Abstract:
Provided are a fixture of a dental implant and a method of manufacturing the same, and more particularly, a method of manufacturing a fixture of a dental implant easily that allows fast bone formation at an early stage and prevents infection and inflammation, and a fixture of a dental implant having an improved structure that can be manufactured by using the method of manufacturing the same. The fixture of a dental implant with an improved structure in which the performance of osseointegration is excellent and spread of inflammation is reduced, and the method of manufacturing the fixture of a dental implant easily are provided. In the method of manufacturing a fixture of a dental implant, the fixture of the dental implant in which the performance of osseointegration is excellent and spread of inflammation can be reduced, can be easily manufactured. Furthermore, in the fixture of the dental implant, the performance of osseointegration is excellent and spread of inflammation can be reduced.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2008-0117323, filed on Nov. 25, 2008, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a fixture of a dental implant and a method of manufacturing the same, and more particularly, to a method of manufacturing a fixture of a dental implant easily that allows fast bone formation at an early stage and prevents infection and inflammation, and a fixture of a dental implant having an improved structure that can be manufactured by using the method of manufacturing the same. 
         [0004]    2. Description of the Related Art 
         [0005]    Generally, dental implants include a fixture, an abutment, and a crown. 
         [0006]    A male screw portion is formed in the fixture, is inserted in an alveolar bone of a human body and supports and fixes a dental implant. 
         [0007]    The abutment is combined with an upper portion of the fixture and is exposed to an upper portion of gingiva. 
         [0008]    The crown is one kind of prosthesis that replaces natural tooth, is engaged with the abutment and is adhered and fixed to the abutment. 
         [0009]    In order to achieve the success of implants, osseointegration between the fixture and the alveolar bone has to be successfully performed. When osseointegration is not successfully done, bone resorption or progressive bone loss occurs. 
         [0010]    It is widely known that a surface roughness of the fixture affects the success of osseointegration. When the surface of the fixture becomes rough by increasing the surface roughness of the fixture, a contact surface between the implant and a surrounding bone is increased, and cell adsorption is improved, so that positive effects can be obtained. 
         [0011]    However, the rough surface of the fixture promotes progress of infection when inflammation occurs around the implant. In other words, it is reported that, when the surface of the fixture is rougher than a polished surface, infection progresses more quickly along the surface of the fixture. 
         [0012]    In order to solve the problem, as illustrated in  FIG. 1 , Korean Patent Application No. 283988 and Korean Patent Application No. 718278 disclose an ‘osseointegration artificial tooth’ in which the surface of a fixture  1  is overall rough and a polished band  3  having a low surface roughness is formed in a waist portion of a screw portion  2  of the fixture  1  so as to improve the performance of osseointegration and prevent progress of inflammation around a dental implant due to the polished band  3 . 
         [0013]    A method of manufacturing a dental implant or a fixture of a dental implant having the above structure with high productivity easily is necessary, and the fixture of a dental implant having an improved structure so as to use the method is also necessary. 
       SUMMARY OF THE INVENTION 
       [0014]    The present invention provides a fixture of a dental implant with an improved structure in which the performance of osseointegration is excellent and spread of inflammation is reduced, and a method of manufacturing the fixture of a dental implant easily. 
         [0015]    According to an aspect of the present invention, a method of manufacturing a fixture of a dental implant includes: cutting the fixture of the dental implant to form a male screw portion of the fixture; performing jig fixing in such a way that a protection jig is inserted in the ring-shaped male screw portion to surround portions of the male screw portion of the fixture in a circumferential direction of the protection jig; performing surface processing on the male screw portion of the fixture to increase a surface roughness; and performing jig removal in such a way that the protection jig fixed on the male screw portion is removed from the male screw portion of the fixture. 
         [0016]    According to another aspect of the present invention, a fixture of a dental implant fixed on an alveolar bone by using a male screw portion includes: a polished portion formed along an outer diameter of the male screw portion so as to have a low surface roughness; and an unpolished portion formed at the remaining portions of the male screw portion excluding the polished portion so as to have a surface that is more rough than a surface of the polished portion. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: 
           [0018]      FIG. 1  illustrates a structure of a fixture of a dental implant according to the related art; 
           [0019]      FIGS. 2 through 5  illustrate a method of manufacturing a fixture of a dental implant, according to an embodiment of the present invention; 
           [0020]      FIGS. 6 through 9  illustrate a method of manufacturing a fixture of a dental implant, according to another embodiment of the present invention; and 
           [0021]      FIG. 10  is a perspective view of a protection jig having another shape that can be used in  FIGS. 6 through 9 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. 
         [0023]      FIGS. 2 through 5  illustrate a method of manufacturing a fixture  100  of a dental implant, according to an embodiment of the present invention. 
         [0024]    Referring to  FIG. 2 , the method of manufacturing the fixture  100  of the dental implant according to the current embodiment of the present invention includes cutting the fixture  100  of the dental implant to form a male screw portion  110 . A polished surface having a low surface roughness to a level of a machined surface is formed by a cutting tool of machine tools at the entire surface of the male screw portion  110 . In this regard, the male screw portion  110  has an overall surface roughness in the range of 0.1 to 0.5 μm. 
