Source: https://patents.google.com/patent/JP4732368B2/en
Timestamp: 2019-10-21 19:29:18
Document Index: 186555184

Matched Legal Cases: ['art 11', 'art.\n5', 'art 11', 'art 11', 'art 12', 'art 11', 'art 12']

JP4732368B2 - Implant transplanted into bone tissue, its production method and transplantation method - Google Patents
Implant transplanted into bone tissue, its production method and transplantation method Download PDF
JP4732368B2
JP4732368B2 JP2006553408A JP2006553408A JP4732368B2 JP 4732368 B2 JP4732368 B2 JP 4732368B2 JP 2006553408 A JP2006553408 A JP 2006553408A JP 2006553408 A JP2006553408 A JP 2006553408A JP 4732368 B2 JP4732368 B2 JP 4732368B2
JP2006553408A
JP2007522847A (en
エシェリーマン，マルセル
トルリアーニ，ローラン
ラスト，クリストファー
2005-01-28 Application filed by ウッドウェルディング・アクチェンゲゼルシャフト filed Critical ウッドウェルディング・アクチェンゲゼルシャフト
2007-08-16 Publication of JP2007522847A publication Critical patent/JP2007522847A/en
2011-07-27 Publication of JP4732368B2 publication Critical patent/JP4732368B2/en
The present invention relates to implants implanted in bone tissue in the field of medical technology, even if this implant is a standardized implant implanted in a cavity that is specially made or adjusted for implantation purposes. Or it may be an individual implant (eg, a dental implant, a joint implant or an implant that fills a bone defect) implanted in an individual bone cavity. The present invention further relates to an implant production method and a transplantation method.
Implants that are implanted into bone tissue are usually in bone cavities specially made for implantation purposes (eg bores or stepped bores) or in bone cavities caused by other situations (eg trauma or debilitating disease) Transplanted. According to the state of the art, such implants are fitted into the cavity by cement placed around the implant, or as many functionally essential implant surfaces as possible come into direct contact with the bone tissue after implantation. As such, the shape of the implant is very accurately adapted to the cavity. For individual implants, this means that the shape of the implant is irregular, in particular an irregular cone with no continuous circular cross section and / or no straight axis.
Dental implants that are implanted in the jawbone to replace natural roots and to support, for example, artificial crowns, abutments, bridges, or a set of dentures, are specially created cavities or at least correspondingly Known as standardized implants that are implanted in an adapted cavity and even as individual implants that are adjusted to the shape of individual roots or alveoli.
Standardized dental implants that are implanted in specially made bores are cylindrical or slightly conical and are essentially rotationally symmetric pins, mostly screws. They are available in the market with various sizes and shapes, from which the dentist chooses the implant that best fits the specific case. In general, transplantation of such dental implants is not possible until the cavity resulting from the removal of the replacement natural tooth root is filled with regenerated bone tissue, i.e. after a waiting period of 3 to 6 months after the removal. Is possible. Normally, immediately after implantation, the screwed implant is not stressed because the risk of stress moving the implant excessively relative to the bone tissue is too high. It prevents the implant from osseointegrating in bone tissue. Thus, in most cases, until after a further waiting period of 3 to 6 months, ie the implant is fully integrated into the bone tissue and the relative movement between the implant and the bone tissue due to normal loading Until the physiologically tolerable range is no longer exceeded, the part protruding from the jaw (crown, bridge, etc.) is not attached to the implant.
Experience has shown that screw-shaped dental implants fully integrated in the jawbone are sufficiently stable under normal loading conditions and do not change over time. This is especially because the implant is firmly fixed laterally to the bone tissue by the threaded portion, which reduces shear on the bone tissue and prevents unwanted pressure on the alveolar base.
It is well known that bone tissue tends to recede in an undesirable manner during the aforementioned waiting period when the dental implant or jawbone is not locally loaded. Furthermore, it is also known that relative movement between the implant and bone tissue that does not exceed the physiologically tolerable range will stimulate bone regeneration and thus osseointegration of the implant. For these reasons, many attempts have been made to find methods and means for reducing or eliminating the waiting period.
The first waiting period, i.e. the time it takes for the cavity created by the extraction of the natural root to be filled with regenerated bone tissue, and the denser bone layer surrounding the natural cavity (alveoli) as a support element In order to reduce the time it takes to take advantage of the (alveolar bone), the shape of the natural tooth root (individual implant) that replaces the implant instead of being rotationally symmetric and circular like a screw It is proposed to mold to essentially correspond to Such implants can be implanted into existing cavities (natural alveoli) immediately after the removal of the natural root or shortly thereafter.
However, under natural conditions, there is a supporting thin film of fibers between the root and the alveolar wall so that an exact replica of the natural root (eg produced by a negative-positive casting method) An implant that does not settle firmly in the alveoli. This is because during the second waiting period a kind of connective tissue is formed in the gap between the alveolar wall and the implant, which at least locally impedes osseointegration and gives the implant sufficient stability. Demonstrate negative effects on osseointegration that cannot be done.
US-5562450 (Gielov et al.) To improve implant stability during the osseointegration phase (second waiting period) and to improve the initial state for successful osseointegration therewith. And in WO-88 / 03391 (Lundgren), increasing the size of the implant relative to the natural root, i.e. giving the implant a slightly larger cross-sectional area, the implant surface being bone, in particular a recess ( It is proposed to structure it in contact with a honeycomb structure, a structure with an undercut). The implant is suitable for example by non-contact measurement of the extracted natural roots or alveoli, by processing the measurement data with a CAD system, and with a CAM system based on the processed measurement data. Produced by forming implants from blanks by milling, grinding, electronic erosion and the like.
Such larger sized dental implants settle into the alveolus by “press fit” much more firmly than an exact replica of the natural root. However, experience shows that the deformation process and mechanical relaxation cause the alveolar wall to weaken the applied pressure force in a short time. The implant is therefore no longer stabilized by “press fit” and is again loosely placed in the alveoli, which results in improved primary stability immediately after implantation, but the conditions for osseointegration are optimal is not. It is also clear that even after the osseointegration period (second waiting period), these implants tend to loose their grip within the jawbone when loaded. As reported by RJ Kohal et al. (DentSci () at the 52nd Annual Meeting of the German Society for Dental Prosthetics and Material Science (DGZPW) in May 2003 2) published at 7:11), the jawbone can regress significantly in such implant regions under the osseointegration phase and subsequent loads, and even the implant can be completely dislodged.
The aforementioned findings are explained, inter alia, by the large surface contact between the implant and the bone tissue that undergoes extreme deformation due to surgery (extraction), and therefore very little stress induced in the bone. be able to. This is generally true for implants implanted in bone cavities as well as dental implants. The surface shape can increase tension very locally via “press fit”, however, the associated volume is too small to appear to effectively reach the mechanically induced stimulation of bone regeneration. is there. The pressure on the implant generated by the load (chewing movement) results mainly in shear forces in the cavity wall. Furthermore, the shape fit between the implant and the cavity wall can provide little enough stability against torsional forces. Due to the lack of sufficient rotational stability, dislocations may occur in the area of the bone being regenerated, and this dislocation prevents the success of osseointegration. These issues have been discussed in detail particularly with respect to hip prostheses. For dental implants, transmission of axial pressure to the outer alveolar wall is only possible to a certain extent because of the steep wall. This can cause stress to move from the proximal portion of the alveolar (natural tooth) towards the distal portion of the alveolar (implant), resulting in excessive loading on the alveolar base, which can cause blood vessels and nerves to Since it is an exit point, it naturally means that it is not completely ossified immediately after extraction. This can result in other problems caused by compression necrosis and loading in the wrong direction. In this case, the alveoli are usually completely ossified, but much attention is paid to these problems in conventional screw implant designs.
In summary, of the known bone implants that are implanted without cement, screw-shaped implants are preferred over all other types in terms of stability, but they are often the unavoidable geometric prerequisites required for application. It cannot be used, or at least without incurring other disadvantages. The same applies to many other implants implanted in bone tissue.
