DE29620972U1 - Device for holding a removable denture on a fixed denture - Google Patents

Description

Device for holding a removable Dentures on a fixed denture

10

The invention relates to a device for holding a removable denture to a fixed denture with

a matrix with a receiving space for attachment to the fixed denture,
an anchoring element with an insertion space for attachment to the removable denture and

a male part with a first insertion part on the female side for immersing into the receiving space of the female part and a second insertion part on the anchoring element side for immersing into the insertion space of the anchoring element.

15 Such a holder is a rigid, intracoronal holding element (also called a T-attachment) in which the frictional connection between the male and female parts can be adjusted in a defined manner using an activation or adjustment screw or by locking

Telephone: (0221) 916520 · Fax: (0221) 134297

Fax: (G EZI) (0221) 91 2030

Telegram: Cathedral Patent Cologne

or is specified in another way. The matrix is firmly connected to the tooth stump crown (fixed denture), i.e. embedded in this crown. The repeated removal and insertion of the removable denture causes abrasion and wear on the matrix-side, first insertion part of the patrix, which is usually made of a softer material than the matrix, which makes it necessary to restore the desired frictional connection by adjusting the adjustment screw. If the patrix is too worn, it must be replaced with a new one. In order to be able to do this, the patrix has an extension connected to the first insertion part, in which there is a through hole through which a fastening screw that can be screwed to an anchoring element extends. The anchoring element is anchored in the removable denture and is usually designed as a cap element that is open towards the patrix and downwards, thus enclosing the process.

From DE 92 07 562 Ul an intracoronal T-shaped attachment of the above type is known, in which the male part is provided with a second plug-in part on the anchoring element side, which is inserted into the anchoring element and wedged there by means of a grub screw. In this T-shaped attachment too, the anchoring element is open on two sides, namely towards the male part 0 and towards the underside of the removable denture. This opening, particularly towards the underside of the denture, is problematic in terms of care and hygiene, since food residues can collect on the open underside of the anchoring element. Furthermore, when assembling the anchoring element, there is a risk of

When using the anchoring element, there is a risk that solder, which is used to attach the anchoring element to the substructure of the removable denture, will flow into the anchoring element from the underside, rendering it unusable.

The invention is based on the object of creating a device for holding a removable denture to a fixed denture, in which the risk of solder penetrating the anchoring element during its assembly is reduced and food residues can accumulate in the basal area to a much lesser extent than before.

To solve this problem, the invention proposes a device for holding a removable denture on a fixed denture of the type mentioned above, which additionally provides

0 - that the second insertion part of the male part has at least one elastic locking leg with a locking projection,

that the insertion space of the anchoring element has a locking recess assigned to the locking projection of the at least one elastic locking leg and designed to be complementary to the locking projection,

that a through hole extends through the male part, which is parallel to the

0 extension of at least one locking leg and is partially limited by it, and

that a locking element can be inserted into the through hole, which rests against the at least one locking leg and prevents a backward movement

of at least one locking leg with its locking projection immersed in the associated locking recess of the insertion space of the anchoring element.
5

In the T-attachment according to the invention, the male part is provided with at least one elastic locking leg, which has a locking projection and is arranged on the second insertion part that can be inserted into the anchoring element. The locking projection on this at least one elastic locking leg is inserted into a locking recess that is designed to be complementary to the locking projection and is arranged in the inside of the insertion space of the anchoring element.

A through hole extends through the male part, which runs parallel to the at least one locking leg and is partially delimited by it. When the locking leg is immersed in the insertion space of the anchoring element, a locking element can be inserted into the through hole, which rests against the locking leg and prevents the at least one locking leg from moving back. In other words, when the second insertion part of the male part is inserted into the insertion space of the anchoring element, the locking element ensures that the locking projection cannot move out of the locking recess of the anchoring element when tensile loads occur between the male part and the anchoring element. The basic principle for the design of the locking projection and locking recess is that each locking leg automatically moves against the build-up of mechanical stress both when it is pushed into the insertion space of the anchoring element and when it is intentionally removed if pressure is applied to the second inner insertion part of the male part (for pushing in).

ben into the insertion space) or pulling (to intentionally move out of the insertion space). A (semi-)spherical (concave/convex) design could be considered as a possible shape; but other spherical or trapezoidal or triangular cross-section designs are also possible.

