AU427450B2 - Permanently implantable fixture means for prothesis andthe like - Google Patents

Description

2 i.84 6/7 As a permanently inzplantable fixture means for prosthesis and the like in a human body, especially for implanting a dental prosthetic structure, a means composed by at least two parts has been proposed for attaching the prosthetic structure to bone tissue. A first part of the attachment unit is intended to be applied in such a way in the bone tissue that it will remain embedded in said tissue during all of the time required for healing the damage which occurs when the first part is attached to the bone and while the bone tissue grows into the attachment, and a second part of the attachment unit, serving as mounting unit for the prosthetic structure and so shaped that it may be attached to the first part of the attachment unit and pass through such weak tissue covering the bone tissue. The mounting unit is intended to combine the attachment unit inserted into the bone tissue with a prosthetic structure located outside of the weak tissue. Such permanently implantable attachment means have been used for permanently attaching dental prosthetic structure to the jawbone in human bodies. The jawbones rather often have a narrow cross-section, and the longitudinal direction of the cross-section may diverge sharply at different parts of the same jaw and/or the same jawbone but especially between the upper jaw and the lower jaw. This, among other reasons results in so called over-bite or under- bite, respectively. As the attachment units must, for technical reasons, be well centred in the jawbone, the longi- tudinal directions of the attachment units will not always be in alignment mutually in the same jaw, nor between the upper jaw and the lower jaw. This is a serious disadvantage, 2 427450

(.84 6/71 because the longitudinal direction of the teeth.in the

p'osthetic structure should be in alignment with the longi-

tudinal direction of the attachment unit. A compromise between these demands causes either a weak or completely

unsatisfactory attachment in the jawbone or non-aligned

prosthetic structure. Therefore, there is a need for an attachment means of the kind indicated above, in which the first part attached

to the jawbone may form an angle with the second part to

which the prosthetic structure is to be attached.

The present invention refers to an arrangement in attachment means of the above indicated kind, by which said

need is satisfied. According to the invention, there is provided

between the part of the attachment means intended to grow together with the bone tissue, on the one hand, and the

part of the attachment means which carries up the prosthetic

structure on the other hand, a ball Joint'like arrangement,

comprising at least one joint but perhaps two or more joints. Further details of the invention will be apparent from the following description in connection with the attach-

ed drawings, showing a number. of different forms of execution

of the invention. However, it is understood that the in- vention shall not be limited to one or more or all of these

forms of execution, but that all different kinds of modifica-

tions or combinations between the different forms of execution

may be made within the frame of the invention.

In the drawings: Figure I shows an arrangement according to the inven- tion, in Which only one. single ball joint appears, and in which the ball is applied on the part of the attachment means 3 427450

96,84 6171 int~ended to grow into the skeleton tissue, whereas the ball

claw: cooperating with the ball is applied on the Part, to which the prothesis is intended to be attached. Figure 2 shous an arrangement, in which the two means contained in the ball2 joint are applied in the opposite way. Figure 3 shows the same arrangement as in figure. 2, however doubled so that there are two ball joints in cascade after each other.* In all of the said three forms of execution there is a ball claw for clamping the ball. Figure 4, however, shows an arrangement in which the ball clawi has been r eplaced by a stretch joint arrange- ment,. running through part of the contact surface of the ball joint, Figire 5 shows the corresponding arrangement with a spherical ball,and Figures 6 and 7 show a variation of the arrangement according to figure 2. In the arrangement according to figure 1 the part growing together with the jaw bone comprises a bolt formed part 10, which is provided with outside threads for screwing into a hole, drilled in the jaw bone and provided with inside threads. The part 10 further is provided with a well 11 entering from 1mlov;, which communicates through radially directed openings 12 with the outside of the part 11 provided with the threads 13. The holes are intended for making it possible for skeleton tissue. to. Orow in, in connection with the part 10 growing together with the skeleton tissue. At the upper end the part 10 is provided with a flange 14, havinga L-formed section for the reception of a free collar