Accordingly, it is an object of the present invention to create an implant (individually or standardized) that is implanted into bone tissue, its production method and implantation method. Once fully integrated into the bone tissue, the stability of the implant according to the invention is at least comparable to that of a screw-shaped implant that is screwed into the corresponding bore. However, the primary stability (immediately after implantation) of the implant according to the invention is much higher (especially against torsional loads) than the primary stability of screw-shaped implants. Furthermore, the implant according to the invention is significantly less limited in shape than screw-shaped implants. Nevertheless, the implant according to the invention can be implanted in a manner known per se and the implant can be produced in a manner known per se.
This object is achieved by the implants and methods defined in the corresponding claims.
The implant according to the present invention is implanted essentially parallel to the implant axis (ie without substantial rotation), with a distal end region facing forward in the implantation direction and facing the distal end region along the implant axis And a proximal end region located there. When implanted, the proximal end region may be positioned in the bone surface region or may protrude from the bone. The implant surface between the distal end region and the proximal end region is at least partially brought into contact with bone tissue during implantation and comprises a cutting edge that forms a tip. These cutting edges do not extend in a common plane with the implant axis (ie during implantation), move essentially perpendicular to their length in the bone tissue and not towards the distal end, and towards the distal end region Yes. In addition, the implant comprises a material that can be liquefied by mechanical vibration, e.g. a thermoplastic, which material is located in a surface area without the cutting edge or is or can be located in a hollow space within the implant. The hollow space is connected to the surface area without the cutting edge by an opening.
The implant according to the invention is inserted into the bone cavity substantially in the axial direction of the implant, ie without substantial rotation, and the cutting edge cuts into the bone surface. Simultaneously with the insertion of the implant into the bone cavity, the implant collides with mechanical vibrations. Thereby, in this case, the liquefiable material, which is advantageously a thermoplastic material, liquefies at the point of contact with the bone material, with irregularities and holes,
Or it is pushed into the structure in the cavity wall specially formed for this purpose, thus causing intensive contact with the bone surface. When the liquefiable material re-solidifies, it forms a link between the implant and the bone tissue, connecting the two by shape matching and possibly material matching.
If the liquefiable material is positioned in the hollow space of the implant, it is advantageous that no mechanical vibration is applied to the implant until the implant is positioned in the cavity, and then mechanical vibration is applied only to the liquefiable material. It is. In this case, the liquefiable material may be a thermoplastic material or thixotropic, particulate, hydraulic, or used in orthopedics to fix the implant or for example infiltration of pathologically destroyed vertebrae Polymer cement may also be used.
Implants according to the invention are stabilized in the cavity immediately after implantation by connection with bone tissue through a liquefiable material, this stabilization being against pressure and tension (eg parallel to the implant axis) as well as torsional loads. Even it is effective. The cutting edge that cuts into the bone tissue during implantation also contributes to the fixation of the implant. Fixing by both the liquefiable material and the cutting edge is particularly effective on the outer wall of the cavity, so that the load on the cavity substrate is reduced or eliminated is particularly important for dental implants. All the effects listed give primary stability to the implants according to the invention, which stability is in most cases sufficient to withstand the loads immediately after implantation. The connection structure of thermoplastic material has a lower elastic modulus than the bone matrix, especially the implant itself, and is particularly advantageous for absorbing shock and reducing excessive stress due to its ability to creep. Its elasticity can reduce the relative motion between the implant and the bone tissue, thereby promoting osseointegration by stimulating the bone tissue, particularly in the cutting edge region. At the same time, these connections prevent large displacements between the implant and bone tissue that lead to disruption of the osseointegration process.
Since the implant according to the invention is implanted essentially without rotation (especially without rotation greater than 360 °), it is possible to form the implant in such a way that the shape of the implant contributes to stability against torsional forces in the cavity. And advantageous. Although not yet shown, it is possible to design an implant according to the invention to be suitable for implantation into a cavity (bore or stepped bore) with a circular cross section.
If the implant according to the invention is an individual implant, it will most likely have an irregular (not round) conical shape, i.e. taper towards the distal end, in the case of a dental implant, natural The shape is essentially adapted to the shape of the root. Such individual dental implants according to the present invention are implanted immediately after removal of the natural root, as are known dental implants that replicate the natural root. However, in contrast to the known individual dental implants, also called tooth replicas, the implants according to the invention remain stable during the osseointegration period and for a long period thereafter, as in the case of screw-shaped dental implants. The same applies to individual joint prosthetic implants according to the invention and to such implants for the reconstruction of individual bone defects.
If the implant according to the invention (for example a dental implant) is tapered towards the distal end, the cutting edge is designed as the outer edge (step) of the stepped reduction in cross section. Again, the cutting edge is sized relative to the cavity in a manner that cuts into the cavity wall during implantation and remains at least partially there after implantation.
The cutting edge, or the step comprising the cutting edge, extends entirely or partially around the implant, is essentially orthogonal or at an angle to the implant axis and has a wedge angle of less than 90 ° (FIG. 5). Implants designed as cones, in addition to the cutting edge,
It may also include a step-like reduced portion (step) of a cross section without a cutting operation (the wedge angle is 90 ° or more).
For a step without a cutting edge and / or for a relatively deep step, it is advantageous to make a suitable shoulder in the cavity prior to implantation, for example with the aid of a shaped tool adapted to the implant. Whether the method with or without the shoulder preform in the cavity is selected depends in particular on the conditions of the bone tissue at that time, but also on the surgeon and patient . Shoulder preform (its depth is approximately equal to the depth of the corresponding implant step) reduces mechanical stress on the bone tissue during implantation, making this method particularly suitable for older patients with poor bone quality .
Once implanted, the cutting edge of the implant according to the invention remains in the bone tissue of the cavity wall, similar to the threaded portion of the screw-shaped implant, so that the lateral support on the bone tissue, i.e. the pressure acting on the implant, is present. It forms a point that is joined to the bone tissue from the lateral implant region, which is in fact much more than is possible with a conical or cylindrical, essentially smooth implant surface without cutting edges and steps. It becomes a right angle. These lateral supports represent points that are particularly stressed when bone regeneration is stimulated.
In addition to the structure described above, the implant according to the invention may further comprise a constriction or self-tapping structure extending in a plane common to the implant axis, ie essentially in the implantation direction. These structures penetrate the cavity wall and provide primary stability to the implant, especially with respect to torsional forces. The implant according to the invention may also include a notch ring in the proximal region to further stabilize the implant on the surface of the bone cortex.
The surface of the cutting edge of the implant according to the invention consists of a material suitable for cutting into bone material, which does not liquefy under the conditions of implantation. It consists, for example, of titanium, titanium alloy, zirconia, or another suitable metal or ceramic material, or a suitably reinforced polymer.
The liquefiable material applied to the implant according to the invention is advantageously biologically resorbable. The liquefiable material does not extend over the surface area with the cutting edge, where it is advantageous if the implant surface is biologically compatible, i.e. has the properties of being bone-friendly and capable of osseointegration. On these surfaces, the osseointegration of the implant can be started immediately after implantation and the fixation by the absorbent thermoplastic material can be released continuously. It is also possible to use non-absorbable thermoplastic materials in such a way that the fixation of the non-absorbable thermoplastic material in the bone tissue permanently complements or replaces the fixation by osseointegration. In this case, it would be useful to cover the implant surface more extensively with the polymer.
Suitable bioabsorbable liquefiable materials for the individual implants according to the invention are thermoplastic polymers based on lactic acid and / or gluconic acid (PLA, PLLA, PGA, PLGA, etc.) or polyhydroxyalkanoates (polyhydroxyalkanoates). ) (PHA), polycaprolactones (PCL), polysaccharides, polydioxanones (PD), polyanhydrides, polypeptides (polypeptides), trimethylcarboxyl (triTMylcarb) Or a corresponding copolymer, mixed polymer, composition comprising said polymer. Suitable thermoplastic materials that are not absorbent include, for example, polyolefins (eg, polyethylene), polyacrylates, polymethacrylates, polycarbonates, terpolymers, polyesters, polyesters, polyesters, polyesters, polyesters, and polyesters. Polyurethanes, polysulfones, liquid-crystal-polymers (LCP), polyacetals, halogenated polymers, especially halogenated polyolefins, polyphenylene sulfones lene sulphones), polysulfone (polysulfones), polyether (in Polyethers), or the corresponding copolymers, and mixtures polymer or composition comprising said polymer.
