rigidity, contact ratio and a bone volume ratio of the implant. However, these problems are illustrative, and thus the scope of the present invention is not limited thereto.

According to an aspect of the present invention, there is provided a screw for orthodontic treatment, comprising: a body portion formed of a titanium metal or a titanium alloy, the screw portion being formed on an outer circumferential surface thereof and fixed to the alveolar bone through the gum; And a head portion formed at one end of the body portion and exposed to the outside of the gum and supported at one side of the tooth for orthodontic wire by being hung on the outer circumferential surface of the body portion and an adhesive material is injected or a bone tissue of the tooth is introduced And a plurality of grooves formed so as to be filled can be formed.

According to an aspect of the present invention, the groove may be formed as a groove having a first diameter in a threaded hole of the body portion.

According to an aspect of the present invention, the groove may be formed from one end to the other end of the body along the longitudinal direction of the body.

According to an aspect of the present invention, the groove may be formed from a central portion of the body portion to a side of the other end along a longitudinal direction of the body portion.

According to an aspect of the present invention, the groove may be formed in a linear shape.

According to an aspect of the present invention, the groove may be formed in a curved shape.

According to an aspect of the present invention, the one end and the middle portion of the body portion are formed in a cylindrical shape, the other end portion is formed in a conical shape, the thread is formed on the outer peripheral surface of the central portion of the body portion, A supporting plate having a diameter smaller than the diameter of the boundary plate and integrally formed on the boundary plate and having a support hole into which one side of the wire is inserted and supported, And a support plate having a diameter larger than the diameter of the support bar and integrally formed on the support bar, and a jig for engaging the body part with the gum is engaged and supported.

According to an aspect of the present invention, a TiO ₂ nanotube array formed by anodizing the body portion for loading a drug may be further included.

According to an aspect of the present invention, the TiO ₂ nanotube array may have a tubular structure having an open upper portion and a closed lower portion and having an inner diameter of 10 to 300 nm.

According to the screw for orthodontic treatment according to the present invention, a plurality of grooves are formed on the outer circumferential surface of the body portion having the threads. Thereby, there is an effect that the body part is firmly coupled to the alveolar bone due to the bone tissue of the tooth which is filled and adhered to the groove or the adhesive material injected into the groove without affecting the rigidity of the body.

In addition, according to the present invention, a TiO ₂ nanotube array is formed on an implant and a drug such as a recombinant human bone morphogenetic protein-2 (rhBMP-2) and an anti-inflammatory agent can be inserted. Drug-loaded implants thus fabricated have high bone to implant contact ratio (BIC) and bone volume ratio. The scope of the present invention is not limited by these effects.

1 is a perspective view showing a screw for orthodontic treatment according to an embodiment of the present invention.
2 is a perspective view showing a screw for orthodontic treatment according to another embodiment of the present invention.
3 is a cross-sectional view showing the line "AA" in Fig.
4 is a perspective view showing a screw for orthodontic treatment according to another embodiment of the present invention.
5 is a flowchart showing a method of manufacturing a screw for orthodontic treatment according to an embodiment of the present invention.
6 is a schematic configuration diagram of equipment for performing an anodizing process.
7 is a schematic diagram showing the structure of a device for observing an interference measurement biosensing method for a TiO ₂ nanotube array.
8A and 8B are views showing a typical image and microstructure of a titanium implant as a processing implant.
Figures 9a and 9b show the rough surface image and microstructure of sandblasted large-grit and acid-etched (SLA) implants.
Figures 10a and 10b show the rough surface of a TiO ₂ nanotube array fabricated by anodization.
Figure 11a through 11d are diagrams showing the TiO ₂ nanotube array FESEM image of the surface and TiO ₂ nano-tube array is loaded in the rhBMP-2.
Figure 12 is a graph showing optical thickness changes over 10 days following rhBMP-2 loading.
Figure 13 shows the results of histomorphometric analysis.
Figures 14-17 show fluorescence and histologic staining images of the four groups observed with an optical microscope.
18 is a view showing stress distribution and measurement positions of the threaded bones.
FIG. 19 is a graph showing the stress distribution and the effective stress per position according to the measurement position of the thread of FIG. 18; FIG.
20 is a view showing a measurement position of a model of each groove formed in a thread for orthodontic treatment according to an embodiment of the present invention.
FIG. 21 is a view showing effective stresses at measurement positions according to the diameter of the grooves in FIG. 20; FIG.
22 is a view showing a measurement position of a model according to a length of a groove formed in a screw for orthodontic treatment according to an embodiment of the present invention.
Fig. 23 is a view showing effective stresses of the grooves formed on the teeth for orthodontic treatment shown in Fig. 22, according to measurement positions. Fig.
24 is a view showing a stress distribution along the length of the groove formed in the screw for orthodontic treatment shown in Fig.
25 is a view showing the internal stress distribution along the length of the groove formed in the screw for orthodontic treatment shown in Fig.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are described in order to more fully explain the present invention to those skilled in the art, and the following embodiments may be modified into various other forms, It is not limited to the embodiment. Rather, these embodiments are provided so that this disclosure will be more thorough and complete, and will fully convey the concept of the invention to those skilled in the art. In the drawings, the thickness and size of each layer are exaggerated for convenience and clarity of explanation.

