WO2009072788A1

WO2009072788A1 - A implant consisting of ball and manufacturing method thereof

Info

Publication number: WO2009072788A1
Application number: PCT/KR2008/007107
Authority: WO
Inventors: Boo Rak Lee
Original assignee: Boo Rak Lee
Priority date: 2007-12-03
Filing date: 2008-12-02
Publication date: 2009-06-11

Abstract

Disclosed is an implant composed of an aggregate of spherical balls which are connected to each other through sintering and a manufacturing method thereof. Upon use of the implant having numerous pores defined by spherical ceramic balls which are aggregated, cell affinity and ability of the cells to survive can be increased. The implant can be used for a long period of time without it becoming loose, and can prevent the hole in the alveolar bone where the implant (fixture) is installed from being enlarged.

Description

A IMPLANT CONSISTING OF BALL AND MANUFACTURING

METHOD THEREOF

Technical Field

[1] The present invention relates to an inplant having superior biocompatibility and a manufacturing method thereof.

[2]

Background Art

[3] Generally, an implant made of metal such as titanium is used. The metal implant may be installed as an artificial tooth or as part of a spine, a hip joint, a knee joint, a bone, etc. In this case, however, the metal implant makes it impossible to grow the cells thereon and rejection ensues, undesirably creating aftereffects of the surgical operation. In particular, when the metal implant is used as a bolt implant for fixing fractured bone or as an implant for an artificial tooth, the bone cells near the surface of the installed metal implant are impaired. Accordingly, 5 to 10 years after the installation of the implant, the hole formed in the bone where the implant (fixture) is installed is enlarged, and thus subsequent installation of the implant is impossible.

[4] Korean Utility Model No. 0433571 discloses a zirconia dental implant, which includes a fixture embedded in the alveolar bone at a space where a tooth was lost and an abutment to which an artificial crown is fixed. The fixture has a shape which is tapered downwards, and includes a screw having a threaded portion formed on the outer surface thereof and recessed in a round shape from the ridge of the threaded portion toward the lower end of the fixture, and the fixture is made of a zirconia- alumina composite. However, the above utility model is disadvantageous because the implant powder composed of zirconia-alumina and an apatite-based compound is pressed and processed into the shape of the implant, and thus the implant has poor strength and is broken upon use. Specifically, when zirconia-alumina is melted at a high temperature in the forming process, the surface of the implant is smooth and hard but it is difficult for cells to adhere onto the implant. So, with the goal of increasing the cell adhesion, if the surface of the implant is formed to be rough, the implant has poor strength and thus may become broken or fractured upon use after installation.

[5] Korean Patent No. 0755950 discloses an implant fixture, which has a fixture body, a part of which is formed with a threaded portion and the other part of which is porously formed through sintering of metal powder, so that the fixture is provided with a screw and a porous portion. This fixture includes a head of a predetermined height, which has an insert hole in the center thereof and is provided with a female threaded portion, and the fixture body under the head. The implant fixture is embedded in the alveolar bone in a manner such that the fixture body is installed in the alveolar bone and an abutment and a dental prosthesis are sequentially fixed thereto through the insert hole. The fixture body includes the threaded portion formed at a part thereof and the porous portion formed through sintering using metal powder at the other part thereof. In the above patent, the fixture body is made of metal and has numerous pores formed through sintering of metal powder between the upper and lower ends thereof at the outer surface thereof. However, upon extended use of the fixture, the fixture made of metal has lower cell affinity than ceramics, and thus impairs the cells in the surrounding area, consequently causing problems of enlarging the bored hole in which the implant is installed.

[6]

Disclosure of Invention Technical Solution

[7] Therefore, the present invention provides an implant composed of an aggregate of spherical balls which are connected to each other through sintering and a manufacturing method thereof. The implant, which is used as an artificial bone, in particular, an artificial tooth, is formed to have numerous pores in a body thereof, and thus, upon installation of the implant into the alveolar bone (dentary bone), rejection does not occur, and bone cells are introduced into the pores and thus efficiently live therein, thus increasing ability of the cells to survive and cell affinity and enabling the semipermanent use of the installed implant without it becoming loose.