Particularly suitable as absorbable liquefiable materials are poly-LDL-lactide (for example the trade name Resomer® LR708 available from Bohringer) or poly-LDL-lactide. DL lactide (for example, trade name Rhizomer® R208 available from Boehringer), non-absorbable liquefiable materials include polyamide 11 or polyamide 12.
The most important advantages of the implant according to the invention are as follows.
Since the implant according to the invention can be implanted essentially without rotation around the implant axis, it can be adapted to fit into existing cavities, such as the alveoli, and essentially eliminates the extraction of natural roots Immediately there can be transplanted there. This means that there is no waiting period for the patient between extraction and transplantation. Furthermore, there is no need for complex measures and additional parts (abutments, crowns, etc.) for precise alignment of the dental implant.
In the case of dental implants adapted to natural roots, during implantation, the alveolar wall remains largely intact as a region of dense bone structure, rather than the low density bone tissue that is further removed from the alveoli. Better support.
-Implants can be loaded immediately after implantation because they are sufficiently stabilized by fixation with a liquefiable material, by penetration of the cutting edge into the bone material and by a shape that prevents rotation in the cavity.
The dental implant according to the invention can be loaded essentially immediately after implantation, so it can be designed as a whole tooth with roots and crowns in one piece. No further procedures are needed to supplement the implant in the patient's mouth.
-Since the implant is supported laterally within the cavity wall by the cutting edge, the pressure on the implant is locally coupled to the bone tissue, giving the implant a long-term stability equal to the long-term stability of the screw-shaped implant.
-The lateral support of the implant in the bone tissue of the cavity wall prevents or at least adequately reduces the impact on the cavity substrate, thus avoiding cavity substrate complications. This is particularly important for dental implants where the alveolar substrate does not provide for heavy loads.
-There is no bone regression caused by lack of stress due to the loading of the implant immediately after transplantation.
The relative motion induced by stress between the implant and the bone tissue is reduced to a physiological range by immobilization of the implant through the liquefiable material, thus not only eliminating the limitation of osseointegration, but also in practice. Promoted.
• Using non-absorbable liquefiable materials allows for strong long-term fixation of the implant, even in weak bone tissue or bone tissue that is difficult to regenerate due to illness or age.
Various exemplary embodiments of the implant according to the invention, its production and implantation will be described in detail with reference to the accompanying drawings.
In all the drawings, the same elements are represented by the same reference numerals.
FIG. 1 shows a natural tooth 1 in cross section across the ridge of the jaw, with its root 2 growing inside in the jawbone 3. The jawbone 3 is covered with gingiva 4 (connective tissue and skin). The crown 5 protrudes from the jawbone and gingiva 4 and is coated with a layer of enamel 6, while the interior of the crown 5 and the root 2 are made of dentin. The root 2 is located in the alveoli (dental socket) of the jawbone, and the bone tissue (alveolar bone) of the alveolar wall 7 is usually more dense than the bone tissue that is further removed from the root 2 and is therefore superior. It has high mechanical stability. A dental thin film 8 including collagen fibers is located between the alveolar wall 7 and the root 2, whereby the tooth root 2 is in close contact with the alveolar wall 7. The fibers support the teeth and couple the forces acting on the teeth laterally to the bone tissue. During extraction, the tooth thin film is destroyed. It doesn't play.
FIG. 2 shows an individual dental implant 10 according to the invention in a cross-section similar to FIG. 1, replacing the tooth 1 shown in FIG. 1 by being implanted in a fixed position (implantation direction or implant axis I) of the jawbone 3. To do. In the case shown, the dental implant 10 has a crown portion 12 adapted to a natural tooth crown 5 as well as a root portion 11 shaped essentially adapted to the root of the tooth 1 and the alveolar wall 7. Including. The dental implant 10 is for example a single piece made of titanium, the crown part is coated with a ceramic layer (not shown), and the surface of the root part 11 is at least locally provided for osseointegration or at least biologically. Suitable for bones. Dental implant, in place of the crown portion 12, the abutment, or abutment, crown, bridge, or may comprise means for attachment of a set of dentures.
The root portion 11 of the dental implant 10 is tapered towards the distal end and includes a step 13 whose outer edge is designed as a cutting edge 14 towards the distal end region and remains in the alveoli during implantation. The cross section of the implant remains essentially constant during step 13, or is continuously reduced towards the distal end. In the region 15 during the step, the implant is connected to the bone tissue of the alveolar wall 7 by a thermoplastic material. As described above, these connections are created during implantation. Mechanical vibrations that impact the implant cause the thermoplastic material to liquefy and be pushed into the irregularities and holes in the alveolar wall and remain fixed after re-coagulation, and form and / or material fit between the implant and bone. Link.
FIG. 3 shows an individual dental implant 10 similar to FIG. 2, but prior to implantation. In the root portion 11 of this implant, the cutting edge 14 and the step 13 are clearly visible, and the surface area 16 of the thermoplastic material located between them and protruding from the surrounding surface region 17 is also clearly visible. The surface region 17 is biocompatible and advantageously provides for osseointegration. If the thermoplastic material is absorbent, the entire surface of the root portion 11 is advantageously provided for osseointegration.
The shape of the root portion 11 is at least partially adapted to the shape of the alternative natural root, or the mechanically related portion of the root, and the shape of the corresponding alveolar wall, i.e. generally at least some cross-sections. Are not circular and / or include the same conical shape whose axis is not straight. However, unlike natural roots and alveoli, the root portion 11 of the implant comprises a step 13 in which at least some edges are designed as cutting edges 14 and a surface of thermoplastic material protruding from a surface region 17 that can be osseointegrated. Range 16 is included. The surface area 16 of the thermoplastic material is arranged and dimensioned in such a way that as little of the material that is liquefied during implantation is pressed against the surface area 17 that can be osseointegrated, so that the surface area is The osseointegration effect can be started immediately after transplantation.
FIG. 4 shows three cross-sections through the implant according to the invention (cut lines AA, BB and CC in FIG. 3), for example corresponding to the dental implant of FIG. From the cross section BB it is clear that the surface area 16 of the thermoplastic material protrudes from the surrounding surface area 17.
As described above and as indicated by the dashed lines in FIG. 4, the implant according to the invention is essentially a constricted or tapped end that is axially extended and dimensioned to cut into the cavity wall during implantation. 21 may be further included. Such a structure provides a primary stability factor for the implant, particularly with respect to torsional forces, and continues to couple torsional forces acting on the implant after osseointegration to the bone tissue. The root portion 11 of the dental implant according to the invention can achieve good results when dimensioned as follows.
-The cross-sectional area of the root portion 11 is the same size as the corresponding cross-sectional area of the corresponding alveoli (root with a tooth thin film). The cutting edge 14, possibly step 13, and the constricted structure 21 extending in the axial direction, as well as the surface area 16 of the thermoplastic material, protrude from these diameters.
On the other hand, the axial distance between adjacent steps 13 depends on the step depth and the local steepness of the root part. On the other hand, the step depth is increased especially in the proximal direction, the distance is reduced, and if possible, the cutting edge is made to protrude slightly, allowing the cutting edge to penetrate deeper into the alveolar wall to optimally secure the implant. It would be advantageous to do so.
The depth of step 13 does not exceed 1 mm, preferably between 0.1 mm and 0.5 mm. This depth is further limited by the space available between the two teeth. If the step protrudes beyond the alveolar wall dimension by about 0.3 mm or more, it is recommended to make a corresponding shoulder in the alveolar wall prior to implantation.