With the T-attachment according to the invention, the male part is no longer held to the anchoring element by screwing. The male part and anchoring element are instead coupled to one another by a locking connection, with the locking element locking the locking connection. The design of the T-attachment according to the invention makes it possible to design the anchoring element as a basally closed part that only has an opening facing the male part as access to the insertion space of the anchoring element. This has advantages when assembling the anchoring element, as the risk of solder penetrating into the interior of the anchoring element is now reduced. Furthermore, the basally closed T-shaped attachment also has an advantageous effect in terms of hygiene. Finally, the design according to the invention also makes it possible to reduce the size of the T-shaped attachment, since the previously required retaining screw extending parallel to the insertion direction of the male part into the female part for fastening the male part to the anchoring element is no longer required.

In an advantageous development of the invention, it is provided that the male part of the male part has several elastic locking legs, each with one or more locking projections. These locking legs are in particular evenly distributed around the

Through hole and limit it on all sides. The flexibility and elastic mobility of the locking legs is expediently achieved by arranging slots between adjacent locking legs, which run in the extension of the through hole and are radially continuous. In the device according to the invention, each locking leg can therefore move elastically transversely to its longitudinal extension towards or away from the through hole. This elastic movement of each locking leg is necessary so that the male part with its second insertion part having the locking leg(s) can be inserted into the insertion space of the anchoring element. Due to the locking projections of the locking legs that protrude radially outwards in relation to the through hole, these move towards the through hole when the anchoring element-side second insertion part of the male part is inserted into the insertion space of the anchoring element. When the plug-in part is fully inserted, each locking leg moves radially outwards again when its locking projection is opposite the locking recess of the anchoring element.

If there are several locking legs, the inside of the insertion space of the anchoring element can be provided with several individual locking recesses assigned to the individual locking projections of the locking legs or with a common locking recess for all locking projections. The latter is advantageous from a manufacturing point of view.

In the case of the locking element, which, when the second plug-in part is inserted into the insertion space of the anchoring element,

the male part rests on the side of the at least one locking leg facing away from the locking projection and consequently prevents the locking projection of the locking leg from moving out of the locking recess of the anchoring element, it is in particular a pin, bolt or similar cylindrical element. This is expediently the case with T-attachments in which the male part is held in the female part by locking. If, on the other hand, the retention of the male part in the female part is achieved by frictional forces, the threaded section or bolt section (i.e. thread-free part on the head side) of an activation or adjustment screw of the T-attachment serves as the locking element, by means of which the frictional force with which the male part is held in the female part can be adjusted. In this case, the first plug-in part of the male part, which can be inserted into the receiving space of the female part, has a dovetail-like shape. The receiving space of the die is designed to complement this dovetail-shaped first insertion part. The first insertion part itself consists of two spring-elastic expansion elements or legs that engage behind undercuts in the receiving space of the die. Between the two expansion elements is the activation or adjustment screw, which has a conical screw head that is arranged between the expansion legs. The adjustment screw also runs through the through hole of the die in order to interact with an internal threaded hole, designed in particular as a blind hole, which is located coaxially to the insertion space of the anchoring element. The adjustment screw is in threaded engagement with the internal thread of this threaded hole, so that when the adjustment screw is turned, a more or less strong

The expansion elements or expansion legs of the male part are spread. In its middle threaded section, this adjusting screw rests on the individual locking legs, preventing their movement so that the locking projections remain in the locking recesses, meaning that the male part is reliably locked to the anchoring element.

An embodiment of the invention is explained in more detail below using the figures. In detail:

Fig. 1 is a plan view of a part of a sublin-

gual bar prosthesis with T-attachment,
15

Fig. 2 is a side view of the prosthesis according to Fig. 1 when removed from the fixed denture,

0 Fig. 3 a side view of the inserted prosthesis

according to Fig. 1,

Fig. 4 is a perspective view of the T-attachment as used in the sublingual prosthesis of Figs. 1 to 3,

Fig. 5 is a section along the line V-V of Fig. 4,

Fig. 6 a section along the planes VI-VI of Figs. 4 and 5 through the T-attachment,

Fig. 7 is a section along the line VII-VII of Fig. 6 and

&bull; <

Fig. 8 is a perspective view of the male part to illustrate the design of its locking legs.

