Implant for covering bone defects in the jaw region and method for producing the same

Abstract

The invention relates to an implant for covering bone defects in the jaw region, which comprises a magnesium film.

Claims

1. A method for cosmetic or surgical jaw reconstruction, comprising the steps of: providing an implant consisting of pure magnesium having a purity of more than 99%, the implant being in the form of a film having a central area without openings and a thickness between 70 and 200 μm, cutting the implant to a size appropriate for covering a defect site in a jaw region to be covered, bending the implant into a curved shape, placing the implant over the defect site in the jaw region such that the central area without openings is arranged directly above the defect site and seals the defect, immovably fixing the implant in the jaw with at least one fastener in a fixed position at the time of placing the implant over the defect site, closing soft tissue over the implant, and leaving the implant to decompose in the fixed position.

2. The method of claim 1, wherein the implant contains less than 500 ppm of iron, copper or nickel.

3. The method of claim 1, wherein prior to the placing of the implant, further comprising the step of filling the defect site with a bone substitute material or bone graft.

4. The method of claim 1, wherein the at least one fastener comprises a pin, a screw, or a suture.

5. The method of claim 1, wherein the step of cutting the implant to a size comprises providing at least one recess for a tooth in an edge of the implant.

6. The method of claim 1, wherein the step of bending the implant into a curved shape comprises bending the implant so as to form a radius of curvature between 0.5 and 10 cm.

7. The method of claim 6, wherein the implant is bent so as to form a radius of curvature between 0.7 and 1.5 cm.

8. The method of claim 6, wherein the step of bending the implant into a curved shape comprises bending the implant about an angle of greater than 30°.

9. The method of claim 1, wherein prior to the step of bending the implant, further comprising the step of subjecting the implant to a surface treatment comprising etching, coating, or passivating.

10. The method of claim 1, wherein prior to the step of bending the implant, further comprising the step of structuring the implant along peripheral areas thereof.

11. The method of claim 10, wherein the structuring comprises producing at least one of bores, perforations, a mesh-like structure, and a pleated structure along peripheral areas of the implant.

12. The method of claim 1, wherein the defect site in the jaw region includes a jaw bone defect or a Schneiderian membrane defect.

13. The method of claim 1, wherein immovably fixing the implant in the jaw comprises fixing the implant on a jaw ridge.

14. The method of claim 1, wherein immovably fixing the implant in the jaw comprises introducing sutures, pins, screws, or nails through bores which are arranged on longitudinal edge portions of the implant.

15. The method of claim 1, further comprising: waiting for natural bone tissue to form at the defect site under the implant; and introducing a dental pin into the natural bone tissue.

16. The method of claim 15, wherein introducing the dental pin into the natural bone tissue is performed before the implant has decomposed.

17. The method of claim 1, wherein the implant has a smooth surface with an average roughness of less than 0.08 μm.

18. The method of claim 1, wherein the implant has a smooth surface with an average roughness of less than 0.03 μm.

19. The method of claim 1, wherein sealing the defect includes sealing the Schneiderian membrane.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The subject matter of the invention will now be explained in more detail by way of exemplary embodiments with reference to the drawings of FIGS. 1 to 8.

(2) FIG. 1 shows an exemplary embodiment of an implant 1 for covering bone defects in the jaw region.

(3) FIG. 2 shows a side view of the implant.

(4) FIG. 3 shows another embodiment of an implant.

(5) FIGS. 4 to 6 are raster electron micrographs of an implant.

(6) FIG. 7 schematically illustrates the use of an implant according to the invention for the prevention or treatment of injuries to the Schneiderian membrane.

(7) FIG. 8 schematically illustrates the use of an implant according to the invention for so-called “lateral augmentation” (reconstruction of the jaw bone).

DETAILED DESCRIPTION OF THE DRAWINGS

(8) FIG. 1 shows a first exemplary embodiment of an implant for covering bone defects in the jaw region.

(9) In this exemplary embodiment, the implant 1 consists of a magnesium film 2 of a thickness from 50 to 150 μm, which is in particular made of a magnesium alloy. Implant 1 has rounded corners, and in this exemplary embodiment it has two recesses 3 which are intended for an adjacent tooth.

(10) Thus, the implant is in particular designed for covering a defect site in the jaw, where one tooth or several teeth are missing.

(11) FIG. 2 shows a side view looking towards the recess (3 in FIG. 1) of the implant 1 illustrated in FIG. 1.

