KR20000022173A - Fixture, prosthesis anchoring device and prosthesis - Google Patents

Abstract

PURPOSE: A prosthesis anchoring device is provided to attach a prosthesis to one or more fixtures anchored in a person's bone tissue. CONSTITUTION: A fixture(1) has a fastening part (8) for the prosthesis and fastening part has a supporting surface (9) that engages a bearing surface (13) on the prosthesis. A fixture (1) on supporting surface (9) is provided with a deformation device (18). This is plastically deformable in a direction perpendicular to supporting surface (9) to compensate for any misalignment between supporting surface(9) and bearing surface (13). The deformation device is, instead, arranged on the prosthesis supporting surface (13) in a corresponding way. A prosthesis also incorporates a prosthesis anchoring system that includes a fixture having a deformation device.

Description

Fixtures, prosthetic fixtures and prostheses

The present invention relates to a fastener of the type described in the above-mentioned first part of claim 1, the second of the fixing device of the type described in the above-mentioned part of claim 12 and thirdly to the above-mentioned claim 15 The prosthesis of the type described in the Part.

It is known to implant fixtures into human bone tissue to attach other types of prostheses, for example dental prostheses.

In order to make the fastening of the fixture permanent, a number of factors must be met with respect to the material selection and manipulation techniques, among others. In practice, the fixture developed by Professor Branemark made of pure titanium with a surface with fine depressions is very good and has a long term fixing ability. Screwed fixtures are applied to bones, for example jaw bones, and at certain periods of time, typically have to be treated for several months (integral bone). Thereafter, the prosthesis may be installed on the fixture.

Most of these types of fasteners are provided with outer threads, which are implanted screws, which are attached by screwing them in holes made of bone tissue. Sometimes the holes are pre-formed, but it is also possible to screw them with self tapping screws. Typically, fixtures require a shorter or longer time for healing before they are exposed to significant load. On the fixture, different types of prostheses can be attached and in dental prostheses, a bridge structure can be attached to an individual tooth, for example one tooth, but also two or more fixtures comprise a plurality of teeth or a whole row of teeth. It is possible to be used as an attachment point for. The fasteners are thus designed in an appropriate way at their free ends.

The free end of the fixture to which the prosthesis is secured, for example the fastening end, is equipped with a fastening device of a type capable of coupling a corresponding fastening device to the prosthesis. Typically the attachment is arranged such that the retaining surface on the prosthesis or prosthetic support element is in contact with the support surface at the anchoring end of the fixture. The support and retaining surfaces must be configured in parallel to ensure sufficiently satisfactory functionality. For a prosthesis of the type attached by means of only one fastener, there is no problem, in which case the prosthesis, which is usually fixed to the fastener by the threaded joint when the prosthesis is screwed in place, is fixed over the entire area. This is because it has a holding surface that is exerted a force in contact with the supporting surface of the.

In many cases, the prosthesis will be secured using one or more fixtures. This is especially true when it involves reconstruction of the jaw when a prosthesis comprising a row of teeth is attached but can also occur for prostheses used for other parts of the body.

When a prosthesis and a holder for such a prosthesis are attached to one or more fasteners, the fastener to which the prosthesis is attached and screwed in place first forces the prosthesis to a specific position, against the support surface of the fastener. This is due to the fact that the holding surface to be pressed is forcibly in its orientation determined by the supporting surface. In order to thread the prosthesis to the second fastener and, if necessary, to a further fastener, it is preferred that the corresponding holding and supporting surfaces at the fastener are configured in parallel so that no misalignment occurs. When attempting to fix the fixture in bone tissue, it is of course assumed that having a support surface is in the intended direction in relation to each other with the greatest accuracy possible, and these directions must be configured to fit the corresponding retaining surface in the prosthesis. Typically, the fixture surfaces should lie in the same plane or at least parallel.

It is difficult to achieve this completely. In fact, one should expect fixed fixtures to deviate from their intended purpose. It is very difficult to secure two or more fasteners in parallel enough, and the possibility of accurately adjusting the height is far from high. Only a slight deviation will result in a lack of engagement between the support surface and the holding surface when the prosthesis is attached to the fixture as described above. Since the prosthetic element or prosthetic holder is generally made of a completely rigid material, such as stainless steel, a defective bond cannot be compensated for by an element or holder. Instead, the contact of the support surface of the one or more fasteners becomes poor and the structure of the prosthesis is deformed when the prosthesis is tightened at the threaded joint to attach to the fastener. In addition, these deformations propagate down the bone tissue. This causes discomfort and difficulty for the patient while reducing the functionality of the prosthesis and shortening its life expectancy.

