Patent Publication Number: US-2004049201-A1

Title: Implant comprising a grooved structure

Description:
SCOPE OF THE INVENTION  
       [0001] The present invention relates to an implant insertable into the human body during an operation having an implant body, the surface of which has a plurality of groove-shaped recesses, as well as a method for its manufacture.  
       STATE OF THE ART  
       [0002] The applicant&#39;s EP 1 013 236-A discloses a cylindrical or conical tooth implant, the surface of which has a plurality of groove-shaped recesses running along its longitudinal axis or at a sharp angle thereto, and which may also be arranged to run crosswise. In another embodiment of the implant, the surface of the implant body is divided along its longitudinal axis into numerous sections or steps separated from one another by radial bands and having a plurality of peripheral groove-shaped recesses. The dimensioning to the groove-shaped recesses is adapted to the dimensions of the osteons of the jawbone tissue which attach to said groove-shaped recesses. In manufacturing the tooth implant, a cylindrical, conical or stepped implant body is pre-formed with a smooth surface into which the groove-shaped recesses can then be created by means of a material removal process. A plurality of small, spatially and densely-distributed concave recesses are provided in the groove-shaped recesses to receive the osteocytes of the bone tissue surrounding the implant and hence serving to further improve the contact between the implant and the bone.  
       [0003] Such a surface structure allows bone tissue osteons to attach to the groove-shaped recesses and to grow into the implant. The dimensioning of the groove-shaped recesses being adapted to the dimensions of the osteons and their receiving of those osteons coming into contact with the implant favorably facilitates the growing in of the implant. As a result of this surface structure and due to the pressure acting upon the implant, compacta forms around the implant in the spongiosa region of the bone which affords a good absorption of the forces acting upon the implant as well as a stable and permanent seat for the implant.  
       SUMMARY OF THE INVENTION  
       [0004] The present invention further enhances the described effect based upon a further improved adaptation of the surface structure of an implant of the type described above to the osteon profile and the behavior of the osteons during the healing phase.  
       [0005] In accordance with the invention, as defined by the claims, the groove-shaped recesses on the surface of the implant are inclined toward the longitudinal axis of the implant body. They form an angle α to the longitudinal axis and are of varying depths across their length. The surface structure which thus results is accommodating of bone tissue anatomy. It has been found that the osteons accumulating on the implant tend to align less toward the implant axis than they do transverse thereto. Such a depositing of osteons on the implant surface mainly ensues at an acute angle, which represents a spatial condition for the accumulating of a large number of osteons. The osteons can hereby grow into the groove-shaped recesses at an oblique angle from above or at an oblique angle from below. The canted profile to the groove-shaped recesses supports this form of accumulation, improves the contact between the bone tissue and the implant, and shortens the healing phase.  
       [0006] Further improvement is attained by curvature across the lengthwise extension of the grooves. According to one aspect of the invention, the grooves are configured such that in an implementation of the peripheral region, their profile exhibits a curved wedge shape or is in the shape of elongated curved segments.  
       [0007] According to an inventive method for manufacturing the grooved structure, a blank of the implant body is made in which grooves are be produced in at least one of its sections in a material removing process. Said grooves form an angle α radial the longitudinal axis of the implant body and their depths vary across their lengths. The material removing process preferably utilizes metal cutting and a synchronous feed of implant body and the cutting tool which can be varied from section to section. The synchronous feed is preferably selected such that the grooves will have a curvature to at least one of their sections. According to a further aspect of the invention, the synchronous feed is preferably selected such that the grooves will be narrow and shallow at both edges of a section and exhibit their maximum width and depth at their center.  
       [0008] In accordance with a further step of the inventive procedure, a metal layer is sputtered on the surface of the grooves, said layer preferably being a titanium layer. 