[8] An aspect of the present invention provides an implant composed of an aggregate of spherical balls which are connected to each other.

[9] In the present invention, the spherical balls may have a diameter of 0.05-1 mm.

[10] In the present invention, the spherical balls may have a size difference of 0.2 or less or a sphericity of 0.05 or less.

[11] In the present invention, the implant may be composed of two or more kinds of spherical balls having different diameters which are connected to each other.

[12] In the present invention, the implat may haver a porosity of 30-70%

[13] In the present invention, the spherical balls may be made of ceramic, titanium or polyketone.

[14] The implat of the present invention may be an implant for an artificial tooth.

[15] Another aspect of the present invention provides a method of manufacturing an implant composed of the ceramic balls, including pre-sintered the ceramic balls at 500~800°C, charging the pre-sintered ceramic balls, sintering the ceramic balls charged in the pre-mold at 1000~1800°C, and processing the ceramic balls sintered in the pre- mold into a shape of the implat.

[16] In the method, charging the pre-sintered ceramic balls in the pre-mold may be performed by filling the pre-mold with the ceramic balls while the pre-mold is vibrated.

[17] In the method, water sprayed onto the ceramic balls may contain at least one binder selected from among B₂O₃, ceramic powder and glaze.

[18] In the method, the binder may be used at a concentration of 0.01-10 wt%.

[19] A further aspect of the present invention provides a method of manufacturing an implat composed of the titanium balls or the polyketone balls, including charging the titanium balls or the polyketone balls in a pre-mold and connecting the balls to each other, and processing the titanum balls or the polyketone balls connected to each other in the pre-mold into a shape of th implant.

[20] The implant according to the present invention may be used as an implant for an artificial tooth or an implant for fixing the bone including a spinal implant and an implant for a knee joint and a hip joint, all of which are installed in the human body. In the present invention, the meaning of the word 'implant' includes a fixture, an abutment, a female screw (bolt) and the like.

[21] In the present invention, a material for the spherical balls is not particularly limited as long as it has a predetermined strength and biocompatibility, and examples thereof include ceramic, titanium, and polyketone. Among ceramic materials, particularly useful is zirconia which is metal oxide having excellent biocompatibility. The polyketone is exemlified by polyktheretherketone. The reason why spherical balls are used to form the implant is that the pores are naturally formed when the spherical balls are connected to each other in all directions through sintering, and also because, as biotissue grows on the surface of the implant with which it is in contact or in the pores of the implant, the spherical balls remarkably reduce a concern of hurting the biotissue and causing inflammation, compared to materials having sharp or pointed surfaces or lines.

[22] The spherical balls have a diameter of 0.05-1 mm, preferably 0.1-0.8 mm, and more preferably 0.2-0.6 mm, When the diameter of the balls is less than the lower limit, the balls are arranged too close to each other, thus making it impossible to obtain a desired porosity. In contreast, when the diameter thereof exceeds the upper limit, the number of balls in the implant having the same size is reduced, and thus the number of points of contact between the neighboring ball is decreased, undesirably weakening compressive strength of the implant. Further, because the size of the pores defined by the balls is increased in proportion to the size of the balls, the survival of the calls is reduced.

[23] Also, when the spherical balls have a uniform size with a size difference of 0.2 or less, preferably 0.1 or less, and more preferably 0.01 or less, the implant having uniform compressive strength and porosity may be manufactured. In some occasions, spherical balls having uniform sizes, for example, two or more kinds of, preferably two to five kids of and preferably two or three kinds of spherical balls having different diameters, may mixed, so that the implant is controlled to have desired compressive strength and porosity.