This problem is particularly common with jaw bone reconstructions and the superstructure with tooth prostheses is screwed in place either directly on the fixture or by an attachment bar. This lack of parallelism in fixtures is a major problem, especially with regard to the use of prefabricated superstructures which are not intended to be individually broadly applicable. It is already known from EP 0126 624, EP 0 126 624, and EP 0466 267 to provide an intermediate ballistic device between the fixture and the prosthesis to compensate for this inaccuracy.

In view of the foregoing, the object of the present invention is to eliminate the above-mentioned disadvantages encountered when the orientation of the fixtures or their height position does not align sufficiently with the intended and intended without inserting a particular correction element. To achieve that.

According to the invention it is claimed by means of fastener means of the type claimed in the preceding part of claim 1 representing the features described in the characterizing part of claim 1, in the tactic part representing the features described in the characterizing part of claim 12. By means of the prosthesis fixation device of the enclosed form and by means of the prosthesis of the form described in the above-mentioned part which exhibits the features described in the features of claim 15.

The deformation device will be deformed according to the corresponding range, since the support surface in the fixture or the holding surface in the prosthesis is provided with a deformable device which can be deformable in a direction perpendicular to each surface when misalignment occurs. As a result of this, the retaining surface will be in sufficient contact with the support surface despite misalignment. Since misalignment in each direction is absorbed by this deforming device, tightening of the retainer device will not perform any deformation in the bone tissue of the patient.

Preferably, the fixture is designed with at least parts that are symmetrically in the direction of rotation, the supporting surface of which is perpendicular to its central axis.

In one preferred embodiment, the deformation device is designed as an axially aligned flange coaxial with the central axis and suitably cylindrical.

It is desirable to be peripherally aligned to the flange circular support surface to provide an optimal strain distribution. This will occur due to the fact that the flange will be located as far away as possible from the central axis.

In another preferred embodiment, the flange is provided with a slot and tilted outward in the axial direction to facilitate deformation.

In addition, the outer end of the flange is pointed and sharpened, for example, to provide improved resistance to deformation.

Other preferred embodiments of the invention have been described in the dependent claims.

The invention will be explained in more detail in the following detailed description of the preferred embodiment of the invention with reference to the attached drawings.

1 schematically shows a device of the prior art.

2 is a side view partially showing the fastener according to the first embodiment;

3 is a view schematically showing a part of a fastener as shown in FIG.

4 is an enlarged view taken from a portion of FIG. 3.

5-7 illustrate regions corresponding to those shown in FIG. 4 and illustrate a fifth embodiment to a second embodiment of the present invention.

8 is a cross-sectional view of a fixture according to a sixth embodiment of the present invention.

9 is a view schematically showing a part of FIG. 8.

10 is an enlarged view of the prosthetic fixing device according to the present invention.

FIG. 11 is a view showing a length direction in which one portion of the one shown in FIG. 10 is taken.

12 is a side view showing a part of the prosthesis according to the present invention.

13 is a cross-sectional view of a portion of FIG. 12.

The purpose of Figure 1 is shown in schematic form to clarify the problem to be solved by the present invention. Denoted at 101 is a bridge foundation for a prosthesis, for example a tooth bridge. Prosthesis 101 is fixed to a person's jawbone by a number of fastener means screwed into a hole made in the jawbone. Only two fasteners 102, 103 are shown in the figure, and only the upper end is shown. Each fixture takes a direction determined by the hole in the jawbone to be fixed. Very often these holes are not perfectly parallel, which leads to corresponding mutual misalignment of the fixtures 102 and 103. When the prosthesis 101 is tightened with respect to the first fixture, the prosthesis 101 is supported by the support surface of the first fixture when the corresponding retaining surface 105 on the prosthesis 101 is brought into contact with the support surface 104. Force is applied to the position determined by the direction of 104.

Then, if the second fastener 103 is deflected from parallel with the first fastener 102, tightening the threaded joint located in the second fastener 103 is associated with the corresponding retaining surface 107 on the prosthesis. 2 will cause misalignment of the fixture support surface 106 so that the contact will be in point-to-point form, as shown approximately 108. When both fasteners are tightened against the prosthesis 101, the torque will develop in the direction as shown by the arrows in each fastener. This torque will cause deformation in the jawbone where the fixture is fixed. The adverse effect of this is as described earlier. Similar problems are encountered if the position of the fixture holding surface is not aligned with respect to height.