     
    
    
     DESCRIPTION OF THE DRAWINGS  
     [0009] Various embodiments of the invention will be depicted in the following in conjunction with the drawings, which show:  
     [0010]FIG. 1: an embodiment of a tooth implant according to the present invention having a cylindrical implant body divided into various sections;  
     [0011]FIG. 2: a partial section along line  2 - 2 ′ from FIG. 1;  
     [0012]FIG. 3: a schematic representation of an implementation of a peripheral segment of one of the sections from FIG. 1;  
     [0013]FIG. 4: a partial section along line  4 - 4 ′ from FIG. 3;  
     [0014]FIG. 5: a schematic representation of an implementation of a peripheral segment comprising grooves exhibiting increasing groove depth toward the head of the implant;  
     [0015]FIG. 6: a section along line  6 - 6 ′ from FIG. 5;  
     [0016] FIGS.  7 - 8 : schematic representations of implementations of a peripheral segment of the implant exhibiting grooves spiraling to the left or to the right;  
     [0017] FIGS.  9 - 10 : sections along line  9 - 9 ′ from FIG. 7 and line  10 - 10 ′ from FIG. 8;  
     [0018] FIGS.  11 - 12 : schematic representations of implementations of a peripheral segment of the implant exhibiting grooves spiraling crosswise to the left and right;  
     [0019] FIGS.  13 - 14 : schematic representations of implementations of a peripheral segment of the implant having diamond-shaped grooves;  
     [0020]FIG. 15: a section along line  14 - 14 ′ from FIG. 13;  
     [0021] FIGS.  16 - 18 : embodiments of the inventive implant having a stepped implant body;  
     [0022] FIGS.  19 - 20 : embodiments of the inventive implant having a conical implant body;  
     [0023] FIGS.  21 - 22 : embodiments of the inventive implant having an implant body comprising a combination of groove structures;  
     [0024] FIGS.  23 - 24 : schematic representations of implementations of a peripheral segment of an inventive implant comprising curved grooves having a profile in the form of a curved wedge and spiraling to the left or to the right;  
     [0025]FIG. 25: a schematic representation of the implementation of a peripheral segment of an inventive implant comprising curved grooves having a profile configured as elongated curved segments;  
     [0026]FIG. 26: a schematic representation of the implementation of a peripheral segment of an implant having curved grooves of the type as depicted in FIG. 25 spiraling crosswise;  
     [0027]FIG. 27: an embodiment of the implant having a stepped implant body exhibiting the type of groove structure combination as depicted in FIGS. 25 and 26; and  
     [0028]FIG. 28: an embodiment of the inventive implant having a curved longitudinal axis as may be utilized, for example, in hip joint replacements. 
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS OF THE INVENTION AS DEPICTED IN THE DRAWINGS  
     [0029] The tooth implant depicted in FIG. 1 comprises a cylindrical implant body  11  made from titanium, ceramic or other sufficiently hard enough material tolerated by the bone tissue of a human body. Implant body  11  has a head area  12  disposed with bevels  13 ,  14  on its bucal and lingual sides as disclosed in EP-A 0 868 889. Said head area  12  serves to receive supports (not shown) for a tooth crown. A body area  15  divided into sections  16  is adjoined to head area  12 , bands  17  being disposed between said sections. The example depicted in FIG. 1 exhibits five sections  16  separated by four bands  17 . The base of implant body  11  terminates in a rounded foot area  18 .  
     [0030] The perimeters of sections  16  are disposed with densely-distributed groove-shaped recesses  20 , referred to in the following simply as grooves, running parallel to the implant axis relative the perimeter of implant body  11 . Grooves  20  preferably have a concave profile, the edges of which run to the perimeter of body area  15  and form a rounded comb  22  with each of both adjacent recesses at the area of greatest depth (FIG. 2 sectional representation). Grooves  20  have a width which is preferably in the range of between 0 and 300 micrometers and a depth which varies from between 0 micrometers and preferably up to 150 micrometers.  
     [0031]FIG. 3 shows a schematic representation of an implementation of one of sections  16  in which three grooves  20  are depicted. Grooves  20  form an angle α radial the longitudinal axis  41  of implant body  11  and are of varying depth across their length (FIG. 4). This results in grooves  20  exhibiting what approximates a wedge-shaped profile at the implementational level. The apexes  31  to the limiting lines are situated at the peripheral diameter at the upper edge of depicted section  16 . The wedge shape exhibits its greatest width in area  32  at the lower edge of the section and, at the same time, this is where the grooves have their greatest depth, as is shown in FIG. 4. Very nearly wedge-shaped spans  33  running in the opposite direction are found between grooves  20  which widen through to apexes  31  of grooves  20 , their height determining the perimeter of the section. It should be apparent that the limiting lines to grooves  20  in the actual implementation of the perimeter exhibit curvature at the imaging plane, which is not shown in FIGS. 3 and 4 for reasons of simplifying the representation.  
     [0032] Angle α is defined by the maximum depth of the grooves and the axial length of sections  16 . With a maximum groove depth of 150 micrometers and a sectional length of roughly 2 mm, α has a value in the proximity of 4.5°.  