Hereinafter, embodiments of the present invention will be described with reference to the drawings schematically showing ideal embodiments of the present invention. In the figures, for example, variations in the shape shown may be expected, depending on manufacturing techniques and / or tolerances. Accordingly, the embodiments of the present invention should not be construed as limited to the particular shapes of the regions shown herein, but should include, for example, changes in shape resulting from manufacturing.

Hereinafter, the term " nano " refers to a size in the range of 1 nm to 1 [mu] m in terms of a nanometer unit size, and the nanotube has a tubular structure and has an inner diameter of nano.

1 and 2 are perspective views showing a screw for orthodontic treatment according to an embodiment of the present invention, and Fig. 3 is a sectional view showing the line "A-A" in Fig.

As shown in FIGS. 1 to 3, the screw for orthodontic treatment according to the present embodiment may include a body 110 and a head 120.

The body 110 is fixed to the alveolar bone through the gums. For this, the upper end side and the center side of the body 110 may be formed in a cylindrical shape, the lower end may be formed in a conical shape, and the thread 112 may be formed in a spiral shape on the outer peripheral surface on the central side.

The head 120 may include a boundary plate 121, a support bar 123 and a support plate 125. The head 120 may be formed at an upper end of the body 110 and exposed to the outside of the gum. In addition, one side of the wire for orthodontic treatment can be hooked on the head 120.

More specifically, the boundary plate 121 may be integrally formed on the upper surface of the body 110, and may have a diameter larger than a diameter of the upper end of the body 110. The boundary plate 121 may divide the body 110 and the head 120 such that only the body 110 is fixed to the gum.

Here, the support bar 123 may be integrally formed on the upper surface of the boundary plate 121 and protrude upward, and may have a diameter smaller than the diameter of the boundary plate 121. A support hole 123a may be formed in the support rod 123 and one side of the wire may be inserted and supported in the support hole 123a.

The support plate 125 may be integrally formed on the upper surface of the support rod 123 and may have a diameter larger than the diameter of the support rod 123. The support plate 125 may be coupled and supported by a jig such as a screwdriver or a wrench for coupling the body 110 to the gums.

The body 110 may also include a TiO ₂ nanotube array 130 formed by anodizing the body 110 to load the drug.

The TiO ₂ nanotube array 130 is formed by first anodizing the body 110 made of a titanium metal or a titanium alloy by using an electrolyte containing fluorine F and ultrasonically removing the body 110, Or the like.

More specifically, the TiO ₂ nanotube array 130 has a tubular structure having an open upper portion and a closed lower portion, and may have an inner diameter of 10 to 300 nm.

Thus, drugs such as recombinant human bone growth factors, anti-inflammatory agents and the like can be inserted into the implants.

The teeth for orthodontic treatment according to the present embodiment may have a plurality of grooves 113 and 114 formed on the outer circumferential surface of the body 110.

The groove 113 may be formed as a groove having a first diameter in a thread of the body 110. The grooves 114 may extend from the center of the central portion of the body 110 along the longitudinal direction of the body 110 to the lower end of the central portion.

In the grooves 113 and 114, a gel-like adhesive material harmless to the living body can be injected. That is, when the body 110 is inserted into and bonded to the gum while the adhesive material is injected into the grooves 113 and 114, the body 110 can be firmly coupled to the alveolar bone through the adhesive material .

Alternatively, when the body 110 is inserted into the gums, the bone tissue of the teeth is filled into the grooves 113 and 114 after a predetermined time has elapsed, so that the body 110 is firmly coupled to the alveolar bone .

Since the grooves 113 and 114 are formed on the outer circumferential surface of the body 110 in accordance with the present embodiment, the rigidity of the body 110 may be hardly affected by the grooves 113 and 114.

The grooves 114 may be formed in a linear shape. At this time, it is preferable that the groove 114 is formed radially with respect to the center of the body 110. The grooves 114 may be formed in a curved shape.

Fig. 4 is a perspective view showing a screw for orthodontic treatment according to another embodiment of the present invention, and only differences from Figs. 1 and 2 will be described.

4, the groove 214 formed in the outer circumferential surface of the body 210 may be formed from the upper end of the center of the body 210 to the lower end of the center along the longitudinal direction of the body 210 .

Therefore, the body part can be firmly coupled to the alveolar bone due to the bone tissue of the teeth that are introduced and filled into the adhesive material or grooves 113, 114, and 214 injected into the grooves 113, 114, and 214 as described above.

