PT1924212E - Two-part dental implant - Google Patents

Description

DESCRIPTION " DENTAL IMPLANT OF TWO PARTS " The present invention relates to a two-part dental implant. A distal implant part is made as an artificial tooth root for implantation into a maxillary bone and a proximal implant part supports an artificial tooth crown. The invention relates in particular to the connection between distal and proximal implant parts, also hereinafter referred to as implant abutment attachment and abbreviated as IAV. The proximal end of the distal implant part and the distal end of the proximal implant part are configured by geometrically adapting to one another and contiguous with one another in the implanted condition of the shank.

Dental implants are used to replace missing teeth. In dental implants it distinguishes between one-part and two-part systems. The present invention relates to a two part system. Two-part systems of this type have a distal implant part and a proximal implant part. The distal implant part is inserted into the maxillary bone and stratified there with the bone. The proximal implant part - also called abutment - projects a few millimeters into the buccal space and serves as an artificial tooth nucleus. In the present case, the distal implant part forms an artificial tooth root, while the proximal implant part forms the above-mentioned artificial tooth core. The proximal implant part assumes the 1 more different forms of tooth replacement, for example in the form of a crown and attaches these to the jaw through the distal implant part. The distal implant part and the proximal implant part are usually connected together in a longitudinal direction through a threaded stud projecting in the longitudinal direction. The geometry of the bonding zone between the distal implant part and the proximal implant part is such that the bond between both implant parts is made in positive or non-positive bond, or both.

The most important requirements in the connection between the distal implant part and the proximal implant part are: the bond must be stable since it is exposed to enormous chewing forces. The adaptation parts have to be worked very accurately and should not present any slits in the assembled condition. The assembly must be able to be separated from the implant and connected to the implant at any time. The assembly must be replaceable with other structures. The two parts of the implant, when assembled, must be rigid and free, as well as secure against rotation about the longitudinal axis of the implant. This is of particular significance when several implants are introduced into a jawbone and these individual implants must accommodate a complex coherent construction, such as a screw-on fixed implant bridge. Only such precision-engineered implant construction can be produced with precise safety against torsion. When several implant structures are to be connected directly to one another, for example, in the case of a bridge subconstruction, which, as a rule, supports a removable prosthesis, a safety against rotation can be dispensed with. In the bridging structures 2 provided for this application a further requirement is placed in addition to the requirements already mentioned: the bridge structures must give the possibility that several structures connected to each other can also be placed without problems on the implants and connected to these, when the implant fixings, as usual, were not introduced into the bone, parallel to one another.

Known two-part dental implants do not meet the above requirements to the desired extent. A particular problem in many known two part implants is the transition between the two implant parts. Known solution proposals, for example, from EP 0842643, US 5919043, EP 1371342 or US 6152737 are not satisfactory. EP 0323823 A2 relates to an implant for the fixing of dental prostheses, consisting of a primary part and a secondary part, the primary part of which is provided for anchoring in the maxilla bone and the secondary part is fixed against the in a notch of the primary part through an insertion pin and can be inserted loosely in the radial direction, wherein at least one O-ring covers the radial distance between the primary part and the secondary part, elastically defined by force and remoteness. WO 99/52464 AI relates to an individual dental implant, having a base body and a crown, wherein the base body has a positive joint with attachment elements for positive engagement with the crown and a the centering zone and the crown further presents to it a positively coupled section and a centering section, wherein the positive attachment members of the positive attachment section are positioned lowered by the front wall of the base body. The object of the invention is to provide a two part dental implant which ensures a stable attachment of the two implant parts and prevents the formation of a gap between the two implant parts.

This object is achieved by means of a two-part dental implant having the features indicated in claim 1. Some preferred embodiments result from the dependent claims.

In a preferred variant of the sealing body, it has sealing surfaces of resilient material, so that the sealed surfaces abut sealingly or sealingly on surfaces provided for this purpose of the distal and proximal implant parts, when the distal implant part and the implant part of proximal implant are attached to one another. The sealant, as well as the proximal and distal implant parts, are configured such that, upon establishment of definitive bonding between the distal and proximal implant parts, a surface compression reigns between the sealing surfaces of the sealing body and the corresponding surfaces of the two parts of the implant, which is also maintained when the implant is subjected to chewing forces and elastically deforms as a result of these chewing forces also in the transition zone from the proximal to the distal implant part.

Accordingly, according to the invention, between two front surfaces, facing each other in the longitudinal direction of the rod and situated outwardly with respect to the radial direction of the rod, with the two-part rod mounted ready, is provided a sealing member which is dimensioned such that, in the event of axial loading of the dental implant, it is not compressed in the axial direction of the rod and in the case of lateral loading it is always compressed in a minimum dimension. In the assembly of the implant, the seal is thus compressed only to the required size, so that the implant abutment connection ensures leaktightness under all possible circumstances. The size of the compression is dependent on the material and the thickness of the material; with the use of a greater height of assembly of the seal, the possibility of compression of the material could no longer be realized in a smaller way, to compensate for the movements in the sealing zone.

For the assembly of the sealing body, a sealing body support is preferably provided, which serves as a positioning aid for the sealing body and may already be placed by the sealing body manufacturer, so that the dentist who makes the sealing end of the implant can easily mount the seal body with the aid of the seal body. The test explained in more detail below shows that seals with a sealing body made of rigid material can not guarantee the desired tightness:

An analyzed implant was tightened to the height of the implant shoulder (proximal end of the distal implant part) rigidly in a retaining device.

On the distal implant part the proximal implant part was bolted by means of a threaded stud, with a defined mounting force. A force of 100 N was applied at an angle 5 of 30Â ° to the longitudinal axis of the implant on the proximal front surface of the proximal implant part and, thereby, caused an elastic deformation of (reversible) material of the implant components mounted.