2 shows a fastener 1 having a fixed end fixed to a person's lower jawbone. At the upper end of the fastener 1, at its anchoring end, a bar 3 is provided to hold the dental prosthesis bridge (not shown) attached thereto.

Typically, the fixing part 7 of the fastener 1 is designed with a screw part 7 with a conical part 5 provided with a slot 6 at its end. The fixing part 7 made of titanium is fixed by an automatic tapping screw into a hole previously drilled in the jawbone 2. The upper end, the fixing end of the fixture comprises a gap 8 which can be combined with the fixture 7 to form a single part or more typically aligned as a separation device, which separation interpolation bore (Not shown in FIG. 2) is screwed into the fixing part 7 provided.

The securing end is provided with an attachment device which engages with another attachment device adapted to be applied to the bar 3, the two being attached to each other. The attachment device at the securing end comprises a support surface 9 aligned perpendicular to the fixture longitudinal axis A, an axially aligned protrusion 10 extending from the support surface 9 and having a hexagonal outer profile, and the protrusions. An interpolated bore 12 in the fixture axially aligned with the top. The corresponding attachment device of the bar 3 comprises the area of its bottom surface comprising the retaining surface 13, the through bore 14, the cylindrical conical portion 15 at the upper end of the bore, the lower end of the bore. Hexagonal conical portion 16 and retainer screw 17.

Bar 3 forms a direction that depends on the direction of the first (not shown) fixture as described in connection with FIG. 1. As already mentioned, the normal alignment B in the direction is intended to correspond to the illustrated direction A of the fixture 1. This is not the case with the drawings. Instead, an angular deflection of α ° occurs between them. The corresponding angular deflection also takes place between the support surface 9 and the holding surface 13.

The holding surface 9 of the fastener is provided with a deformation device in the form of a flange 18 which is aligned at the outer periphery of the bearing surface 9 and extends therefrom. The flange is about 0.05 mm, relatively thin and about 0.15 mm in height. When the fastener 1 is pulled tightly on the bar 3 by the fastening screw 17, a part of the support surface of the fastener constituting the flange will be in direct contact with the support surface 13 of the bar 3. Since the surfaces are not parallel, contact initially occurs at a single point on the flange 18. Tightening the screw continuously deforms the flange 18 in this position and when the screw is further tightened, this deformation extends throughout the flange 18. Since the deformation is plastic, the change in shape is maintained. The left side of the figure shows the flange deformed in this form 19. The deformed flange will take an end surface that is parallel with the bearing surface 13 of the bar 3 and contacts over the entire range. Accordingly, correction is made for each deflection α, and excellent contact is performed between the fixture 1 and the bar 3 and the deformation of the jaw bone 2 is not developed.

3 is a view schematically showing the upper end of the fixture 1. This is also indicated by the break line and by means of a threaded bore 20 which engages a corresponding threaded stud end (not shown) in the gap 8, the gap 8 of the fixture is fixed 7. Shows how it can be attached. This figure clearly shows how the axial flange 18 provided at the outer periphery of the support surface 9 at the upper end of the gap 8 is formed. This is shown in FIG. 4, which shows a large scale area taken through the flange. In this embodiment, Fig. 18 has an end portion formed in a portion having a uniform thickness and perpendicular to the axial direction.

The embodiment shown in FIGS. 5 and 6 differs from that shown in FIG. 4 due to the fact that the outer ends of the flanges 18a and 18b are provided with bevels 21a and 21b on their inner and outer sides, respectively. In both cases, these bevels extend across the entire width of the flange such that pointed, for example sharp edges are formed at the outer end. The bevel can, of course, be arranged differently so that it extends beyond only a portion of the width of the flange, leaving a flat edge surface at the outer end of the flange. Similarly, the flange may be provided with bevels on the inner side and the outer side. When the initial contact is made, the slope allows the resistance to deformation to be kept relatively low. The resistance then increases further as the screw is tightened.

In FIG. 7, the deforming device comprises a radially aligned flange 18c, and a circular slot 22 radially aligned around the spacing 8 has an flange axially from the remaining gap 8. Remove 18c). When the pressure is concentrated at the point farthest from the top side, the flange 18c is deformed because it bends downwardly towards the slot 22 as indicated by the ring line.

In the embodiment shown in FIG. 8, the flange 18e is provided with a slot 23 to facilitate deformation of the flange 18e. They took a larger scale in FIG. As shown in FIG. 8, the slot 23 extends axially through the entire flange 18e or extends through only a portion of the axial bump as shown in FIG. 9. In the case of Figure 9, a low initial strain provision is obtained.