FIG. 5 is a flowchart showing a method of manufacturing a screw for orthodontic treatment according to an embodiment of the present invention, and FIG. 6 is a schematic configuration diagram of equipment for performing an anodizing process.

5, a method of manufacturing a screw for orthodontic treatment according to an embodiment of the present invention includes firstly anodizing a titanium metal or a titanium alloy using an electrolyte solution containing fluorine (F) to form a TiO ₂ nanotube array forming (S1) and the titanium metal or the step (S2) of removing by ultrasonic treatment the TiO ₂ nanotube array formed on the surface of a titanium alloy, wherein the TiO ₂ nanotube array is titanium metal of the removed surface or titanium with respect to the alloy using the electrolytic solution containing fluorine (F) a second anodization and TiO ₂ nano-forming a tube array (S3) and formed by the second anodizing TiO ₂ nanotube array drug therein (S4). ≪ / RTI >

The TiO ₂ nanotube array formed by the second anodization has a tubular structure having an open upper portion and a closed lower portion, and preferably has an inner diameter of 10 to 300 nm.

The drug may comprise one or more substances selected from recombinant human bone growth factors and anti-inflammatory agents.

The electrolytic solution may be selected from the group consisting of sulfuric acid (H ₂ SO ₄ ), phosphoric acid (H ₃ PO ₄ ), citric acid, oxalic acid, ethylene glycol, glycerol, dimethyl sulfoxide DMSO) may be a solution in which NH ₄ F is mixed.

Wherein the first anodization or the second anodization is performed by disposing a positive electrode and a negative electrode in which a titanium metal or a titanium alloy is disposed apart from each other so that the positive electrode and the negative electrode are contained in the electrolytic solution in an electrolytic bath containing the electrolytic solution, The voltage to be applied to form the TiO ₂ nanotube array formed by the first anodization or the second anodization is such that the voltage difference between the anode and the cathode is less than or equal to 80 V .

Hereinafter, a method of manufacturing a dental implant according to a preferred embodiment of the present invention will be described in more detail.

A TiO ₂ nanotube array can be formed by first anodizing titanium metal or a titanium alloy using an electrolyte containing fluorine (F).

The first anodization may be performed by disposing a positive electrode and a negative electrode having a titanium metal or a titanium alloy disposed thereon apart from each other, inserting the positive electrode and the negative electrode into the electrolyte in an electrolytic bath containing the electrolyte, .

The material for the first anodization may be titanium (Ti) or titanium (Ti) alloy. The titanium (Ti) alloy is an alloy including at least a titanium (Ti) component such as a Ti-6Al-4V alloy.

Titanium and titanium alloys are widely used in the field of dental implants because of their excellent mechanical properties and biocompatibility. However, the native oxide layer of titanium can bind directly to the bone at an early stage of osseointegration. Implant surface chemistry by methods such as blasting, plasma spraying of hydroxyapatite, sandblasting, etching, and anodic oxidation. There is research to optimize dental or orthopedic implants by changing the surface shape of the implant.

The important factors for anodic oxidation include electrolyte, applied voltage, anodic oxidation time, and temperature. 6, the anodic oxidation equipment includes an electrochemical bath 10, an electrolytic solution 20, an anode 30, a cathode 40, a power supply 50, a magnetic stirrer 50, A stirring bar 80, a stirring bar 90, a chiller 85, a thermometer 95, and the like.

The anode 30 and the cathode 40 are spaced apart from each other by a predetermined distance. The anode 30 may be made of titanium (Ti) or a titanium alloy, which is the same as the metal component of the TiO ₂ nanotube array to be obtained.

The electrolytic solution for the first anodic oxidation may be at least one selected from the group consisting of sulfuric acid (H ₂ SO ₄ ), phosphoric acid (H ₃ PO ₄ ), citric acid, oxalic acid, ethylene glycol, glycerol, And a solution in which NH ₄ F is mixed with at least one solution selected from dimethyl sulfoxide (DMSO).

A titanium or titanium alloy is prepared to form a TiO ₂ nanotube array and mounted on the anode (30). As the cathode 40, an acid-resistant metal electrode such as platinum (Pt), tantalum (Ta), silver (Ag), or gold (Au) The anode 30 is installed at a predetermined distance from the cathode 40 so as to be locked in the electrolyte 20. The anode 30 and the cathode 40 are connected to a power supply 50 for applying a voltage or current. The voltage difference between the anode 30 and the cathode 40 is appropriately adjusted in consideration of the diameter of the formed TiO ₂ nanotube, the length of the TiO ₂ nanotube, and the like. The voltage applied to form the TiO ₂ nanotube array formed by the first anodization is preferably such that the voltage difference between the anode and the cathode is less than or equal to 80V. It is preferable that the TiO ₂ nanotube array formed by the first anodization has a tubular structure having an open upper portion and a closed lower portion and having an inner diameter of 10 to 300 nm.

