DE202018006810U1 - Titanium matrix based on a stress-free metal mesh for targeted tissue regeneration - Google Patents

Abstract

Titanium matrix based on a stress-free metal mesh for directional tissue regeneration, characterized in that the matrix is made of a warp-knitted fabric formed from titanium threads, the structure of the knitwear being executed as a combined simple two-bar metal mesh formed on the basis of plain weaves and derivatives of plain weaves and alternating small rods, each consisting of one and two titanium threads, the surface of the titanium threads being made in relief.

Description

FIELD OF TECHNOLOGY

The invention relates to medicine, namely surgery and oral surgery.

STATE OF THE ART

Different types of titanium membranes are known: resorbable and non-resorbable membranes (https://www.bebdental.it/ru/регенерация-кости/титановые-мембраны-t-barrier). A disadvantage of non-resorbable membranes is their swellability when closing the bone defect, which causes tension in the sutures of the mucous membrane covering them and, in some cases, wound dehiscence and, as a result, infection of the wound and bone defect. Inadequate mechanical and scaffolding function of the membrane results in the prolapse of the central part of the membrane into the defect area and thus decrease in volume, the space required for filling with the new tissue. The protein structure of the collagen membrane exhibits high antigenicity, resulting in a slowly progressive inflammatory response that develops following implantation of the material. These disadvantages of the membrane can be eliminated by using a perforated titanium foil as the membrane. Thus, the titanium membranes make it possible to limit the area to be regenerated, keeping the space for ossification and the osteoplastic materials at the defect site by fulfilling a barrier function. Thanks to the presence of microperforations, the circulation of liquids and oxygen takes place in the membrane area and the protective cells can migrate smoothly between the clot and the flap. The membranes are stabilized by special titanium screws and require careful suturing of the mucosal flaps for complete closure of the membrane. Normally, the membranes are removed 6 to 8 months after the necessary bone volume has been completely formed. The disadvantages of perforated titanium membranes include excessive rigidity, excess fluid, sharp edges, which often leads to traumatization of the mucosa, dystrophy of tissues above the membrane, wound dehiscence, partial necrosis of the mucosal-periosteal flap. Because of the lack of porosity and the rigidity of the construction, this material cannot integrate into the tissue, requiring a repeat operation to remove it.

A device made of titanium fibers for the targeted regeneration of bone tissue is known ( RU128098 U1 , published on 05/20/2013). The device for the directional regeneration of bone tissue, consisting of a membrane in the form of a sponge shaped as a ring with a thickness, is characterized in that the mesh-like plate, consisting of titanium wire threads coated with calcium phosphate ceramics with a diameter of 0, 1-1.5 mm, has a hole with the dimensions of the tooth neck, which is covered with a titanium wire fiber with a diameter of 0.5-2 mm with two free ends, consisting of mucosa, soft tissue and bone, this invention can used for bone sculpting. When using such a material, it is necessary to avoid contact of the titanium threads with a diameter of 0.1-0.15 mm and the mucous membrane, as there is a risk of perforating it. These disadvantages are all due to the superfluous thickness and thus the elasticity of the titanium thread that the inventors use in the invention. Said thickness of the titanium thread makes it possible to create the porous material only by knitting, ie the material is knitted from a thread, has limited elasticity, tends to unravel when cut and the excess weight and stiffness of the stitches from the Threads of this diameter can lead to a risk of mechanical trauma to the mucosa and gum tissue. Additional rigidity is given to the titanium threads in this construction by the titanium ceramic.

Also known is a braided titanium-nickelide shape-memory membrane for directional tissue regeneration in the form of a net-like plate made of superelastic TN-10 alloy threads braided using textile technology with a diameter of 50-60 μm and a distance between adjacent threads of 100-100 μm. 200 pm, is curved in the shape of the crest of the alveolar process and maintains the predetermined shape by the shape memory effect ( RU117087 U1 , published on 06/20/2012). The disadvantages of this design are that the material is titanium nickelide, which has disadvantages in terms of its biologically inert behavior. The disadvantage of the known device is the use of titanium nickelide as a titanium alloy. The implant described by the inventors represents a net-like plate (a body bounded by two parallel planes, the distance between which, referred to as plate thickness h = const, is small compared to its other dimensions). Starting from this, the free movement of the Fluid in tissues and tissue ingrowth is only possible in one direction (up/down), while fluid movement and tissue ingrowth are still in the transverse direction due to geometric peculiarities is limited. It should be noted that the same property affects the drainage of the postoperative wound, preventing wound exudation and creating conditions for wound infection.