The surface area 16 of the thermoplastic material projects beyond the surrounding surface area 17 by 0.05 mm to 2 mm (preferably 0.2 mm to 1 mm).
The surface area 16 of the thermoplastic material advantageously covers 10% to 50% of the total surface area of the root portion 11 and advantageously extends axially between the surface regions 17;
According to the expected collective load, the above specifications can be adapted to other than dental implants. As long as the corresponding bone mass is available, the step depth is not only to match the steepness of the cavity, but also to an optimal force that allows the bone to be fully stimulated without undue local stress. It can actually be increased to allow coupling. The load coupled to the bone tissue by the cutting edge and step induces an average bone tissue elongation of less than 0.5% but greater than 0.05% after osseointegration.
Other implants mentioned above are shafts of joint prostheses (for example hip joints, knee joints or finger joint prostheses) implanted in tubular bones prepared as such, for example in the shape of epiphysis, diaphysis, metaphysis. Adapted or adapted to the cavity to be created or existing in this shape. The implant may further be an implant for reconstruction of a damaged bone region (eg, a defect in the skull or jaw region or a defect caused by a tumor in any bone region). Furthermore, it may be considered that the present invention is applied to a replica of an existing implant, in which case the existing implant is adapted to the existing implant in a revision surgery with minimal loss of critical bone tissue. Or replaced with an individual implant adapted to the cavity resulting from removal of an existing implant.
The surface area 16 of thermoplastic material preferably includes energy directors, i.e. these surfaces include edges or points or include protruding patterns. The energy director causes a concentration of tension when the implant positioned in the bone tissue is excited by mechanical vibration, the thermoplastic material begins to liquefy in the area where it contacts the bone material, and / or the thermoplastic material either To ensure that it can be liquefied.
The thermoplastic material is advantageously selected and arranged on the implant in such a way that the entire implant is acoustically excited by applying mechanical vibrations, ie functions as a resonator. Mechanical vibrations are therefore not damped in relation to the interior of the implant, in particular at the interface between the non-thermoplastic material and the thermoplastic material, or within the thermoplastic material. The thermoplastic material thus liquefies, particularly at the implant surface where the energy director contacts the bone tissue. In order to ensure that there is little moisture in the thermoplastic material, it is advantageous if a material with an elastic modulus of at least 0.5 GPa is selected. In order to prevent energy loss in the boundary region between the two materials, it is advantageous if the connection between the thermoplastic material and the non-thermoplastic material has as large a surface as possible and is strong.
When ultrasound energy is used for implantation, the thermoplastic material can be pressed against the bone tissue during implantation at a depth of two trabecular chambers, i.e., in the range of about 0.2 mm to 1 mm. it can. In order to achieve such penetration depth, the thermoplastic material must be present in the proper amount and the implant design is a radial force large enough for the surface area between the thermoplastic material and the cavity wall. Should be guaranteed.
As can be seen from FIGS. 2, 3 and 4, in addition to the root region 11, the dental implant comprises, for example, a crown region 12 (FIG. 2), a cone 18 for attaching an artificial crown 19 (FIG. 3), Or it may include means for fixing a fixation implant for a cone, an abutment, or a bridge or a set of dentures (eg pocket hole 20 with internal thread in FIG. 4). Such a configuration is well known in the state of the art.
5A and 5B each show an axial cross section of the cutting edge 14 of an implant according to the present invention at a slightly larger scale, with the implant shown with the proximal end facing upward and the distal end facing downward. Cutting edges 14 have either direction towards the implant distal end (downward in FIGS. 5A and 5B), comprising a wedge angle β of less than 90 ° (preferably 80 ° from 45 °). The cutting edge is designed to project slightly from the implant axis. Depending on such a protruding design, a clearance angle α (FIG. 5A) or clearance space a (FIG. 5B) results for the cavity wall K (bore) extending parallel to the implant axis I. Such clearance reduces friction between the cavity wall and the implant, thereby reducing heat generation. The clearance angle α is advantageously small (for example, 1 ° to 15 °), and the depth of the clearance space is, for example, 0.1 mm to 0.3 mm. In order to allow the cutting edge 14 to cut into a tip, the cutting angle α + β is less than 90 °, or the angle γ between the tip-supporting surface 22 and the implant axis I is less than 90 °. It is. The chip S formed from the cavity wall by the cutting edge portion is pressed against the undercut on the lower side of the surface 22 supporting the chip and functions as a chip space 23. Depending on the size of the tip space 23, the effect of the cutting edge portion 14 is not only a cutting effect but also a compression effect that increases the density of bone tissue.
If an implant with a cutting edge 14 similar to the cutting edge 14 shown in FIGS. 5A and 5B is implanted in a slightly conical cavity (cavity wall K not parallel to the implant axis), the cutting edge needs to protrude. There is no. At this time, the clearance angle α is equal to the angle between the cavity wall K and the implant axis I, for example.
FIG. 6 also shows a series of cutting edges 14, 14 ′ and 14 ″ in axial section, which are arranged behind each other in the implantation direction (downward in FIG. 6) and are designed similarly to the cutting edge shown in FIG. 5A. The distance between the cutting edge and the implant axis I decreases in the direction of the implant, so that a chip is formed on the cavity wall K (K ′ before the cutting edge collision) extending parallel to the implant axis I. In this case, the cutting edges 14 and 14 'and 14 "are clearly combined with the smallest possible reduction. However, unlike in the case of conical implants (eg according to FIGS. 2 and 3), the step depth (d) does not depend on the general shape of the cavity or implant, but on the optimal notch and tip formation and Can be designed for fixation of implants. For dental implants that are implanted in the corresponding bore, it is advantageous that the depth or step does not exceed 0.3 mm.
If the tip space 23 is not large enough relative to the total tip material on the implant side (tip) of the cutting edge, the tip material is compressed there. To avoid undue compression, at least a portion of this material may be removed, for example, by sucking or rinsing through channel 25, for example. It should be noted that when the material is removed by flushing, the implant design is such that the material (chip material and flushing aid) removed by flushing can be drained from the cavity between the cavity wall and the implant.
FIG. 7 is also an axial cross-sectional view showing step 13 (a step-like reduced portion of the cross section) not provided with a cutting edge (in the bore, the cutting angle α + β = 90 ° and the cavity wall is parallel to the implant axis I) In a conical cavity with a cavity wall K greater than 90 ° and an angle γ of 90 ° or more), so that it works at best in a manner that rubs on the cavity wall. In a conical implant, such a step 13 can be provided in addition to the step with the cutting edge. Furthermore, a surface area 16 of the liquefiable material M is seen in FIG. 7, where the liquefiable material is located in a recess and protrudes from the surrounding surface area. If step 13 does not include a cutting edge, the liquefiable material and its associated recess may extend throughout the step, as shown in FIG. 8 with another axial section through such step 13. .
FIG. 9 is also an axial cross-sectional view showing an implant according to the present invention, wherein the implant includes a hollow space 26, the liquefiable material M is positioned therein prior to implantation, and further includes an opening 27, where the liquefiable material is implanted. When liquefied in (M ′), it is pushed against the implant surface. The extruded liquefied material then forms a surface area outside the implant and, after re-coagulation, forms a fixation between the bone tissue and the implant. The hollow space 26 is advantageously provided with an energy director 28, for example in the form of an angled shoulder, minimizing energy consumption for optimal liquefaction of the liquefiable material and reduction of its viscosity.
FIG. 10 shows, as a further example of an implant according to the invention, an individual dental implant comprising a plurality of root portions 11 like a natural molar. The root portion 11 does not necessarily have to replace the entire natural root, and may be limited to its mechanically relevant and / or extractable portion. In this case as well, it is possible to implant the implant immediately after the extraction of the molar teeth and to load the implant immediately after the implantation. Thus, the implant may include a crown portion 12 that is, for example, a replica of the extracted dental crown.
