HK1238178A1 - Implant for covering maxillary bone defects and method for producing the same - Google Patents

Description

Implant for covering a bone defect in the jaw area and method for producing the implant

Technical Field

The invention relates to a bioabsorbable implant for covering a bone defect in the jaw region and a method for producing the implant. In particular, the present invention relates to an implant that is placed over a defect site filled with a bone substitute material and then soft tissue is sealed over the implant.

Background

Implants for covering bone defects in the jaw area are known. There are not only bioabsorbable implants, which slowly dissolve after insertion, but also implants which remain in the body or have to be removed after a certain time.

The Liu et al article, "mechanics of Guided Bone Regeneration: A Review, the open Dentistry Journal,2014,8, P.56-65," provides a general overview of known implants for covering Bone defects.

Thus, non-absorbable PTFE membranes exist. The PTFE membrane can be easily inserted, but must be removed.

In addition, collagen membranes are present in particular as an absorbable material.

Said collagen membrane has the advantage that it does not have to be removed, which is, however, associated with the disadvantage that it is not particularly tight, so that there is a risk of soft tissue growing into the filled bone defect or bone material flowing out of the defect.

Object of the invention

In contrast, the present invention is based on the object of reducing the disadvantages mentioned in the prior art.

The object of the invention is, in particular, to provide a bioabsorbable implant which can be inserted in a simple manner and which, in the initial phase after insertion, reliably separates soft tissue from bone material, in particular from bone substitute material.

Disclosure of Invention

The object of the invention is achieved by an implant for covering a bone defect in a jaw region according to one of the independent claims and by a method for producing an implant for covering a bone defect in a jaw region according to one of the independent claims.

Preferred embodiments and further developments of the invention can be gathered from the respective dependent claims.

The invention relates to an implant for covering a bone defect in the jaw area, comprising a magnesium film.

A film made of magnesium or a magnesium alloy is understood to be a magnesium film, which is made mostly, i.e. more than 50% (unless otherwise stated,% always means wt.%), of magnesium.

It has surprisingly been demonstrated that such a magnesium film results in a complete separation of the soft tissue from the defect site, which is filled in particular with a bone replacement material, for example also in particular with a homologous or autologous bone graft.

The bio-absorbable properties of magnesium are known per se. It is completely unexpected, however, that the film in the jaw area has been resistant to erosion in such a long time that the growth of natural bone tissue into the defect site has ended up to that time, so that no soft tissue growth has occurred until the implant has at least partially disintegrated.

The invention is suitable for all types of treatment of bone defects in the jaw area, in particular sinus lift correction.

In particular, calcium phosphate-containing or hydroxyapatite-containing materials are used as bone substitute materials. In this case, not only artificial materials but also natural materials can be used, in particular materials made of donor bones from humans or pigs. The bone substitute material can be inserted both in the form of granules and in the form of a suitable shaped body which at least partially approximates the contour of the defect site.

The implant is preferably shape stable. This means that, for example, a curved implant does not change shape due to its own weight.

For this purpose, in particular, thin films of magnesium are used having a thickness of between 50 and 300. mu.m, preferably between 70 and 200. mu.m.

Preferably, the implant is configured to be curved. The implant can thus be placed onto the defect site and in the most advantageous case even clamped onto the maxilla.

In particular at least in regions with a radius of curvature of 0.5 to 10cm, preferably 0.7 to 1.5 cm.

It has been demonstrated that: magnesium films having the stated thicknesses can also be bent, in particular, at angles of > 30 °. The angle is defined by the angle formed by the tangents to the ends of the implant with respect to each other. In particular, provision is made for: the sides of the implant are arranged parallel to one another or even form an angle of more than 180 ° in order to fix, in particular clamp, the implant.

In a further development of the invention, the implant has at least one recess for a tooth. The implant is preferably recessed on the front end and/or the rear end in such a way that the adjoining side partially surrounds the tooth. This facilitates the insertion on the one hand and further reduces the risk of soft tissue growth on the other hand.

The implant preferably has a thickness of 0.5 to 25cm²The size of (2). If recesses for teeth are provided, the recesses preferably occupy more than 0.25cm²The area of (a).

In a further development of the invention, the implant comprises a coated and/or etched surface.