The electrolyzer (10) is provided with a cooling device (85) for preventing an abrupt temperature rise due to an exothermic reaction during the anodic oxidation process and for increasing the uniformity of electrolysis or chemical reaction on the entire metal film, A magnetic stirrer 80 and a stirring magnetic bar 90 may be provided in order to facilitate the anodizing process with stirring. In addition, although not shown, a temperature regulating device such as a hot plate for maintaining the temperature in the electrolytic bath at a constant level may be provided.

The temperature of the electrolytic bath 10 is preferably set in the range of about 0 to 50 占 폚.

The electrolyte solution 20 facilitates the movement of charged electrons and ions to form a titanium oxide film (TiO ₂ ) on the surface of titanium (Ti) or a titanium alloy. The titanium metal ion (Ti ⁴⁺ ) is dissolved in the electrolyte solution 20 at the interface between the electrolyte solution 20 and the oxide film. The electrolyte solution 20 is combined with O ^2- and OH ^- ions so as to form an oxide film at the interface between the oxide film and the metal. can do.

In the anodic oxidation process, the water molecule (H ₂ O) in the electrolyte (20) can be electrolyzed by the hydrogen ion (H ⁺ ) and the hydroxyl group ion (OH ^- ) according to the following reaction formula 1.

[Reaction Scheme 1]

H ₂ O → H ⁺ + OH ^-

The hydrogen ion H ⁺ moves toward the cathode 40 and can be released to the hydrogen gas H ₂ by coupling with electrons between the surface of the electrolyte 20 and the cathode 40.

The hydroxyl group ion (OH ^- ) migrates toward the anode 30 and is separated into oxygen ions (O ^2- ) and hydrogen ions (H ⁺ ) in the natural oxide film formed on the surface of the anode 30. The separated oxygen ion (O ^2- ) penetrates the natural oxide film and reacts with the titanium ion (Ti ⁴⁺ ) between the natural oxide film and the titanium (or titanium alloy) to form a titanium oxide film (TiO ₂ ) .

[Reaction Scheme 2]

Ti ⁴⁺ + ² O ^2- ? TiO ₂

Further, the hydrogen ion H ⁺ reacts with the titanium oxide film (TiO ₂ ) to partially break the bond between titanium (Ti) and oxygen to form a hydroxide, which can be dissolved in the electrolyte solution 20. That is, oxide etching may occur on the surface between the titanium oxide film (TiO ² ) and the electrolyte solution 20. Thus, a titanium oxide film (TiO ² ) may be formed at the interface between the natural oxide film and the titanium (or titanium alloy).

If this is expressed as a reaction formula, the following reaction formula 3 is obtained.

[Reaction Scheme 3]

_{Ti + 2H 2 O → TiO 2} + 4H + + 4e -

The water molecules in the electrolyte solution meet with titanium at the anode and form a titanium oxide (TiO ₂ )

The titanium oxide (TiO ₂ ) thus formed can be dissociated as shown in Scheme 4 by a small amount of fluorine ion (F ^- ) contained in the electrolyte solution.

[Reaction Scheme 4]

TiO ₂ + 6F ^- + 4H ^{+ -} [TiF ₆ ] ^{2 -} + 2H ₂ O

This dissociation occurs over the entire titanium oxide (TiO ₂ ) and can form a nanotube array. Also, as the anodic oxidation time is increased, the oxidation reaction of Reaction Formula 3 and the dissociation reaction of Reaction Formula 4 occur at the same time, and thus a nanotube array can be obtained.

The TiO ₂ nanotube array formed on the surface of the titanium metal or titanium alloy can be removed by ultrasonic treatment. Generally, ultrasound refers to a sound wave having a frequency of 20 kHz or more, and the frequency of ultrasonic waves for removing the TiO ₂ nanotube array may be about 28 to 40 kHz. When the ultrasonic treatment is performed, the TiO ₂ nanotube array formed on the surface of the titanium metal or the titanium alloy may be removed while being separated from the surface of the titanium metal or the titanium alloy. The TiO ₂ nanotube arrays produced by the first anodization are not easy to mount on the drug because the surfaces are dirty and the pores of the nanotubes are clogged. Therefore, the TiO ₂ nanotube array formed by the first anodization removal and, TiO ₂ nano-tubes will the array is formed in the TiO ₂ nanotube array having a clean surface through the second anode oxide with respect to titanium metal or titanium alloy of the removed surface, TiO ₂ nano-formed by the second anodizing Most of the pores of the tube array are open, which makes it easy to mount the drug.

The TiO ₂ and nanotube array have a second oxide cathode using an electrolyte solution containing fluorine (F) with respect to the titanium metal or titanium alloy of the removed surface can be formed in the TiO ₂ nanotube array.

The second anodization may be performed by disposing a positive electrode and a negative electrode having a titanium metal or a titanium alloy disposed thereon apart from each other so that the positive electrode and the negative electrode are contained in the electrolytic solution in an electrolytic bath containing the electrolytic solution, Can be performed.