This provided the following measurement results:

In the area of the two facing surfaces of the two implant parts the following changes occurred during the force effect:

On the force incidence side, the nominal mass dimension foreseen for the seal (defined slit) increases by a value > 1 pm.

On the side opposite the force effect, the nominal mass dimension foreseen for the seal (defined slit) decreases, at the same time, by a value of > 50 pm. The test was performed with the materials of a titanium alloy (Ti6AI4V) and a ceramic (ZrC > 2).

These measurements support the recognition which is at the basis of the invention, that a rigid or plastic deformable seal does not represent any protection against a penetration of bacteria in this zone.

The seals which are based on the principle of permanent deformation of a sealing body only work on connections whose components do not have any forces. 6

Dental implants serve to replace missing chewing organs and thus have to withstand forces called chewing forces and are permanently exposed to them. Already with reduced extra-axial forces and axial forces, which exceed the mounting force of the threaded connection, arise in the use of a rigid or ductile sealing body, slits that are not reclosed. Thus, these bonds can not be designated as impermeable to bacteria.

The forces required for surface compression between the sealing body and the respective implant part can be produced in two ways. On the one hand, the sealing body may be elastically compressed during connection of the proximal implant part and the distal implant part between the two implant parts, when the type of the connection - for example, an axial screw connection - and the type and sealing arrangement are chosen accordingly. An arrangement in which the sealing body is in the form of a circular disc with a central through aperture and is positioned between two surfaces that extend radially from the distal and proximal implant part is advantageous.

On the other hand, the seal may also have a seal, which expands upon establishment of the connection between the distal and proximal implant part. Such an arrangement can best be realized when the surfaces of the two parts of the implant are situated facing each other in the radial direction so that an intermediate space to be filled by the seal between the proximal and distal implant part must be filled by a sealing body, which is in the form of a short tube which narrows eventually towards the distal end. It is advantageous when the sealing body exhibits the elastic characteristics already described or is inserted into the proximal implant part or the distal implant part in its contracted condition, for example by cooling, then the other respective implant part is attached to the first implant part and the sealing body then expands - for example as a result of heating. The same principle can also be applied to a seal in which the sealing body is in the form of a circular disc with a central through-opening.

Suitable materials for the sealing body are biocompatible plastics, and in particular elastomers or duromers. For this, a particularly suitable mixture of rubber and PTFE should also be considered. This blend preferably contains carbon black as a filler. Also contemplated are thermoplastic elastomers and elastomeric alloys (e.g., polyolefins polypropylene), thermoplastics (for example, perfluorelastomers (PTFE, FKM, FFKM, FFPM) and polyetheretherketone (PEEK)) and thermoplastic (amino or phenolplastic) or a silicone, as elastic plastic for the sealing body.

Among these elastomers, FFKM, which contains PTFE as the base material, with silicic acid as the filler, is especially suitable. A black coloration of such an elastomer can be obtained with carbon black and a white coloration with titanium dioxide or barium sulfate. Silicic acid, on its own, can provide sufficient white coloration.

Especially suitable is also a sealing body which is largely formed by an elastomer which is coated on its outer side with a thermoplastic or a diene, and in particular preferably with PTFE. Here, the elastomer permanently resists strain and PTFE is mouth-resistant and durably seals.

Another suitable coating material is a dimer, such as diapraxylylene, which is also known as Parylene and can be applied to surfaces to be coated in a plasma coating process. Suitable layer thicknesses are between 0.5 Âμm and 50 Âμm. Especially suitable are layer thicknesses between 1 pm and 5 pm, for example 3 pm. In the following there is shown, by way of example, structural formulas of such a coating material:

The surface of the Parylene coating may additionally be provided with a metal coating, such as titanium or silver - also in combination with a ceramic. The coating provides both an impermeability to the bacteria and, at the same time, a neutral behavior towards the cellular tissue. The respective surface to be coated is preferably polarized to raise its adhesiveness to the coating. Such a biasing of the surface may occur in a known manner, basically, with the aid of a plasma process.

In addition, it may be advantageous to bias surfaces of the implant or its integral parts, in particular the surface 9 facing away from the sealing body, to obtain better compatibility of the body. By a polarization it is achieved that the adjacent tissue, such as bone and gum, behaves or behaves in a way that does not reject the coating.

With respect to a partially lined sealing body, it is convenient when the coated surfaces do not have any sharp edges. On the contrary, all the coated edges must be rounded, to avoid a desquamation of the coating, when the sealing body conforms. It is advantageous when the elastic material of the sealing body is elastically expandable or compressible by at least 5%, better still by more than 20%. In one example, for example, the predetermined distance by means of the abutment surfaces between the facing surfaces of the two implant parts is 250 Âμm, so that the seal has a nominal size of 250 Âμm. In this case, the sealing body is to be produced, for example, 50 Âμm above the nominal size (250 Âμm) of the seal, so that, after assembly together, a compression of 50 Âμm (20 percent compression) already appears. These magnitudes represent an ideal ideal dimension. The height of the construction of the seal should be kept as low as possible so as not to offer, for aesthetic reasons, a construction height for the future dental crown; nominal dimensions are in particular dimensions between 0,1 mm and 3 mm. For sizing it is decisive that the seal is also deformed under the effect of chewing forces only in the area of its elastic deformability and that it also remains compressed in partial zones, for example in case of lateral loading, always by a minimum dimension. The sealing body is thus compressed only in the necessary dimension 10, when assembling the implant, so that the implant abutment connection ensures a leakproofness under all possible circumstances. The size of the compression is dependent on the material and the thickness of the material, with the use of a greater height of assembly of the seal it would be possible to reduce the possibility of compression of the material, to compensate for the movements in the sealing zone.

For a sealing body which expands under the action of heat, plastics with a high coefficient of thermal expansion, in excess of 75 x 10-6 / K at 20 ° C, are advantageously advantageous.