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Vihich forms, 26,84 6i on its inner side, the ball cup for reception of the ball 16 in the above mentioned ball joint. VWhen it is spoken here in the following about a ball cup, this shall be understood as any means for retaining a ball in its position contained in the ball joint, independently or if this part is really cup-formed or perhaps for instance claw-formed. However, it may happen that a separate ball claw is applied between the ball and the ball cup. This ball claw initially is open, but is staved after the intro- duction 'of the ball, so that it will permanently embrace the ball. The ball claw may be cut up or closed all around. The ball 16 is attached to a shaft 17, which is provided at its lower end with threads and is screwed into the bolt-formed part 10, said part for this purpose being orovided with a well 18 having inside threads. Between the concave part of the collar 15 forming the ball cup, and the convex spherical part of the ballA16, a ball claw 19 is placed, which is attached to the upper part 20 of the attach- ment means. This part 20 is built out in such a way that it will give a good fixture for the prothesis 21, but this detail does not form subject of the present invention per se, and it will therefore also not be further described here. The upper part 20, however, is drilled througi with a hole 22, running in the axial direction and inwardly threaded, in the threads of which it is possible to screw in a bolt 23 along with an arrangement for drawing it, for instance in the form of a screw driver groove 24. In figure 1 the screw driver groove and the parts adjacent thereto of the cavity within the part 20 have been shoim to be filled with cement, amalgams or any similar filler mass. The bolt 23, at its

A42 77 A 5 0

26;. 846' lower end, is provided with a preferably conical cavity

having such a top angle that, when the bolt is drawn, the

edges of the cavity will mesh with the ball 16 and lock

this against mutual movement between the ball 16 and the

upper part 20 of the attachment means. When an attachment means of the kind described above

should be attached to the jaw bone of a patient, who should

be provided with a permanently implanted prothesis 21, the

tooth surgeon acts so that he will first drill, and if re-

quired provide threads in the opening in the jaw bone for the

lower part 10 of the attachment means. Thereby he can de-

termine the axial direction of the opening so that this

opening will in the best possible way be centred in the jaw

bone, and so that it will not get in immediate vicinity of

the surface parts of the jaw bone. In many a case, however,

this makes it possible regarding the form of the jaw bone,

that the drilled and perhaps also threaded hole runs in a

direction, forming an angle with the direction, which the

upper part 20 of the attachment means must assume on basis

of the form and the situation of the prothesis. In the

drilled and threaded hole thereafter the tooth surgeon screws

in the lower part 10 of the attachment means, and he puts on

a temporary used sealing arrangement of some suitable kind in the mouth of the bored and perhaps also threaded hole 18 in

the lower part 10, and he folds over the weak tissue, folded away at the earlier treatment, in order f.healing this, and also healing the damages, caused in the jaw bone. Simul-

taneously the lower part 10 is allowed to grow together by skeleton tissue or other hard tissue growing together with the outer surface of the lower part 10, which has for this

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26,846/ 71 purpose been rifled or in any other suitable way made uneven.

Further, skeleton tissue will grow into the hole 12. Screw- ing up the lower part 10 thereafter is effectively prevented.

The lower part 10 thereafter is left in the way men- tioned above to grow together with the jaw bone, which usually will take a time of for instance six weeks. After fulfilled

healing, the tooth surgeon again cuts up the weak tissue over the lower part 10, which has now been healed, and he uncovers

the lower part, screwed into the threaded hole 18, along with its cover screw by folding away and/or operating aray skin

and gums and he removes the cover screw and screws in the bolt 17 along with the ball, after having applied the collar

in its place. At this time the part 20 and the bolt 17 should assume a straight line and be locked in this position by means of the screw 22. When the bolt 17 is completely screwed into the hole 18 so that the part 19 is in contact with the ball cup 15 the screw 20 is slightly released and the part 20 is corrected into the desired direction. The part 20 thus having been given the correct direction is again locked in this position by means of the screw 22, so that it cannot be moved any further. When all attachments are mounted according to the above, the tooth dentist makes a print, and guided by this the tooth technician thereafter

makes a prothesis, which may be cemented to the part

In this connection it should be observed that the attachment means according to the present invention may, of

course, be used for attachment of a prothesis in the lower

jaw as well as for attachment of a prothesis in the upper

jaw, and when it is spoken here about a "lovwer" and an "upper"part, these expressions refer to the use of the