The voltage applied to form the TiO ₂ nanotube array formed by the second anodization is preferably such that the voltage difference between the anode and the cathode is less than or equal to 80V.

The electrolytic solution for the second anodization includes at least one of sulfuric acid (H ₂ SO ₄ ), phosphoric acid (H ₃ PO ₄ ), citric acid, oxalic acid, ethylene glycol, glycerol, And a solution in which NH ₄ F is mixed with at least one solution selected from dimethyl sulfoxide (DMSO).

The TiO ₂ nanotube array formed by the second anodization has a tubular structure having an open upper portion and a closed lower portion, and preferably has an inner diameter of 10 to 300 nm.

The drug can be loaded into the TiO2 nanotube array formed by the second anodization. The drug may comprise one or more substances selected from recombinant human bone growth factors and anti-inflammatory agents.

As described above, the TiO ₂ nanotube array, which is a columnar porous titania, can be formed by performing two-step anodization (first anodization and second anodization) on the surface of pure titanium or titanium alloy, The nanostructure has great advantages. The formation of the implant surface can enhance osseointegration, since the surface area is significantly increased and the surface morphology can be altered similar to the original bone tissue.

Aligned TiO ₂ nanotube arrays with controlled diameters of void space can be fabricated through control of process elements such as voltage, current density, and electrolyte. TiO ₂ nanotube surfaces with optimal lengths for cell adhesion and differentiation can induce osteoblast migration and mesenchymal stem cells, The interaction between the surface of the implant and the cell can be enhanced.

The void space of the TiO ₂ nanotubes can act as a drug reservoir. Drugs such as antibiotics, anti-inflammatory drugs, and growth factors can be prescribed to be injected into the mouth, vein, and muscle. However, some medications are not effective when delivered through these routes. Systemic delivery of these drugs can lead to adverse effects and organ toxicity at high concentrations. Thus, local drug therapy is becoming an accepted type of treatment.

On the other hand, recombinant human bone growth factors are known to improve osteoblast differentiation and bone formation and remodeling.

The proper amount of rhBMP-2 induces bone formation, but too much can be associated with unwanted effects. Systemic delivery of rhBMP-2 can have undesirable effects because it has an uncontrolled adverse effect, such as unwanted ectopic bone formation. Thus, rhBMP-2 must be immobilized on the surface of the implant to have sufficient time to promote osseointegration.

Hereinafter, an experimental example to which the technical idea described above is applied will be described in order to facilitate understanding of the present invention. It should be understood, however, that the following examples are for the purpose of promoting understanding of the present invention and are not intended to limit the scope of the present invention.

[Experimental Example 1]

Experimental results of the welding quality by the spot welding control method according to some embodiments of the present invention are as follows.

In the experimental example of the present invention, a TiO ₂ nanotube array was formed on the surface of a dental implant by two-step anodization. The TiO ₂ nanotube array provides a void space for drug loading and shows biocompatibility. A dental implant with a TiO ₂ nanotube array, a structure suitable for insertion of drugs such as antibiotics, anti-inflammatory agents and growth factors, was designed. To improve implant-bone adhesion, rhBMP-2 is loaded into the storage space of the TiO ₂ nanotube array. Effects of TiO ₂ nanotube arrays and rhBMP-2 on implant-bone adhesion and remodeling in dental implants were studied by in vitro and in vitro experiments on rabbits.

A TiO ₂ nanotube array was prepared on the surface of the implant by two-step anodization using an electrolyte solution containing ethylene glycol and 0.5 wt% NH 4 F. To obtain an appropriately microstructured TiO ₂ nanotube array, the anodization voltage and time by a DC power supply were computer controlled by the LabVIEW program. _Two -step anodization was performed to obtain clean surfaces and open windows of the TiO ₂ nanotube array. Implants were first oxidized with a voltage of 60V and a time of 60 minutes. The TiO ₂ nanotube array fabricated by the first anodization was removed by ultrasonication. A TiO ₂ nanotube array with a clean open window was then finally produced by the second anodization. The voltage and time of the second anodization was 15V and 15 minutes. The thickness of the TiO ₂ nanotube array and the open window size were observed by field emission scanning electron microscopy (FESEM). rhBMP-2 (Cowellme Co., Busan, Korea) was loaded into the interior space of the TiO ₂ nanotube array by a dip coating process in a vacuum chamber. The concentration of rhBMP-2 was 1.5 mg / ml. Each implant was soaked in rhBMP-2 solution three times for 5 seconds and dried at a temperature of 20 ° C.

The elution of rhBMP-2 was observed by an interferometric biosensing method.

7 is a schematic diagram showing the structure of a device for observing an interference measurement biosensing method for a TiO ₂ nanotube array.

Referring to FIG. 7, the incident white light source A uses a tungsten lamp. It is preferable to focus the white light incident on the TiO ₂ nanotube array using an optical fiber and a lens so as to be included in a circle having a diameter of 0.1 to 1 mm.