[24] Also, the spherical balls have a sphericity of 0.05 or less, preferably 0.005 or less, more preferably 0.0005 or less, and most prefeably 0.00005 or less, When the spherical balls having low sphericity are used, there is a low concern of causing the spherical balss to hurt the biotissue at the contact surface between the balls and the biotissue. Further, when the ceramic balls having low sphericity and size difference are used, it is possible to manufacture an implat having more uniform compressive strength and porostiy

[25] A method of maunfacturing the spherical balls for the implant according to the present invention is described below.

[26] In the method of manufacturing the ceramic balls, ceramic powder is introduce into a molding machine or a chambe, and the water is sprayed onto the power while the molding machine is roataed at 5-100 rpm and preferaly 10-30 rpm, thus forming and sorting seeds having a spherical shape adequate for the formation of the balls. Such seeds are placed in the molding machine having a cylindrical shape and the manually stirred while water is sprayed theron, and simultaneously, the molding machine is rotated and vibrated, thus spheroidizing the seeds into caramic balls having a prede- terminded size. Also, the ceramic balls thus obtained may be passed through a standard sieve, thus enabling only the ceramic balls having a specific size to be sorted apart from one another.

[27] In a method of manufacturing the implant composed of the ceramic balls according to an embodiment of the present invention, the ceramic balls thus formed are pre- sintered at 500~800°C and preferably 600~700°C, before being placed in a pre-mold. When the pre-sintering process is performed in the above temperature range, strength able to maintain the shape of the spherical balls unchanged in a sintering process may be obtained. If the pre-sintering temperature is less than the lower limit, a period of time required for performing the pre-sintering and enhancing the strength of the ceramic balls is lengthened. In contreat, if the pre-sintering temperature exceeds the upper limit, the ceramic balls may be broken of deformed and thus cannot be restored. Also, in the case where the ceramic balls are directly sintered without pre-sintering, part of the ceramic balls may be broken or deformed, thus making it difficult to obtain an implant having uniform inner cross-sections and compressive strength. When the pre-sintered ceramic balls are palced in the pre-mold, the ceramic balls are slowly charged therein layer by layer while water is sprayed onto the ceramic balls so that the entire surface of the balls is covered with water.

[28] The reason why water is sprayed onto the entire surface of the pre-sintered ceramic balls is that the connection between the neighboring balls is further enhanced in the sintering process to thus increase the compressive strength of the implant. Although only water may be sprayed, in order to further increase the connective force between the balls, at lest one binder selected from among B₂O₃ cermic powder and glaze may be added to the water. The binder may be used at a concentration of 0.001- 10 wt%, preferably 0.005-5 wt%, and more preferably 1-3 wt%.

[29] Upon placing the ceramic balls in the pre-mold while water is being sprayed onto the pre-sintered ceramic balls, the vibrating of the pre-mold is perferable for the purpose of filling the pre-mold with the ceramic balls without creating void spaces. To this end, the pre-mold is placed on a vibrating plate or a vibrating jig and then vibrated at a predetermined rate.

[30] The ceramic balls placed in the pre-mold are sintered at 1000-1800 and preferably

1200-1600. While the pre-mold is shrunk at the above temperature, pressure is applied to the spherical balls and thus the spherical balls are also shrunk so that the contact state between the neighboring ceramic balls is changed from the point contact to the surface contact, thereby firmly connecting the sintered balls to each other.

[31] In addition, in a method of manufacturing the implant composed of titanium balls or polyketone balls according to an another embodiment of the present invention, the titanium balls or the polyketone balls are uniformly placed in a pre-mold without the presence of any void spaces and then fused to each other at 1000-1200 with a high frequency, thus forming a ball aggregate in which the balls are welded to each other.

[32] The shape of the pre-mold includes but is not limited to a cylindrical post, a tetragonal post, a hexagonal post, an octagonal post, etc. In order to reduce the cutting amount of a molded body upon processing into an implant, the cylindrical shape is preferable.