         [0025]    Separately, a protection jig  130  illustrated in  FIG. 3  is provided. The protection jig  130  is ring-shaped and may be formed of polymer having elasticity. 
         [0026]    Jig fixing is performed in such a way that the protection jig  130  is inserted in the male screw portion  110  to surround portions of the male screw portion  110  of the fixture  100  in a circumferential direction of the protection jig  130 , as illustrated in  FIG. 4 . 
         [0027]    When the protection jig  130  is pushed into the male screw portion  110  of the fixture  100 , the protection jig  130  is elastically deformed to securely surround an outer diameter of the male screw portion  110  of the fixture  100 . In some cases, a female screw portion may be formed at an inside of the protection jig  130  so as to be screw-combined with the male screw portion  110  of the fixture  100  so that the male screw portion  110  of the fixture  100  and the female screw portion may be fixed to each other. 
         [0028]    In this state, surface processing is performed in such a way that surface processing is performed on the male screw portion  110  of the fixture  100  so as to improve surface roughness. In other words, surfaces of the remaining portions excluding portions surrounded by the protection jig  130 , of the male screw portion  110  of the fixture  100  are made rough. Surface processing may be performed by a method, such as sandblasting, anodization, etching, or the like. Such surface processing is performed so that the surface roughness of the male screw portion  110  is between 1.2 and 2.0 μm. 
         [0029]    In this state, jig removal is performed in such a way that the protection jig  130  fixed on the male screw portion  110  is removed from the male screw portion  110  of the fixture  100 . 
         [0030]    Referring to  FIG. 5 , portions of the male screw portion  110  in which the protection jig  130  is inserted, are not surface-processed but are maintained in the state of a low surface roughness and become a polished portion  112 . The remaining portions of the male screw portion  110  excluding the polished portion  112  are surface-processed and become an unpolished portion  111  having a surface that is rougher than the surface of the polished portion  112 . 
         [0031]    In the fixture  100  of the dental implant manufactured by the method, a degree of osseointegration is improved due to the unpolished portion  111  having a high surface roughness, and inflammation may be prevented from being spread due to the polished portion  112  having a low surface roughness. Also, in the method of manufacturing the fixture  100  of the dental implant described above, the polished portion  112  may be easily formed at the fixture  100  of the dental implant having the above effects so that productivity of the fixture  100  may be improved. 
         [0032]    Next, a method of manufacturing a fixture  200  of a dental implant, according to another embodiment of the present invention will be described. 
         [0033]      FIGS. 6 through 9  illustrate a method of manufacturing the fixture  200  of a dental implant, according to another embodiment of the present invention. 
         [0034]    Referring to  FIG. 6 , the method of manufacturing the fixture  200  of the dental implant according to the current embodiment of the present invention includes cutting the fixture  200  of the dental implant to form a male screw portion  210 . 
         [0035]    Next, as illustrated in  FIG. 6 , forming of a fixed groove  212  is performed in such a way that the fixed groove  212  is formed in the male screw portion  210  of the fixture  200  to surround portions of the male screw portion  210  in a circumferential direction of the male screw portion  210 . 
         [0036]    By performing the cutting of the fixture  200  and the forming of the fixed groove  212 , the male screw portion  210  of the fixture  200  has a surface roughness in the range of 0.1 to 0.5 μm. 
         [0037]    Separately, a protection jig  230  is provided, as illustrated in  FIG. 7 . The protection jig  230  includes a body portion and fixed protrusions  233 . A combination hole  232  is formed in the body portion  231 , and an inner diameter of the combination hole  232  is equal to or slightly smaller than an outer diameter of the male screw portion  210 . The fixed protrusions  233  are formed in internal sides of the combination hole  232  so as to be inserted in the fixed groove  212  of the fixture  200  and fixed therein. The fixed protrusions  233  are ring-shaped, and may be formed of polymer having elasticity. 
         [0038]    Jig fixing is performed in such a way that the protection jig  230  is inserted in the male screw portion  210  of the fixture  200  to surround portions of the male screw portion  210  in the circumferential direction of the protection jig  230 , as illustrated in  FIG. 8 . In this regard, the fixed protrusions  233  of the protection jig  230  are inserted in the fixed groove  212  of the fixture  200  so that the protection jig  230  may not be shaken with respect to the fixture  200  and may be securely fixed on the fixture  200 . 
         [0039]    In this state, surface processing is performed in such a way that surface processing is performed on the male screw portion  210  of the fixture  200  so as to improve a surface roughness. In detail, surfaces of the remaining portions of the male screw portion  210  of the fixture  200  excluding portions surrounded by the protection jig  230  are made rough. Such surface processing may be performed by a method, such as sandblasting, anodization, etching, or the like. 