FIG. 11 shows a further individual dental implant according to the invention, which also includes a root portion 11 having a step 13 which at least partially comprises a cutting edge. These steps 13 are randomly distributed axially in the root portion 11 and do not extend all around, but are oblique rather than orthogonal to the implant axis I. Accordingly, the surface area 16 and the osseointegration surface area 17 of the thermoplastic material form an irregular pattern. The implant further includes an abutment-like proximal portion 30 that protrudes from the jawbone to the gingiva after implantation and that includes a pocket hole 20 with, for example, an internal thread to secure the other portion. The abutment 30 includes an annulus 31, and the lower edge of the annulus 31 is cut to form a cutting edge. After implantation, the abutment 30 is supported on the lower edge that cuts slightly into the surface of the jawbone. Underneath the ring 31 is a ring 32 of thermoplastic material, which fixes the implant in the outer layer of the jawbone by liquefying during implantation. Particularly for elderly patients, this ring 32 is advantageously made of a non-absorbable thermoplastic material, so that it can function to insulate the bone tissue in addition to the fixation function and fits tightly around the implant. Strengthen the insulating function of the gingiva, which may not be compatible.
Ring 31 and ring 32 may be designed to be functionally independent of each other. Furthermore, they can be used individually, even in combination with standardized dental implants and non-dental implants for fixing the implant to the bone surface and for tightly closing the bone cavity around the implant. Can be used.
Since the shape of the implant according to the invention is not a circular cylinder or a circular cone and is not rotationally symmetrical in the case of individual implants, the orientation of the implant in the cavity is precisely defined. For this reason, as shown in FIG. 11, the annulus 31 is not in a plane perpendicular to the implant axis, nor is it circular (invariably rotationally), so that it is adapted to natural teeth, ie It can be designed to be almost elliptical and curved like a natural ridge (scalloped).
FIG. 12 shows a further implant according to the invention, again designed as a dental implant as an example. The implant thus comprises a root part 11 at least partly in this case limited to the part of the outer periphery of the implant and provided with a step 13 as the cutting edge 14, so that they are scale-like from the rest of the implant surface. Protruding. These scale-like structures may be essentially rectangular or square as shown on the root portion 11, and as described above (FIGS. 5-7), the edge (lower edge) is the outer periphery. Extending along and they may be dull or sharp. The same applies to the essential axial edges of the scaly structure, and if designed to cut, it functions as a constriction or tapping structure extending in the axial direction.
In FIG. 12, a further exemplary shape of step 13 having a scaly shape is shown on the right side of the root portion 11. These include, for example, an axially concave (curved towards the center or outer point) or convex (not shown) lower edge, or an axial edge that is inclined at an angle toward the lower edge. May be included. The lower edge and the area above the lower edge may be either flat in the radial direction or curved in irregularities, so that the “scale” may be straight, conical or hollow conical in shape .
It is also possible to provide the root part 11 of the individual dental implant with one or more through openings 33 in a manner known per se. During the osseointegration phase, bone tissue grows through such openings.
Figures 13 and 14 show a further embodiment of an implant according to the invention which can be used, for example, as a dental implant. FIG. 13 shows the implant viewed from the side, and FIG. 14 shows the implant viewed as a cross section perpendicular to the implant axis I (cut line XIV-XIV in FIG. 13). The implant is essentially cylindrical and is designed to be implanted in a cylindrical bore. On the two sides facing each other with respect to the implant axis, the implant comprises a surface area 16 of thermoplastic material M, in which the thermoplastic material is located in a recess 40 (here an axially closed groove) and the surrounding surface Project from the region 17. On the outer periphery of the implant between the surface areas 16 of thermoplastic material and towards the proximal end of the implant is a protruding region 41 having a cutting edge 14. These essentially extend across the implant axis and are at a distance from the implant axis, which decreases in the implantation direction, as shown in FIG. These distances vary by about 0.3 mm (in the case of dental implants) depending on the cutting edge, so that the implant can be implanted in a cylindrical cavity (bore) without prior conformation. In other words, the cutting edge portion 14 is designed in such a way that each cutting edge portion cuts the tip from the cavity wall to change the cavity wall, thereby allowing the next cutting edge portion to cut the tip again. The distance between the axially arranged cutting edges may exceed 0.3 mm when measured perpendicular to the implant axis for implants larger than dental implants.
Thus, the implant according to FIGS. 13 and 14 is implanted in a rotationally invariant cavity (circular cylindrical bore) and its non-rotatable shape is still stabilized against torsional loads after implantation. . Compared to screw-shaped implants, the implants shown here can be implanted in a precisely defined rotational position, so that other than rotationally invariant, such as scalloped rings, crowns, etc. Has the advantage that it can also support the abutment.
For the implants according to FIGS. 13 and 14, it is not a requirement that the recess 40 provided for the thermoplastic material is an axially extending groove. These grooves may extend in particular spirals to improve the ability of the implanted implant to absorb the torsional forces. If the implant according to FIGS. 13 and 14 is implanted in a cavity having a stepped bore or conically narrowing inner end, the implant may include a step (not shown) in addition to the cutting edge. Thus, the recess 40 and the liquefiable material disposed in the recess may be continuous throughout the step, as shown in FIG.
15, 16A and 16B show another implant according to the invention (FIG. 15 is an axial cross section, FIG. 16A is a cross sectional view across the implant axis by section line XVI-XVI, FIG. 16B is a side view), eg Is a dental implant that practically corresponds to an implant according to 13, but includes a hollow space 26 and an opening 27, the opening 27 being essentially circular or slit-shaped, for example, with the hollow space 26 on the outer surface of the implant. Connecting. Opening 27 opens into recess 40, which includes, for example, a roughened bottom surface to improve the adhesion of the liquefiable material. The liquefiable material M, which in this case can be a thermoplastic or thixotropic material, is positioned in the hollow space 26 prior to or during implantation, and is at least partially liquefied with the aid of mechanical vibration, and the opening 27 And is pushed into the recess 40. These recesses form a pocket between the implant and the cavity wall, and the liquefied material is extruded into it, so that it is brought into intensive contact with the cavity wall. As is apparent from FIG. 16A, the recess 40 can be designed as a helical groove around the implant. This is particularly advantageous for implants with a hollow space 26, since the spiral groove does not tend to turn the implant during implantation, but still makes the implant more stable against rotation within the cavity after implantation. It is.
The implant according to FIGS. 15, 16A and 16B is advantageously implanted without liquefying the liquefiable material M, ie brought into the final position in the cavity. To that end, the implant is returned to the home with a normal tool or pushed with a mechanical vibration element (eg a sonotrode of an ultrasonic device). Thereafter, the implant position is checked and, if necessary, fine-tuned with respect to depth and rotational position. Only then can the liquefiable material impinge on mechanical vibrations and be pushed against the distal end of the implant, thereby liquefying and appearing through the opening 27, filling the recess 40 and entering the surrounding bone tissue. In order to give the implant sufficient stability within the cavity during said check and possible adjustment of the implant position, in such a way that the cutting edge not only stays in the bone tissue, but the implant is held by press fit in the cavity, It may be advantageous to make the implant dimensions slightly larger than the cavity.
To liquefy the liquefiable material, a sonotrode adjusted with respect to the cross-section of the hollow space 26 may be used, or a piston 42 that is a component of the implant may be used. The sonotrode is positioned at the proximal end 43 of the piston 42 to couple mechanical vibration to the piston. The piston 42 is designed to enter the hollow space 26 with its liquefiable material liquefying and increasing displacement until its proximal end 43 reaches the opening of the hollow space 26. The piston 43 is made of titanium, for example, and has a fine screw 44 in the region of its proximal end 43. When the fine screw is also made of titanium, the piston 43 is cold welded to the wall of the hollow space when pushed into the hollow space 26. Is done. Thus, the proximal opening of the hollow space 26 is tightly sealed, ensuring insulation between the oral cavity and bone tissue, which is critical for dental implants. If the liquefiable material is resorbable, the bone tissue gradually replaces it after implantation, i.e., the bone tissue grows into the opening 27 and the hollow space 26, and the hollow space 26 is tightly sealed from the oral cavity. It is even more important.