[33] Also, the pre-mold may be made of the same material as that of the spherical balls. If so, the mutual connection of the sintered or welded spherical balls may be prevented from being broken due to the difference in the shrinkage rate between the spherical balls and the pre-mold in the sintering process. Further, in order to facilitate the release of the pre-mold, a release agent may be applied on the inner surface of the pre-mold coming into contact with the spherical balls. However, even when the release agent is not applied, the pre-mold may be adequately cut and removed in the course of processing the balls into the implant, thus obviating a need for the separation between the pre-mold and the spherical balls.

[34] In the present invention, the implant or the molded body for an implant may have the volume of the pores, namely the porosity of 30-70%, preferably 40-60%, and more preferably 45-50%. To adjust the porosity of the implant, two or more kinds of, preferably two to five kinds of, and more preferably two or three kinds of the spherical balls having different diameters may be mixed.

[35] Further, it is preferred that the implant have as high a compressive strength as possible. However, when the pores necessary for the survival of the cells are increased, the compressive strength may be reduced. Thus, the compressive strength of the implant may be set to 40 kgf/πmf or more, preferably 60 kgf/mnf, and more preferably 70 kgf/πmf or more.

[36]

Brief Description of Drawings

[37] FIG. 1 illustrates a state in which a pre-mold is filled with ceramic balls.

[38] FIG. 2 is a fragmentary enlarged view of FIG. 1, which shows a contact surface and pores between the neighboring spherical balls which are layered and sintered.

[39] FIG. 3 illustrates an outer appearance of an implant after having had its shape processed.

[40] FIG. 4 illustrates the implant composed of the spherical balls.

[41]

[42] <Description of the Reference Numerals in the Drawings>

[43] 10: spherical ball 20: implant

[44] 21: etching portion 22: threaded portion

[45] 23: groove 24: pore

[46]

Best Mode for Carrying out the Invention

[47] A better understanding of the present invention may be obtained through the following examples and experimental examples related to the implant for an artificial tooth, which are set forth to illustrate but are not to be construed as limiting the present invention.

[48]

[49] Preparative Example: Preparation of Ceramic Balls

[50] In order to form ceramic ball seeds, 3 kg of ceramic (zirconia) powder composed of fine particles such as wheat flour was placed in a molding machine, and water was intensively sprayed only onto the ceramic powder using an air brush while the molding machine was rotated at 18 rpm. The reason why water is sprayed only onto the ceramic powder is that, when water is sprayed onto any position other than the ceramic powder, the ceramic powder adheres onto the position and thus is not spheroidized and loss of the material occurs. [51] In the course of forming the ceramic powder into spherical particles, part of the ceramic powder was not spheroidized but remained in a powder state, and thus only the seeds having a shape adequate for the formation of balls were selected.

[52] Thereafter, these seeds were placed in the same molding machine as above, after which water was sprayed using an air brush until a diameter of spherical balls reached the desired size, for example, 0.2-1 mm, and water was sprayed using a spray gun when the diameter of the balls was 0.2 mm or more. The pressure of the air brush was set to 0.3 kg/cm². In the case where too much water is sprayed in the spheroidizing process, the cylinder of the molding machine is run idle. Thus, the amount of water being sprayed was adjusted while the ceramic powder was further added.

[53] Upon the spheroidizing work, the ceramic sample was removed from the molding machine and the degree of spheroidizing thereof was periodically observed, after which only the ceramic balls having a size of about 0.4 mm were stepwisely sorted by use of a sieve.

[54] The ceramic balls thus obtained had a diameter of 0.4 mm, a size difference of 0.01, and a sphericity of 0.00005.

[55]

[56] Example 1

[57] The ceramic balls obtained in the above preparative example were pre-sintered at

600. The pre-sintered ceramic balls were air cooled, and then charged in a pre-mold while water was sprayed thereon. The pre-mold had a cylindrical shape having a diameter of 4.5 mm and a height of 10 mm and was formed from zirconia powder. While the pre-mold was placed on a vibrating plate and vibrated, the ceramic balls were charged in the pre-mold.