     [0033] The implant surface structure as described accommodates the anatomy of the jawbone tissue. During the implant healing phase, osteons of the bone tissue surrounding the implant can collect in grooves  20 . It has been found that the osteons depositing on the implant tend to align less with the implant axis than they do transverse thereto. Such a depositing of osteons on the implant surface mainly ensues at an acute angle, which represents a spatial condition for the accumulating of a large number of osteons. The osteons can hereby grow into grooves  20  at an oblique angle from above or at an oblique angle from below. The canted profile to grooves  20  supports this form of accumulation, fosters a close contact between the jawbone tissue and the implant, and shortens the time period needed for growing in.  
     [0034] Deviating from the form depicted in FIGS.  1 - 4 , the grooves may also be arranged differently or have a different shape. FIGS. 5 and 6 show a groove profile to grooves  50  which has been rotated  1800  compared to the groove profile depicted in FIGS. 3 and 4; i.e., apexes  51  of grooves  50  are positioned at the lower edge of depicted section  16  and the greatest groove depth is at area  52  at the upper edge of said section  16 , as shown in the FIG. 6 sectional representation.  
     [0035]FIGS. 7 and 8 show an implementation to sections  16  of implant body  11  in which the grooves have a spiraling profile relative the perimeter of implant body  11 . FIG. 7 shows a progression to grooves  70  which winds to the right and which additionally extends in wedge-shaped form from upper edge  71  of section  16  to the lower edge of said section, area  72 , having the greatest depth to grooves  70  (FIG. 9). FIG. 8 shows a progression to grooves  80  which winds to the left, extending from lower edge  81  of section  16  to the upper edge of said section which is, in this case, area  82  showing the greatest depth to grooves  80 , as shown in the FIG. 10 sectional representation.  
     [0036]FIGS. 11 and 12 show implementations of a crosswise progression to the grooves. The embodiment according to FIG. 11 provides for first grooves  110  extending in a first direction winding to the left at an acute lead angle and second grooves  111  extending at an acute lead angle in a second direction winding to the right and intersecting with first grooves  110 . Grooves  110  and  111  have a wedge-shaped profile from the upper edge of section  112  to the lower edge of said section, area  112 , being the region of greatest depth for grooves  110  and  111 . Such a groove progression produces the cut spans  33  as depicted in FIG. 3 resulting in a plurality of knob-shaped protrusions, their height extending to, respectively defining, the perimeter of sections  16 .  
     [0037] In the embodiment according to FIG. 12, grooves  120  and  121  exhibit a crosswise progression like grooves  110  and  111  from FIG. 11, although grooves  120  and  121  are arranged here such that the wedge-shaped progression runs from the lower edge of section  122  to the upper edge of said section, the area of greatest depth to grooves  120  and  121 .  
     [0038] In the embodiment according to FIGS.  13 - 15 , the grooves exhibit what approaches a diamond-shaped profile in the implementation of the perimeter which results in a pair of wedge-shaped grooves set in arrangement against one another. FIG. 13 shows the implementation of a section  16  of implant body  11  having grooves  130 , the limiting lines of which extend in approximate diamond shape. Grooves  130  are arranged densely adjacent one another and parallel to the implant axis relative the perimeter of the implant body. Each of grooves  130  is comprised of two wedge-shaped groove segments  131 ,  132 , wherein the profile to the groove of the one groove segment  131  forms an angle α to the implant&#39;s longitudinal axis  41  and the profile of the groove to the other groove segment  132  forms an angle β to the implant&#39;s longitudinal axis  41  (FIG. 15). The two outermost apexes  133  and  134  of each of grooves  130  are thus, in this embodiment, situated on the peripheral line of section  16 , and the area  135  of maximum depth of each one of grooves  130  is at its center where the two groove segments  131  and  132  meet.  
     [0039]FIG. 14 shows the implementation of an implant body section  141  comprising grooves  140  which likewise have a diamond-shaped configuration to their limiting lines. Yet grooves  140  extend here in coiling fashion relative the perimeter of the implant body as described above with reference to FIGS. 8 and 9. In all other respects, the configuration of grooves  140  corresponds to that of grooves  130  in FIG. 13.  
     [0040] The groove structures shown in FIGS.  5 - 15  provide favorable conditions for osteons to accumulate during the healing phase and additionally secure against axial shifting/rotation of the implant once ingrown. According to need, various different groove structures can also be advantageously combined within one implant, as described with reference to FIGS. 21 and 22, for example.  
     [0041] Drawing upon FIGS.  16 - 22 , the following will detail different embodiments of tooth implants which make use of such groove structures as described above. The tooth implants as depicted are preferably made from titanium.  