Preferably, at least one outer surface of the seal body, which forms an outer surface of the implant, is coated with a metal or ceramic layer, in the manner described above, wherein the metal layer of Parylene or ceramic prevents a penetration of bacteria into the seal components, coated by the metal or ceramic layer. A nanorevestimento, for example with titanium particles, is especially suitable. The sealing surface itself may consist directly of a biocompatible plastic or be coated in the above-mentioned manner. As the material for the metal layer, titanium, silver or gold, optionally also in the form of a component of an alloy, are considered. All materials on the surface of the seals are mouth-resistant and sterilizable and do not absorb any water or absorb it only in very small dimensions. The sealing body may contain, in addition to elastic plastic, also a metal spring or a separate plastic element, made of another plastic, such as PEEK. The spring element may for example be in the form of a disk spring or a ring having a U-shaped cross-section, opened inwardly and ensuring the durable tensile elasticity and force of the sealing member. A metal spring may be advantageous, in particular in a sealing body in which the elastic plastic is at least partially made up of polytetrafluoroethylene (PTFE, Teflon), polypropylene (PP) or also polyetheretherketone (PEEK). The invention is based on the knowledge that a two-part dental implant has no micro-cleft in the area of the bone exit point, since the implant abutment (IAV) is precisely at this point, the connection between the proximal implant part and the distal implant part. This bond causes a micro-fissure, this micro-fissure, in turn, is the subject of current scientific discussion. It is known that the bone reabsorbs up to about 0.5 mm below the implant abutment attachment (provided it is located exactly at the height of the bone). The tissue adjacent to the implant abutment attachment (gum and bone) has been shown to show signs of inflammation. There are proven to be, among others, polymorphic nucleus leukocytes, which are derived from bacterial induced processes. As a basis for this phenomenon, the lack of watertightness of BTI and its colonization by bacteria is discussed. The result of bone loss is a regression of the gum, resulting in teeth that become longer (implant crowns). In aesthetically demanding regions, such as in the frontal area of the teeth, bone loss is a major problem. The sealing body is preferably in the form of a ring which should be positioned between two abutment surfaces 12 which extend perpendicularly to the longitudinal axis of a respective implant part and which provides a bacterial impermeable seal. Such a sealing body or sealing ring preferably consists of a plastic material, which has a higher elasticity or a lower hardness than the material of the two implant parts. The two implant parts preferably consist of a metal, ceramic or plastic compatible with the body.

In an advantageous variant of the two-part implant, the surfaces of the two implant parts facing each other, between which the sealing member is positioned, run transversely to the longitudinal axis of the dental implant - hence in the radial direction - and in parallel each other. The surfaces of this type are especially suitable for placing between them a sealing body, which is in the form of a circular disc with a central through-opening. The central through aperture allows to produce the connection between the proximal and distal implant part, with the aid of a threaded stud which extends in the axial direction of the implant. The threaded stud also enables the sealant body to be sufficiently compressed so that the desired surface compression between its sealing surfaces and the surfaces of the implant parts occurs. The surface compression is limited here, through the abutting surfaces in contact with each other. In certain use cases, it is advantageous if the sealing member is thicker in the region of its outer edges than in a central region of the seal. Thus, the sealing body in the region of its edges in the assembly of the proximal and distal implant parts can be deformed such that its sealing surfaces abut exactly on the surfaces of the two implant parts. In alternative embodiments, the sealing body may, however, also have sealing surfaces that run parallel to each other or may be so shaped as an O-ring. The geometry of the proximal and distal partial shank is configured, in the transition zone between both portions of the shank, preferably such that the connection between both shank portions is not only suitable for directly transmitting chewing forces from the shank. rod from one part to the rod of the other part, but at the same time it is also protected against twisting.

According to a preferred embodiment, a distal partial shank forming a distal implant part has an oblong opening, open toward its proximal end, with an inner wall, having a basic geometry with a circular cross-section and into which V-shaped cavities are inserted, open towards the proximal end of the partial rod, which extend at least approximately in the longitudinal direction of the partial rod. A partial shank, which forms a proximal implant part, has at its distal end an outer wall with a basic geometry with a circular cross-section which fits the longitudinal opening of the distal partial shank.

Preferably, the outer wall of the mounting partial rod has, in the region of its distal end, V-shaped shoulders, which are so adapted to the V-shaped recesses of the distal shank that the side sections of the V-shaped recesses of the distal part rod cooperate with flank sections of the V-shaped shoulders of the mounting part rod such that the V-shaped shoulders of the mounting part rod move inwardly, such as a wedge, in the V-shaped recesses of the distal partial shank, until respectively two flanks of a V-shaped shoulder and two flanks of a V-shaped cavity come into reciprocal contact and, therefore, loosely attach the position relative to the distal partial rod and the partial mounting rod either in the axial direction or also in the rotational direction, when the distal split rod and the mounting split rod are connected to one another, or are connected to each other The. The mutually contacting flanks act as abutment surfaces and form an abutment of defined height. The height stop is shown by a defined geometric shape of the implant parts themselves. With this, the forces incident from above on the proximal implant part (proximal partial shank) are transmitted only to the distal implant part (distal partial shank). If the forces incident thereto were not diverted over the described height stop but rather through a seal, this seal would be destroyed throughout the duration of use.

In this case, the configuration of the distal partial shank offers the advantage of being able to accommodate also a partial mounting shank without V-shaped shoulders, so that the partial stems connected together in the result are fixed with the greatest precision, namely in direction, but not in the direction of rotation. This is advantageous, in space, when the rod serves for the attachment of a bridge. Then, no other element is required to house the bridge. The operator has to screw in the integration only a single element coherent with the implant fasteners that are in the mouth of the patient.

The flanks of the V-shaped shoulders or cavities extend in relation to a cross-sectional plane which runs perpendicularly to the longitudinal axis of the implant, preferably radially outwardly and thus run perpendicular to the direction of the periphery . Thus, the flanks that come in contact after the implant assembly do not transmit any radial forces, which could, for example, destroy a distal partial stem made of ceramic.

