Implant for covering bone defects

Abstract

A method for producing an implant for covering bone defects, wherein the implant consists of a magnesium or magnesium alloy film, comprising the steps: Providing a magnesium or magnesium alloy film; and removing a layer of material on both sides of the magnesium or magnesium alloy film by grinding.

Claims

1. A method for producing an implant for covering bone defects, wherein the implant consists of magnesium or magnesium alloy, comprising: providing a rolled magnesium or magnesium alloy film; and removing a layer of material on both sides of the rolled magnesium or magnesium alloy film.

2. The method according to claim 1, wherein the layer of material is removed by grinding or polishing.

3. The method according to claim 1, wherein a thickness of the rolled magnesium alloy film is reduced by 3 to 60%.

4. The method according to claim 1, wherein a thickness of the rolled magnesium or magnesium alloy film is reduced by a minimum of 10 m on each side.

5. The method according to claim 2, wherein a remaining thickness of the rolled magnesium or magnesium alloy film after grinding is further reduced on each side by 5-30 m by etching.

6. The method according to claim 5, further comprising cutting or shaping the rolled magnesium or magnesium alloy film between the grinding or polishing and the etching.

7. The method according to claim 1, wherein the rolled magnesium or magnesium alloy film is produced with a material area ratio in a core zone of +/1 m as determined from the Abbott-Firestone curve which is greater than 95%.

8. A Method for producing an implant for covering bone defects, wherein the implant consists of magnesium or magnesium alloy, comprising: providing a rolled magnesium or magnesium alloy film; and laser treating a surface of the rolled magnesium or magnesium alloy film.

9. The method according to claim 8, wherein the surface of the magnesium or magnesium alloy is laser-polished.

10. A Method for producing an implant for covering bone defects, wherein the implant consists of a magnesium or magnesium alloy film, comprising: purifying a surface of the magnesium or magnesium alloy film by mechanical means or by physical means.

11. The implant, being produced with the method according to claim 10.

12. The implant according to claim 11, wherein the implant is embodied as a convex bulge consisting of the magnesium or magnesium alloy film.

13. The implant according to claim 11, wherein the implant is folded.

14. The implant according to claim 11, wherein the magnesium or magnesium alloy film has a reduced valley depth Rvk of less than 0.6 m, according to DIN EN ISO 21920Parts 1-3:2021-12 and ISO 25178Parts 1-3; and/or wherein the magnesium or magnesium alloy film has a maximum surface roughness Rt of less than 3 m, according to DIN EN ISO 21920Parts 1-3:2021-12 and ISO 25178Parts 1-3); and/or wherein the film has a root mean square gradient Sdq of less than 5, according to DIN EN ISO 21920Parts 1-3:2021-12 and ISO 25178Parts 1-3; and/or wherein the film has a thickness between 100 and 200 m.

15. The implant according to claim 11, wherein a profile of the relative Material Ratio Curve ranges from 2.0 m to +1.7 m, according to DIN EN ISO 21920Parts 1-3:2021-12 and ISO 25178Parts 1-3.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0161] The subject matter of the invention will be now explained in more detail with reference to FIG. 1-FIG. 22b.

[0162] FIG. 1 is a flowchart of a method of producing an implant according to an embodiment of the disclosure.

[0163] FIG. 2 is a schematic illustration of the step of grinding.

[0164] FIG. 3 shows how the implants are further processed to be etched and cleaned.

[0165] FIG. 4-FIG. 7 show various embodiments of an implant.

[0166] FIG. 8-FIG. 10 are cross sections of the various embodiments of an implant.

[0167] With reference to FIG. 11, the relative material ratio curve of the surface of the implant shall be explained in more detail.

[0168] FIGS. 12 and 13 show alternative embodiments of an implant with a perforation.

[0169] With reference to FIG. 14-FIG. 17, embodiments of a method for inserting a dental implant are explained.

[0170] FIGS. 18a and 18b illustrate the use of a magnesium or magnesium alloy film for single wall defects.

[0171] FIGS. 19a and 19b illustrate the use of a magnesium or magnesium alloy film for double wall defects.

[0172] FIG. 20 shows an embodiment of a magnesium or magnesium alloy implant which is folded to a convex bulge.

[0173] FIG. 21 shows an implant for stabilizing the wall of a alveolar channel.

[0174] FIG. 22a shows the surface of an etched implant in comparison with a laser polished and etched surface according to FIG. 22b.

DETAILED DESCRIPTION

[0175] FIG. 1 is a flowchart of a method of producing an implant according to an embodiment of the disclosure.

