KR101144273B1 - Laser surface treated Method for Dental implants having the improved coefficient of surface friction and Dental implants thereby - Google Patents

Abstract

The present invention relates to a dental implant surface treatment method, and more specifically, to increase the surface area per unit area of the implant to increase the adhesion force between the implant and bone tissue is a dental implant surface treatment method having an increased surface friction coefficient and It relates to a dental implant treated by the above method.

Description

Laser surface treatment method for dental implants having the improved coefficient of surface friction and dental implants

The present invention relates to a dental implant surface treatment method, and more specifically to dental implant laser surface treatment method of increasing the surface friction coefficient that can increase the adhesion between the implant and bone tissue by increasing the surface area per unit area of the implant It relates to a dental implant treated by the method.

In general, titanium and its alloys have been spotlighted as a conventional implant material for securing the function of each part of the body as the clinical effectiveness of the dental implant material has been scientifically proven.

However, structurally, the implant and its surrounding bone tissue are interfacing by contacting two materials with different physical properties, so many researchers have found how biological tissue and bone cells can be well-osseinintegrated to the artificial implant surface. Attention is focused.

Among them, there is a method of improving biocompatibility by changing the surface structure of the implant to increase the unit area. For example, Titanium plasma sprayed (TPS), Blasting treatment, TiN coating, Hydroxyapatite (HA), and the like. Currently, implant products using this technology are commercially available. The implant fixture has a screw type and a cylinder type, and the screw type is surface treated by etching (SLA), TPS, and RBM (resorbable blast media) process on the thread.

The dental implant structure consists of an implant piercing (abutment) at the top and a screw-type implant at the bottom, with screw-type threads and bones at the bottom. At this time, the biocompatibility of the bone and implant fixture of the human body acts as an important variable during the procedure.

The human bone can be divided into hard and dense cortical bone and relatively weak and low sponge bone. During implantation, the screw structure should be tightly and tightly coupled to the rigid cortical bone, and the screw structure of the relatively weak spongy bone should be able to withstand the load and to facilitate bone fusion. In order to achieve this purpose, the screw structure of the implant fixture is designed in a complex manner in consideration of the stress distribution, placement force, friction coefficients, etc. according to the bone quality, and the effective surface treatment method is implemented accordingly. It is very important to.

One of the surface treatment methods, TPS treatment, is called plasma spraying, which is a high temperature melting method. The body of the implant is machined and machined so that another titanium is melted at a high temperature and sprayed to attach to the surface of the implant. TPS-treated implants are advantageous for adhesion of bone surface, and are less likely to be removed early in the early stages due to a 6-fold increase in surface area, and clinically the alveolar agent is not absorbed. If the absorption progresses and the TPS surface is exposed to the oral cavity, it is susceptible to plaque invasion and consequently causes inflammation around the implant, which can cause serious consequences.

In order to solve this problem, researches on implant surface treatment using a laser have been conducted in recent years. The patent is applied to orthopedic implants, and in the paper, researches to modify the implant surface with a laser, which is a high-density energy beam, are mainly focused on pulse lasers.

Looking at the previous studies that modified the surface of the implant using a laser in more detail as follows. Gaggl et al. [1] improved the surface area of the implant by irradiating a laser beam between the screw thread and the bone on the aluminum oxide powder blasted implant. Secondly, the size and shape of secondary structures resulting from melting processes were studied and EDS analysis was performed to analyze the chemical properties of titanium surface. Peto et al [2] and Karacs et al [3] investigated the implant surface by varying the pulse duration (30 ns) and pulse energy (0.5–5 J) of the Nd: glass laser in a similar manner to Gaggl et al [1]. The ablated surface layer was studied. Cho et al. [4] show that the contact interface between bone and implant is good by force removal (removal torque) after attaching it to the rabbit tibia using a machining implant and a laser surface treated implant after machining. The assessment was made of whether or not consolidation was achieved. Cho demonstrated that the laser surface-treated implant improved about 2 times as compared with the mean removal value of Cordiolie et al. [4-5]. Wennerberg et al. [4-13] show that surface roughness alone is not a measure when considering optimal osseointergaration, and surface pattern, size, and valley-peak It can be influenced by distribution. The mechanical interlocking and biocompatibility of the bone and implant interface is an important variable.