If the distal end rod consists of a more tensile material such as metal, in particular titanium, the flanks may also be inclined with respect to the rigid radial direction described above, such that flanks belonging to a respective shoulder of the (i.e., the proximal implant part) or belonging to a respective cavity of the distal partial shank (distal implant part) converge towards one another in an outwardly directed direction. The flanks may, for example, be inclined with respect to the radial direction and hence also at 45 °, with respect to the peripheral direction. With this, the flanks have a centering effect, not only in relation to the direction of rotation, but also in the lateral direction. The basic geometry of the outer wall of the partial mounting rod is advantageously conical, at least in the region of the V-shaped shoulders. Correspondingly, advantageously, the basic geometry of the inner wall of the oblong aperture of the distal partial shank, at least in the region of the V-shaped pockets.

For certain use cases, and in particular when the distal partial stem is ceramic, it may be advantageous when the basic geometry of the outer wall of the partial mounting rod, as well as the basic geometry of the inner wall 16 of the oblong aperture of the distal shank are cylindrical, at least in the region of the V-shaped cavities.

In both cases, the fit between the outer wall of the mounting partial shaft and the inner wall of the partial shaft distal, at least in the region of the V-shaped wells, is preferably a slack fit.

In addition, there are provided on the distal partial stem as well as on the mounting partial stem, preferably respectively four V-shaped cavities or V-shaped shoulders, which are evenly distributed over the periphery of the respective partial rod. In this way, four positioning possibilities, defined exactly in the direction of rotation between the distal partial stem and the partial assembly rod, result. Alternatively, there may also be provided more or fewer recesses and recesses in number corresponding to each other, which are preferably evenly distributed over the periphery of the respective partial rod. Some suitable numbers are, for example, 3, 6 or 8.

A very open V-shaped shoulder (obtuse V-angle) may also be convenient, in connection with a corresponding cavity in the distal partial shank.

As angles in V (opening angle of the respective V-shape) angles between 10 ° and 170 ° are considered. In the sense of a self-centering embodiment, it is advantageous when in this case the angle at V is less than the vertex angle of the respective friction cone, which results in virtue of the pair of materials in the region of the opposing flanks of the V-shaped shoulders or recesses.

A particular aspect of the invention, which may also be embodied in a manner different from that presented concretely herein, is that, from those front surfaces of a distal partial shank and a proximally mounted part shank, there may be a on the other, at the assembly of the two partial shafts, before the two partial shafts have assumed their definitive axial position relative to each other, none of the front surfaces is situated in a plane running perpendicular to the longitudinal axis of the two partial shafts. In known bipartite rods for dental implants with a rotation protection, which, as a rule, have such frontal surfaces running perpendicular to the longitudinal axis, which, with partial rods rotated relative to each other, may strike one another, before the two partial rods are moved completely into each other, there is a danger that a proximal mounting part rod is attached to a distal part rod in a rotated position, which results in the rod resulting from this False assembly has a longer length than expected because the two partial rods are not yet definitely moved one into the other. The final adjustments, in fact, for limiting the relative axial position of the two partial rods, in this case, have not yet come into reciprocal contact, because, by virtue of the rotation of the two partial rods previously, with respect to each other, at least a further surface running perpendicularly to the longitudinal axis of a respective respective shank struck an opposing surface of the other respective shank which is not actually provided for engagement with the front surface running perpendicularly to the longitudinal axis of the first shank . There is also no automatic correction of the failure of the angle of rotation because the two surfaces which abut one another in this way can not slide one over the other in the manner of an inclined plane and thus automatically suppress the angle of rotation. rotation.

In known rods for dental implants, a doctor or an operative technician should be aware that the two partial rods are placed one inside the other without failure of the angle of rotation, so that the two partial rods are not fixed one relative to the other to the other in a false position.

In the rod according to the invention, this problem is prevented by any of these frontal surfaces running perpendicular to the longitudinal axis of the respective partial rod - except for the surfaces provided for the definitive longitudinal end stop - are provided. This is achieved concretely through the V-shaped recesses or V-shaped shoulders. However, other geometric solutions are also conceivable.

This is based on the fact that the surfaces serving as a longitudinal end stop are arranged with a radius different from that of the other front surfaces which are used for positioning in the direction of rotation, which, in this case, are formed by the shoulders and recesses in shape of V.

Upon displacement of the two partial rods one into the other, the oblique surfaces of the V-shaped recesses or the opposing V-shaped shoulders lie respectively on an inclined plane. Upon further mounting of the partial shafts, the flanking surfaces which face one on top of the other slide over each other until the two partial shafts have assumed their final relative axial position and also the correct rotation angle relative to each other.

Suitable materials for the distal implant part and the proximal implant part are in particular metals, such as steel or titanium, but also ceramic or plastic.

To advantageously create reliably shaped implant parts, the proximal partial stem and the distal partial stem are preferably produced by means of metal injection molding (MIM) or by hot extrusion. The injection molding of metal allows, in only one working operation, the filling of the injection mold, to give the entire component its definitive geometry, which can be almost as complex as desired.

For injection molding of metal, no solid metal body is used, but rather as fine powder for the component to be produced. This powder is mixed with a binder containing plastic and kneaded to form a so-called feedstock. The feedstock is compressed in an injection mold (tool) under high pressure at approximately 100øC in a commercially available injection molding press which is a negative image of the respective partial rod. The resulting green part, respectively, for the proximal partial stem or the distal partial stem already has the desired final geometry, but has to be released back from the binder in the following operations to obtain a pure metal part. For this, the binder is removed in a multi-stage chemical and thermal process and, at the same time, the component is " agglutinated " by sintering at approximately 20-1200 ° C. In this case, metal, preferably titanium, is considered.