     [0042]FIGS. 16 through 18 show embodiments of tooth implants in which the implant body has gradations in diameter. A plurality of such stepped diameters may be provided, whereby the height of a gradation measured at the diameter is preferably of a magnitude ranging between 20 and 300 micrometers. The embodiment depicted in FIG. 16 comprises an implant body  161  having four steps  162 . Conical transition areas  163 , also referred to herein as bands, which are narrow in relation to the length of the steps, are arranged between said steps. The perimeter of each one of steps  162  is disposed with a groove structure of the type depicted for grooves  20  in FIGS.  3 - 15 . Grooves  160  are provided at the periphery of each one of steps  162 , extending along the longitudinal axis of implant body  11  in relation to the perimeter, said grooves being the type of grooves  20  as described in conjunction with FIGS. 3 and 4. In area  164  of greatest depth, grooves  160  all have the same width, which results in a differing number of grooves  160  within each step  162 . In the case of implants in accordance with FIG. 17, grooves  170  which wind to the right are arranged at the perimeter of steps  172 , said grooves being the type of grooves  70  as described in conjunction with FIGS. 7 and 9. In all other respects, the implant according to FIG. 17 corresponds to the FIG. 16 implant. The implant according to FIG. 18 differs from the implant according to FIG. 17 in that the peripheral area of each one of steps  181  is provided with cross-wise grooves  180  in the manner of grooves  111  as described in conjunction with FIGS. 11 and 12. Grooves  160 ,  170  and  180  are only depicted schematically in FIGS.  16 - 18 .  
     [0043]FIGS. 19 and 20 show embodiments of tooth implants having a conical implant body. In the embodiment according to FIG. 19, the conical implant body  191  is divided into sections  193  by bands  192  running along the perimeter. Crosswise grooves  190  are disposed at the periphery of sections  195 , said grooves being the type of grooves  111  as described in conjunction with FIGS. 11 and 12. FIG. 20 shows an embodiment in which the sections comprise diamond-shaped grooves  200  in the manner of the grooves as described in conjunction with FIGS.  13 - 15 . In all other respects, the implant according to FIG. 20 corresponds to the implant depicted in FIG. 19. Grooves  190  and  200  are only partially shown in FIGS. 19 and 20; and in the case of these embodiments as well, the groove structure as respectively described extends across the entire perimeter of sections  193  and  203 .  
     [0044]FIGS. 21 and 22 show tooth implants in which each different section segment will exhibit different groove structures. FIG. 21 shows an implant having a cylindrical implant body  211  with a series of grooves  210  arranged at its periphery such that the implant body is divided into four sections  212 ,  213 ,  214 ,  215 . The grooves of the uppermost section  212 , situated closest to the implant head, comprise wedge-shaped grooves  210  at its periphery of the type of grooves  20  as described in conjunction with FIGS. 3 and 4. Section  213  which follows in the direction of the implant foot, has peripheral grooves  216  of reversed wedge configuration of the type of grooves  50  as described in conjunction with FIGS. 5 and 6. Section  214  adjoins thereto, having again the same groove configuration as section  212 , and is then followed by section  215  having grooves of reversed wedge shape. Sections  212 - 216  merge together seamlessly and are only marked by the change in groove structure. Also in FIG. 21, only a portion of the grooves are shown for purposes of representation.  
     [0045]FIG. 22 depicts an embodiment of a tooth implant in accordance with the type of stepped implant as described in conjunction with FIGS.  16 - 18 . In this embodiment, implant body  221  comprises groups of sections wherein the groove structure of one group differs from that of the other groups. Implant body  221  is divided into four steps  222 - 225 , connected together by means of conical transition areas  226 . The two uppermost steps  222  and  223  have crosswise grooves  210  at their periphery of the type of grooves as described in conjunction with FIGS.  11 / 12 . Sections  224 - 225  which follow in the direction of the implant foot, have grooves  227  at their periphery of a wedge shape which runs the longitudinal direction of the implant in relation to the perimeter of implant body  221 , said grooves being of the type of grooves  20  as described in conjunction with FIGS. 3 and 4.  
     [0046] By making use of a surface structure having varying steps within the same implant, the varying bone thicknesses surrounding the length of the implant can be taken into account. This allows, for example in the case of an implant according to FIG. 22, the two uppermost steps  222  and  223  with their crosswise-running grooves to provide a good anchoring for the implant within the compacta and the adjacent area, while the surfaces of the subsequent steps can be adapted to the bone tissue increasing in porousness further below. The combination of different surface structures across the length of the implant body also supports the objective of securing the implant against axial shifting/rotation during the healing and healed phases, and provides for a better conducting of pressure to the bone.  