It has been demonstrated that: in particular, implants immersed in acid have improved properties with respect to possible radii of curvature and with respect to corrosion properties.

Furthermore, the implant preferably has a smooth surface with an average roughness Ra of less than 0.08 μm, preferably less than 0.03 μm and particularly preferably less than 0.02 μm. Such a smooth surface can be achieved in particular by acid treatment, for example with nitric acid.

In particular, corrosion and/or passivation is provided as a surface treatment. It has proven particularly suitable to immerse the precleaned implant, in particular the implant precleaned with acid, in hydrofluoric acid for at least 10 minutes, whereby a protective layer made of magnesium fluoride is formed by agitated immersion. The passivated surface, in particular the magnesium fluoride layer, preferably has a thickness of less than 5 μm, particularly preferably less than 2 μm.

In particular, provision is made for: resulting in a layer with a thickness between 0.2 and 2 μm, preferably between 7 and 1.5 μm.

A well-bonded, preferably pore-free scratch-resistant layer is thus formed, which is not susceptible to tearing even in the case of narrow radii of curvature.

The film preferably has no openings at least in the central region, i.e. in particular in the region arranged directly above the defect. Thus ensuring a sealed closure of the defect.

In a further development of the invention, the implant is partially structured and/or perforated, in particular at the edge. In particular, the bending of the implant can be facilitated and/or the attachment of the implant to the adjoining tissue can be improved, for example, by perforations in the form of a grid structure or by structuring, in particular pleating.

The implant is preferably made of pure magnesium (purity over 99%) or a magnesium alloy. The magnesium alloy may include 1 to 6% yttrium, 0.5 to 3% zinc, 0.1 to 2% calcium, and/or 0.6 to 1.5% manganese.

And the magnesium film preferably has less than 500ppm of iron, copper and/or nickel.

Furthermore, the invention relates to an assembly for covering a bone defect in the jaw area, comprising the above-described implant and a Pin (Pin) for fixing the implant in the jaw. In the sense of the present invention, in particular pins, hooks (Nagel) or screws are understood as meaning pins. The pin is also preferably made of magnesium or a magnesium alloy.

As provided in a further development of the invention, the implant can have holes through which the pins are guided. It is also conceivable, however, to introduce the fixing holes by means of the pin itself, in particular when the pin has a pointed end.

Furthermore, the invention relates to a method for producing an implant, in particular an implant as described above, which is designed to cover a bone defect in the jaw region.

According to the present invention, a magnesium thin film is provided. The magnesium thin film is shortened to the length of the site to be covered and bent.

The bending of the magnesium film is preferably effected by means of a die or by means of a bending machine, since this reduces the risk of breakage and sharpening (Kanten).

In order to shorten the implant to a desired length and/or to introduce recesses, for example for teeth, the implant can be cut or punched out, for example.

The magnesium film is preferably treated with hydrofluoric acid, in particular with hydrofluoric acid at a concentration of more than 30% (30% igen), in order to form a layer, and in particular over a time interval of more than 10 hours, preferably more than 12 hours.

The invention further relates to a method for cosmetic and/or surgical jaw reconstruction, wherein the implant is placed above a defect, in particular filled with a bone replacement material, and soft tissue is closed above the defect, in particular by suturing.

It has been demonstrated that: the use of the magnesium film according to the invention makes it possible in a simple manner to provide a bioabsorbable implant which prevents soft tissue growth as far as possible during the formation of natural bone material.

The implant need not be removed but instead disintegrates itself. Surprisingly, although the surface of the film used is relatively large, the bubble-forming gas generation does not occur to an undesirably high degree.

After the natural bone tissue is formed, a post-crown dental implant, for example, may then be inserted into the previous defect site. It is possible that the post-crown dental implant is already inserted before the magnesium film has decomposed.

The implant according to the invention is particularly suitable for the following application possibilities:

in one aspect, the implant constructed as a magnesium film can be used to treat damage to the littercloud membrane (schneiderschenmran).

The schlittercloud membrane separates the jaw bone from the jaw sinus. There is an extreme risk of infection when the schlitt cloud membrane is damaged.

It has been demonstrated that: such defect sites can be closed by embedding a thin magnesium film. Here, magnesium may also appear to have an anti-inflammatory effect due to the increase in pH and furthermore, for example, in the case of bone filling materials, accelerates the formation of natural bone tissue.

