Devices and medical membranes used for bone regeneration

DEVICES AND MEDICAL MEMBRANES FOR BONE GENERATION

Background The present invention relates to devices and medical membranes for active bone regeneration by callus distraction against an artificial boundary, according to the preamble of the independent claims.

State of the art

Callus distraction has been known for over 100 years and has now become the treatment of first choice. The most important biological stimulus for bone formation is the mechanical stress. This piezoelectric forces are released, the first osteoblasts and activate osteoclasts. The Distraktionsosteo- genesis induces bone formation by by slow separation of bone segments biological Wachstu s- incentives are triggered. Through this method, the direct formation of woven bone is achieved by distraction. The defined tensile stress in the bone regeneration is essential and is apparent when it is compared with each other at fixed bone defect bridging. Even with 5 mm expansion can not be bridged suffizient bone defects. If you put on the bone fragments at a defined tensile stress, so the mesenchymal tissue wins in the gap and on the adjacent fragment ends back its osteogenic potential-al. If there is sufficient vascular potency occurs under progressive distraction for metaplasia of organized hematoma in a zone of longitudinally arrangiertem, fibrous tissue, which can be converted under optimal external and internal conditions directly in Geflechtskno- chen. Over time, shows that after the completion of distraction there is no substantial increase in the total mass formed bone. The rate and the frequency of distraction is important. After following retention period of 6 weeks, repeated six weeks consolidation phase osteogenesis has been completed. The distraction osteogenesis is currently the most innovative surgical technique in the fields of orthopedics, traumatology and maxillo-facial surgery.

The use of medical membranes in guided tissue regeneration evolved from wound healing. The therapeutic concepts GTR (Guided Tissue Regeneration) and GBR (Guided Bone Regeneration) are based on the consideration that resident cell types with different growth rate by the interposition of special membranes are selectively affected during the healing process in the wound area. Unwanted cell lines with higher growth rates to be shielded and the colonization of the defect with cells that can form the desired tissue newly promoted. With the GTR technique rapidly growing epithelial and connective tissue cells are inhibited and the slow-growing bone cells take undisturbed the defect healing. Although the use of special membranes in periodontal regeneration techniques allows the formation of new bone and connective tissue, the results are limited. These methods allow only limited apposition, because on the membrane no biomechanical stimulus is transmitted to the bone that it is exercised neither train nor pressure on the diaphragm.

All previous techniques Distraktion- sosteogenese in common is that the formed callus is stretched between two bone fragments. The invention is therefore based to provide funds to allow bone regeneration between callus and artificial interface the task.

Summary of the Invention This object is solved by the independent claims of the present invention. The present invention provides Zugbefestigungsvorrichtungen and medical membranes available that allow callus between bone and medical membrane to produce, by a tensile stress is generated on the membrane via an associate with the traction device fastener tension element. The membrane is fused with the callus and their dose movement induced bone neoplasm. The objects of the present invention are used, for example in dentistry in periodontal regeneration in the jaw ridge augmentation in implantology or aesthetic Gesichtschirugie, in orthopedics and traumatology. The present invention provides a medical membrane for bone regeneration available. The membrane has at least one surface with fastening elements for a traction means and / or reinforcement points. When fasteners for example eyelets, solutions rather in the membrane, starting points on the membrane can be used. The fasteners allow for attachment of a pulling means for generating an adjustable tension on the membrane. The gain points allow power transmission to the membrane, for example, is moved by means of a lift located below the membrane lifting means in the distraction direction. The transmitted from below the diaphragm exerts force on the underlying membrane and associated with this bone in turn train out, resulting in the induction of bone regeneration. As gain points as densely configured parts of the membrane, selected points on the reinforcing bars are used.

Advantageously, at least one surface of the membrane reinforcing bars that allow a uniform power transmission to an inventive membrane. In a preferred embodiment, the uniform transmission of force to the membrane obtained by means of chemical surface hardening.

Advantageously, the surface facing the bone is roughened, in particular porous to allow anchoring of the collagen and ingrowth of osteoblasts. The cell attachment and anchorage of collagen of the underlying bone with the bone-facing side of the membrane leads to an anchoring of the membrane in the callus. This allows the membrane tension can be affected without peeling the membrane from the substrate. In a preferred embodiment, the bone-facing side of the inventive membrane made of a non-absorbable material such as titanium. In a further preferred embodiment, there is a bone-facing surface of a resorbable material, preferably made of collagen with a mesh size of 20-100μm.