     [0047] Examples of other embodiments of the present invention are depicted in FIGS.  23 - 28 . These embodiments exhibit curved wedge-shaped grooves or grooves in the form of elongated segments of coiling or crosswise-coiling progression.  
     [0048]FIG. 23 shows the implementation of the perimeter of an implant section  232  having right-spiraling grooves  231  with a profile in the form of a curved or bending wedge. The degree of curvature to the wedge exceeds the above-cited curvature to the limiting lines of linearly straight grooves  20  in the actual implementation of the perimeter at the imaging plane and which are not shown in FIGS.  3 - 14  for reasons of simplifying the representation. The progression of depth to grooves  231  corresponds to the progression of depth as depicted for grooves  20  and  70  in FIGS. 4 and 9. Apex  233  of the curved wedge is situated at the diameter of the perimeter at the upper edge of depicted section  232 . Area  234  is situated at the lower edge of section  232  where the curved wedge exhibits its greatest width and, at the same time, its greatest depth. The correspondingly inverted curved wedge-shaped spans  236  are situated between the densely-adjacent and adjoining grooves  231 , widening to the apexes  233  of grooves  231  and with their height defining the perimeter of section  232 . At area  233  of least groove depth, longitudinal axis  235  of grooves  231  forms an angle σ to the upper boundary of section  232 , while longitudinal axis  235  forms an angle σ′ to the lower boundary of section  232  at area  234  of greatest groove depth, whereby σ&lt;σ′.  
     [0049]FIG. 24 shows the implementation of the perimeter of an implant section  242  comprising left-coiling grooves  241  having a profile in the form of a curved or bending wedge as do grooves  231 . In all other respects, the configuration and arrangement of grooves  241  corresponds to that of grooves  231  in FIG. 23.  
     [0050]FIG. 25 shows the implementation of a section  252  of an implant body comprising grooves  251  with a profile configured as an elongated curved segment in a shape similar to a banana. Grooves  251  are arranged densely adjacent one another and exhibit a coiled profile with respect to the implant body periphery, as described above, for example with reference to FIG. 14. Each of the grooves  251  can be considered as consisting of two seamlessly merging grooves  231 ,  241 . As the progression of depth is concerned, that as realized for these grooves applies. The two outer apexes  253  and  254  of each one of grooves  251  is situated at the peripheral line of section  252 , and the area of maximum depth of each one of grooves  251  may be in the proximity of the center of its longitudinal extension, as depicted in FIG. 25 with respect to area  255 . The area of maximum depth to each one of grooves  251  may also be situated away from the groove center, for example in the first or last fourth or in the first or last third of the longitudinal extension to the grooves  251 .  
     [0051] Correspondingly curved wedge-shaped spans  256  and  257  lie between adjacent grooves  251 , widening in extension to apexes  253 ,  254  of grooves  251 , their height defining the perimeter of section  252 . Longitudinal axes  258  of grooves  251  form an angle σ to the upper boundary of section  252  at area  253  and an angle σ′ to the lower boundary of section  252  at area  254 , whereby σ&lt;σ′.  
     [0052]FIG. 26 shows the implementation of a section  263  of an implant body comprising grooves  261 ,  262  having a profile configured in the shape of an elongated banana-like curved segment of the type as grooves  251  in FIG. 25. Grooves  261 ,  262  extend crosswise to one another, as is described with respect to grooves  111  and  121  in conjunction with FIGS. 11 and 12. In the configuration according to FIG. 26, grooves  261  coil to the left and intersect with grooves  262  progressing in coiled fashion to the right. The depth progression to grooves  261  and  262  corresponds to the depth progression of curved grooves  251  as described in conjunction with FIG. 25. Due to this groove profile, spans are cut between adjacent grooves  261 ,  262  of the type as spans  256  and  257  so that a plurality of knob-like protrusions result, their height extending to the perimeter of section  263 , defining same respectively.  
     [0053] The groove structures represented in FIGS.  23 - 26  offer an additional advantage in that the horizontally-aligned osteons of the compacta and the vertically-aligned osteons of the spongiosa will merge together.  