FIG. 17 shows in cross-section, as in FIG. 15, a piston 42 positioned within the proximal opening of the hollow space 26 for displacing the liquefiable material. The piston is such that the proximal end 43 of the piston reaches the proximal surface 45 of the implant when sufficient liquefiable material is extruded from the hollow space 26 through the corresponding opening 27 to the outer surface of the implant. It is designed in various ways. The proximal end 43 of the piston extends conically, and the piston 42 in this case consists of a thermoplastic material, for example PEEK. When the edge around the proximal opening of the hollow space 26 touches the oscillating wide end of the piston 43, it acts as an energy director and causes tension concentration, so that the thermoplastic material is liquefied. The liquefied material penetrates between the wall of the hollow space 26 and the piston 42, advantageously provided with the back layer groove 47, so that the proximal opening of the hollow space 26 together with the piston 42 is firmly secured. close.
FIG. 18 again shows an axial section through the implant according to the invention, which comprises a hollow space 26 connected to the implant external surface by an opening 27. In order for the liquefiable material, in this case the thermoplastic material, to be liquefied by the effect of mechanical vibrations, in particular in the region of the opening 27, the shape of a sharp edge, for example extending along the outer periphery of the hollow space The energy director 28 is provided at the internal outlet of the opening 27. The distal end of the hollow space 26 may be provided with, for example, a barb shaped energy director 28. A piece of liquefiable material that travels through the hollow space 26 and impinges on mechanical vibrations strikes the energy director 28, resulting in local stress concentrations and local liquefaction there in the vibrating material.
Further, in FIG. 18, various embodiments of the opening 27 and its outlet to the recess 40 become apparent. The cross section of the opening 27 is, for example, circular (upper part in FIG. 18) or slit shape (lower part in FIG. 18), and the recess is separated from the opening by the edge (left in FIG. 18), or The outlet can be designed to be wide (right of FIG. 18). Combinations of the listed characteristics may also be considered.
FIG. 19 shows an intermediate element 52 based on the exemplary implant according to FIGS. 13 and 14, which is particularly suitable for implanting an implant by mechanical vibrations such as ultrasonic vibrations. The intermediate element 52 is adapted on the implant side to a specific, possibly the proximal end region of the individual implant 10, and on the excitation side is adapted to an advantageously standardized sonotrode 53 which is part of the ultrasound device. The connection of the intermediate element is advantageously designed as a loose fit that is connected on one or both sides, i.e. as a connection with play in the axial direction and with a guiding function in the radial direction. The other connection may be fixed with, for example, a friction fit clamp fit or screw connection.
The intermediate element 52 is advantageously made of a material with little acoustic damping (high modulus) (eg PEEK) and may be designed in a corresponding manner or acoustically adapting the implant 10 and the sonotrode 53 It may be made of a corresponding material so that it can. This means that the intermediate element 52 may have an acoustic adaptation function in addition to the interface function between the standardized sonotrode shape and the specific implant shape. The intermediate element may further have a marker for orientation and measurement purposes during implantation. The intermediate element may function as a part that does not belong directly to the implant and is easily accessible by the surgeon, making it easier to handle, especially in the case of relatively small dental implants. The intermediate element 52 is advantageously attached to the implant 10 during production and is discarded after implantation. In this way, the intermediate element can also form part of the implant packaging. If the intermediate element 52 is made of a transparent material, the intermediate element can also have a light transmission function, where light for illuminating the cavity and the implant is coupled from the sonotrode side to the intermediate element.
A loose mating connection between the implant 10 and the intermediate element 52 and / or between the intermediate element 52 and the sonotrode 53 (or between the sonotrode and the implant if no intermediate element is used) is directed towards the implant. Only the transmitted axial vibration component, i.e. the component that drives the implant into the cavity, can be transmitted. The vibration component that pulls the implant out of the cavity is not transmitted. Empirical evidence has shown that implantation with the half wave produced by the aforementioned loose mating connection is advantageous. One reason is probably that there is no movement to pull the implant into the cavity, and therefore less frictional heat is generated between the cavity wall and the implant. A further advantage of a loose mating connection is that it acoustically isolates the implant from the sonotrode and, if applicable, from the intermediate element, and therefore less accurate acoustic tuning between the excitation part and the implant. It is no longer important.
A loose mating connection is achieved, for example, by a gap between the implant and the intermediate element, which acts like a capillary and is supplied with liquid just before implantation. The implant inserted into the intermediate element and facing upwards is attached to the sonotrode and then a liquid, for example water, is provided between the proximal end of the implant and the intermediate element. Due to the capillary effect, the liquid spreads between the two parts and holds them well together so that the implant can be turned to turn downwards without falling off the fit.
FIG. 20 shows a further embodiment of a loose fitting connection between an implant 10 and an intermediate element 52 according to the invention (or between an intermediate element and a sonotrode or between an implant and a sonotrode), Shown in cross section. This loose mating connection essentially includes a tension ring 54 positioned in a snap ring groove 55 that is aligned and axially sized, one of which is on the implant 10 and the other on the intermediate element. It is made of a material that can be placed at 52 and that can hold the weight of the implant, yet still allows the breaking of the ring to separate the implant from the fit with little force. Further examples of loose mating connections are known by those skilled in the art and may be applied to this case as well.
As shown in FIG. 20, the intermediate element 52 need not fill the entire space between the sonotrode 53 and the implant 10. The intermediate element 52 may include an opening or other suitable partially hollow structure.
FIG. 21 illustrates a method of producing a dental implant 10 according to the present invention. This method essentially comprises three steps, all of which are based on methods known per se. These steps are as follows:
Step to measure. The tooth 1 to be replaced and / or the corresponding alveolar 57 or the alveolar wall 7 are each measured, for example, to generate a three-dimensional image. Measurement data representing the image is prepared for further processing.
Data processing step. Measurement data representing the image can be adjusted, especially by adding the cutting edge and liquefiable material structure, and by adding a larger size or axially extending constriction or tapping structure where applicable. Is done. If the image is not a complete three-dimensional image, it is completed using an empirical implant shape. The processed measurement data is prepared for implant production.
Implant production step. Implants are produced in a series of production steps, if necessary, based on the processed measurement data.
Various methods such as computed tomography (CT) or MRI (magnetic resonance imaging) are particularly suitable for the measurement step, and by these methods, for example, images of teeth 1 and alveoli 57 are simultaneously obtained for teeth that have not yet been removed. Can be generated. Such a method makes it possible to produce an implant prior to the extraction of the replaced natural tooth, so that the replacement of the replaced tooth and the implantation of the implant in place can be performed in a single motion. Become.
However, the extracted teeth and / or the alveoli 57 can be measured after extraction, and in particular the alveolar deformation caused by the extraction can be included in the measurement.
Instead of obtaining a three-dimensional image that requires complex instruments, it is also possible to make appropriate measurements from a two-dimensional X-ray image or a plurality of such images. In order to create a three-dimensional model for an implant, the image is complemented by corresponding values based on experience.
The data processing step is advantageously performed in a CAD system (computer aided design), which is supplied with data from the measurement step. If measurement data for the alveoli 57 are available, it is advantageous if the root portion of the implant is made based on these data. As long as alternative tooth measurement data are available, experience-based tooth film thickness may need to be added. An implant with a hollow space may need to be oversized for press fit. Furthermore, the outer surface of the root part is modified by the cutting edge and the surface area of the thermoplastic material, and possibly by a structure that promotes osseointegration. The pre-implant 10 'may need to be provided with a recess for the surface area of the thermoplastic material, which is advantageously provided with a portion of the thermoplastic material and secured by conformal fit. For surface regions that can be osseointegrated, for example, a suitable surface structure is provided.
In the data processing step, data is also generated that provides the basis for the production of an intermediate element 52 that is fitted as accurately as possible to the proximal end of the implant, for example the crown portion 12. Similar data can be generated for the production of a processing tool 58 or a set of such tools, which are adapted to the root portion of the implant (one processing tool is slightly smaller in size). Or a set of processing tools will be smaller and smaller in size). The processing tool 58 helps prepare the alveolar wall prior to implant implantation.