The closest solution in terms of its technical nature is the mesh-like titanium implant ( RU121735 U1 , 10.11.2012) created by the limited liability company “TEMP Scientific and Manufacturing Company”; sold under the brand “Титановый шелк” (“titanium silk”), is made of alloy VT1-00 with a titanium content of over 99%, using 0.03-0.25 mm thick threads, which has good biological compatibility in tissues and does not cause toxic, allergic and other side reactions during implantation. The material has proven itself well in surgical plastic, its properties allow implantation in some soft tissues. Among the metal mesh types offered for the manufacture of implants, metal warp knitted fabric, available from 65 µm threads, seems to be the most promising. The goods made from these threads have a high elasticity of 45%-70%, a minimum areal density of 40-45 g/m ² and a high material porosity of up to 92%. Furthermore, the structure of the warp-knitted fabric has a pronounced three-dimensionality, which can also be set in a wide range and thus influence not only the width and length of the material, but also its thickness even in single-layer knitting. The material can be successfully used in surgical plasty of skin, subcutaneous fat, adipose tissue, muscle, aponeuroses, fascia and intermuscular connective tissue. Biologically inert behavior can be guaranteed by using titanium alloys GRADE 1 and GRADE-5 (Russian analogues VT1.00, VT1.00sv, VT6). The disadvantage of this material is that the material exhibits reversible (elastic) deformation, which is unavoidable when the material stretches. As a result, the mesh created can deform, wrinkle, put pressure on adjacent structures, and cause tension in the body tissues to which it is sutured. The existing reversible deformation can result in decubitus ulcers on the tissues, perforation through delicate structures, tearing of the mesh from the sutures, implant shrinkage. This limits the use of the material in such a sensitive area of surgical plastic as the mucous membrane of the oral cavity. The disadvantages mentioned limit the conditions for the use of the material in targeted tissue regeneration operations, since they entail the risk of the material breaking through or the mucous membrane being perforated by individual titanium mesh threads.

The claimed invention makes it possible to eliminate the aforementioned disadvantages inherent in the prototype.

DISCLOSURE OF THE INVENTION

The technical task that the technical solution according to the invention is intended to fulfill is the creation of a titanium matrix which improves the results of the operation for a directed tissue regeneration of the alveolar process and has the physical and mechanical properties required for this.

The technical results consist in reducing the elasticity and increasing the plasticity of the matrix, so that the specified implant dimensions can be obtained after removing all loads on the material, increasing the adhesive properties of the matrix to the wound bed, separating the growth of the mucous membrane and bone tissue, in the quality formation of the required bone tissue volume for the subsequent insertion of the dental implant, in the elimination of the probability of a biomechanical conflict between the knitted fabric and the mucous membrane, in the reduction of the risk of traumatization.

These technical results are achieved due to the fact that the titanium matrix is formed on the basis of the tension-free metal mesh for directional tissue regeneration from a warp-knitted fabric made of titanium threads, the structure of the knitwear being made as a combined simple two-bar metal mesh made on the basis of plain weaves and derivatives of plain weaves is formed and has alternating rods, each consisting of one and two titanium threads, the surface of the titanium threads being designed in relief.

An oxide layer is applied to the surface of the titanium relief threads.

The oxide layer is 1-3 µm thick.

The diameter of titanium threads is 20-80 µm.

The surface relief of the titanium wire is made with an uneven diameter of the titanium wire with a fluctuation of 1-10 µm.

The knitwear has a mesh module of 70-300.

The metal mesh has a maximum cell size of 2 mm.