At this time, the reflected light coming from the interference of the TiO ₂ nanotube array C can be collected by using the CCD spectrometer (B). In FIG. 7, 'D' is titanium (Ti).

Hereinafter, a method of measuring the interference reflected light for the TiO ₂ nanotube array will be described. In the absence of the drug in the TiO ₂ nanotube array, it is possible to measure the intensity variation according to the wavelength of the reflected light spectrum using the CCD spectrometer (B). In the case of administering the drug to the TiO ₂ nanotube array It is possible to measure the change in intensity according to the wavelength of the reflected light spectrum.

First, the interference phenomenon with the Fabry-Perot will be explained. When a mirror with a high reflectance is placed parallel to each other and light is incident on the mirror, the light transmitted through the mirror transmits some light on the surface of the parallel mirror, but most of the light repeats transmission and reflection. On the opposite side of the incidence direction, the number of reflections between the two mirrors is transmitted through the lower mirror, where each light exhibits interference as much as the path difference.

When white light is incident on a TiO ₂ nanotube array having nano-sized pores, an interference pattern related to the optical thickness appears due to a difference in optical path between the upper end of the pores formed in the TiO ₂ nanotube array and the lower end of the pores.

Optical thickness refers to the distance between the lower end of the pores on the opposite side in the longitudinal direction of the TiO ₂ nanotube array at the upper end of the pore, that is, the length of the space in which the drug is loaded in the TiO ₂ nanotube array, as described above. At this time, if a drug is contained between the upper end of the pore and the lower end of the pore, the thickness of the drug becomes the optical thickness.

Equation (1) shows the relationship between the refractive index (n) and the optical thickness (L).

[Equation 1]

m? = 2nL

Where m is the interference order, λ is the maximum interference wave obtained by the m degree, n is the refractive index of the drug contained in the TiO ₂ nanotube array and TiO ₂ nano-tube array, L is the TiO ₂ nanotube array optical thickness of lt; / RTI >

The optical thickness L can be changed according to the concentration of the electrolytic solution, the voltage, the anodization time, and the like. The longer the optical thickness, the greater the number of fringes and changes the characteristics of the interference wavelength.

TiO ₂ nanotubes irradiated with a white light on the array, TiO ₂ nano-tube array fabrication by the optical path difference between the top and the bottom of the pores of-the fringe losses in the form of reflected waveform is displayed.

As the drug is administered, the reflection waveform of the Fabry-Perof fringe shape can confirm the intensity change of the white light and the shift of the reflection wavelength.

We attempt fast Fourier transformation (FFT) on the spectrum for the reflected wavelength in the form of a Fabry-Perof fringe for white light. Fast Fourier transform is an algorithm designed to reduce the number of operations when computing a discrete fourier transform based on Fourier transform.

Fast Fourier transform is a function calculation method that converts the temporal flow sound information into frequency flow.

And performs a fast Fourier transform (FFT) on the reflected light spectrum obtained from the TiO ₂ nanotube array.

A peak having a specific optical thickness can be obtained, and such optical thickness is referred to as effective optical thickness. This effective optical thickness is shifted according to the change in spectrum depending on the size and refractive index of the drug contained in the TiO ₂ nanotube array.

Such effective optical thickness may be determined by sensing the loading and elution of a particular drug by attaching a suitable capture probe to the inner surface of the TiO ₂ nanotube and using specific binding It is possible.

The machined implant shown in Figs. 8A and 8B is a view showing a typical image and microstructure of a titanium implant. The machined implants have one-way machined grooves. By machining using the CNC mechanism, the surface is smooth as shown in Fig. 8B.

Figures 9a and 9b show the rough surface image and microstructure of sandblasted large-grit and acid-etched (SLA) implants.

Figures 10a and 10b show the rough surface of a TiO ₂ nanotube array fabricated by two-step anodization. The surface of the TiO ₂ nanotube array is less rough than the SLA implant surface. However, the TiO ₂ nanotube array has nano-sized holes for loading drugs such as BMP-2, PEP7, ibuprofen.

Figure 11a through 11d are diagrams showing the TiO ₂ nanotube array FESEM image of the surface and TiO ₂ nano-tube array is loaded in the rhBMP-2. And Figure 6a is a TiO ₂ FESEM image of a nanotube array, and Fig. 11b is an enlarged image of Figure 11a, Figure 11c is a rhBMP-2 are FESEM images of the loaded TiO ₂ nanotube array, Figure 11d is an enlarged image of Figure 11c to be. TiO ₂ nanotube arrays were fabricated by two-step anodic oxidation. TiO ₂ The diameter of the nanotubes windows and TiO ₂ nano-tubes, each was ~70nm and ~110nm. The windows of the TiO ₂ nanotubes are clean and open, and these microstructures are suitable for drug loading. The thickness of the TiO ₂ nanotubes was ~ 17 μm as shown in FIG. 11A. As shown in Figure 11 (d), the window of TiO ₂ nanotubes is slightly clogged with rhBMP-2 loading. The diameter of the TiO ₂ nanotube window was reduced to ~ 50 nm by rhBMP-2 loading. Surface-loaded rhBMP-2 is expected to improve osseointegration.