Fig. 1 shows a top view of a human lower jaw with a sublingual bar prosthesis 10, of which only one part is shown. The sublingual bar prosthesis 10 replaces the molars 12 and is anchored to the crown 14 of the rear premolar 16. The anchoring is carried out by a T-attachment 18, which consists of a matrix 20 embedded in the crown 14 of the premolar 16, an anchoring element 22 embedded in the first molar 12 of the prosthesis 10 and a patrix 24 that mechanically interacts with both the matrix 20 and the anchoring element 22. The structure of the T-attachment 18 is explained below using Figs. 4 to 8.

As can be seen in particular in Fig. 6, the matrix 20 is provided with a receiving space 26 which is closed at the base at 28 and is open on its opposite upper side. Furthermore, the receiving space 26 is open towards the anchoring element 22. According to Fig. 4, the receiving space 26 is essentially dovetail-shaped and has two lateral undercuts 30.

The anchoring element 22 is closed on all sides with the exception of its inner side 32 facing the male mold 24 or female mold 20. On this inner side 32, an insertion space 34 is introduced into the anchoring element 22, which is limited in depth by a bottom wall 36. In the area of the side wall 38 of the insertion space 34 adjacent to the bottom wall 36, there is a circumferential (locking)

Recess 40, which will be discussed in more detail below. Furthermore, starting from the bottom wall 36 of the insertion space 34, a threaded hole 42 with an internal thread 44 is made in the anchoring element 22, the function of which will also be explained below. As can be seen in particular from Figs. 4 to 6, the anchoring element has a thickened end 46 facing away from the matrix 20, while the anchoring element 22 is reduced in cross-section in its area 48 adjacent to the matrix 20. This design of the anchoring element 22 allows it to be embedded in the first premolar 12 of the prosthesis 10, protected against tensile loads.

The design of the male part 24 can be best seen in Fig. 8. The male part 24 essentially consists of two insert parts 50, 52 arranged at right angles to one another, of which the first insert part 50 is intended for insertion into the receiving space 26 of the female part 20 and the second insert part 52 is intended for insertion into the insertion space 34 of the anchoring element 22. The first insert part 50 has two expansion legs 54 which are provided with projections 56 facing away from one another, which reach behind the undercuts 30 of the receiving space 26 of the female part 20. The two expansion legs 54 are separated from one another by a slot 58. The two expansion legs 54 are connected on their side facing away from the die 20 by diametrically opposed (locking) legs 60, which run at right angles to the straight extension of the expansion legs 54 and belong to the second insertion part 52. Between the two locking legs 60 there are two further locking legs 62, which are also diametrically opposed.

are arranged one above the other. In a plan view of the free end 64 of the second insertion part 52 formed by the locking legs 60 and 62, this has an essentially oval shape with two parallel side surfaces and upper and lower semi-cylindrical surfaces connecting them. Between adjacent locking legs 60 and 62, slots 66 are made which are open towards the free end 64 of the second insertion part 52. Furthermore, a through hole 68 extends through the second insertion part 52, which also extends through the expansion legs 54. According to Fig. 8, the locking legs 60 and 62 have locking projections 70 on their outside facing away from the through hole 68, the shape of which is complementary to the locking recess 40 in the side wall 38 of the insertion space 34 of the anchoring element 22.

The male part 24 is made in one piece, i.e. all the expansion and locking legs of the male part 24 are connected to one another in one piece. The expansion legs 54 can be moved away from one another using an adjusting screw 72 (see arrows 73 in Fig. 5). This allows the pressure force with which the expansion legs 54 rest against the female part 20 from the inside to be adjusted.

The adjusting screw 72 has a conical screw head 74 and a threaded bolt 76 with an external thread 78. The screw head 74 is conical on its underside and rests on the likewise conical contact surfaces 80 of the expansion legs 54. In its section adjoining the screw head 74, the threaded bolt 76, which extends through the through hole 68, rests from the inside on the locking legs 60, 62 essentially without play in order to be in threaded engagement with the

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the threaded bore 42 of the anchoring element 22.