Titanium threads are made of GRADE-5 alloy.

character list

• 1 .: View of the combined warp knitted fabric;
• 2a .: Example of thread surface relief after chemical etching;
• 2 B .: example of thread surface relief after ion treatment;
• 3 .: Strain diagrams of the titanium metal meshes;
• 4 .: Diagram for zero stiffness in elongation of knitted fabrics;
• 5a .: Thread cross-section with longitudinal pointed defects before treatment;
• 5b .: Thread cross-section with smoothed longitudinal defects after treatment.

1

Maschenstäbchen, die aus einem Faden bestehen;

2

Maschenstäbchen, die aus zwei Fäden bestehen;

3, 4

Flottierfäden zwischen den Maschen, die in verschiedene Richtungen gezogen sind;

5, 6, 7, 8

Druckkräfte bei den Maschen, die aus zwei Fäden bestehen;

9, 10

Gesamtdruckkräfte bei den Maschen, die aus zwei Fäden bestehen;

11, 12

Druckkräfte bei den Maschen, die aus einem Faden bestehen;

13

Gesamtdruckkräfte bei den Maschen, die aus einem Faden bestehen.

14

Dehnungsdiagramm des erfindungsgemäßen Materials für die Titanmatrix;

15

Dehnungsdiagramm für das Material „Titanseide“.

Explanations of the reference symbols on the figures:

1

wales consisting of a thread;

2

wales consisting of two threads;

3, 4

Floating threads between the stitches, drawn in different directions;

5, 6, 7, 8

compressive forces in the stitches, which consist of two threads;

9, 10

total compressive forces in the meshes composed of two threads;

11, 12

compressive forces in the stitches, which consist of a thread;

13

Total compressive forces in the stitches consisting of one thread.

14

Elongation diagram of the material for the titanium matrix according to the invention;

15

Elongation diagram for the material "Titanium Silk".

CARRYING OUT THE INVENTION

The matrix for directional tissue regeneration, e.g., the alveolar process, is made of a 0.08-0.32 mm thick warp-knitted fabric with a mesh modulus of 70-300, formed from titanium threads with a diameter of 20-80 µm .

The structure of the fabric is made as a combined simple two-bar metal mesh formed on the basis of plain weaves and derivatives of the plain weaves and the sequence of wales 1 and 2 ( 1 ), each consisting of one and two titanium threads, in the goods. The threads can be made of titanium alloys VT 1-00, VT-1.00sv (GRADE-1) or VT6 (GRADE-5). The titanium threads used ensure a high level of biological inert behavior and high plasticity of the threads and do not allow any damage to the tissue.

The structure of the fabric has no fillet perforations, which means that the fabric's ability to stretch is reduced, which is important both for the formation of the matrix and for its function in the postoperative process. The number of floats 3 and 4 between the stitches ( 1 ) drawn in different directions will be different; the number of floats in the stitches consisting of two threads is twice as many as in the threads consisting of one thread: four and two, respectively. In the case of the two-threaded meshes, the floating threads are pulled in different directions and the tensile and compressive forces 5, 6, 7, 8 ( 1 ) act in different directions, which after the removal of the tensile force equalizes the total compressive forces 9, 10 ( 1 ) results. The compressive forces 11, 12 ( 1 ) in the single-thread stitches produce the total compressive force 13, which is insufficient for the shrinkage of the knitted fabric, which is caused by: first, plastic deformations generated during the elongation of the metal knitted fabric by the thread distortion from needle loops into the float threads; secondly, by the existence of at least sixteen points of contact in two-threaded stitches, with float threads, which prevents the threads from drawing into the warped stitches, which are reduced in size during stretching.

Another important factor is giving the metal knitwear freedom from tension (relaxation in the area of mesh contact) by making a relief in the form of chaotically distributed depressions and elevations ( 2a and 2 B ) on the surfaces of the titanium threads, with a general reduction in the thread diameter of the knitted fabric and, consequently, with a reduction in the mesh contact area.