Bereznai et al. [5] used an UV-based ArF and KrF excimer laser to polish the round surface of the implant material using the UV-based ArF and KrF excimer lasers. After making changes, the morphological aspects and chemical properties were studied. However, it is not efficient in terms of productivity because additional equipment construction is required to implement vacuum conditions and continuous beam irradiation is performed to improve surface area.

As such, the existing researchers have investigated the osseointergaration state by increasing the bone and implant contact area by changing the surface shape and structure by irradiating various lasers on the implant surface. In order to improve the inherent corrosion resistance of titanium, the oxide layer formed on the surface before and after the laser beam was analyzed to evaluate biocompatibility, and some researchers compared the contact force between bone and implant through animal experiments.

However, existing researchers have used Nd: YAG, Nd: glass, and excimer lasers, but have not studied the change of implant surface for more precise process characteristics. For example, focal length, frequency, beam transport speed, and energy are very important for repeatability and reproducibility during laser beam irradiation. In particular, since the laser beam concentrates high-density energy on the local element, the surface shape is changed due to the scribing width, depth, and secondary ridges generated by the difference in the height of the thread and the valley when surface treatment of the screw-type implant.

Without considering this problem, it is impossible to realize a uniform surface shape when the process is performed arbitrarily, and it is impossible to constantly remove the annealing and the surface oxide film. Therefore, it is very important to establish more precise and systematic process variables for repeatability and reproducibility when surface treatment of implant using laser.

In addition, Nd: YAG lasers and excimer lasers are often used as lasers for surface modification of dental implants. Nd: YAG lasers do not form stable oxide films on the surface, and excimer lasers are expensive and emit excimer gas. There was a problem that the risk of leakage and costly operation.

Therefore, there is a need for development of a laser surface treatment method of a new configuration in which the above-mentioned problems are solved.

The present inventors endeavored to solve the above-mentioned disadvantages and problems of the prior art, and completed the present invention in which the conventional implant surface treatment method can compensate for the disadvantages.

Accordingly, an object of the present invention is to provide an ideal implant surface treatment method for increasing the adhesion between the implant and bone tissue by increasing the surface friction coefficient per unit area of the implant and the implant treated by the method.

It is another object of the present invention to provide an implant surface treatment method in which a uniform surface shape can be realized on an implant and an implant treated by the method.

Another object of the present invention is to use a fiber laser to form a stable oxide film on the surface compared to the conventional Nd: YAG laser, and a relatively low operating cost and safe implant surface treatment method compared to the excimer laser and treated with the method It is to provide an implant.

It is still another object of the present invention to establish an accurate and systematic laser surface treatment process variable to provide an implant surface treatment method having excellent repeatability and reproducibility and suitable for a living body, and an implant treated by the method.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention in the dental implant surface treatment method; Providing a laser beam of a selected wavelength and a selected peak power; Focusing the laser beam on a prepared implant surface; And scanning the laser beam on the implant surface in accordance with a predetermined process variable.

In a preferred embodiment, the selected wavelength is between 300 nm and 1100 nm.

In a preferred embodiment, the scanning step comprises the steps of providing a scanning area of the implant surface; Irradiating a focused laser beam according to the predetermined process variable in the scanning area; And blocking the focused laser beam simultaneously with completion of scanning of the scanning area.

In a preferred embodiment, the process variable includes one or more of laser power, laser beam transport speed, frequency, laser beam irradiation interval, and overlap range.