The connective tissue covering, outer surface of the membrane is preferably roughened to an anchorage of the covering connective tissue to allow. The roughened surface is preferably be porous to allow a Attachement of the connective tissue and an anchoring of the collagen. This configuration prevents separation of the connective tissue when the diaphragm is moved. The surfaces of the membranes used today are such that movement of the membranes leads to easy detachment of the surrounding connective tissue. The detachment of the fabric from the membrane surface leads to an invasion of bacteria into the resulting gap and infections. The surface texture of the novel membrane now allows for movement of the diaphragm without detachment of the surrounding connective tissue. These properties of the novel membrane achieved includes these new applications in medicine, such as induction of bone regeneration by transmitting a biomechanical stimulus to a bone via a membrane. the membrane of serum advantageously is permeable to allow a diet of the surrounding tissue. the membrane is advantageously impermeable to epithelial and connective tissue cells, to prevent immigration of competing cells in the regeneration area.

Preferably, a membrane which is dimensionally stable. Under dimensionally stable membrane, a membrane is understood that substantially retains its shape when loaded with the weight in. As tension means are useful, for example filaments of eg polypropylene, polyester, polyamide and wire ligatures.

The membrane may be made of absorbable as well as from non-absorbable materials. The resorbable materials are such that they ensure the existence of the membrane during the distraction, retention and consolidation phase of bone regeneration. The distraction takes about 2-6 weeks, the retention time has about a duration of 6 weeks and the consolidation phase lasts about 6 weeks.

Preferably, membranes that form a three-dimensional surface and are segmented. Under segmented oriented membrane is understood that the individual segments of the membrane are hinged together.

The segmented design of the membrane allows for a large target bone degradation a different elevation of the different segments and thus enables optimum adaptation for large-area, different defects. the membrane according to the invention is advantageously elastically to allow large adaptation to the various circumstances.

The novel membranes have different shapes. The various embodiments of the membranes ensure optimum adaptation to the circumstances. The membranes are eg surgically placed in use in periodontal bone regeneration by flap, horizontal periosteal incision and precise adaptation of the membrane to the patient. After adaptation of the membrane, the pulling means is threaded on the fastening elements of the membrane surface and the wound closed.

Another object of the present invention is a traction device fastener to the bone regeneration which can be connected by means of a traction mechanism with the implanted medical membrane in order to exert a tensile stress on the membrane. The traction device fastener comprises a fastening means and an adjustable tensioning means by which the traction means is con- nected and causes, for example, by rotating a metered tension on the membrane. As fastener base plates are for example useful and as clamping means such as bolts, slides, gears and Spulräder useful. The traction means can, for example by rolling up or raising the translational

transferred clamping device voltage on the associated membrane.

The invention relates to a method for treating a bone defect in the dental field, wherein a membrane according to the invention is applied to a bone segment to be regenerated and this membrane over a traction device fastener, a tensile stress is exerted.

Brief Description of Drawings

Further embodiments, advantages and applications of the invention result from the dependent claims and from the following description with reference to FIGS. In the drawings: Figure 1 shows a section through an exemplary arrangement of the present invention when used for bone regeneration in dental field, Figure 2 is an exploded view of an embodiment of the traction device fastener,

Figure 3 is a plan view of the same embodiment of Figure 2, Figure 4 shows a side view of the embodiment of Figures 2 and 3,

Figure 5 is a plan view of another exemplary embodiment of the traction device fastener, Figure 6 shows a side view of the embodiment of Figure 5,

Figure 7 shows a side view of an embodiment of the traction device fastener,

Figure 8 is a plan view of another exemplary embodiment of the traction device fastener,

Figure 9 shows an exemplary embodiment of a membrane with a hardened surface,

Figure 10 shows the membrane of Figure 9 in an applique shape between two teeth, Figure 11 shows the membrane of Figure 9 in an applique shape of a plurality of teeth,

Figure 12 shows an exemplary embodiment of a membrane with reinforcing bars,

Figure 13 shows the membrane of Figure 12 in an applique shape between two teeth,

Figure 14 shows the membrane of Figure 12 in an applique shape of a plurality of teeth,

Figure 15 shows an exemplary embodiment of a segmented membrane of teeth, Figure 16 shows an exemplary arrangement of an inventive membrane for bone regeneration by raising by eg temporary implants and

17 shows a cross section through an exemplary recordable dreichschichtige membrane with two roughened surfaces.

WAYS OF CARRYING OUT OF THE INVENTION 1 shows an arrangement of the inventive membrane and the inventive traction device fastener when used to Knochenregenerati- on the teeth. In the Overview Figure 1 is a cross-section of a tooth 1 is shown, which shows the bone 2, a lesion of the periodontal tissue 3, an inventive membrane 4, a traction means 6 and an inventive traction device fastener 5, the gum 7 and the periodontium eighth

The inventive membrane 4 is connected via the traction mechanism 6 with the traction device fastener 5 and by eg roll of the traction mechanism 6, a tensile stress exerted on the diaphragm. 4 The inventive membrane 4 transmits biomechanical stimulation on the underlying bone 2, resulting Paradontalrege- generation, which includes the regeneration of bone, periodontal ligament, the periodontal ligament, the gingiva and papillae. Embodiments are of

Invention with reference to the drawings in more detail.