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96,.84 6171, attachment mcans for attachment of a prothesis to the lower F'ormally, for a com]pLlete prothesis, a plurality of such attac.Irfient means are required, but it iili~be obvious to the tooth surgeon in any specific case how they should be distributed along the jay: bone in order of gLiving patisfactory attachment..Forthat reason only one single attachment means is shovhn in the drawings. Of course, the same attachment means may be used for attachment of a prothesis, representing a single tooth. Figure 2 shows a variation of the arrangement according to figure The lower part of the attachment means 27 has here only been shown quite schematically. One may directly screw this lower part into the drilled and threaded hole in the jaw bone, but it is also possible to let the lower part 27 replace the bolt 18 in the arrangement according to figure i. The essential difference between the arrangements according to figure I and figure 2, as a mtter of fact, rather is concentrated to the arrangement of the ball joint. In the arrangement according to figure 2 the ball claw 28 is provided In a direction upwardly and made In one piece with the lower part 27. It encloses in itself a ball 29, which is oval in cross-section, said ball being provided with a threaded hole 30 for reception of a downwardly direc- ted pin 31, made in the same piece as the attachment pin 32 for the prothesis 33. By the pin 32 being threaded on its outside for meshing into the inwardly threaded hole through the ball 31, all of the ball joint may be locked in its adjusted position by turning all of the pin construction 31- 32, whereby the ball claw 28 is clamped between the ball 31

-8 and the ball CUP 15. 2 6.8461 The attachment of the prothesis 33 may in the arrangement according to figure 2 take place in the same way as already described in connection with figure 1, but it may also take place in such a way that a screw 34 is screwied down through the prothesis 33 and into a threaded hole 35 in the pin 32. Figure 3 shows a modification of the ai'rangement according to figure 2, in vtiich one has pr ovided for the pos- sibility that a parallel displacement must take plaee before the lower and the upper part of the attachment means, per- haps in connection with a change of direction. This makes it necessary to have two ball jointB,.which have been shown in figure 3 to be made in the same way as the single ball joint according to figure 2. For this reason also the same reference numerals have been used, however regarding the lower ball joint provided with a prime and regarding the upper ball joint provided with a second. The locking of the ball joint must not necessarily take place by means of a locking bolt of the type shown in the earlier forms of execution, but it may also advantage- ously take place by means Of a thiread, a wire or the like. In this way one may avoid the ball claw 19 or 28, reap,, according to the figures I 3. An arrangement of the last mentioned type is shown in figure 4. In this case, therefore, no such ball claw as shown in figure I at 19 and in figure 2 and 3 at 28 is required, because in place thereof a thread formed means, for instance a wire 36 has been provided. The ball is attached in fig- ure 4 to the upper end of the lower part 27 of the attachment