In a preferred embodiment, the laser power of the process variable is 50 ~ 100%, the laser beam transfer speed is 50 ~ 500mm / sec, the frequency is 30 ~ 100kHz, the laser beam irradiation pitch is 55 ~ 65㎛, overlap The range is preset to 50% or more.

In a preferred embodiment, the scanning process is controlled to target only the screw bone formed in the implant by the predetermined process variable.

In a preferred embodiment, a plurality of threads and screw valleys are formed in parallel to the threads forming the screw valleys by the predetermined process variable.

In a preferred embodiment, a plurality of threads and thread valleys are formed perpendicular to the threads forming the thread valleys by the predetermined process variable.

In a preferred embodiment, the overlap range, in which the area scanned by the laser beam overlaps, is 60 to 98%.

In a preferred embodiment, the laser used for the laser beam is a fiber laser.

The present invention also provides a dental implant, characterized in that the treatment by the laser surface treatment method of any one of claims 1 to 11.

In a preferred embodiment, the dental implant has a uniform surface shape.

The present invention has the following excellent effects.

First, the implant surface treatment method of the present invention and the implant treated by the method increases the surface friction coefficient by increasing the surface area per unit area, thereby increasing the adhesion between the implant and bone tissue.

In addition, the implant surface treatment method of the present invention and the implant treated by the method can be implemented in a uniform surface shape on the implant.

In addition, the implant surface treatment method of the present invention and the implant treated by the method can form a stable oxide film on the surface than the conventional Nd: YAG laser using a fiber laser, it is relatively inexpensive operation cost and safe compared to the excimer laser Do.

In addition, the implant surface treatment method of the present invention and the implant treated by the method is precise and systematic laser surface treatment process parameters are established, excellent repeatability and reproducibility, and is suitable for living body

1 is a schematic diagram showing a surface changed according to the prior art using a pulsed laser to increase the surface friction coefficient,
2 is an enlarged cross-sectional view of a hole formed in the surface shown in FIG.
Figure 3 is a schematic diagram showing the effect of implantation and laser beam intensity appearing after laser beam irradiation according to the prior art,
4 is a schematic diagram showing a method of irradiating the surface of the implant with the actual laser beam to perform the laser surface treatment method of the present invention,
5 is a schematic diagram showing the effects of implant formation and laser beam intensity after laser beam irradiation by the laser surface treatment method of the present invention;
6 is a schematic diagram showing a surface changed by the laser surface treatment method according to an embodiment of the present invention,
7 is a schematic view showing a surface changed by the laser surface treatment method according to another embodiment of the present invention,
8 is a graph showing the surface area increase rate according to the surface treatment method of the present invention,
9 is a graph showing the coefficient of friction according to the frequency and overlap change when performing the laser surface treatment method of the present invention,
10 is a graph showing a surface treatment depth change according to a frequency change after fixing different process variables when performing the laser surface treatment method of the present invention;
11 is a SEM photograph of the implant surface treated by the surface treatment method according to the prior art,
12 is a SEM photograph of the surface of the implant treated with the surface treatment method of the present invention.

The terms used in the present invention were selected as general terms as widely used as possible, but in some cases, the terms arbitrarily selected by the applicant are included. In this case, the meanings described or used in the detailed description of the present invention are considered, rather than simply the names of the terms. The meaning should be grasped.

Hereinafter, with reference to the preferred embodiment shown in the accompanying drawings will be described in detail the technical configuration of the present invention.

However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Like reference numerals used to describe the present invention throughout the specification denote like elements.

First, the present invention provides a dental implant laser surface treatment method having a uniform surface shape and an increased surface area, that is, an increased surface friction coefficient.

The laser surface treatment method of the present invention comprises the steps of providing a laser beam of a selected wavelength and a selected peak power; Focusing the laser beam on a prepared implant surface; And scanning the laser beam on the implant surface according to a predetermined process variable.

In this case, it is preferable to use a fiber laser having superior characteristics and relatively low operating cost as a laser, in particular, a wavelength selected within the range of 300 nm to 1100 nm. More preferably, a wavelength of 542 nm or 1064 nm is used.