Another possibility of use is to avoid wound dehiscence, which often occurs in conventional films, for example in PTFE films.

These materials must also be removed in additional procedures.

It has been demonstrated that: the crack opening above the magnesium film spontaneously resulted in complete wound closure.

Defects of up to 10mm can thus be tolerated without infection.

Surprisingly, the film corrodes rather slowly and remains mechanically stable over a long time interval.

In addition, the defect site in the maxilla can be eliminated.

In particular, the magnesium membrane under the periosteal flap can automatically lead to regeneration of the cortical wall. A treatment for cortical wall regeneration is possible in any region of the cortical wall, in particular in the region of the lateral cortical wall.

A cortical wall surrounding the defect site is formed below the defect site, for example below the bare area of a pin implant (stifitemplat).

Finally, magnesium films may also be used prophylactically for initial postoperative infection protection.

Furthermore, the implant according to the invention is suitable for the formation of complex three-dimensional bone regeneration on the basis of shape stability.

Here, the filler material is introduced into the defect site below the magnesium film.

The magnesium film ensures the three-dimensional, form-stable free-forming surface, until the bone is consolidated and then completely dissolves.

Brief description of the drawings

The solution according to the invention is explained in more detail below with reference to exemplary embodiments with the aid of fig. 1 to 8.

Fig. 1 shows an embodiment of an implant 1 for covering a bone defect in a jaw region.

Fig. 2 shows the implant in a side view.

Fig. 3 shows another embodiment of an implant.

Fig. 4 to 6 show photographs of the implant under an electron scanning microscope.

Fig. 7 schematically shows the use of an implant according to the invention for preventing or treating damage to the listeria cloud membrane.

Fig. 8 schematically shows the use of the implant according to the invention for the so-called "lateral ridge augmentation" (jaw reconstruction).

Detailed description of the drawings

Fig. 1 shows a first exemplary embodiment of an implant for covering a bone defect in a jaw region.

In this embodiment, the implant 1 comprises a 50 to 150 μm thick magnesium film 2, in particular made of a magnesium alloy. The implant 1 has rounded corners and in this embodiment has two recesses 3 provided for adjoining teeth.

The implant is therefore in particular designed to cover a defect in the jaw bone, in which one or more teeth are missing.

Fig. 2 shows the implant 1 shown in fig. 1 in a side view, more precisely in a top view of the recess (3 in fig. 1).

It can be seen that the implant is curved. In this embodiment, the ends of the implant are approximately opposite one another, so that the implant can be fixed, in particular glued or clamped, to the maxilla.

Fig. 3 shows a further development of the implant 1.

The implant 1 has, on the one hand, a lead-in wire for introducingHoles 5 for pins, screws or hooks. Furthermore, the implant 1 comprises a web-like region 7, i.e. a region with recesses, on the edge side in this embodiment. These recesses may be used to ease bending or to improve adhesion on tissue.

A structured area 6 is also shown. This structured region can be configured in particular as a fold and serves to adapt the implant 1 to the jaw bone.

Fig. 4 shows a photograph under an electron scanning microscope of the surface of an implant in which a magnesium film is provided with a magnesium fluoride layer by immersion in hydrofluoric acid.

A smooth scratch-resistant layer, for example 1 μm thin, is obtained, which also enables a narrow radius of curvature.

Fig. 5 likewise shows a photograph of a cross section of the film under a scanning electron microscope, in which film the magnesium fluoride layer is already well visible.

Fig. 6 shows a detail of fig. 5.

A thin magnesium fluoride layer 9 is visible, which is formed on the magnesium layer 8.

It is well seen that the magnesium fluoride layer 9 bonds well to the underlying magnesium layer, which might otherwise explain good adhesion of the layer.

Fig. 7 shows a schematic view of a first possible application of the implant according to the invention.

Implants constructed as thin films of magnesium in accordance with the present invention can be used to treat damaged Smith's cloud.

Especially when inserting a pin implant 14 as shown here, which is advantageous for receiving a dental implant, damage to the schlieren film 12 may occur, which separates the jaw bone 13 from the jaw sinus.