[58] FIG. 1 shows the state in which the cylindrical pre-mold is filled with the ceramic balls to form a base body of an implant. The ceramic balls charged in the pre-mold were layered through two-step procedures including forming an odd-numbered layer and forming an even-numbered layer, consequently forming a total of 30 layers. The odd-numbered layers of the ceramic balls in the pre-mold were configured in a manner such that a total of 11 ceramic balls having a diameter of 0.4 mm were linearly arranged in a length direction in a circle having a diameter of 4.5 mm on the basis of length and width, and the dimension of the remaining space was divided by 11, thus determining intervals of the balls. Also, the even-numbered layers of the balls were configured in a manner such that the balls were charged between the 11 balls of the odd-numbered layer in the circle having a diameter of 4.5 mm based on the odd- numbered layer. The ceramic balls charged in the mold in this way were layered so that the odd-number layers and the even-numbered layers were partially overlapped, and consequently, the pre-mold was filled with a total of 2295 ceramic balls. [59] After the filling of the pre-mold with the ceramic balls, sintering was performed at

1200. In this procedure, as the pre-mold was shrunk by the high temperature, the ceramic balls therein were also shrunk so that the contact state between the neighboring ceramic balls was changed from point contact to surface contact, thereby connecting the sintered balls to each other.

[60] FIG. 2 shows the contact surface and the pores between the neighboring ceramic balls which are layered in the pre-mold in the sintering process. The ceramic balls having a diameter of 0.4 mm were aggregated while the contact surface between the neighboring balls had a size of 0.12 mm. The horizontal interval between the centers of the neighboring aggregated balls was 0.33 mm, and the vertical height interval therebetween was 0.38-0.39 mm. Thus, numerous pores 24 were defined by the neighboring ceramic balls.

[61] When the sintered ceramic balls were released from the pre-mold, a cylindrical sample composed of the ceramic ball aggregate was formed and then processed into an implant having a bolt and an etching portion on the outer surface thereof, as shown in FIG. 3. In FIG. 3, the implant 20 indicates a fixture, and a groove 23 is formed in the top of the implant as in a typical implant and processed so that an abutment is fixed thereto. A threaded portion 22 formed on the outer surface of the implant (fixture) is screwed into the alveolar bone (jaw bone). When the implant is installed into the alveolar bone, the etching portion 21 ensures that the alveolar bone is coupled with the implant without breakage.

[62] FIG. 4 illustrates the implant composed of the ceramic balls, in which the ceramic balls are aggregated by sintering the ceramic balls 10 in a state of being densely layered in all directions. The implant according to the present invention includes the aggregate of the ceramic balls. Hence, when this implant is fixed to the bone, the cells are introduced into numerous pores 24 between the neighboring ceramic balls and survive, thereby increasing the adhesion between the implant (fixture) and the alveolar bone.

[63]

[64] Example 2

[65] An implant was manufactured in the same manner as in Example 1, with the exception that, upon filling of the pre-mold with the ceramic balls, water containing 1 wt% sintering glaze (barium, lime) diluted therein was sprayed onto the ceramic balls.

[66]

[67] Example 3

[68] An implant was manufactured in the same manner as in Example 1, with the exception that water containing 1 wt% B₂O₃ diluted therein was used as the spraying solution upon filling of the pre-mold with the ceramic balls. [70] Example 4

[71] An implant was manufactured in the same manner as in Example 1, with the exception that water containing 3 wt% B₂O₃ diluted therein was used as the spraying solution upon filling of the pre-mold with the ceramic balls. [72]

[73] Example 5

[74] An implant was manufactured in the same manner as in Example 1, with the exception that water containing 5 wt% B₂O₃ diluted therein was used as the spraying solution upon filling of the pre-mold with the ceramic balls. [75]

[76] Example 6

[77] An implant was manufactured in the same manner as in Example 1, with the exception that a ceramic powder slurry containing 2 wt% zirconia powder diluted therein was used as the spraying solution upon filling of the pre-mold with the ceramic balls. [78]