In addition, the process variable includes one or more of laser power, laser beam transfer speed, frequency, laser beam irradiation interval, overlap range, wherein the laser power of the process variable is 50 ~ 100%, the laser beam transfer speed is 50 ~ 500mm / sec, the frequency is 30 ~ 100kHz, the laser beam irradiation pitch (55 ~ 65㎛), the overlap range is preferably set to more than 50%, wherein the limited value of the process parameters through a number of experiments If the optimal range is smaller or larger than the defined numerical range, the surface of the implant cannot be machined into the desired shape. In addition, when the laser beam feeding speed is 500mm / sec, the frequency should be increased above 30kHz. When the overlap range for each process variable is represented, the overlap range is 62 ~ 82% when the laser power is 50 ~ 100%, and the laser beam When the feed rate is 50 ~ 500mm / sec, the overlap range is 74 ~ 98%, and when the frequency is 30 ~ 100kHz, the overlap range can be 79 ~ 93%.

In particular, as shown in FIG. 4, which is a schematic diagram illustrating a method of irradiating an implant surface with an actual laser beam in order to perform the laser surface treatment method of the present invention so that only the screw bone formed on the implant is a target area by a predetermined process variable. Likewise, the laser beam is preferably controlled so that a plurality of threads and thread valleys are formed in a scanning area perpendicular to the threads forming the thread valleys, or a plurality of threads and thread valleys are formed parallel to the threads forming the thread valleys. It is more desirable that process variables be controlled. As such, when treated by the laser surface treatment method of the present invention overlaps as shown in Figure 5 to change the implant surface shape, so that the surface area is increased and the surface roughness improves the surface contact force between the bone (bone) and the implant surface In addition to being increased, it is controlled to scan only the screw bone of the implant by a predetermined process variable, thereby realizing a uniform surface shape after surface treatment.

In more detail, the pattern shown in FIG. 6 or 7 may be scanned by a predetermined process variable so that the pattern shown in FIG. 6 or 7 is formed on the screw bone included in the implant, and the pattern shown in FIG. 6 or 7 is included in one implant. It may be formed so as to be parallel.

That is, the laser beam is irradiated to the screw thread located on the first screw thread and the screw thread in the direction in which the implant is rotated into the upper and lower parts to form a kind of finely protruding threads on the existing screw bone as shown in FIG. As shown in FIG. 7, when the laser beam is irradiated to the second screw bone in a direction opposite to the direction in which the implant is rotated to the upper and lower parts, the surface area of the bone and the implant surface is improved. The implant surface is formed by engaging like a kind of gear to improve bone and implant surface adhesion compared to the conventional method. As such, when one implant surface is processed such that the patterns shown in FIGS. 6 and 7 are parallel, a moment is formed by a large load on the upper and lower portions generated in the screw type implant which is rotated and fastened to the upper and lower portions. This can reduce the adhesion between the bone and the implant.

On the other hand, among the preset process parameters, the laser beam irradiation pitch means an interval at which the second laser beam is irradiated after the first laser beam is overlapped and irradiated, and the overlap range is an area scanned by the laser beam. It means this overlapping range, and the overlapping range is 50% or more, more preferably 60 to 98%. If the scanned area overlaps more than 50%, the implant surface area can be increased by more than 120% compared with the conventional method.

Next, in the scanning step, when the scanning area of the implant surface is provided, the focused laser beam is irradiated according to a predetermined process variable in the scanning area, and the focused laser beam is blocked at the same time as scanning of the scanning area is completed. Is done.