10 illustrates a dental prosthesis device of particular importance in providing the advantages of the present invention. The dental prosthesis device has an upper structure with the tooth prosthesis and a bridge 30 provided with a bar 4, wherein the bar 4 has a bridge 30 in the threaded hole 32 of the bore 4. It is attached by means of a number of screws 31. The bar 4 is fixed in the human jawbone by three fasteners 1, to which the bar 4 is attached by means of a plurality of screws 17, each of which is a hole 14 in the bar. It is passed through and threaded into the threaded bore at the appropriate fixture (1). Each support surface 9 will be in contact with the corresponding retaining surface 13 at the bar 4 and any angular deflection will be taken in the manner previously described by the flange 18 as shown in FIG. 11. .

Figure 12 is a side view of a bar 4 'of a type similar to that previously described, but illustrating another embodiment of the present invention. Each individual retaining surface 13 'is located adjacent to the anchoring hole 14' at the bottom side of the bar. Each retaining surface 13 'is provided with an axially aligned flange 18' concentric with the anchoring holes 14 '. As an enlarged cross sectional view, FIG. 13 shows how this flange 18 'is aligned. In this embodiment of the present invention, the flange 18 'replaces the corresponding flange of the previously described embodiment. Instead of being taken by the device of the support surface of the fixture here the deformation is absorbed by the deformation device at the holding surface 13 'of the bar 4'. With respect to others, the apparatus shown in this embodiment acts the same as previously described, and therefore need not be described further herein. In the embodiment of the present invention, the deforming device formed as the flange 18 'can be deformed by the other methods described in the above-described embodiment in which the deforming device is located in the fixture.

Claims (14)

A fixture (1) for implanting by integrating bone with the bone tissue (2) to support the prosthesis, wherein the fixture (1) is used to fix an attachment (8) to fix the prosthesis to the bone tissue (2) In the fastener 1, which is provided with a fixing part 7, which is provided with a supporting surface 9 arranged to engage the retaining surface 13 with the prosthesis. The support surface 9 is provided with a deforming device 18 which is an integral part of the fixture 1 and the support surface 9 is shaped and deformed in at least one direction perpendicular to the support surface 9. Fixtures that can be. 2. The fastener (1) according to claim 1, wherein the fastener (1) is formed as a body which is at least partly symmetric in the rotational direction, which body is formed as a central axis (A) on the fastener (1), and the support surface (9) ) Is perpendicular to the central axis. The fastener as set forth in claim 2 wherein said deformer comprises an axially aligned flange. 4. The fastener of claim 3 wherein the flange (18) is cylindrical and coaxial with the central axis. The fastener according to claim 4, wherein the support surface (9) is circular and the flange (18) is aligned on the outer circumference of the support surface (9). The fastener according to any one of claims 3 to 5, characterized in that a slot (23) is provided in the flange (18e). The method according to any one of claims 3 to 6, wherein the flanges 18a, 18b at the outer end in the axial direction are inclined to at least one of the radially outer side or the radially inner side of the flange. Characterized by fasteners. 8. A fastener according to claim 7, characterized in that the axial outer ends of the flanges (18a, 18b) are provided with axially aligned sharp, for example sharp edges. 3. The support surface (9) according to claim 1 or 2, wherein radially slots (22) are mounted on the inner surface of the support surface (9) at short distances at all peripheries of the fastening portion (8). And a radially aligned ring-shaped flange (18c) which is used as a deforming device between and the slot (22). 10. A fastener according to any one of the preceding claims, which is arranged to support the dental prosthesis (30). In a prosthetic fixation device comprising at least two fasteners, the at least one fastener is in accordance with any one of claims 1 to 10, wherein the prosthetic fixation device comprises a prosthesis foundation (4) which engages the fastener. Prosthesis fixing device, characterized in that it comprises. 12. Prosthesis fixing device according to claim 11, characterized in that the retaining surface (13) is coplanar. 13. The prosthesis fixing device according to claim 11 or 12, wherein the prosthetic base (4) is arched to fit the jawbone of the human body and is arranged to be attached to the dental prosthesis (30). As a prosthesis comprising a plurality of attachment units 14 'and a retaining surface 13', the plurality of attachment units 14 'are aligned directly to the prosthesis or on a separate prosthesis base 4'. In addition, the retaining surface 13 ′ is a prosthesis in which the retaining surface 13 ′ is aligned with the support surface at a suitable fixture when the prosthesis is attached to the fixture, At least one retaining surface 13 ′ is provided with a deforming device 18 ′, which is characterized in that the deforming device 18 ′ can be deformed in a direction perpendicular to the holding surface 13 ′. .