As can be seen from the figures and the above description, the connection of the male part 24 to the anchoring elements 22 is achieved by locking, in that the locking projections 70 of the locking legs 60, 62 enter the locking recess 40 of the anchoring element 22. Due to the introduction of the slots 66 into the second plug-in part 52, its locking legs 60, 62 can be moved elastically transversely to their extensions. When the second plug-in part 52 is introduced into the plug-in space 34, the locking legs 60, 62 are moved towards one another when their locking projections 70 rest against the inner side wall 38 of the plug-in space 34. This results in a mechanical internal tension in the material of the locking legs 60, 62, as a result of which the locking legs 60, 62 automatically move apart again when the second plug-in part 52 is completely pushed into the plug-in space 34 and the locking projections 70 can enter the locking recess 40. The adjusting screw 72 is then inserted from the side of the male part 24 facing away from the anchoring element 22 into its through hole 68 and brought into threaded engagement with the threaded hole 42 arranged as an extension of the through hole 68. By screwing the adjusting screw 72 to the anchoring element 22 with a correspondingly strong force, the spread position of the spread legs 54 and thus the frictional force with which the male part 24 is held in the receiving space 26 of the female part 20 can be adjusted.

To avoid misunderstandings, it should be mentioned that 5 for reasons of better understanding of the construction

tion of the T-attachment 10, this is shown in the figures differently than in the assembled state, as excessive clearance fits are shown between the individual parts (matrix, patrix and anchoring element). In fact, the matrix, patrix and anchoring element are manufactured to such an exact fit that they can be joined together essentially without clearance or with only minimal clearance.

Claims (1)

- 14 - EXPECTATIONS 1. Device for holding a removable dental prosthesis to a fixed dental prosthesis, with
a matrix (20) having a receiving space (26) for attachment to the fixed dental prosthesis (14), - '"an anchoring element (22) having an insertion space (34) for attachment to the removable dental prosthesis (12) and
a male part (24) with a first insertion part (50) on the female side for immersing in the receiving space (26) of the female part (20) and a second insertion part (52) on the anchoring element side for immersing in the insertion space (34) of the anchoring element (22),
characterized ,
that the second insertion part (52) of the male part (24) has at least one elastic locking leg (60; 62) with a locking projection (70), that the insertion space (34) of the anchoring element (22) has a locking recess (40) associated with the locking projection (70) of the at least one elastic locking leg (60; 62) and designed to be complementary to the locking projection (70), that a through hole (68) extends through the male part (24), which runs parallel to the extension of the at least one locking leg (60,-62) and is partially delimited by it, and that a locking element (76) can be inserted into the through hole (68), which is attached to the at least one locking leg (60,-62) and prevents a backward movement of the at least one locking leg (60,-62) immersed with its locking projection (70) in the associated locking recess (40) of the insertion space (34) of the anchoring element (22). 2. Device according to claim 1, characterized in that the second insertion part (52) of the male part (24) has a plurality of elastic locking legs (60, 62) with locking projections (70). 3. Device according to claim 2, characterized in that the locking legs (60, 62) are evenly distributed around the through hole (68) and delimit it on all sides, with radially continuous slots (66) being arranged between adjacent locking legs (60, 62) extending in the extension of the through hole (68). 4. Device according to one of claims 1 to 3, characterized in that the insertion space (34) of the anchoring element (22) has individual locking recesses assigned to the locking projections (70) in the case of several locking legs (60, 62). (40) or a common locking recess (40) for all locking projections (70). 5. Device according to one of claims 1 to 4, characterized in that the locking element (76) is a pin. 6. Device according to one of claims 1 to 5, characterized in that the first plug-in part (50) of the patrix (24) against unintentional - 16 - Slipping out of the receiving space (26) of the die (20) is securely held therein. 7. Device according to one of claims 1 to 6, characterized in that the first insertion part (50) of the male part (24) has expandable expansion elements (54) for frictionally engaging with undercuts (30) of the receiving space (26) of the female part (20). 8. Device according to claim 7, characterized in that the spread position of the spreader legs (54) is adjustable by means of an adjusting screw (72) with a screw head (74) and a threaded bolt (76) and that the threaded bolt (76) the adjusting screw (72) extends through the through hole (68), wherein the adjusting screw (72) in the section of its threaded bolt (76) adjoining the screw head (74) rests as a locking element on the at least one locking leg (60; 62) and in the end section of its threaded bolt (76) facing away from the screw head (74) is in threaded engagement with a threaded hole (42) introduced into the anchoring element (22) and arranged in extension of the through hole (68) of the male part (24). 9. Device according to one of claims 1 to 8, characterized in that the anchoring element (22) is only open on its side (32) facing the die (20). 10. Device according to one of claims 1 to 9, characterized in that the plug-in parts (50, - 17 - 52) of the male part (24) are spaced substantially at right angles from one another.