Example 1

After the 1064nm wavelength was selected from the prepared fiber laser beam, the laser beam was focused on the screw bone surface formed on the screw type implant. After the scanning is completed by irradiating the laser beam according to the preset process variable set to have the pattern of FIG. 6, blocking the focused laser beam, and then repeating the same process on the next screw bone, the dentist having the surface shown in FIG. 6. Implant 1 was obtained. At this time, when looking at the predetermined process variable, the energy (J) of the laser beam is kept constant at about 75 (J), and then the beam transfer speed is 100-200 (mm / sec), the frequency is 50 (kHz), The laser power was controlled to meet the conditions of 70 (%), laser beam irradiation pitch (60 μm) and overlap range of 74 to 93%.

Example 2

A dental implant 2 having the surface shown in FIG. 7 was obtained in the same manner as in Example 1 except that the preset process variable was set to have the pattern of FIG. 7.

Comparative Example

1 to 3 illustrate a surface obtained by performing a conventional scribing method, which is one of known laser drilling methods, on a thin titanium sheet using a pulsed laser beam (Nd: YAG). The process conditions are laser power, beam transfer speed and frequency of 30%, 500 mm / sec and 20 kHz, respectively. In the conventional method, as shown in FIG. 1, the surface of the laser beam is changed at a predetermined interval by irradiating the pulsed laser beam (Nd: YAG) to change the surface shape such as the groove 2 and the ridge 3. It can be seen that the surface friction force (surface area increase) was improved by making a hole of the micro bar by a kind of drilling method while maintaining the constant spacing of 2) and the groove 2.

As a result, as shown in FIG. 2, in the conventional surface treatment method, after the laser beam is irradiated, the surface adhesive force of the bone and the implant is increased by the characteristics of the aspect ratio D and d of the surface and the raised shape 8. Although it can be seen that the surface of the implant by conventional machining has a similar value.

In addition, referring to Figure 3, which is a schematic diagram of the effect of the implant formation and the laser beam intensity appearing after the laser beam irradiation according to the conventional method, after the laser beam is irradiated in the existing method, the burrs are formed at both ends It can be seen that the implant surface treatment method to increase the surface area and surface roughness.

Experimental Example 1

In order to examine the surface area increase rate in the screw type implant, the result obtained by applying a pulsed laser beam (Nd: YAG) to the conventional scribing method, which is one of laser drilling methods, on the implant surface as in the comparative example (Overlap 0) %) And the result (Overlap 50%) obtained after irradiating a beam on the implant surface such that the pattern of FIG. 7 is formed by the laser surface treatment method of the present invention as shown in Example 2 is shown in FIG. 8.

When the conventional scribing method is applied, the portion irradiated with the laser beam exists in a raised form with the surface treatment shape as shown in FIGS. 1 and 2, wherein the surface area of the bone and the implant is partially Increased. However, since the laser beam generally maintains a single mode Gaussian beam distribution, the shapes of D and d do not have a hemisphere surface area as shown in FIG. 2. The results of the actual experiment are very similar to the shape of the cone.

As shown in FIG. 8, the laser surface treatment method of the present invention has an increase in surface area of about 120% when compared with the results of experiments using the conventional laser beam and the result values obtained by the laser surface treatment method of the present invention. It can be seen.

Experimental Example 2

The relationship between the superposition ratio and the friction coefficient according to the frequency change is shown in FIG. 9.

As shown in FIG. 9, when the friction coefficient of the implant surface was compared with the machined implant surface, the surface friction coefficient of the untreated specimen was about 0.184. 0.45 ~ 0.542 was confirmed that about two times improved.

Experimental Example 3

After fixing other process variables, the change in surface treatment depth according to the frequency change is shown in FIG. 10.

As shown in FIG. 11, as the frequency was increased, the surface treatment depth (scribing depth) increased, and was about 10 to 27 μm.

In particular, the same experiment was obtained by changing other process variables, including laser beam feed rate and power, within the numerically defined range of process variables as described above.

When the surface treatment was carried out within the conditions of the laser process parameters as described above, the surface treatment width and depth showed a difference of 5 ~ 10㎛, but it was confirmed that it was a more efficient laser surface treatment method than the conventional method due to the almost similar surface shape.