Ultrasonic force treatment, chemical etching, electrochemical polishing, ion treatment etc
The above treatments reduce the diameter of the titanium thread already in the structure of the knitted fabric by 10-35% of the initial diameter, at the same time they reduce the area of contacts between the meshes and relieve stresses in the area of contacts between the meshes, thus closing the elastic ones Properties and increase the plasticity of the metal mesh by forming a porous structure with high adhesion to the wound surface. The result is a “telescope effect”: the stitches and the floating threads between the stitches penetrate into the area of the closest stitches. This effect is not evident in the untreated (native) metal mesh.

The tension-free properties of the metal mesh solve the problem of residual elasticity, and the telescopic effect ensures the goods unfold more easily.

So are in 3 the diagrams for the elongation of the material according to the invention and the material "titanium silk"; 14 and 15, respectively, where P is the tensile force and L - the elongation of the stretched materials. From these diagrams it can be seen that the plastic deformation of the material 14 according to the invention occurs earlier than in the sample of the material "titanium silk" 15, since the elongation is Δ12 < Δ11, demonstrating the reduction in elastic deformations of the material for the matrix according to the invention. The material according to the invention has a percentage of resilient (elastic) deformations of 35-40%, the said elasticity for the material "titanium silk" being 45-70%.

When stretching knitted fabric meshes, there is also a period with zero stiffness Z ( 4 ), ie the area on the chart when the knitted fabric is stretched without resistance, where Zata represents zero stiffness of the stress-free metal mesh with relief yarns and Znat represents zero stiffness of the native metal mesh with unembossed yarns. Comparing the native and the stress-free metal mesh of the same knit type and with the same thread thickness, it is found that the zero-stiffness range of the stress-free metal mesh is 20% and more larger than that of the native material.

In addition, pointed defects in the form of longitudinal grooves ( 5a ) on the surface of the thread in the structure of the knitwear, which occur when the thread is wire-drawn, is smoothed during treatment, for example by electrochemical polishing. Smoothing the defects after treatment is in 5b shown. The smoothing of longitudinal defects, which are concentrators of internal tension, harmonizes the residual tension in the actual yarn and reduces the risks of knitwear breakage.

The consequence of the treatment is also an unevenness of the diameter of the titanium thread with fluctuation in its longitudinal course of 1-10 µm, which also provides additional freedom for the distances between the meshes.

A 0.3 to 3 µm thick oxide layer can be applied to the surface of the stress relieved metal mesh to further increase plasticity. It is known that the application of the titanium oxide reduces the friction factor by about three times and
significantly increases the dynamics of the tension-free metal mesh, which allows the meshes to slide easily against each other, which has a positive effect on the elasticity of the material. The superficial oxide layer reduces the friction between the knitting stitches and reduces the associated negative properties such as thread breakage when the material unfolds, etc.

The oxide layer is created by immersing the net-like goods made of relief threads in a direct current electroplating bath filled with the required solution for a certain time. Depending on the time and the voltage selected, a 0.3-3 µm thick titanium layer is formed on the surface of the titanium thread. The actual thread does not become thicker.

No less important is the property of the oxide layer that it can be made in different colors, which depends on the thickness of the oxide layer. The metal mesh color setting allows the color of the metal mesh to match the color of the mucosa
and thus to enhance the cosmetic effect upon placement of the metal mesh implant.

Due to the use in warp knitting of a knitting pattern representing the structure of a combined simple two-bar metal mesh fabric based on plain weaves and derivatives of the plain weaves, successive wales consisting of one thread or two threads are present in the structure of the fabric, which stabilizes the structure, reduction in the elastic deformation phase and the fastest possible transition to plastic deformations, allowing the dimensions of the implant shape to be maintained after the removal of all stresses.

The metal mesh has a maximum mesh size of 2 mm, which is an additional factor in holding the bone substitute material in place.

Giving the material freedom from stress finally solves the problem of residual elastic deformation. The resulting telescopic effect ensures a long period in which the knitwear stretches without resistance.
The high plasticity of the warp knit fabric to be produced eliminates the likelihood of a biomechanical conflict between the mesh fabric and the mucosa and allows the material to be placed under the mucosa even with a very thin mucosa. In contrast to the net-like titanium implant "titanium silk", the titanium matrix unfolds freely on the surface of the postoperative wound and shows a pronounced adhesion to the surface of the postoperative wound; it easily takes and keeps the set shape, if necessary it can be adjusted to the shape of the postoperative wound by stretching.