Figure 2 shows an exemplary embodiment of the traction device fastener in side view. The traction device fastener includes a base plate 10 with a flexible locking pin 11 and a substantially flat supporting surface 16, a spool wheel 12 with notches 13 and a spreader 14. The winding wheel 12 is rotatably supported by the expander pin 14 on the baseplate 10th The flexible locking pin 11 snaps into a cores be 13 of Spulrades 12 and fixes this in a defined position. On winding wheel 12, the traction means 6 is fixed.

Figure 3 shows the embodiment of Figure 2 as supervision. The winding wheel 12 is placed in the starting position shown in which the number "0" of the scale 15 of Spulrades 12 coincides with the locking pin 11th by turning to the next digit of the scale 15 of the winding- rads 12 the pulling means 6 is additionally raised by 1 mm. The spool wheel is designed for a total stroke of 10 mm.

Figure 4 shows the embodiment of Figure 2 in side view. The substantially flat configuration of the bearing surface 16 of the base plate 10 is visible. The substantially flat configuration of the bearing surface 16 allows an adhesive attachment of the traction device fastener, for example, to a tooth. Another exemplary embodiment of the traction device fastener is shown in Figures 5 and 6. FIG.

Figure 5 shows a plan view of the embodiment. The apparatus includes a base plate 20 with an ner nose 21, a winding pin 22, which is provided with a plurality of grooves 23, a hexagonal nut 24 and a resilient washer 25 and the traction means 6. In the initial position, the nose of the base 21 snaps into the groove 23 of the winding pin 22 a. Upon rotation of the winding bolt 22 the head of the winding pin 26 lifts off. This longitudinal movement is accommodated by the resilient washer 25th This also ensures that the winding pin 22 locks rotation continues in the next groove 23rd By the number of grooves and the corresponding dimensioning of the winding bolt diameter, a precisely defined Fadenhub per partial rotation is achieved. Figure 6 illustrates a side view of the embodiment shown in Figure 5. The substantially flat configuration of the bearing surface 27 of the base plate 20 is visible.

Figure 7 illustrates another embodiment in side view. In this embodiment erfindungemässen raising the pulling means 6 is accomplished by a slide 30 which moves in a base plate 31. The slide 30 is moved by turning a screw 32 of the lower starting position in the upper end position. By means of deflection Pulling means 6 by a pin 33, an additional Fadenhub is achieved. By turning the screw 32 in a counterclockwise direction, the slider 30 is moved back into the lower initial position. By deflecting the thread dens around the pin 33 results in downward movement only half Fadenhub per revolution of the screw 32. The overall Fadenhub this device is 7.7 mm.

8 shows a plan view of another embodiment is shown wherein in by turning a gear 40 via a gear wheel 41 has two gears 42

Rotation will be displaced. The axes of the gears 42 and gear 40 wrap in turn simultaneously on several pulling means 6th This embodiment allows a voltage transmission over several traction means. In a preferred embodiment the Zugbefestigungsvorrichtungen the present invention have a value, which allows for attachment to a tooth.

Allen described embodiments have in common that they allow a precisely adjustable Fadenhub and thus a metered tension can be applied to the medical membrane connected to the device. The exact dosage of tension is essential for bone regeneration, since in a over-stretch tion result in undesirable tissue changes and is not regenerated the desired tissue.

The Zugbefestigungsvorrichtungen as may be fixed by the acid etching on the buccal and lingual enamel of the tooth or in a pre-mounted bracket. To attach the devices also implants, provisional implants, rails and plastic prostheses are for example.

An arrangement consisting of an inventive traction device fastener and a medical membrane allows a complete regeneration of periodontal defects. It allows the transfer of mechanical strain on the membrane lying below the the callus, which stimulates bone formation. This provides completely new perspectives in the treatment of Paradonto- pathies. Both the surrounding soft tissue and the alveolar bone can be constructed re- to the original level. Even large-scale defects can be reconstructed by using the inventive arrangement.

Figures 9-15 illustrate exemplary embodiments according to the invention are membranes. 9 shows an embodiment of a surface-hardened membrane. The membrane consists of a part 50 with lug 51 and a portion 52 with the passage opening 53 for the tab 51. The two parts of the exemplary embodiment have pores 54 and fastening elements 55 for fastening a traction device 6. The edge zones 56 of the two parts of the membrane 50 , 52 are soft configured to allow a dense, tight fit to the tooth root. The central zone 57 of the two parts 50,52 of the membrane is cured by chemical methods in order to enable a uniform distribution of the pulling force on the membrane. In a preferred embodiment, the curing of the membrane takes place during the operation in situ.