(12) It can be seen that the implant is curved. In this exemplary embodiment, the longitudinal edge portions of the implant are almost opposed to each other, so that the implant can be fixed on a jaw ridge, in particular clamped or clipped thereon.

(13) FIG. 3 shows another embodiment of an implant 1.

(14) On the one hand, the implant 1 has bores 5 which are used to introduce sutures, pins, screws, or nails.

(15) In this exemplary embodiment the implant 1 furthermore has a mesh-like area 7, that is to say an area with perforations. These perforations may serve to facilitate the bending or for improved adhesion to the tissue.

(16) Furthermore, a structured area 6 is also shown, which may in particular be in the form of a pleating and serves to conform the implant 1 to the jaw bone.

(17) FIG. 4 shows a scanning electron micrograph of the surface of an implant, for which a magnesium film was provided with a magnesium fluoride layer by immersion into hydrofluoric acid.

(18) The result is a smooth scratch-resistant thin layer of approximately 1 μm thickness, which allows for even rather narrow bending radii.

(19) FIG. 5 also shows a scanning electron micrograph, in this case of a section of the film, in which the magnesium fluoride layer is already clearly discernible.

(20) FIG. 6 is a view of a detail of FIG. 5.

(21) The thin magnesium fluoride layer 9 formed on the magnesium layer 8 can be seen.

(22) It is readily apparent that the magnesium fluoride layer 9 is well interlocked with the underlying magnesium layer, which is probably the cause for the good adhesion of the layer, inter alia.

(23) FIG. 7 schematically illustrates a first possible application of the implant according to the invention.

(24) The implant of the invention in the form of a magnesium film can be employed for the treatment of injured Schneiderian membranes.

(25) In particular when pin implants 14 are placed, as illustrated here, which serve to receive a dental implant, injury may occur to the Schneiderian membrane 12 which separates the maxillary bone 13 from the maxillary sinus.

(26) In many cases, as illustrated here, an interspace between the jaw bone 13 and the Schneiderian membrane 12 is filled with a bone substitute material, in particular a calcium phosphate granulate, in order to increase the thickness of the receding jaw bone so that the implant 14 can be placed.

(27) Injury to the Schneiderian membrane 12 is accompanied by an extremely high risk of infection. If, during surgery, such an injury is detected, the surgical procedure is usually interrupted, and only after a healing period of several months the pin implant 14 is again tried to be placed.

(28) It has been found that this can be avoided by using an implant according to the invention in the form of a magnesium film which closes the Schneiderian membrane 12.

(29) For example, in case of a defect the magnesium film can be introduced either through the bores for the pin implants 14 or through a lateral opening of the jaw ridge 13.

(30) It will be understood that if the magnesium film is introduced through the bores for the pin implants, it can be rolled up previously, for example.

(31) The Schneiderian membrane 12 is sealed by the magnesium film. Surprisingly, already a thin magnesium film of at least 50 μm provides sufficient sealing without decomposing within a very short period of time as would actually be expected.

(32) Thus, the magnesium film can therefore allow to immediately continue the surgical procedure and moreover offers the advantage that the magnesium film, in particular if it is sufficiently thick, provides a good backing for the bone material used. The growth of natural bone tissue is also promoted by the magnesium film.

(33) It will be understood, however, that the magnesium film may as well be used preventively, without an injury to the Schneiderian membrane.

(34) FIG. 8 schematically illustrates the use of an implant 1 according to the invention for a three-dimensional reconstruction of defect sites in the jaw bone.

(35) A jaw bone 10 which has a defect site 11 is covered with a bent implant 1 consisting of a magnesium film. The implant 1 defines a three-dimensional free-form surface.

(36) As can be seen in the figure on the right, the bone tissue of the jaw ridge 10 that is being formed follows this free-form surface and forms a rounded jaw ridge which approximates the natural shape. This approximation will in particular usually be better than when using inserted bone blocks of donor material.

(37) The invention permits to provide, in a straightforward way, a resorbable implant for covering bone defects in the jaw region.

LIST OF REFERENCE NUMERALS

(38) 1 Implant 2 Magnesium film 3 Recess 4 Corner 5 Bore 6 Structured area 7 Mesh-like area 8 Magnesium layer 9 Magnesium fluoride layer 10 Jaw ridge 11 Defect site 12 Schneiderian membrane 13 Jaw bone 14 Pin implant 15 Filler material