The porosity of the material, which is ensured by the existing free space between the mesh legs and the float threads, increases the speed of penetration of liquids into the implant, accelerates its colonization by fibroblasts and osteoblasts and improves the integration of the material; when the titanium matrix touches the surface, it is immediately saturated with blood and wound exudate and shows a pronounced adhesion to the wound surface, which ensures temporary self-fixation, so that the surgeon does not have to use any fixing elements such as pins, microscrews, etc. needs to apply.

The high adhesion of the titanium matrix of tension-free metal mesh to the wound surface allows the titanium mesh to be placed without tension of the muco-periosteal flap, thus preventing the common complication such as wound dehiscence. At the same time, the highly porous structure does not stop the wound secretions and thus excludes the possible accumulation of liquid and its subsequent infection.

The relief of the thread surface significantly improves the attachment of fibrin fibers to it and thus contributes to the attraction of fibroblasts, which serve as a source of newly formed connective tissue.

The titanium matrix can optionally be of any required size such as 2*2; 2*3; 3*3 cm etc. can be designed.

An important property is also easier cutting of the implant after formation of the bone layer. Thus it enables
Insertion of the dental implants without removing the titanium matrix, which is not the case when using a titanium perforated foil as the titanium membrane.

The basis of the technology of targeted tissue regeneration operations is the principle of separating the bone surface with the soft tissue above it in the area of the bone defect and the prospective placement of the dental implant in the alveolar process of the upper or lower jaw. This separation occurs through the physical separation of the anatomical formations (gum piece from bone and implant) from each other through the porous titanium matrix, which is made as a thin titanium mesh.

Preoperative planning consists in measuring the dimensions of the tissue defect to be covered with the titanium matrix for people who have indications for performing targeted tissue regeneration operations, for example, the alveolar process. The procedure of directed tissue regeneration assumes the use of a separating membrane and xenogeneic or allogeneic hydroxyapatite granules, and in many cases also autogenous bone chips. The surgical technique for directed tissue regeneration is as follows. The line of the horizontal section of the mucosa is usually drawn on the alveolar process. Bone defect revision is performed, which is filled with bone replacement granules, xenogeneic bone debris and/or auto-bone. Then the formed complex is covered with titanium matrix, which is placed under the mucosa. It is permissible to close the defect only using the titanium matrix, for example to eliminate the gum pockets. The operation is completed with the sutures on the mucous membrane and the gingival bandages. It is prescribed Trichopol for 5-7 days when observing careful oral hygiene. The position of the membrane between the lobe and the root surface is favorable for the repopulation of the periodontal ligament cells on the root surface. The technical solution to be notified makes it possible to exclude swelling and wound dehiscence, to ensure the ergonomics of the surgical procedure for directed tissue regeneration and the secure attachment of the bone substitute material throughout the bone defect, thus restoring the anatomical integrity of this area. The use of ultra-light titanium matrix reduces the number of complications and improves the outcome of the operation by reducing the antigenicity and increasing the biological compatibility of the material. The use of this matrix eliminates the need for its revision before implantation of the dental implant because the holes for the implants can be easily cut and the material is designed to remain in the body for a long time. The efficiency of using the claimed matrix has been proved by a number of clinically observed cases.

Example 1.