When the implant parts are not to be metal, but rather ceramic, ceramic injection molding (MIC) is considered as a suitable manufacturing process. The CIM process works exactly like the MIM process, the only difference being the use of the material. Also here we speak of feed load, with ceramic powder instead of metal powder. Correspondingly, in accordance with an alternate embodiment, ceramic components of the implant produced by MIC are used in spatially partial ceramic rods.

Alternatively, both of the partial shafts may also be produced by cold or hot extrusion.

For the alternative production of the proximal partial shank and the distal shank by means of hot extrusion, two shaping tools must be produced for each implant geometry for the production of the implant abutment attachment zone. The first processing tool is produced for the hot extrusion process.

In hot extrusion, titanium is brought into the " dynamic recrystallization zone " (this means heated to a temperature between 700 ° C and 900 ° C). The transformation operation of the assembly part (proximal partial shaft) is referred to as full forward extrusion or full forward extrusion by heating. The transforming operation of the implant part (distal partial stem) is referred to as hot back cup extrusion or back cup extrusion by heating.

For this, a rod-shaped material is cut to length, heated and placed in the transformation tool. The transformation takes place under high compression.

With a first transformation operation a result is achieved which is already very close to the end result that can be achieved.

After the first transformation operation, the entire geometry of the implant parts is already represented, which forms the implant abutment connection. Due to the thermal shrinkage of the cooled workpieces, small tolerances are still present. In addition, the surfaces are still blunted due to the strong heating of the workpieces required for hot extrusion. With titanium there is no danger of adhesion (the bonding of the titanium with the tool).

In another transformation step, the exact final shape and smooth smooth surfaces are then achieved in the region of the implant abutment connection between the two partial rods.

For the second transformation operation, a second transformation tool is used, with which a cold calibration or a hot calibration of the workpieces (proximal or distal part) is performed. The second transformation operation may occur at a defined time point during the cooling phase after the first transformation operation, in which the workpiece still has a temperature between about 400 ° C and 450 ° C.

For the second transformation operation, the respective workpiece is removed, fully automatically, from the first transformation tool and introduced into the second transformation tool. The alteration of the geometries through the second transformation operation occurs only very modestly, since the preferred material, titanium, behaves very uncomfortably in relation to a transformation, in the cold and hot state. Once the titanium metal grid has begun to flow, in a short time and locally, it becomes very rapidly fragile in another transformation. In case of too strong hot or cold transformation, the titanium microstructure is destroyed. In the case of a very small transformation, however, in addition to a defined final form of the parts to be worked in the area of the implant abutment connection, in addition, a hardness increase is also achieved by cold local hardening of the parts working.

The transformation processes are completed, respectively, after the second transformation operation and the geometry described below for the implant abutment connection between the two partial rods is ready. The tool set required for the hot extrusion, with the two transformation operations described previously for the transformation of a respective implant component, consists, respectively, of two transformation tools.

For the production of transformation tools, graphite bodies with a 5-axis micro-mill are initially produced. For the production of the transformation tool, the graphite bodies are eroded by EDM in a tempered steel block.

The resulting processing tool surfaces, which subsequently stamp the pieces in series, have to be polished by hand, in a very expensive process.

Eventually, it may still be necessary to mechanize one or both of the workpieces (proximal or proximal partial shank) into areas located outside the implant abutment attachment. The necessary conformation of the workpieces to the desired final shape is achieved by means of a chip start. This conformation refers to the geometries of proximal partial portions of the proximal partial stem for corresponding structures, for example crowns, as well as to the geometries of distal partial regions of the distal partial stem for the creation of an artificial tooth root.

For such shaping by chip trimming, the workpieces must be tightened onto a part holder of a corresponding machine. For this, it is possible to grasp the workpieces in the exact geometries thereof, produced by hot extrusion and to keep them during the starting of the trimmings.

To exclude inaccuracies, each workpiece is tightened only once for the trimming start.

A rotary machining center is therefore suitable as a machine for forming by chip trimming, and hence a machine in which all necessary trimming machining operations can be performed sequentially.

In order to reach the final shape of the assembly and the implant, the use of both stationary tools (in turning) and rotating tools (in milling) is usually required. In this process, there is also produced an axial through-hole in the proximal partial shaft, as well as an axial drilling with an internal thread, for the housing of a threaded stud, which connects both of the partial rods. In the figures, an embodiment of a rod according to the invention for a dental implant, including some variants for the sealing body, is shown in detail, as well as an example of a sealing body support, as an auxiliary tool for the assembly of the two partial stems. The figures show:

Figure 1: a perspective representation of a partial mounting rod, as part of a proximal implant;

Figure 2: a perspective representation of the distal partial shank, as part of a distal implant; 25

Figure 3: a representation of the stem, with distal partial stem and mounting partial stem attached to each other, the distal partial stem being partially transparent;

Figure 4 shows the distal partial stem and the partial mounting stem, in the shape of an exploded drawing, in perspective representation;

Figure 5: a longitudinal section through the rod;

Figure 6: a cross-section through the rod, from the portion designated D-D in figure 5;

Figure 7 shows an exploded drawing of the rod, with all its components, namely proximal and distal partial rod, sealing body, as well as threaded stud for connecting the partial rods to form the rod;

Figure 8: a longitudinal section through the assembled finished rod according to figure 7;

Figure 9: a longitudinal section through the distal partial stem;

Figure 10: another longitudinal section, rotated 30ø in relation to Figure 8, through the distal partial stem;

Figure 11: a longitudinal section through the proximal partial shaft; 26

Figure 12 shows a section similar to Figure 8, however without a sealing member;

Figure 13 is a preferred configuration of surfaces which are exterior to the longitudinal axis of the stem, distal partial stem and proximal mounting partial stem and a sealing ring, in a cross-sectional view;

Figure 14: the outer contour of a preferred transition from the proximal partial shank to the distal shank, in a perspective exterior view;