         [0040]    When surface processing is performed using sandblasting, the surfaces of the remaining portions of the male screw portion  210  of the fixture  200  excluding the portions surrounded by the protection jig  230  are made rough by ejecting an abrasive into the male screw portion  210  at high speed. When the abrasive ejected into the male screw portion  210  at high speed collides with the protection jig  230 , the protection jig  230  may be shaken with respect to the male screw portion  210  and may be escaped therefrom during the procedure. Since the fixture  200  of the dental implant that is recently used mostly has a tapered male screw portion  210  and an outer diameter of the fixture  200  is downwardly reduced, a possibility in which the protection jig  230  may be escaped from the male screw portion  210  is further increased. 
         [0041]    However, as illustrated in  FIG. 8 , when the fixed protrusions  233  of the protection jig  230  and the fixed groove  212  of the fixture  200  are engaged with each other, the protection jig  230  is prevented from being escaped from the male screw portion  210  so that a defect rate may be reduced, productivity may be improved and quality of the fixture  200  may be improved. 
         [0042]    Next, jig removal is performed in such a way that the protection jig  230  fixed on the male screw portion  210  is removed from the male screw portion  210  of the fixture  200 . 
         [0043]    Referring to  FIG. 9 , portions of the male screw portion  210  in which the protection jig  230  is inserted, are not surface-processed but are maintained in the state of a low surface roughness and become a polished portion  213 , and the remaining portions of the male screw portion  210  excluding the polished portion  213  become an unpolished portion  211  having a rough surface. The surface roughness of the unpolished portion  211  may be between 1.2 to 2.0  82  m. 
         [0044]    Referring to  FIG. 6 , a width W of the fixed groove  212  may be between 0.1 and 0.5 mm. When the width W of the fixed groove  212  is less than 0.1 mm, the fixed protrusions  233  of the protection jig  230  may not be well inserted in the fixed groove  212 , and when the width W of the fixed groove  212  is greater than 0.5 mm, portions of the male screw portion  210  in which no threads are formed, become so large and a combination force between the fixture  200  and the alveolar bone may be reduced. 
         [0045]    Also, a depth D of the fixed groove  212  with respect to screw valleys of the male screw portion  210  may be between 0.05 and 0.15 mm. When the depth D of the fixed groove  212  is less than 0.05 mm, the fixed protrusions  233  of the protection jig  230  may not be well inserted in the fixed grove  212 , and when the depth D of the fixed groove  212  is greater than 0.15 mm, rigidity of the fixture  200  may be reduced. 
         [0046]    Also, the polished portion  213  may be disposed in the range of 2 to 8 mm downwardly from an upper end of the male screw portion  210 . When the polished portion  213  is located in the range of 2 mm from the upper end of the male screw portion  210 , performance of preventing inflammation from being spread may be lowered, and when the polished portion  213  is located in the range of below 8 mm from the upper end of the male screw portion  210 , the combination force between the fixture  200  and the alveolar bone may be reduced. 
         [0047]    In the fixture  200  of the dental implant manufactured by the method of  FIGS. 6 through 9 , a degree of osseointegration is improved due to the unpolished portion  211  having a high surface roughness, and inflammation is prevented from being spread due to the polished portion  213  having a low surface roughness. Also, in the method of manufacturing the fixture  200  of the dental implant having the above-described structure, the polished portion  211  may be easily formed in the fixture  200  of the dental implant having the above effects so that productivity of the fixture  200  may be improved. 
         [0048]    As described above, exemplary embodiments of the present invention have been described. However, aspects of the present invention are not limited thereto. 
         [0049]    For example, the protection jig  230  of  FIG. 7  is used but a protection jig  300  having a shape as illustrated in  FIG. 10  may be used. The protection jig  300  of  FIG. 10  is disposed in such a way that a plurality of fixed protrusions  320  formed in internal sides of a combination hole  311  of a body portion  310  are separated from one another in a circumferential direction of the combination hole  311 . The fixed protrusions  320  of the protection jig  300  are inserted in the fixed groove  212  of the fixture  200  and are fixed therein, like the fixed protrusions  233  of the protection jig  230  of  FIG. 7 . 
         [0050]    In addition, the fixed protrusions  233  of the protection jig  230  of  FIG. 7  and the fixed protrusions  320  of the protection jig  300  of  FIG. 10  are respectively located adjacent to an upper side of the body portion  231  of the protection jig  230  of  FIG. 7  and an upper side of the body portion  310  of the protection jig  300  of  FIG. 10 . However, in some cases, the fixed protrusions  233  of  FIG. 7  and the fixed protrusions  320  of  FIG. 10  may be respectively located adjacent to a lower side of the body portion  231  of the protection jig  230  of  FIG. 7  and a lower side of the body portion  310  of the protection jig  300  of  FIG. 10  or may be disposed at middle inner walls of the body portion  231  of the protection jig  230  of  FIG. 7  and middle inner walls of the body portion  310  of the protection jig  300  of  FIG. 10 . 
         [0051]    As described above, in a method of manufacturing a fixture of a dental implant according to the present invention, the fixture of the dental implant in which the performance of osseointegration is excellent and spread of inflammation can be reduced, can be easily manufactured. 
         [0052]    Furthermore, in the fixture of the dental implant according to the present invention, the performance of osseointegration is excellent and spread of inflammation can be reduced. 
         [0053]    While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.