     [0054] The groove structures according to FIGS.  23 - 26  can be combined within one implant subject to need. FIG. 27 shows an example of this, making use of a tooth implant  270  of the type as described above in connection with an embodiment of an implant configured in accordance with FIGS.  16 - 18  and  22  in which the implant body is configured as a stepped cone. Implant  270  comprises four sections  272 - 275 , the upper sections  272 ,  273  of same having crosswise-coiling grooves of the type of grooves  261  and  262  of FIG. 26. Grooves  271  of the uppermost section  272  extend here in the head region of implant  270  up to a narrow edge region  276  which runs virtually parallel to the upper edge of the implant. Sections  274 ,  275  have grooves  271  winding to the left and the right, said grooves being of the type as depicted in FIG. 25.  
     [0055] In addition, groove structures as in accordance with FIGS.  23 - 26  can be used in cylindrical tooth implants of the implant type as depicted in FIGS.  1 - 21  as well as in conical tooth implants of the implant type as depicted in FIGS. 19 and 20.  
     [0056] The invention can be used in the case of implants having an implant body which is not rotationally symmetrical or which has a curved longitudinal axis, as can be the case, for example, with hip joint implants. FIG. 28 shows a segment  281  of such an implant having a longitudinal axis extending in curved fashion with sections  282 ,  283  and  284  arranged thereupon, each being of wedge-shaped cross-section and joining seamlessly with one another. Sections  282 - 284  have grooves  281  of the type of grooves  251  from FIG. 25 which wind to the left in head section  282 , then wind to the right in section  283  which follows, and then again wind to the left in the following section  284 . Segment  281  as depicted may exhibit a non-rounded cross-section in the area of sections  282 - 284 , the grooves adapted accordingly as far as length, inclination and curvature.  
     [0057] The surface of the inventive implant is provided with a metal layer by means of sputtering which gives the surface the necessary roughness for fostering the depositing of osteons. The metal layer is preferably of titanium. The titanium layer will cover, on the one hand, the surface of the grooves of the configuration described in conjunction with FIGS.  2 - 15  or  23 - 26  and, on the other hand, also the spaces between the grooves, which also includes the surfaces of spans  33 ,  236 ,  256  and  257  in implants of the type as described in conjunction with FIGS. 3, 23 and  25 , as well as the radial bands disposed between the sections as seen in the embodiments depicted in FIGS.  3 ,  16 - 20 ,  22  and  27 . A surface given this type of treatment has the additional advantage that the osteocytes of the osteons can accumulate not only in the area of the grooves but also externally of same in the troughs of the metal layer created by the sputtering process.  
     [0058] A preferred method of manufacturing implants according to the present invention consists of manufacturing a blank of the implant body in conventional manner as a cylinder, or in conical or stepped conical form, or as an implant body having a curved longitudinal axis, in each case with a smooth surface. The blank implant body then undergoes a material removing process in which grooves of the types as depicted in FIGS.  2 - 15  or  23 - 26  are discretionarily created in at least one segment of the sections. The material removal process preferably consists of a metal cutting process with which the profile, form and dimensions to the grooves are created by synchronous feed of the implant body and the cutting tool. In this manner, the synchronous feed can be selected so as to produce wedge-shaped grooves which form a first angle α radial the longitudinal axis of the implant body over one segment of a section and form a second angle β radial the longitudinal axis of the implant body over another segment of the same section. The synchronous feed can furthermore be selected so as to produce grooves of diamond-like or curved configuration or grooves which take the form of elongated banana-like segments and extend in axial, spiraling or crosswise-coiling manner relative the perimeter of the implant. When producing the grooves in sequential implant sections, the synchronous feed can be changed from one section to the next in order to create a combination of sections having differing groove structures on the same implant. In so doing, the groove structure can be extended at the head area of implant  270  to a narrow edge region  276  which extends in virtually parallel manner to the upper edge of the implant.  
     [0059] In a further step, a metal layer is applied to the surface of the inventive implant by means of which the surface acquires the necessary roughness to foster the depositing of osteons. This ensues by metal being sputtered onto the surface of the implant, said metal preferably being titanium. The titanium layer coats the inventive implant&#39;s groove surfaces as well as the spaces between the grooves including spans  33 ,  236 ,  256  and  257  in the case of implants of the type as described in conjunction with FIGS. 3, 23 and  25 , the radial bands between the sections in implants of the type as described in conjunction with FIGS.  3 ,  16 - 20 ,  22  and  27 , and the head region  13 ,  276 .  
     [0060] While the invention has been depicted and described on the basis of preferential embodiments, additional further variations and other embodiments of the invention may also be realized without resulting in any departure from the scope of the invention as defined by the claims.