[0176] As raw material, a rolled pure magnesium film is provided with a thickness to match the desired final thickness of the implant of 120-160 m. A raw material having a thickness of 220-280 m may be preferable for such a final implant thickness.

[0177] The raw material is inserted into a grinding or polishing machine and a first layer of material is removed on both sides. Now, the raw material has a thickness of 150-200 m.

[0178] Then, the raw material is cut which defines the size and/or shape of the implant. In further the pieces can be shaped, in particular by bending.

[0179] Then, a second layer on each side of the implant is removed by immersing the implant into an etching bath.

[0180] Then, the implants are cleaned, preferably in alcohol.

[0181] Then, the implants are dried, preferably by storing the implants in a desiccator.

[0182] Then, the implants are passivated by storing the implants in a cabinet or clean room, preferably class 7 or better.

[0183] Aften a protective oxide film is formed on a surface, the implants are packed into a gas-tight foil bag, which is flooded with an inert gas.

[0184] Then, the package including the implant can be sterilized by using gamma radiation.

[0185] FIG. 2 shows schematically how the raw material 12 is grinded by using a horizontal grinding machine.

[0186] A magnesium foil is used as raw material 12, which is removably attached to a substrate holder 11.

[0187] The substrate holder 11 is eccentrically placed relative to the axis of a rotating grinding disk 10. While the grinding disk 10 rotated, the substrate holder is rotated 11 also.

[0188] The substrate holder 11 may comprise an adhesive surface onto which the raw material 12 sticks. Alternatively, the magnesium sheet 12 may be mounted on the substrate holder 11 by vacuum.

[0189] The grinding disk 10 has a grain size between 1000 and 2000 according to DIN ISO 6344-1-2000-04.

[0190] The grinding process is performed on both sides of the raw material and results in a roughness Ra below 0.2 m, preferably below 0.1 m.

[0191] Then, the raw material 12 is cut into pieces. According to an embodiment of the invention, a laser cutting process is used. Preferably, the implants can be cut in such a way that that the implants are still connected to the entire sheet by bridges. Before packaging, the implants can by separated by breaking the bridges.

[0192] As shown in FIG. 3, stackable holders 13 are used for further processing of the implants 1.

[0193] The implants are inserted into the holders 13 and are spaced from each other in the stacked trays.

[0194] The holders 13 with the implants 1 are immersed into an etching bath.

[0195] The holders 13 are used also for the subsequent cleaning and drying of the implants 1.

[0196] FIG. 4 shows three embodiments of an implant in a plan view.

[0197] The implant 1a-1c consists of magnesium foil with a thickness of 100-200 m. As shown, the implant can be embodied four-sided (1a), in particular rectangular with rounded edges, oval (1b) or the implant can have an hourglass-like shape (1c).

[0198] The embodiment with an hourglass shape 1c is preferably placed between two adjacent teeth, respectively tooth implants.

[0199] As shown in FIG. 5 all embodiments can have a central opening 2 for another implant, in particular for a tooth implant.

[0200] As shown in FIG. 6 the implant 1 can comprise at least one, in particular, exactly one finger-like extension 3 extending from the body 6 of the implant. The finger-like extension can comprise an area 4 with an increased width towards the end and a narrower neck-like portion 7 between the end 4 and the body 6. In particular, the finger-like extension 3 can comprise a circular shaped area 4.

[0201] As shown in a plan view according to FIG. 7, the implant 1 may comprise several, in particular 2-5 finger-like extensions 3. The teeth, especially tooth implants, can be placed between these finger-like extensions 3. The finger-like extensions 3 may pass through two existing teeth or a tooth implant may be placed between finger-like extensions 3.

[0202] FIG. 8-FIG. 10 are cross-sections of a various embodiments of an implant.

[0203] According to the embodiment of FIG. 8, the implant 1 is flat.

[0204] FIG. 9 shows an implant 1 with an L-shape cross-section and which comprises an optional central opening 2.

[0205] At least one shank of the L-shaped implant can have a rounded edge 5 in order to form a stopper.

[0206] FIG. 10 shows an implant 1 which is U-shaped. This embodiment also comprises a optional central opening 2.

[0207] With reference to FIG. 11 the relative material ratio curve shall be explained in more detail. The material ratio curve describes which portion of the area is material if a plane which is parallel to the mean plane of the surface intersects with a sample starting from the highest peak and moved into the material to the lowest valley.

[0208] The results can be displayed either as a histogram which shows the percentage of the material above and below a median plane of the surface structure or as the Abbott-Firestone curve respectively a material area ratio curve. The more material is within a functionally derived core zone, the more homogenous the surface is.

[0209] Two horizontal lines in the surface Abbott-Firestone curve are drawn with a deviation of +/1 m.