9 427450 means and foru there a semi-spherical calotte with a rather or com- wide opening 37, which should preferably be close to pletely frusto-conical. From the bottom of the recess a into the lower well 38 is drilled in a direction dovmwardly part 27 of the attachment means. This well suitably is 39 with a provided with threads for attachnent of a plug under such central bore, through vfnich the wire 36 runs circumstances that it will be retained in a given position into the well. against drawing, When the plug is screwed is in this case The ball cup 40 cooperating with the ball 16 the attachment formed at the lower end of the upper part of surface is provided means 20, and also this concave calotte may run in stretched with a recess for the wire 36, so that it if there should state through both of these recesses, even between the lower exist an essential angular difference means. part 27 and the upper part 20 of the attachment means there In the upper part 20 of the attachment stretching the is provided some suitable arrangement for part 20 has been wire 36, after the upper attachment means to the lower placed in correct angular position in relation attachment means part 27. This stretching device may for comprise a piston instance in the way, shown in figure 4 20, running quite through 41, threaded into a bore in the part and further being pro- it and provided with internal threads, the wire 36, which vided with a hole for the attachment of of an inwardly is widened at its upper part in the form threaded well 42. The wire is attached to the hole, so 4 is screwed upwardly. that it is stretched, When the piston take place The attachment of the orothesis 48 may suitably by means of a sleeve

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2 6,84 6/71 Another form of the arrangement according to figure 4 is shown in figure In this case the ball, 49 is not mechanically combined with the lower part of the attachment means, nor with the upper part thereof. It is spherical, but it contains two conical recesses opposing each other, and meeting-in the centre part o f the ball. The conical recesses 50 and 51 have, at the place of meeting, such width, that the wire. 36 may pass throufft the ball. The wire 36, as earlier described, is stretched at both ends. Thus, a conventional wire lock 52 is provided in the interior of the lower part 27 of the attachment means.* This wire lock comprises two cup-formed parts 53,.54, directed in opposite direction as far as regards the open, interior parts thereof, said parts being inwardly provided wi~th hooks for attachment with the surface of the wire, and outwardly they are conical in order of being pressed together by pressure fran the in- wardly conical wall of the hole through the lower part 27 of the attachment means. A screw spring 55 is spanned between a washer 56 and the lower surface of the two cups 53, 54 in order of pressing them upwardly, that means into the narrower part of the conical hole in the lower part 27. At its upper end the wire is attached to the piston 41 by means of a hole in this, which is also conical, and in which the end of the wire 36 is mounted after having been widened b) en of a wedge 57. The part 41, as was the case in the arrangement according to figure 4, is screwed into an inwardly threaded hole in the upper part 40 of the attachment means, which carries up the prothesis 48. In the arrangement according to figure 6 the ball is substantially semi-spherically formed. The ball 64 is

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26,84 6/1 Drovided with a do-mviardly directed pin 65, forming the seat of' a screw s-Dring 66, thie other end of which rests onto the bottom, which is in this case completely spherical, of' the recess within the ball claw 28. In other respects the arrangement is in essential parts made in the same way as the arrangement according to figure 2, and par-ts corresponding to each other have therefore also been provided with same reference numerals. By means of the screw spring 66 the ball 64 is pressed upwardly onto the ball claw 28, so that by friction between these two parts the ball 64 will be prevent- ed from rotation at turning the screw connected to the part 59.. It m~ay also happen that the tooth surgeon during his work with the attachment means -will cause a turning of' cer- t ain parts, simultaneously as other parts should not be turned. This especially concerns screwing in the threaded parts. For this purpose anehas provided an outer six-edged prof ile 67 on the part 58. A further six-edge profile 68 is provided on the lower part 27 as seen from the arrangement according to figure 7, which is not shown in section. In other parts

this is similarly shaped as the arrangement according to figure 6. The last mentioned six-edge profile is intended to be used when screwing the lower poart 27 into the jaw bone.

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Claims (1)

1. 2 6.84 6171 THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:-

   i. A prosthetic device comprising:

   a first part having means to be permanently implanted

   into a bone such that the bone tissue grows into the first

   part., a second part Including means for attaching the

   prosthetic structure thereon, and a joint connecting said

   first and second parts, said joint being a universal joint

   permitting at least limited universal movement of the second

   part relative to the first part, and said joint including

   means for locking the universal joint in any selected position

   within the range of said limited universal movement to prevent

   further relative movement of the first and second parts, and

   including means for separating said first and second parts

   from each other in the vicinity of said universal joint.