[79] Example 7

[80] Instead of the ceramic balls, titanium balls having a diameter of 0.4 mm, a size difference of 0.01 and a sphericity of 0.00005 were charged in the pre-mold of

Example 1. Thereafter, the titanium balls which were aggregated were heated at

1000-1200 with a high frequency while pressure was applied to the titanium balls from the upper portion of the pre-mold, so that the titanium balls were connected to each other, thus manufacturing an implant sample. [81]

[82] Comparative Example 1

[83] Instead of the production of the ceramic balls from the zirconia powder, the zirconia powder was directly pre-sintered at 600, charged in the pre-mold of Example 1, and then sintered at 1200, thus producing a cylindrical sintered body for an implant having a diameter of 4.5 mm and a height of 10 mm. [84]

[85] Comparative Example 2

[86] A cylindrical sample for an implant, having a diameter of 4.5 mm and a height of 10 mm, was produced from polyetheretherketone (PEEK-OPTIMA LTl, available from

Invibio). [87]

[88] Comparative Example 3

[89] A cylindrical sample for an implant, having a diameter of 4.5 mm and a height of 10 mm was produced from titanium.

[90] [91] Compressive Strength Experiment [92] The maximum load and the compressive strength of the samples of Examples 1, 2, 3 and 7 and Comparative Examples 1 to 3 were measured using a compressive strength tester (Instron 8801). As such, the inventive samples used were those sintered and released from the pre-mold and having a cylindrical shape before being processed into the shape of an implant.

[93] [94] Table 1 [Table 1] [Table ]

[95] [96] As is apparent from the results of measurement of maximum load and compressive strength of the ceramic balls sintered and released from the pre-mold in Examples 1 to 3, in Example 2 using the spraying solution containing the glaze, the maximum load and the compressive strength were the greatest, and thus, the ceramic balls could be seen to be more firmly connected to each other. In all of the cases in which the glaze was applied or not onto the pre-mold, shrinkage occurred in the sintering process, so that the contact state between the neighboring balls was changed from point contact to surface contact. The ceramic balls sintered with the use of the glaze were shrunk less but were more securely connected to each other, and also had an effect of coating the ceramic balls defining the pores. In the case of the ceramic balls without the use of the glaze, the shrinkage rate was increased and the contact area was thus enlarged. The implants resulting from both the case where the glaze was sprayed onto the pre-mold and the case where the glaze was not sprayed had no problems when being used.

[97] In Examples 3 to 5, as the concentration of the B₂O₃ in the spraying solution was higher, the maximum load and the compressive strength were increased, thus increasing the connective force between the neighboring ceramic balls. In Example 6 using the ceramic slurry instead of glaze or B₂O₃, similar results were obtained.

[98] [99] Cell Survival Experiment [100] The bone cells were cultured using the samples of Examples 1 and 7 and Comparative Examples 1 to 3, after which the amount of surviving cells, namely the cell survival rate in the implant sample was analyzed through MTT analysis.

[101] Specifically, 4 mg/ml MTT

(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide, available from Promega) and PBS (Phosphate Buffer Saline, pH 7.2, Giboco, Cat, 200112027) were mixed together, filtered using a 0.2 mm filter to remove bacteria and other microorganisms from the solution, and stored at -20. Thereafter, the sample was disinfected in an autoclave, sprinkled in a lying state with bone cells (Osteoblast, hFOB1.19 cell) and then incubated under conditions of 37, 5% CO₂ and a time period of 48 hours. After the completion of the incubation, a solution in which MTT and a medium (DMEM FBS 10%, Abs 1%, available from Gibco) were diluted at a 1:10 ratio was added to the sample, and the sample was stored for 3 hours so that MTT crystallized in the mitochondria of the cells. Then, the medium was removed, 100 ml of DMSO (dimethyl sulfoxide) was added, the solution was stirred for 2-3 min, and ab- sorbance was measured at 550 nm using an ELISA reader (BioRad Model 550). The measured absorbance indicates the amount of MTT reduced to the cells and is proportional to the number of surviving cells in each sample. The results of absorbance are shown in Table 2 below.