The step of producing the implant is advantageously performed by a CAM system (computer-aided machining), which is supplied with data from the data processing step. In this step, the preliminary implant is produced, for example, from a suitable titanium blank, for example by milling, grinding or electronic erosion. A surface area that can be osseointegrated is now created by a suitable surface treatment, and portions of thermoplastic material are attached (by latching, gluing, molding, ultrasonic, etc.), resulting in the finished implant 10.
The intermediate element 52 and the processing tool 57 for the preparation of the alveolar wall are produced in essentially the same way as the preliminary implant 10 '.
FIG. 22 shows a method for implanting a dental implant according to the invention, the implant 10 shown further comprising a crown part 12 in addition to the root part 11 provided according to the invention, both parts being replaced. Adapted to natural tooth shape. The root portion 11 of the implant 10 shown comprises a step 13 with a cutting edge 14, a surface area 16 of thermoplastic material and, if appropriate, a constricted or tapped shape extending axially (not shown). Including.
The alveolar 57 is cleaned and scraped prior to implantation, for example with the aid of an ultrasonically driven tool (not shown). If it can withstand the stress on the bone tissue caused by direct implantation, the implant is implanted directly into the so-prepared alveoli 57 (example shown on the left side of FIG. 22). If the stress on the bone tissue is kept low, the alveolar 57 is prepared by a processing tool 58 that generates the shoulder 13 'of the alveolar wall 7 corresponding to the step 13 of the implant (shown on the right side of FIG. 22). Example with a treated alveolar 57 '). For this preparation, a processing tool 58 adapted to the root part is introduced into the alveoli. Accordingly, the cross-sectional area of the processing tool 58 must be slightly smaller than the corresponding measurement of the implant there. If required, several such processing tools may be used, each tool being slightly thicker compared to previously used tools.
If the implant is not individually adapted to the alveolus, but a preferred but standardized implant is used, the alveoli are also prepared by the corresponding tool.
The processing tool 58 is placed in the alveoli by appropriate tapping. However, they are preferably excited by mechanical vibrations such as ultrasound and at the same time guided to the alveoli. If necessary, the processing tool 58 is contacted with a slightly abrasive media that is pressed through the opening at the distal end of the tool between the tool and the alveolar wall and the media is further crushed. It plays the role of carrying out bone material.
The implant 10 is placed in a clean or appropriately treated alveoli (57 or 57 '). The implant is advantageously impacted by mechanical vibrations, particularly ultrasound, during the placement of such an implant in the alveoli. Of course, it is also possible to first place the implant in the alveolus using a hammering tool and then hit the ultrasound.
It is advantageous to use an intermediate element 52 that is adapted to the crown part, especially if the implant includes a crown part 12. If the implant includes only a root portion having an essentially flat proximal surface or standard structure, the intermediate element 52 can also be used, but an appropriate standard sonotrode can be used alone. Is possible. By adapting the length and shape of the sonotrode and, if applicable, the intermediate elements, the acoustic excitation of the implant can be optimized. For improved processing, the sonotrode or intermediate element 52 may be provided to assist in linking to the implant by appropriate measures such as shape fit or material fit or application of a vacuum (see FIGS. 19 and 20 and the description). See also the corresponding part).
If the root part of the implant simply represents a mechanically related part or the corresponding natural root, but not all of the natural root has been removed, the part of the alveoli that is not occupied by the implant is used prior to implantation, e.g. for augmentation It is advantageous to be filled with bone replacement materials such as calcium phosphate granules.
The implant is advantageously implanted as fast as possible, i.e. immediately after removal of the replacement tooth.
Of course, it is also possible to create and prepare a cavity for the implantation of the implant according to the invention in the place of the jawbone where there is no alveolar or the previous alveolar is filled with regenerated bone tissue It is. The shape of such cavities and the corresponding implant can be adjusted to the bone structure and can be measured in the same way as the alveoli, for example by computer tomography.
Figures 23A to 23C show the implantation of a joint prosthesis comprising a shaft according to the invention. FIG. 23A shows a cross section through a bone 60 having a metaphyseal region 60.1, a metaphyseal region 60.2, and a metaphysis 60.3, into which a shaft of an joint prosthesis is implanted, which shaft into a particular bone It may be an individual implant specially produced for the implantation of or an appropriate standardized implant. FIG. 23B shows a processing instrument 58 (again in cross section) whose shape essentially matches the shape of the implant and functions to create or process a cavity 62 in the bone 60. FIG. 23C shows a side view of the joint prosthesis 10 implanted in the cavity 62. The shaft is formed as an irregular cone and comprises a step 13 with cutting edges 14, a surface area 16 of thermoplastic material located between the cutting edges and a constriction or tapping structure 21 (rib) extending in the axial direction. Including.
Starting with a bone shape confirmed by CT or MRI, the joint prosthesis 10 and processing tool 58 are selected or produced in essentially the same manner as the dental implant described with respect to FIG. There, the implant 10 and the cavity 62 are planned so that the implant fixation by the cutting edge 14 and the rib 21 is located in the epiphysis and diaphysis region. The surface area 16 of the thermoplastic material is located at a point that is exposed to increased tensile and shear stresses. Thereby, it is possible to reduce bone dislocations that are not favorable for osseointegration or to reduce bone lengthening in the contact area between the implant and the bone to an insignificant level. In creating the cavity, the first opening can be produced with standard instruments. For at least the last clearance step, a processing tool 58 adapted to the shape of the implant is used to fully adapt the shape of the cavity 62 to the shape of the implant 10.
Figures 24A to 24C show reconstruction using an implant according to the present invention for a bone defect resulting from removal of a bone tumor, the implant bridging the defect. FIG. 24A shows a bone 65 with a tumor 66 in cross section. FIG. 24B shows in cross section the bone 66 ′ (resection) to be removed and the processing tool 58 used to complete at least the cavity 62. FIG. 24C shows in cross section the finished cavity 62 and the implant 10 to be implanted in this cavity, which implant is for example an irregular cone comprising step 13 with a cutting edge 14 and a surface area 16 of thermoplastic material. It is formed again in such a shape.
The shape of the bone tumor 66 is first defined by X-ray, CT or MRI. Based on the measured data, the surgeon determines the size of the ablation. The implant 10 and processing tool 58 are selected or specially produced according to the cutting shape.
The processing tool 58 further includes a suction channel 58.1 that leads to the tool surface in the cutting edge region of the step. Through these suction channels 58.1, bone material, bone marrow and tumor cells are sucked out of the cavity, increasing the volume removed by the tool 58 and avoiding the build-up of local pressure that can lead to fat embolism. Sucking out tumor cells also prevents them from metastasizing to healthy tissue, thereby significantly reducing the risk that metastatic cells will remain behind.
The previously described figures and the corresponding explanatory parts are most often related to specific implants (dental implants, joint prostheses, individual implants, standard implants, etc.) and specific properties of these implants. Of course, it is possible to apply the described properties to other implants and in different combinations than those described herein. Thus, although not specifically described, implants belonging to the present invention can be made.