Patient E., 46 years old, diagnosis: "Generalized periodontitis of moderate degree". Local receding of 6 mm in the area of the canines in the maxilla. After professional oral hygiene and sanitation, the patient underwent a Ramfjord flap operation on the upper jaw in the area of teeth 5 to 12. After removing the mucosa-periosteal flap, bone pocket curettage was performed with removal of granulation tissue and treatment of root surfaces of teeth 5 to 12, then bone tissue was treated using a special drill. In view of the pronounced alveolar bone defect and the largely missing bone plate, the bone defect was filled with osteoplastic material and covered with a titanium matrix made of tension-free metal warp knitted fabric made of titanium threads with a diameter of 20 μm (mesh module 70) and a mesh size of 0.7 mm. 2.5 months after the operation, the restoration of the crest of the alveolar bone was examined radiographically. After the second phase of the operation, the bone could be restored to the required extent and with sufficient density. The insertion of dental implants was routinely performed.

example 2

Patient D., 50 years old, diagnosis: "Generalized periodontitis". Local receding of the soft tissue of the gums by 9 mm in the area of the canines in the upper jaw. After professional oral hygiene and sanitation, the patient underwent flap surgery and, after removing the mucosa-periosteal flap, bone pocket curettage with removal of granulation tissue, the root surfaces of teeth 14 to 16 were treated with Piezon-Master devices. The osteoplastic material was placed under the mucosal-gingival flap, then it was covered with porous matrix of tension-free titanium metal warp knitted fabric knitted from titanium threads with a diameter of 80 µm (mesh modulus 300) and a mesh size of 1 mm. After the operation, the restoration of the Zahlfleisch soft tissue and the closure of the tooth necks with soft tissues were examined. 3 months later, the patient was invited to the second phase of placing dental implants, the bone tissue was fully restored, the formation of the implant bed took place without any problems.

The technical solution consists in adapting the titanium mesh for positioning under the mucosa by increasing its plastic properties through the combination of a special textile knitting pattern and imparting tension-free properties.

The claimed titanium matrix, which is designed as a warp-knitted fabric made of titanium threads as a combined simple two-bar metal mesh, formed on the basis of plain weaves and derivatives of plain weaves and providing alternating wales, has a stabilized structure and has faster plastic structural deformation, which allows maintaining the specified Implant dimensions guaranteed after removal of all stresses on the material. The high plasticity of the warp-knitted fabric to be created eliminates the likelihood of a biomechanical conflict between the knitted fabric and the mucosa and allows the material to be positioned under the mucosa even with a very thin mucosa, without risk of traumatizing the oral cavity or bedsores to cause the mucous membrane.

The use of titanium matrix, which has tension-free, low elasticity and increased plasticity, for targeted tissue regeneration leads to increased adhesion to the wound bed, delimitation of growth of mucous membrane and bone tissue and allows placement of mucosa-periosteal flap without tissue tension, ensures a good vascularization and integration of the titanium matrix, which ensures quality formation of the bone tissue volume required for the subsequent insertion of dental implants and, as a result, leads to improvement of surgical results of targeted regeneration of periodontal tissues, which arise due to inflammatory and degenerative processes and efficient solution of the problem with the missing bone tissue, e.g. the alveolar process of the upper or lower jaw.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• RU 128098 U1 [0003]
• RU 117087 U1 [0004]
• RU 121735 U1 [0005]

Claims (9)

Titanium matrix based on a stress-free metal mesh for directional tissue regeneration, characterized in that the matrix is made of a warp-knitted fabric formed from titanium threads, the structure of the knitwear being designed as a combined simple two-bar metal mesh formed on the basis of plain weaves and derivatives of plain weaves and alternating small rods, each consisting of one and two titanium threads, the surface of the titanium threads being made in relief. Titan matrix according to claim 1 , wherein an oxide layer is applied to the surface of the titanium relief threads. Titan matrix according to claim 2 , where the thickness of the oxide layer is 0.3-1 pm. Titan matrix according to claim 1 , where the diameter of the titanium filaments is 20-80 pm. Titan matrix according to claim 1 , wherein the surface relief of the titanium wire is made with non-uniform diameter of the titanium wire. Titan matrix according to claim 5 , where the surface relief of the titanium wire is made with non-uniform diameter of the titanium wire with fluctuation of 1-10 pm. Titan matrix according to claim 1 , the knitwear having a mesh module of 70-300. Titan matrix according to claim 1 , wherein the metal mesh has a cell size of not more than 2 mm. Titan matrix according to claim 1 , where the titanium threads are made of GRADE 5 alloy.

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