Figure 10 shows a membrane of Figure 9 in pushed-together form between two teeth 58. The flap 51 has been carried out and tightened up the membrane parts 50.52 circularly closely and tightly abut the teeth 58 through the passage opening 53rd

Figure 11 shows an embodiment of the membrane of Figure 9 between three teeth 58. The two membrane parts 50,52 are each made in one piece, which are divided into four parts with the same configuration as the membrane of FIG. 9

Figure 12 shows an exemplary membrane with reinforcing bars. The membrane consists of a part 60 with lug 61 and a 62 with an Durchtrittsöff ung 63 for tab 61. Both parts 60,62 have reinforcing bars 64 and pores 65. In a preferred embodiment, the reinforcing strips 64 are titanium lamellae, which are integrated into the membrane. You grant anatomical adaptation and dimensional stability and are useful as Kraftanssatzpunkte for the traction means. 6 The traction means 6 may be fastened, for example by simple serging the titanium blades. Under overlocking is understood that the membrane is pierced and the traction means is guided, for example, a titanium plate fin. Figure 13 shows a diaphragm of figure 12 in pushed-together form between two teeth 58. The flap 61 has been carried out and tightened up the membrane parts 60,62 circularly closely and tightly abut the teeth 58 through the passage opening 63rd Figure 14 shows an embodiment of the membrane of Figure 12 between a plurality of teeth 58. The two membrane parts 60,62 are each made in one piece, which are divided into four parts with the same configuration as the membrane of Figure 12th Figure 15 shows an exemplary embodiment of a segmented membrane of teeth 58th

The individual segments 70 of the membrane are connected to one another via joints 71st When joints expansion zones are preferred which facilitate the application of the membrane and move vertically allow the membrane, as well as ensure a circular cover by tight fit on the teeth. the joints are advantageously 71 arranged about a longitudinal axis of the tooth 72 and bone-facing surface corresponds to the structure of the inventive membrane.

A segmented membrane, as described above, allows a operation an entire jaw can be treated at once. Preferred membrane units, is in which the buccal and lingual part interdental tal connected or subsequently is easily attachable to permit easy handling. 16 shows an exemplary arrangement for bone regeneration, induced by means of raising a fingungsgemässen achieved membrane by a lifting means such as temporary implants in the bone apposition underlying the membrane.

The assembly comprises an inventive medical membrane 75, are shown on which two exemplary gain points 76th The lower surface of the membrane 77 is connected to the bone 78, and its upper surface 79 is of the oral mucosa

80 covered. The membrane 75 is connected via the reinforcement points 76 with a lifting means 81st The lifting means

81 are such that an adjustable raising of the membrane 75 is possible. As lifting agents are pro- plan temporary implants with threads that are raised by rotation, be used. Such an embodiment is suitable for example for bone regeneration in a pine area where the teeth were removed by extraction. the provisional implants are preferred to Replace achieved folgter bone regeneration by definitive implants.

In the figure, 17 is a cross section of an exemplary medical membrane 80 which has a three-layer structure is shown. The bone-facing layer 81 and the bone layer facing 82 made of non-absorbable material such as plastic. The surface 83 of the bone-facing layer 81 is roughened to allow connection to the underlying bone. The surface 84 facing away from the bone layer 82 is roughened to prevent detachment of the membrane 80 covering the connective tissue. The middle layer 85 gives the membrane dimensional stability. As inventive membranes and membranes are used which have a single-layer, two-layer or multilayer structure.

An inventive membrane is characterized by high user-friendliness, as it patient a duck is easy to use by an operator. In the application of closely spaced teeth or splinted crowns the membrane is advantageously produced in a lingual and buccal part and eur only by the operations after insertion connected eg by pushing together of the two parts.

If not closely spaced teeth, ie if no tight interproximal contact point conditions; advantageously a membrane made in one piece is used. A segmented membrane is advantageously used in the application of a plurality of teeth, since their joints, preferably stretching areas, a sufficient flexibility for the application and adaptation of the membrane on different vertical bones in the allow individual teeth.

The use of the objects of the present invention is not limited to the bone regeneration in dental field. You can also eg for ridge structure, used in implantology or in aesthetic surgery GE considerate. They find use everywhere where bone regeneration is needed, but only small fastening devices are used.

The objects of the present invention are also useful in orthopedics and traumatology, to achieve complete bone regeneration of bones by periosteal ossification.

While in the present application preferred embodiments of the invention are described, it is clear to point out that the invention is not limited thereto and may be embodied in other ways innerhal- the scope of the following claims.