FIG. 3 is a diagram showing a natural tooth in a cross section across a ridge of a jaw. FIG. 2 shows an individual dental implant according to the invention replacing the tooth according to FIG. 1. 1 is a side view of a preferred embodiment of a dental implant according to the present invention. FIG. FIG. 4 shows three cross-sectional areas through individual dental implants projected onto each other (cut lines AA, BB and CC in FIG. 3). FIG. 4 is an axial cross-sectional view through the cutting edge region of an implant according to the present invention. FIG. 4 is an axial cross-sectional view through the cutting edge region of an implant according to the present invention. FIG. 3 is an axial section through a series of cutting edges of an implant according to the invention, the cutting edges being continuously arranged in the implantation direction. FIG. 3 is an axial cross section through a step-like reduction (step) in the cross section of an implant according to the invention, the step not having a cutting edge. FIG. 6 is an axial cross-section through a step with a liquefiable material extending throughout the step. FIG. 4 is a partial axial section through an embodiment of an implant according to the invention, with the liquefiable material positioned in the hollow space of the implant. FIG. 3 shows an exemplary dental implant according to the present invention. FIG. 3 shows an exemplary dental implant according to the present invention. FIG. 3 shows an exemplary dental implant according to the present invention. 1 is a side view of an implant according to the present invention suitable for implantation into a bore. FIG. FIG. 14 is a cross-sectional view perpendicular to the implant axis of an implant according to the invention suitable for implantation into a bore (cut line XIV-XIV in FIG. 13). FIG. 6 is an axial cross-sectional view of another implant according to the present invention suitable for implantation in a bore with a liquefiable material positioned in a hollow space. FIG. 16 is a cross-sectional view perpendicular to the implant axis of another implant according to the invention suitable for implantation into a bore with a liquefiable material positioned in a hollow space (cut line XVI-XVI in FIG. 15). FIG. 6 is a side view of another implant according to the present invention suitable for implantation into a bore with a liquefiable material positioned in a hollow space. FIG. 17 shows details of the implant according to FIGS. 15 and 16. FIG. 17 shows details of the implant according to FIGS. 15 and 16. FIG. 15 shows the implant according to FIGS. 13 and 14 with an intermediate element. FIG. 4 shows an exemplary embodiment for a loose mating connection between an implant and an intermediate element or between an intermediate element and a sonotrode (axial cross section). FIG. 3 illustrates the production of individual dental implants according to the present invention. FIG. 3 illustrates the implantation of a dental implant according to the present invention. FIG. 3 illustrates the implantation of a joint prosthesis designed as an implant according to the present invention. FIG. 3 illustrates the implantation of a joint prosthesis designed as an implant according to the present invention. FIG. 3 illustrates the implantation of a joint prosthesis designed as an implant according to the present invention. FIG. 6 illustrates the reconstruction of a bone region damaged by a bone tumor with the aid of an implant according to the invention. FIG. 6 illustrates the reconstruction of a bone region damaged by a bone tumor with the aid of an implant according to the invention. FIG. 6 illustrates the reconstruction of a bone region damaged by a bone tumor with the aid of an implant according to the invention.
A bone implant (10) suitable for implantation in a transplantation direction parallel to the implant axis (I) in a cavity surrounded by a cavity wall (K) of bone tissue (3), comprising an implant part and implanted The implant part pushes the liquefiable material from the first space of the surface (16) of the liquefiable material (M) by mechanical vibration or from the hollow space (26) of the implant through the opening (27). The second type of surface area (16) formed by the tool, wherein the implant part to be implanted has a shape to be implanted without substantial rotation, and is further capable of cutting a cavity wall of bone tissue. Parts (14), the cutting edges of which are located outside a given first type of surface area (16) or a second type of surface area (16) to be formed , the cutting edge being an implant axis( ) And in a common plane does not extend, the cutting edges are had either direction towards the distal end region of the implant, and the cutting edge portion is at least partially extend around the periphery of the implant, the edge portion The bone implant is spaced apart from the implant axis, and the distance between the implant axis and the cutting edge decreases in the direction of the implant.
Bone implant according to claim 1, characterized in that the cutting edge (14) comprises a wedge angle (β) of less than 90 °.
Bone implant according to claim 1 or 2, characterized in that the cutting edge (14) is designed to protrude.
4. Bone implant according to any one of claims 1 to 3, characterized in that the cutting edge (14) is cut out to form a tip space (23).
The liquefiable material (M) is located in a recess (40), and the surface area (16) of the liquefiable material (M) protrudes from a surface region (17) surrounding the recess (40). The bone implant according to any one of 1 to 4.
5. Bone implant according to any of claims 1 to 4, characterized in that the opening (27) leads to a recess (40).
Bone implant according to claim 5 or 6, characterized in that the recess (40) is a groove extending axially or spirally over the implant region to be implanted.
Bone implant according to any of the preceding claims, characterized in that the surface region (17) capable of osseointegration is located between the surface areas (16) of the liquefiable material.
9. Bone implant according to any of the preceding claims, characterized in that the implant part to be implanted further comprises a constriction or tapping structure (21) extending in the axial direction.
10. Bone implant according to any one of claims 1 to 9, characterized in that the cutting edge (14) extends along the outer peripheral part of the implant and forms the lower edge of the scaly structure.
Bone implant according to any of the preceding claims, characterized in that the proximal end region of the implant comprises a ring (31) with a lower edge made as a cutting edge.
12. Bone implant according to any of the preceding claims, characterized in that the proximal end region comprises a ring (32) of thermoplastic material.
13. Bone implant according to any one of the preceding claims, characterized in that the implant part to be implanted is shaped to taper towards the distal end region.
14. Bone according to claim 13, characterized in that it comprises a step (13) extending all or part around the implant and at least partly comprising an end made as a cutting edge (14). Implant.
Bone implant according to claim 14, characterized in that the part of step (13) has a blunt end with a wedge angle (β) of 90 ° or more.
The implant part to be implanted is essentially cylindrical and includes a cutting edge (14) projecting from the cylindrical shape at a distance from the implant axis (I), the distance decreasing in the implantation direction The bone implant according to any one of claims 1 to 12.
The bone implant according to claim 16, characterized in that the cutting edge (14) protruding from the cylindrical shape extends along a part of the outer periphery of the implant and is arranged continuously in the axial direction.
At least two series of cutting edges (14, 14 ', 14 ") facing each other, the surface area (16) of the liquefiable material (M) or the outlet of the opening (27) is a continuous cutting edge on the outer periphery of the implant 18. Bone implant according to claim 17, characterized in that it is located between the parts.
19. Bone according to any of the preceding claims, characterized in that it comprises a hollow space (26) and a piston (42) that can be inserted into the proximal opening of the hollow space (26). Implant.
Around the proximal end (43) of the piston (42) and / or the proximal opening of the hollow space (26), means are provided for an insulating connection between the piston (42) and the implant. 20. Bone implant according to claim 19, characterized.
Bone implant according to any of the preceding claims, characterized in that it has an intermediate element (52) in the proximal end region.
22. Bone implant according to claim 21, characterized in that the intermediate element (52) is connected to the implant by a loose mating connection and / or coupled to the sonotrode (53) by a loose mating connection.
Bone implant according to any of the preceding claims, characterized in that it is a dental implant (10).
In addition to the tooth root (11)
- crown portion (12),
- abutment (30), as well as
- abutment, crown (19), means for securing at least one selected from the group consisting of bridges and a pair of denture (20)
The bone implant according to claim 23, comprising any one selected from the group consisting of:
The bone implant according to any one of claims 1 to 22, characterized in that it is a shaft of a joint prosthesis.
23. Bone implant according to any of claims 1 to 22, characterized in that it is designed to bridge a bone defect.
27. Bone implant according to any of claims 1 to 26, at least one processing tool (58) adapted to the shape of the implant part to be implanted, and / or intermediate adapted to the shape of the proximal end region of the implant A transplant set comprising element (52).
JP2006553408A 2004-02-20 2005-01-28 Implant transplanted into bone tissue, its production method and transplantation method Expired - Fee Related JP4732368B2 (en)
JP2007522847A JP2007522847A (en) 2007-08-16
JP4732368B2 true JP4732368B2 (en) 2011-07-27
JP2006553408A Expired - Fee Related JP4732368B2 (en) 2004-02-20 2005-01-28 Implant transplanted into bone tissue, its production method and transplantation method
JPS63183051A (en) * 1987-01-26 1988-07-28 Toshio Takatsu Ultrasonic vibration applied closing and shaping system for dental adhesive molding material
JPH05178715A (en) * 1990-10-12 1993-07-20 Thera Patent Gmbh & Co Kg Curable material producible and processible by vibrating action and its production
CA2735180C (en) 2015-02-10 Dental bone implant, methods for implanting the dental bone implant and methods and systems for manufacturing dental bone implants