In order to observe the elution of rhBMP-2 from the TiO ₂ nanotube array, an interferometric biosensing method with a flow cell was used. In this method, deionized water (DI water) flows through the dental implant with rhBMP-2 loaded TiO ₂ nanotubes. Changes in optical thickness of rhBMP-2 were monitored in real time. Figure 7 is a graph showing optical thickness changes over 10 days following rhBMP-2 loading. The baseline was established with an optical thickness of deionized water (DI water) for 20 hours. The solution containing rhBMP-2 was induced by deionized water through a dental implant with a rhBMP-2 loaded TiO ₂ nanotube array. Optical thickness was increased by elution of rhBMP-2 from the TiO ₂ nanotube array and gradually increased for 9 days.

We selected rhBMP-2 as a drug to improve new bone formation and osteoinduction induction around the implant surface and evaluated the possibility of using TiO ₂ nanotube arrays as drug stores. Dental implants were classified into four groups. The surface of the implant, the implant SLA, TiO ₂ nanotube array surface of the implant, and TiO ₂ nano-tube array surface implant containing rhBMP-2 were processed respectively named groups I1, I2 group, group I3, I4 group. Four groups of implants were implanted in the proximal tibia of the rabbit for 8 weeks. After 8 weeks, all of the implants were in direct contact with the bone along the stalk histologically.

Figure 13 and Table 1 show the results of histomorphometric analysis.

I1 group I2 Group I3 Group I4 group Bone to implant contact (%)

11.1 ± 17.0
14.7 ± 9.5
16.3 ± 11.9
29.5 ± 3.8
Bone volume ratio (%)

66.9 ± 6.7
53.7 ± 11.5
67.2 ± 7.6
77.3 ± 8.8

Referring to Table 1 and FIG. 13, the maximum BIC (bone to implant contact ratio) of the I4 group was 29.5%, and the I3 group, I2 group, and I1 group were 16.3%, 14.7%, and 11.1%, respectively. Bone volume ratios were measured around the implant threads. The highest bone volume ratio of 77.3% was seen in the I4 group. The bone volume rates of I3, I2, and I1 groups were 67.2%, 53.7% and 66.9%, respectively. These results indicate that the TiO ₂ nanotube array surface implants have a higher osseointegration effect than the surface implants and SLA implants, and the TiO ₂ nanotube array surface implants containing rhBMP-2 have a biochemical effect of bone induction As shown in Fig. TiO ₂ nanotube arrays are believed to enhance bone formation and cell adhesion effects. TiO ₂ nanotube arrays have an excellent oxide microstructure for new bone growth and can affect bone components for protein interaction, fast and permanent bone adhesion.

Although the osseointegration effect of rhBMP-2 coated implants has been reported, simple coating or wetting of rhBMP-2 can not provide sustained osseointegration with organs by rhBMP-2. The TiO ₂ nanotube array enhances wettability and can function as a drug reservoir. rhBMP-2-bound TiO ₂ nanotube implants can enhance bone formation. The I4 group loaded with rhBMP-2 in the TiO ₂ nanotube array showed high bone to implant contact ratio (BIC) and bone volume ratio during 8 weeks after the operation. This demonstrates the long lasting effect of rhBMP-2, and bone remodeling, bone formation and bone reduction are slow to occur. Figure 12, which shows slow elution of rhBMP-2, supports the long lasting effect of rhBMP-2.

Figures 14-17 show fluorescence and histologic staining images of the four groups observed with an optical microscope. The fluorescence and histological staining images shown in Figs. 14 to 17 show the right side and the left side, respectively. Fluorescent images are formed by fluorochrome labeling with alizarin red and calcein green. Other patterns of bone formation and bone remodeling were observed in four groups. Red and green represent new bone formation formed for 3 and 6 weeks after implant placement, respectively. Bone formation and bone remodeling, represented by white arrows, were mainly observed near the periosteum in groups I1, I2 and I3. However, in the I4 group, bone formation and bone remodeling was observed not only near the periosteum but also around all implant threads.

Bone formation and bone remodeling in the I1, I2, and I3 groups can be explained by osteoblast-rich periosteum. In the I4 group, abundant bone formation and bone remodeling in the implant stem is due to the osteogenesis effect of rhBMP-2 eluted from the TiO ₂ nanotube array. In addition, the I4 group showed stronger fluorescent dye labeling. Fluorescent pigment labeling around the periosteum reflects bone formation, and fluorescent dye labeling around the implant stem is thought to be bone remodeling and improve osseointegration. TiO ₂ nanotube arrays containing rhBMP-2 can increase bone formation and bone remodeling near the implant, thus enhancing osteointegration on the surface of the dental implant.