Figure 15 is an enlarged detail view of a variant embodiment of a partial mounting rod according to the embodiments in the perspective representation in Figures 7 and 8;

Figure 15 is a detailed view of a two-part dental implant with a preferred elastomer seal;

Figures 16a to c: the principle of the abutment surfaces facing each other, which limit the maximum compression of the seal;

Figure 17: a preferred ring-shaped sealing body made of an elastomer;

Figure 18 is an enlarged detail view of Figure 17; A sealing body partially coated with a nanorefacturing, according to Figures 17 and 18; a sealing body similar to that of Figures 17 and 18, with a concave outer coating surface; the sealing body 30 in its ready-assembled tablet condition between the proximal and distal partial shafts; an alternative sealing member in cross-section; the alternative sealing body of Figure 22 in its ready-assembled compressed condition between the proximal and distal partial shafts; the alternative sealing body of Figure 22, with a nanorevestimento; a second alternative sealing body, with nanorevestimento and integrated metal spring, in cross-section; an enlarged section of the second alternative sealing body of Figure 25; the reciprocating sealing body of Figures 25 and 26, in its ready-assembled compressed condition, between the proximal and distal partial shafts; 28

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Figure 34:

Figure 35:

Figure 36: the second alternative sealing body of Figures 25 and 26, with a nanorevestimento; an alternative embodiment of a seal; a perspective representation of a sealing body holder, which is not part of the invention; an enlarged section of the housing housing of the sealing body holder, in perspective representation according to Figure 30; a longitudinal section through the sealing body support of Figure 30; an enlarged section of the housing housing of the sealing body holder, in longitudinal section according to Figure 32; a perspective representation of the sealing body holder, with a sealing body inserted; an enlarged section of the perspective representation of the sealing body holder, with a sealing body inserted, in Figure 34; a longitudinal section through the sealing body holder, with a sealing body inserted, according to Figure 34; 29

Figure 37: an enlarged cross-sectional view of the longitudinal section of the sealing body holder, with a sealing body inserted, according to Figure 36;

Figure 38: the sealing body support of Figures 30 to 37, with a sealing body inserted, upon placement of the sealing body on the proximal shank portion.

In the case of the two-part dental implant reproduced in the embodiments, a proximal implant part is formed by a partial mounting stem 10 and a distal implant part by a distal partial shank 20.

As can be seen from the perspective representation reproduced in Figure 1 of the partial mounting rod 10, it has a longitudinal section 12, with a conical basic geometry, which narrows towards the distal end 14 of the partial mounting rod 10. The cone angle is 10 °. In the region of this longitudinal conical section 12, the partial mounting rod 10 presents in its entirety four V-shaped lugs 16, which are oriented with their tips towards the distal end 14 of the partial mounting rod 10. The four V-shaped lugs 16 act as triangular teeth and are arranged symmetrically and at the same distance from one another about the periphery of the conical longitudinal section 12 of the mounting part rod 10. In this way, eight flank surfaces 18, obliquely oriented towards the distal end 14 of the partial mounting rod 10. 30

In Figure 2, the distal split rod 20 is shown in perspective. This has an oblong opening, open toward its proximal end 22, with an inner wall 24 also having a basic conical shape. In the interior wall 24 there are provided four V-shaped cavities 26, which have flank surfaces 28, which are oriented obliquely towards the proximal end 22 of the distal part rod 20.

When the distal split rod 20 and the proximal split split rod 10 are attached to one another (see Figure 3), the relative position of the two split rods is defined as accurately as possible either in the axial direction or in the direction of by means of flank surfaces 18 or 28, which rest closely on each other. The flank oblique surfaces 18 or 28 of the flanges or V-shaped cavities thus form abutting surfaces facing each other, which limit the approach of the two facing surfaces 32 and 34 (see Figures 6 and 7). 7) and thereby the maximum compression of the seal 30 (Figures 6 and 7). This is represented figuratively in Figures 12a through 12c. In particular, Figure 12c shows how the surfaces 18 and 28 are in contact in the condition of the ready assembled dental implant and thereby form a longitudinal abutment.

An exact centering of the two partial rods is effected when mounting, by the opposing flank oblique surfaces 18 or 28, respectively, of the V-shaped flanges or recesses, respectively. In insertion of the partial mounting rod 10 into the oblong opening of the distal partial rod 20, the flank oblique surfaces 18 or 28 of the flanges or recesses are respectively on an inclined plane 31. The partial mounting rod 10 therefore slides with the continuation of insertion into the oblong opening of the distal partial rod 20 until it reaches its axial end position and rotates in this case until all opposing flank surfaces 18 and 28 have a uniform contact with each other. Thus, the partial mounting rod 10 is forced to move, without a slip prevented, to its desired end position and can then be secured by a threaded bolt 40, which projects in the longitudinal direction of the rod (see figure 7). This threaded bolt 40 is tightened with a force of 30 Nm.

The corresponding flank surfaces 18 and 28 serving, at the same time, as longitudinal abutment and as safety against rotation are then advantageously embedded within the oblong opening of the distal partial shank 20 and are not, as in other systems , in the area of the implant shoulder. The implant shoulder, with this, can be maintained at exactly the same level.

In the embodiments shown in Figures 1 to 5 no special measures are shown to configure, in a bacterial impermeable way, the transition from the proximal mounting part to the distal part, in the region of the outer contour of the assembled finished part.

According to the variant embodiment shown in figure 6, a sealing ring 30 is provided for this purpose, which is placed between a front surface 32 of the proximal mounting stem 10 ', which is situated on the outside, and a front surface 34 of the which is located externally, positioned opposite to that. In the assembled rod, therefore, when the proximal mounting stem 10 'and the distal split rod 20' have assumed their final relative relative position relative to one another, the seal ring 30 is compressed in the axial direction. The seal ring 30 is a biocompatible plastic.