[102] [103] [104] Table 2 [Table 2] [Table ]

[105]

[106] The sample of Example 1 composed of the ceramic ball aggregate exhibited the greatest cell survival rate. The sample of Example 7 composed of the titanium ball aggregate exhibited a comparatively higher cell survival rate in relation to the comparative examples. Thereby, it could be seen that the inner pores of the sample increased initial adsorption and growth of the cells. Even when the same balls were formed, the ceramic material which has an affinity for the cells of the human body manifested the higher cell survival rate, compared to the metal material.

[107] However, the samples of Comparative Examples 1 to 3 had no pores, and the survival of the cells was almost impossible. The sample of Comparative Example 1 had compressive strength much greater than the sample of the examples and the sample of Comparative Example 3 gave results similar to the examples, but these comparative samples were inadequate for use in processing into the implant. In particular, when the conventional titanium implant of Comparative Example 3 was used, corrosion occurred on the outer surface of the implant, undesirably enlarging the hole in the alveolar bone.

[108] As mentioned above, in the present invention, the bioceramic is used, thus increasing the cell affinity and the ability of cells to survive. The base body of the implant is produced from the aggregate of balls, thus forming many pores. Thereby, the artificial tooth can be used for a long period of time without it becoming loose, and problems in which the hole in the alveolar bone where the implant (fixture) is installed is enlarged can be solved.

[109]

Industrial Applicability

[110] The present invention provides an implant composed of an aggregate of spherical balls which are connected to each other through sintering. When the implant having numerous pores is installed into the portion of the human body, the cells of the human body are introduced into the pores and survive, thus increasing the cell survival area to thereby result in increased ability of the cells to survive. Further, the bioceramic balls are used, thus increasing affinity for the bone cells, thereby preventing the aftereffects of a surgical operation and enabling the use of an implant without it becoming loose as did the original bone or tooth.

Claims

[I] An implant comprising an aggregate of spherical balls which are connected to each other.

[2] The implant according to claim 1, wherein the spherical balls have a diameter of

0.05-1 mm. [3] The implant according to claim 2, wherein the spherical balls have a size difference of 0.2 or less or a sphericity of 0.05 or less. [4] The implant according to claim 3, wherein the implant comprises two or more kinds of spherical balls having different diameters which are connected to each other.

[5] The implant according to claim 2, wherein the implant has a porosity of 30-70%.

[6] The implant according to any one of claims 1 to 5, wherein the spherical balls are made of ceramic, titanium or polyketone.

[7] The implant according to claim 6, wherein the implant is an implant for an artificial tooth. [8] A method of manufacturing an implant comprising the ceramic balls of claim 6, comprising: pre-sintering the ceramic balls at 500-800; charging the pre-sintered ceramic balls in a pre-mold while water is sprayed onto the ceramic balls; sintering the ceramic balls charged in the pre-mold at 1000-1800; and processing the ceramic balls sintered in the pre-mold into a shape of the implant. [9] The method according to claim 8, wherein the charging the pre-sintered ceramic balls in the pre-mold is performed by filling the pre-mold with the ceramic balls while the pre-mold is vibrated. [10] The method according to claim 8, wherein the water sprayed onto the ceramic balls contains at least one binder selected from among B₂O₃, ceramic powder and glaze.

[I I] The method according to claim 10, wherein the binder is used at a concentration of 0.01-10 wt%.

[12] A method of manufacturing an implant comprising the titanium balls or the polyketone balls of claim 6, comprising: charging the titanium balls or the polyketone balls in a pre-mold and connecting the balls to each other; and processing the titanium balls or the polyketone balls connected to each other in the pre-mold into a shape of the implant.