[Experimental Example 2]

Stress distribution analysis and structure model construction considering the material properties due to the formation of TiO 2 nanotubes on the surface of the implant for the orthodontic screw according to some embodiments of the present invention were experimented.

In order to analyze the stress distribution due to the formation of the tubes in the threaded implants, the analysis was carried out according to the diameter and length of the tube.

Here, the tube may constitute the groove 113.

As shown in FIG. 18, the points P1, P2, P5, and P6 without the threaded bone of the implant model that generated the tube showed a stress distribution similar to that of the implant model without the tube, The stress distribution in the threaded part of P3 and P4 occurred stress concentration around the tube.

Also, in the graph showing the stress distribution of the threaded bones in Fig. 19 and the effective stresses according to the positions along the measurement positions, the effective stresses of the threaded portions of the tubes P3 and P4 in which the tubes are formed are high.

Next, the stress distribution according to the tube diameter of the orthodontic screw was experimented. The tube diameters of the orthodontic screws were tested for 140%, 120%, 100%, 80%, and 60% of the generated diameters, and the tube lengths of the orthodontic screws were 190% %, 130%, and 100%, respectively.

As shown in FIG. 20, the stress distribution along the diameter of the tube was relaxed as the diameter of the tube became smaller. It is also seen that the internal stress concentration is relaxed as shown in Fig.

As shown in FIG. 22, as a result of analyzing the stress distribution according to the tube-formed length, the stress concentration phenomenon around the tube is alleviated as the length of the tube formed becomes smaller, . It can be seen that the internal stress concentration is relaxed as the length of the tube formed is small as shown in Figs. 22 to 25.

Here, FIG. 23 is a view showing effective stresses at measurement positions of grooves formed in the teeth for orthodontic treatment shown in FIG. 22, FIG. 24 is a diagram showing stress distribution, and FIG. 25 is a diagram showing an internal stress distribution.

The concentration of stress on the surface and inside of the TiO 2 nanotube is affected by the diameter and length of the tube. However, since the TiO 2 nanotube has an average diameter of 100 nm and a length of 10 μm or less, And the stress is uniformly distributed. Therefore, the material properties may not have a great influence.

As described above, according to the screw for orthodontic treatment according to the present invention, a plurality of grooves are formed on the outer circumferential surface of the threaded body portion, so that the adhesive material or groove, which is injected into the groove, Due to the bone structure of the teeth, there is an effect that the body part is firmly coupled to the alveolar bone.

According to the present invention, since a TiO ₂ nanotube array is formed on an implant, a drug such as a recombinant human bone growth factor and an anti-inflammatory agent can be inserted, and the drug loaded according to the present invention can be used as a BIC to-implant contact ratio and bone volume ratio are high.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

10: electrolytic cell
20: electrolyte
30: anode
40: cathode
50: Power supply means
80: magnetic stirrer
85: Cooling unit
90: Magnet bar for stirring
95: Thermometer
110:
113, 114, 124: Home
120: Head
121: Boundary plate
123: support rod
125: Support plate
130: nanotube array

Claims (9)

A body portion formed of a titanium metal or a titanium alloy having a thread formed on an outer circumferential surface thereof and fixed and fixed to the alveolar bone through the gum; And
A head portion formed at one end of the body portion and exposed to the outside of the gum, wherein one side of the tooth for orthodontic wire is hooked and supported;
/ RTI >
Wherein a plurality of grooves are formed on an outer circumferential surface of the body so that an adhesive material is injected or a bone tissue of the teeth is introduced and filled. The method according to claim 1,
And the groove is formed as a groove having a first diameter in a threaded hole of the body portion. The method according to claim 1,
Wherein the groove is formed from one end side to the other end side of the body part along the longitudinal direction of the body part. The method according to claim 1,
And the groove is formed from the central portion of the body portion to the other end portion along the longitudinal direction of the body portion. The method according to claim 3 or 4,
Wherein the groove is formed in a straight line shape. The method according to claim 3 or 4,
Wherein the groove is formed in a curved shape. The method according to claim 1,
Wherein one end and a central portion of the body portion are formed in a columnar shape and the other end portion is formed in a conical shape, the thread is formed on an outer peripheral surface of a central portion of the body portion,
Wherein the head part is integrally formed on one end face of the body part and has a diameter larger than a diameter of one end part of the body part, a diameter smaller than a diameter of the boundary plate, And a support plate having a diameter larger than the diameter of the support bar and integrally formed on the support bar and having a jig for engaging the body part with the gum being engaged with each other, Screws for orthodontics. The method according to claim 1,
A TiO ₂ nanotube array formed by anodizing the body portion for loading a drug;
Further comprising a screw for orthodontic treatment. 9. The method of claim 8,
In the TiO ₂ nanotube array,
Characterized in that the upper part is open and the lower part is closed and the inner diameter is in the range of 10 to 300 nm.

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