In many cases, as shown here, the gap between the jaw bone 13 and the schlittlet cloud membrane 12 is filled with a bone substitute material, in particular a calcium phosphate granular material, in order to increase the thickness of the restorative jaw bone in such a way that the implant 14 can be embedded.

Damage to the schlieren membrane 12 is associated with a very high risk of infection. If such damage is noticed at the time of surgery, the surgery is usually interrupted and insertion of the pin implant 14 is only retried after a healing phase of several months.

It has been demonstrated that: this can be avoided by using an implant according to the invention in the form of a magnesium thin film which encloses the schlieren film 12.

Thus, for example, in the case of a defect, the magnesium film can be inserted through the hole of the pin implant 14 or through the lateral opening of the maxilla 13.

Of course, when the magnesium film is inserted through the hole for the pin implant, the magnesium film may be rolled up in advance, for example.

The schlittlet cloud membrane 12 is closed again by the thin magnesium film. It is surprising that a thin magnesium film of at least 50 μm has achieved sufficient closure without decomposing as would be expected within a very short duration.

Thus, the magnesium film may be advantageous to enable direct continuation of the surgery and furthermore provide the following advantages: in particular, when the magnesium film is sufficiently thick, it forms a good resistance to the embedded bone material. The growth of natural bone tissue is also facilitated by the magnesium film.

Of course, the magnesium film can be embedded preventively even without damage to the schlittercloud film.

Fig. 8 schematically shows the use of an implant 1 according to the invention for the three-dimensional reconstruction of a defect site in a jaw bone. The jaw bone 10 with the defect site 11 is covered with a curved implant 1 comprising a magnesium film. The implant 1 here forms a three-dimensional, free-form surface.

As can be seen in the right drawing, the bone tissue of the maxilla 10 which is formed follows the free-shaped surface and forms a rounded maxilla which approximates the natural shape. This approximation is in particular generally better than in the case of the use of embedded bone blocks made of donor material.

By means of the invention, an absorbable implant for covering bone defects in the jaw region can be provided in a simple manner.

List of reference numerals

1 implant

2 thin film of magnesium

3 concave part

4 degree angle

5 holes

6 structured zone

7 mesh area

8 magnesium layer

9 magnesium fluoride layer

10 maxillary process

11 defect site

12 spray cloud

13 jaw bone

14 pin implant

15 filling material

Claims (15)

1. Implant for covering a bone defect, in particular in the jaw area, comprising a magnesium film.

2. Implant according to the preceding claim, characterized in that the implant is configured to be shape-stable and curved, in particular with a radius of curvature of 0.5 to 10cm, preferably 0.7 to 1.5cm and/or with an angle of more than 30 °.

3. Implant according to one of the preceding claims, characterized in that the implant has at least one recess for a tooth.

4. Implant according to one of the preceding claims, characterized in that the implant has a corroded surface.

5. Implant according to one of the preceding claims, characterized in that the implant has a coated surface.

6. Implant according to one of the preceding claims, characterized in that the implant has a passivated surface, in particular a magnesium fluoride layer, which preferably has a thickness of less than 5 μm, in particular preferably less than 2 μm.

7. Implant according to one of the preceding claims, characterized in that the membrane is free of openings at least in the intermediate region.

8. Implant according to one of the preceding claims, characterized in that the implant is structured and/or perforated at the edge side.

9. Implant according to one of the preceding claims, characterized in that the magnesium film has a thickness between 50 and 300 μm, preferably between 70 and 200 μm.

10. Implant according to one of the preceding claims, characterized in that the magnesium film has less than 500ppm of iron, copper and/or nickel.

11. Assembly for covering a bone defect in the jaw area, comprising an implant according to one of the preceding claims and comprising pins, screws or wires for fixing the implant in the jaw.

12. Method for producing an implant for covering a bone defect in the jaw area, in particular an implant according to one of the preceding claims, wherein a magnesium film is provided, shortened to the length of the site to be covered and bent.

13. Method according to the preceding claim, characterized in that the magnesium film is treated with hydrofluoric acid.

14. Method for cosmetic and/or surgical reconstruction of the jaw bone, wherein an implant according to one of the preceding claims is placed over a defect site of the jaw bone and the soft tissue is sealed over the defect site.

15. Method according to the preceding claim, characterized in that the defect site is filled with bone substitute material or bone graft before the placement of the implant.