   2. A prosthetic device according to claim 1, in which

   said universal joint is a ball and socket joint and wherein

   the portion of said second part adjacent the joint is

   adapted to pass through the soft tissue covering the bone

   tissue into which the first part is permanently implanted.

   3. A prosthetic device according to claim 2, wherein

   the ball of the ball joint is attached to one of said parts

   and is embraced by a ball claw which is attached to the

   other of said parts.

   4. A prosthetic device according to claim 2, wherein

   the ball is at least substantially spherical and is attached

   by means of a neck to its respective part.

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   26.84 6/71 A prosthetic device according to claim 2, said ball being formed as an elipsoid, ovaloid or the like, and including a pin connecting said ball to the first part.

   6. A prosthetic device according to claim 2, said ball being substantially semi-spherical and formed integrally with one of said parts and the' socket embracing the semi- spherical surface and attached to the other of said parts, and including a stretching means running through the ball and socket joint and urging said ball and socket together.

   7. A prosthetic device according to claim 2, said ball being substantially spherical and resting in sockets in each of the two said parts.

   8. A prosthetic device according to claim 3, said ball claw having an opening, and a pin connected to the ball and extending through said opening and connected to the part other than that part to which the ball claw is connected.

   9. A prosthetic device according to claim 6, wherein said stretching means includes at least one substantially conical recess passing through the ball for carrying the said stretching means.

   A prosthetic device according to claim 9, wherein the ball is substantially spherical and includes a pair of inwardly converging conical recesses which meet at the centre of the ball to form an opening completely through the ball for said stretching means.

   11. A prosthetic device according to claim 2, wherein said locking means comprises a spring means for urging the ball against its socket.

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   26.846/71 12. A prosthetic device according to claim 11, including

   a ball claw embracing the said ball, and wherein said locking

   means includes a threaded engagement between a pin integral

   with one of said parts and said ball for displacing the ball

   relative to the ball claw for urging these two parts together.

   13. A prosthetic device according to claim 11, wherein

   said locking means includes stretching means running through

   the ball and socket joint, the stretching means being

   attached at one of its ends to one of said first and second

   parts, and the other end of the stretching means being attached

   to the other of said first and second parts, and at least one

   of said parts being displaceable by means of a screw thread

   arrangement in the axial direction under the stretching of

   stretching means.

   14. A prosthetic device according to claim 3, wherein the ball claw is provided on its outer surface with a profile

   which facilitates engaging the ball claw to turn the same.

   A prosthetic device according to claim 3, including

   a sleeve contacting the outer side of the ball claw with a

   partially concave surface to form said socket, and a spring

   means for urging the ball and sleeve together.

   16. A prosthetic device according to claim 15, said

   sleeve being provided on its outside surface with a profile

   to facilitate turning the same.

   17. A prosthetic device according to claim 3, the said

   ball in the ball joint being incompletely spherical, a

   spherical portion of the ball engaging the ball claw, and a

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   26.846/71 non-spherical portion of the ball engaging a spring arranged

   to urge the ball against the ball claw.

   18. A prosthetic device according to claim 17, said ball including a pin for connecting the ball with one of said parts, said pin forming a seat for said spring.

   19. A prosthetic device according to claim 18, said claw being generally spherical and embracing the ball, said spring resting against a spherical portion of said ball claw.

   A prosthetic device according to claim 2, including

   an intermediate part, a first ball and socket joint connecting said intermediate part to said first and second ball and socket joint connecting said intermediate part to the said second part.

   DATED this llth day of August, 1972. AGA AKTIEBOLAG

   Edwd. Waters Sons, Patent Attorneys, Russell Street, MELBOURNE. VIC. AUST.

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   2 6.84 611'

   29 Co

   27

   Fig. 2

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   Fig.3

   2~46171.

   26,84617,

   Fig-s

   Fig. 7

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