In figure 7 there are shown, in an exploded drawing, the essential components of the rod according to the invention for a dental implant, namely the proximal partial stem 10, the distal partial stem 20, the seal body 30 for the transition seal between proximal and distal proximal rods and the threaded stud 40, which serves to screw the proximal and distal partial rods. The longitudinal section through the rod according to the invention for a dental implant, in Figure 8, shows all the essential components in the ready assembled condition, with the correspondingly compressed sealing body 30.

Figures 9 to 11 show individual components in a respective longitudinal section.

12 is shown as the flanks 26 or 28 of the shoulders 16 on the proximal partial shank 10, or the cavities 26 on the distal shank 20 cooperate in such a way that a centering is achieved on these flanks and not on the facing surfaces of the partial stems 10 and 20 that lie between them. The transition view between the partial mounting rod 10 'and the distal split rod 20', shown in the enlarged perspective and partially cut out figure 13, shows that the outer contour of the assembled finished rod in the transition zone of the rod 33 ' the partial distal rod 20 'has no interstices, in which there is a danger of permanently fixing bacteria.

This also results from the exterior view of the transition between the partial mounting rod 10 'and the distal partial rod 20' in Figure 14. Figure 15 shows a detailed enlarged view of the proximal mounting partial stem 10 ', in perspective representation. Also well-known are a support 36 for the sealing body 30, as well as the V-shaped shoulders 16 already discussed with respect to Figures 1 to 6. Figure 16 shows how the flanks 18 and 28 act as abutment surfaces on the longitudinal direction and thus provide a defined compression of the seal body 30 (see also Figure 12).

Figures 17 and 18 show a preferred sealing body 30 ', which is comprised of an elastomer, as FFKM, in cross-section. It can be recognized that the sealing surfaces 36 of the sealing body 30 'are not flat, but instead protrude on the outer edge of the sealing body, in the axial direction of the implant and thus, form flanges 42 and 44. These flanges are deformed in in the case of strong attachment of the proximal and distal implant parts and thus produce a secure seal. Figure 19 shows the sealing body 30 'of Figures 17 and 18, with a coating 38 made of Parylene, as described in the introduction. From Figure 18 it can also be seen that the coated edges 34 of the sealing body 30 'are rounded to prevent peeling of the coating in the region of these edges. Figure 20 shows that the outer shell surface 50 of the seal body can be configured concave so that, as a consequence of the compression of the seal body, upon assembly of the rod to a dental implant, according to the invention, it is stretched both as possible rectilinearly. Figure 21 shows the rounding of the edges of the sealing body 30 and the partial stems 10 and 20 at the locations marked by arrows.

Figures 22 to 24 show a body 30 " sealant 60 with an elastomer body 60 in the form of an O-ring which is inserted into the ring member 62, with an U-shaped cross-section open inwardly. Figure 22 shows the body 30 " alternative seal in cross-section. Figure 23 shows, in an enlarged cross-sectional view, the body 30 " sealant, in the condition of being inserted between the proximal partial stem 10 and the distal partial stem 20. Figure 24 shows that also the body 30 " Alternatively, the sealant may have a coating 38 made of Parylene, for example.

Figures 25 and 27 show, by way of example, another alternate embodiment variant of a body 30 " ' seal having a metal spring 48 therein. The metal spring 48 is in a resilient plastic body 46, which is ring-shaped and has an U-shaped cross-section open inwardly. The plastic body is preferably PTFE and the metal spring 48 is made of stainless steel. As shown in Figure 26, the plastic body 46 may externally have a liner 38, for example of Parylene. Outwardly, the plastic body 46 is covered with a layer 38, a few nanometers thick, which, in the preferred embodiment shown, contains titanium particles. The thickness of the layer 38 is shown greatly exaggerated in the figure to make the layer visible. Such a coating may be provided on all the outer surfaces of the sealing body, and in particular independently of the outer shape of the sealing body.

In alternative embodiments, the springs may also be formed of another elastic material, for example titanium or a plastic, such as PEEK. The springs may also have another shape, provided that they exert an elastic effect in the longitudinal direction of the sealing body, indicated by the dash and dot line (see figure 25). Figure 28 shows a sealing body in which a ring-shaped plastic body, for example made of PTFE, with an U-shaped cross-section open inwardly, is partially filled with elastomer 64. Figure 29 shows a seal with a body 30 " sealant made from an expandable material, such as, for example, expandable metal or a plastic having a high coefficient of thermal expansion. The body 30 " seal of Figure 29 is in the form of a tubular section. The space between part 10 " " of proximal implant and part 20 " " of distal implant is configured accordingly. 36

Figures 30 to 38 show a sealing body holder 70, which serves as a tool for mounting a sealing body 30 on the proximal partial stem 10. The sealing body support 70 has at one end an inwardly open groove 72 into which a sealing body 30 can be inserted. Preferably, the sealing body support 70 is also equipped with the sealing body immediately after the sealing body 30 is produced by the sealing body 30. This facilitates handling by the physician and improves hygiene. An externally knurled gripping zone 74 facilitates handling in this case.

Lisbon, 22 May 2012 37

Claims (28)