[0210] Thus divides the curve, in accordance to DIN EN ISO 21920, into three zones, namely a peak zone, a core zone and a valley zone.

[0211] The material volume per unit sampling area of each zone is actually the area enclosed beneath the surface Abbott-Firestone curve and the horizontal line of this zone. The void volume per unit sampling area of each zone is the area enclosed above the top horizontal line of this zone and above the surface Abbott-Firestone curve.

[0212] According to this embodiment more than 95% is placed in a range of +/1 m.

[0213] A surface structure with such a small bandwidth essentially minimizes the risk of non-uniform corrosion in the initial phase after insertion which would be undesirable as local break-through corrosion spots would annihilate the intended barrier function of the membrane. The implant with such a specific surface structure has improved corrosion properties.

[0214] FIGS. 12 and 13 show alternative embodiments of an implant with a perforation.

[0215] FIG. 12 shows an implant 1 with regular pattern of round holes. FIG. 13 shows an implant 1 with a regular pattern of curves with the shape of a boomerang.

[0216] The perforation helps to bend the implant 1 also to complex 3-dimensional structures.

[0217] Preferably, these embodiments are used a support member for another bioresorbable membrane, e.g. a collagen membrane, a non-woven bioresorbable plastic material etc.

[0218] With reference to FIG. 14-FIG. 17, embodiments of a method for inserting a dental implant are explained.

[0219] According to a first embodiment of the method, shown in FIG. 14, the magnesium or magnesium alloy foil 1 is clamped adjacent to a cavity 11 (defect side) between the soft tissue 10 and the bone.

[0220] The foil 1 is cut and shaped to the desired profile and stabilizes the buccal or palatal wall.

[0221] Then, the cavity 11 is filled with a bone substitution material. As bone substitution material, a granular calcium phosphate material, can be used.

[0222] Optionally, the top side of the cavity 11 can be closes by using another membrane, e.g. a collagen membrane 13. Then, the defect side is closed with soft tissue (not shown).

[0223] After healing of the defect side by forming natural bone tissue, a dental implant can be inserted (see FIG. 17).

[0224] FIG. 15/16 show another embodiment of a method for inserting a dental implant.

[0225] As shown in FIG. 15, the foil 1 is clamped between soft tissue 8 and bone 9 also.

[0226] As shown in FIG. 16, the foil 1 comprises a protrusion, which if folded above the cavity 11, which is filled with a bone substitution material. The folding edge 8, which is formed, stabilizes the three-dimensional shape of the foil 1.

[0227] After healing of the defect side, the dental implant 12, e.g. a screw for an artificial tooth, can be inserted, as shown in FIG. 17.

[0228] With reference to FIG. 14-FIG. 17, embodiments of a method for inserting a dental implant are explained.

[0229] FIGS. 18a and 18b illustrate the use of a magnesium or magnesium alloy film 1 for single wall defects. FIG. 18a is a perspective view and FIG. 18b is a top view.

[0230] The implant consisting of a foil 1 is bent to an appropriate three-dimensional form and closes the sidewall of the cavity 11. Then, the cavity is filled with the bone substitution material.

[0231] In this application, the foil may not be clamped between bone and soft tissues. Instead, a screw fixation using biodegradable Mg-screws allows adjustment and correction (not shown).

[0232] FIGS. 19a and 19b illustrate the use of a magnesium or magnesium alloy film for double wall defects. In this case, the film 1 closes the buccal and palatal wall of the cavity 11.

[0233] FIG. 20 shows an embodiment of a magnesium or magnesium alloy implant which is folded to a convex bulge to increase the volume of the restored bone.

[0234] A bend smooth edge 15 prevents piercing of/cutting through the gingiva. The edge can also be stiffed by single or multiple bending the edge 15.

[0235] The foil 1 can also be folded to convex bulge 16 as shown in FIG. 20. Such a bulge 16, folded like a paper bag, can be inserted and placed onto the bone of a defect side.

[0236] FIG. 21 shows an implant for stabilizing the wall of a alveolar channel.

[0237] The implant being embodied as a magnesium or magnesium alloy film 1 has shield-like shape.

[0238] The film 1 comprises a rounded/acute tip 1a which can be pushed between bone and soft tissue, thereby fixing the foil by clamping only.

[0239] The top edge 1b of the film 1 is preferably substantially straight.

[0240] FIG. 22a shows the surface of an etched implant. Organic inclusions may result in spots 22 on the surface after etching-. This may result due to a reduced corrosive attack during etching in the spot area. By laser polishing, as shown in FIG. 22b, such spots can be avoided.