Experimental Example 4

SEM images of the surface of the implant were observed to confirm whether a uniform surface shape is realized in the surface-treated implant. The SEM photograph of the implant surface obtained by applying a pulsed laser beam (Nd: YAG) in Experimental Example 1 is shown in FIG. 11. SEM images of the implant surface obtained by applying the laser surface treatment method of the present invention are shown in FIG. 12.

As shown in Fig. 11, the conventional method irradiates both a screw thread and a bottom thread when irradiating a laser beam to a screw-type implant, so that the thread and the screw bone are changed according to the focal position of the laser beam. Since the formed surface treatment shape is changed and the laser beam is irradiated to the thread, the surface treatment shape cannot be maintained.

On the other hand, according to the laser surface treatment method of the present invention, as shown in Figure 12 it can be seen that a uniform surface form can be implemented in the screw bone between the thread and the thread formed with thousands of transverse threads and screw bone as shown in FIG. Can be.

In addition, it can be seen that the surface roughness also increased due to the phenomenon (spatter) in which the melts on the surface spread around after the laser beam is irradiated.

The experimental results indicate that the dental implant treated by the laser surface treatment method of the present invention increases surface area by more than 120% as well as a uniform surface shape than the implant treated by the conventional laser surface treatment method. Shows a 2x improvement. Accordingly, the dental implant obtained by the laser surface treatment method of the present invention has an ideal surface, which not only provides an increased surface area and surface friction coefficient but also makes it possible to constantly remove annealing and a surface oxide film.

Therefore, the laser surface treatment method of the present invention is a more efficient method than the conventional method because it forms a moment that can withstand the fluid grip force after the surface of the bone of the implant and the human body bonding, as a result of the laser of the present invention Dental implants with surfaces treated by surface treatment methods have a uniform surface shape and a coefficient of friction of 0.45 to 0.542, so that the screw structure of the implant can be tightly and tightly coupled to the rigid cortical bone. It can be a tolerant and easy structure for bone fusion.

When the dental implant of the present invention is used, biological tissue and bone cells can be well bonded to the implant surface due to the increased unit area through the change of the surface tissue of the implant compared to the existing product.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, Various changes and modifications will be possible.

Claims (12)

In the dental implant surface treatment method;
Providing a laser beam of a selected wavelength and a selected peak power;
Focusing the laser beam on a prepared implant surface; And
And scanning the laser beam on the implant surface according to a predetermined process variable.
The process variable includes one or more of laser power, laser beam transport speed, frequency, laser beam irradiation interval, overlap range,
Among the process variables, the laser power is 50 to 100%, the laser beam feeding speed is 50 to 500 mm / sec, the frequency is 30 to 100 kHz, the laser beam irradiation pitch is 55 to 65 μm, and the overlap range is 50% or more. Pre-set,
By the predetermined process variable is controlled to be a scanning area for only the screw bone formed on the implant,
The dental bone formed on the implant is a dental implant characterized in that it comprises a plurality of threads and screw bone pattern formed in parallel to the thread forming the screw bone or one or more of the plurality of threads and screw bone pattern formed perpendicular to the thread Laser surface treatment method.
The method of claim 1,
The selected wavelength is 300nm to 1100nm dental implant laser surface treatment method characterized in that.
The method of claim 1, wherein the scanning step
Providing a scanning area of the implant surface;
Irradiating a focused laser beam according to the predetermined process variable in the scanning area; And
And the blocking of the focused laser beam simultaneously with the completion of scanning of the scanning area.
delete delete delete delete delete The method of claim 1,
And wherein the overlap range, in which the area scanned by the laser beam overlaps, is 60 to 98%.
The method of claim 1,
And a laser used in the laser beam is a fiber laser.
A dental implant, characterized in that treated by the laser surface treatment method of any one of claims 1 to 3, 9 or 10, wherein the dental implant has a uniform surface form 0.45 ~ 0.542 Dental implant, characterized in that having a coefficient of friction of.
delete

Images