A two-part dental implant having a distal implant part (20) and a proximal implant (10), which, in a condition of being connected to one another at a point of attachment, are contiguous with one another and, in the vicinity of the implant (32, 34) facing one another, between the surfaces (32, 34) facing each other of the distal (20) and proximal (10) implant parts, there is provided a a sealing body (30) having sealing surfaces (36) facing the surfaces (32, 34), which seal in a sealed manner on their surfaces (32, 34) facing each other, in the condition of permanent connection of the two implant parts (10, 20), between the distal implant part (20) and the proximal implant part (10) there are provided abutting surfaces (18, 28) facing one another, which, with the implant ready-made dental implant are in contact with each other and which limit the size of the implant. (32, 34) facing one another of the implant parts (10, 20), between which the sealing body (30) is placed, so that the abutment surfaces (18, 28) define a minimum distance between the two surfaces (32, 34) facing one another of the implant parts (10, 20) which is bridged by the sealing body (30) and wherein the sealing body (30) is at least partially formed of an elastic material, characterized in that the outer surface of the sealing body (30) forms an outer surface of the dental implant. 1 A dental implant according to claim 1, characterized in that the surfaces (32, 34) facing each other run transversely with respect to a longitudinal axis of the dental implant and parallel to one another. Dental implant according to claim 1, characterized in that the surfaces (32, 34) facing each other are conically shaped, have the same cone angle and are concentrically arranged relative to one another and with respect to an axis length of the dental implant. A dental implant according to any one of claims 1 to 3, characterized in that the sealing body (30) is in the form of a circular disc, with a central through-opening. Dental implant according to any one of claims 1 to 4, characterized in that the sealing body (30) has concave shaped front surfaces (36), so that the material thickness of the sealing body (30) measured in the longitudinal direction of the implant, at least in the stress-relieved state, is greater in the peripheral edge region of the sealing body (30) than in a central region of the sealing body (30). A dental implant according to any one of claims 1 to 5, characterized in that the elastic material of the sealing body (30) can be elastically compressed in at least 5% of a stretching direction. 2 A dental implant according to any one of claims 1 to 6, characterized in that the elastic material of the sealing body (30) is a plastic. Dental implant according to claim 7, characterized in that the plastic is an elastomer, thermoplastic or a mixture of duromers. A dental implant according to any one of claims 1 to 8, characterized in that the seal (30) has, along with the plastic, metal or ceramic components, which are preferably an integral component of the body ( 30) sealant. A dental implant according to claim 9, characterized in that at least one outer surface of the seal body, which forms an outer surface of the implant, is coated with a metallic, ceramic or plastic layer (38), wherein the layer 38) prevents the penetration of bacteria into the seal components coated by the metal, ceramic or plastic layer (38). A dental implant according to claim 10, characterized in that the metal layer (38) contains titanium, silver and / or gold or the plastic layer contains PTFE. A dental implant according to any one of claims 1 to 9, characterized in that at least the sealing surfaces of the sealing body (30) are formed of a resilient, biocompatible, mouth-resistant and sterilizable plastic. 3 A dental implant according to any one of claims 7 to 12, characterized in that the plastic has a coefficient of thermal expansion greater than 75 * 1CT6 / K at 20 ° C. A dental implant according to claim 1 or 3, characterized in that the sealing body is placed in a radial free space between the surfaces of the distal and proximal implant part, the expansion of the radially extending sealing body being greater than the clearance between distal and proximal implant portions, in their fully bonded condition. A dental implant according to any one of the preceding claims, wherein a proximal end (22) of the distal partial stem (20) and the distal end (14) of the partial assembly stem (10) are configured by geometrically adjusting a to the other and, in the implanted condition of the stem, are contiguous with each other, the distal partial stem (20) having an oblong opening, open towards the proximal end (22) of the distal partial stem (20), with a wall (24) having a basic geometry with a circular cross-section, wherein V-shaped cavities (26) are opened in the inner wall towards the proximal end (22) of the distal partial rod (20), and wherein the partial mounting rod (10) has at its distal end (14) an outer wall with a basic geometry with a circular cross-section which fits the oblong opening of the distal partial rod. 4 A dental implant according to claim 15, characterized in that the outer wall of the partial mounting rod (10) has, in the region of its distal end (14), V-shaped shoulders (16) which are adapted from such (26) of the distal split rod (20), which, with the distal split rod (20) and the assembled split rod (10) connected to one another, side flange sections (18, 28) V-shaped cavities 26 and V-shaped shoulders 16 cooperate in reciprocal contact and form the abutting surfaces facing each other, which limit the compression of the seal 30. A dental implant according to claim 15 or 16, characterized in that the distal partial stem (20) has four of the V-shaped recesses (26) which are evenly distributed over the periphery of the inner wall (24) and that the stem (10) correspondingly presents four of the V-shaped shoulders (16), which are evenly distributed evenly over the periphery of the outer wall. A dental implant according to claim 16, characterized in that the basic geometry of the outer wall of the partial mounting rod (10) is conical in the region of the V-shaped shoulders (16). A dental implant according to claim 18, characterized in that the basic geometry of the inner wall (24) of the oblong opening of the partial stem (20) distal in the region of the V-shaped cavities (26) is conical. 5 A dental implant according to any one of claims 15 to 19, characterized in that the sealing body (30) is placed between two frontal surfaces (32, 34) which are opposite each other with the rod in the assembled condition and which are outwardly in relation to the radial direction of the rod, acting as a seal, the sealing body (30) being dimensioned so as to be compressed in the axial direction of the rod, when the partial rod (20) is distal and the rod (10) have assumed their final relative axial position relative to one another. A dental implant according to claim 20, characterized in that the sealing body (30) is in the form of a circularly shaped, sealing ring of rectangular cross-section of the material. A dental implant according to any one of claims 15 to 21, characterized in that the distal partial shank and / or the proximal shank are produced in a biocompatible metal. Dental implant according to claim 22, characterized in that the metal is titanium or an alloy containing titanium. A dental implant according to any one of claims 15 to 21, characterized in that the distal partial shank and / or the proximal partial shank are produced in ceramic. 6 A dental implant according to claim 24, characterized in that the ceramic is sickled and / or polished. Dental implant according to claim 24 or 25, characterized in that the ceramic contains Zr02, Zr02 / ZA1203 / Y203 (ATZ), Zr02 / Y203 (TZP) or Zr02 / Y203 / Al203 (TZP-A). A dental implant according to any one of claims 15 to 21, characterized in that the distal partial shank and / or the proximal partial shank are produced in plastic. Dental implant according to claim 27, characterized in that the plastic contains polyether-ether ketone (PEEK). Lisbon, May 22, 2012 7