DE8909755U1 - Telescopic crown - Google Patents

Description

PATENT ATTORNEYS ' · · - ·, , J · " · · ] . .'··." ^Patent signs:

DiPL-iNG. CONRAD KÖCHLINÖ'· ' *·· ^: '··'^; ·· ^: »\

DlPL-ING. CONRAD-JOACHIM KOCH LI NG Note: Regina Kühl

Beyer Street 135,5800 Hagen Buschey Street 25

Call (02331) B1164 + 85033

Telegrams: Patentkochllng Hagen D-5800 Hagen 1 Accounts: Commerzbank AG, Hagen

(Bank code 45040042) 3515095

Sparkasse Hagen 100012043 _____ Postal check Dortmund 5989-460

VNR: IJL_...5Ä...5J,

Serial No. S__a_t___L_ -

from 14. ..._Vug u s t_.ü_39

CJK/Li.

Telescopic crown

The invention relates to a telescopic crown consisting of a primary crown that can be attached to a tooth and a secondary crown that can be pushed onto it.

Such telesynthetic crowns are used to fix dentures, whereby removable, partial dentures are attached to telescopic crowns. Many dentists prefer the telescopic crown technique to all conventionally manufactured retaining elements such as attachments, anchors and the like in order to give removable dentures the right hold in the mouth. Usually, the secondary crown is pushed onto the primary crown using friction. However, the desired friction is not always achieved, and it is also known that after a certain period of time,

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The friction of the telescopic crowns decreases over the period of time the dentures are worn and an exact fit of the denture is no longer guaranteed. The disadvantage for the denture wearer is that even if the denture is slightly lifted, food particles can get stuck under the denture. Even when speaking or laughing, the denture moving between the natural teeth that are still standing is a very unsettling situation for the denture wearer.

The conventional technology of telescopic crowns is very complex in terms of production because the exact friction has to be determined by time-consuming, careful grinding or scaling.

Based on this state of the art, the invention is based on the object of creating a telescopic crown of a type that allows a secure and precisely defined position of the prosthesis equipped with telescopic crowns with little effort.

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To solve this problem, it is proposed that a firing stent part is held in the stent, which is inserted in the desired position with a notch that projects beyond the wall to the outer wall of the primary crown into a locking recess of the same shape in the outer wall of the primary crown.

This design makes it possible for the dental technician to place the secondary crown on the primary crown without friction, whereby the catch in the secondary crown simply clicks into the identically shaped recess in the primary crown in the desired position, thus ensuring that the desired position is secured perfectly. By applying the appropriate amount of force, the secondary crown can be pulled off the primary crown again, overcoming the catch effect to release the dental prosthesis.

Preferably, the catch and the catch recess are hemispherical in shape.

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It is further preferred that the retention part is U-shaped, with its base supporting the catch at least approximately in the middle and its legs projecting towards the side facing away from the catch, and that the retention part is inserted into a recess in the inner wall of the secondary crown, on the side walls of which the legs can be supported and the bottom of which has a distance from the base of the retention part that corresponds to the spring travel of the catch.

This design ensures that the spring effect is sufficient even with the small amount of space available for the retention part in the secondary crown, whereby the spring-elastic retention part springs back when the secondary crown is pushed onto the primary crown, so that the hemispherical catch in particular is pushed back until the desired position is reached, in which the catch fits into the corresponding hemispherical recess in the primary crown with at least partial

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The retention part can click into place by releasing the spring force. This locking process is accompanied by an audible "click" so that the user can also hear whether it is sitting correctly.

It is also particularly preferred that the side walls of the recess are undercut and the legs are arranged so as to engage under the undercut.

In this way, the retention part is held very securely and normally inseparably in the corresponding recess of the secondary crown, whereby the removal of the retention part remains possible using a suitable tool.

It is particularly preferred that the cross-sectional shape of the recess is dovetail-shaped and the legs are inclined at the same angle.

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One possible variant is that the latch of the rotation part is made of metal.

According to a further variant, the retention part is made of metal.

It can also be provided that the retention part is made of plastic.

Preferably, the retention part has a one-piece molded catch.

A particularly preferred embodiment is seen in that the recess receiving the retention part has a height of about 0.7 to 1.1 mm, the retention part can be inserted flush into the recess, its legs having a free length of about 0.3 to 0.5 mm and the catch protruding by about 0.2 to 0.4 mm, in particular 0.3 mm.

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A particularly secure and wobble-free fit of the retention part in the corresponding recess is achieved in that the diverging legs of the retention part have a narrow edge running parallel to the base, their outer leg surfaces adjoining the edge enclose an angle of 50° with each other, their inner surfaces adjoining the edge enclose a flat angle of in particular 140° with each other and run into a more acute angle of approx. 80° to the base.

Furthermore, it is preferably provided that the width of the retention part is approximately 1.1 to 1.5 mm, in particular 1.3 mm.

It is also advantageous that the recess for the retention part and the locking recess are each formed by a lost molded part with the same contour made of residue-free, combustible plastic.

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/ _ s e- i &eegr; It can preferably be provided that the molded part for forming the recess for the retention part is cuboid-shaped with an open cover surface, the narrow side surfaces for forming the undercut being designed to converge towards the cover surface and the undercut ending shortly before the connection to the longer side surfaces.

Furthermore, it can be provided that the molded part for forming the locking recess is a rectangular plate with a central depression, with retaining webs extending towards the top being molded onto the short edges thereof, which are connected to the plate in particular via predetermined breaking points.

Embodiments of the invention are shown in the drawing and described in more detail below. It shows:

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Fig. 1 a telescopic crown during the assembly process;

Fig. 2- e1r:c Ei &eegr; «elht.it in side view and in Di looking up;

Fig. 3 another detail in side view; Fig. 4 the retention part of the telescopic crown in

different load conditions; Fig. 5 ei ¹ " molded part in plan view and in cross section

Fig. 6 another molded part in plan view in

Section; Fig. 7 a retention part in view and in section.

The telescopic crown, which is shown in Figure 1, for example, consists essentially of a primary crown 2 attached to a ground tooth stump 1 and a secondary crown 3 that can be pushed onto it. The secondary crown 3 has

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an inner hollow core which is adapted to the outer shape of the primary crown 2 with a small amount of play. To ensure the desired position, a resilient retention part 5 is held in the inner wall of the secondary crown 3, which is directed parallel to the direction of insertion (shown by arrow 4), which engages with a catch 6 projecting beyond the wall towards the outer wall of the primary crown 2 in a locking recess 7 of the same shape in the outer wall of the primary crown 2. The retention part springs in the direction transverse to arrow 4, as can be seen in Figure '·. (see arrow 8). The catch 6 and the locking recess are each hemispherical, with the functional parts engaging with one another in the desired position without play or almost without play. The retention part 5 is essentially U-shaped, with its base 9 carrying the catch 6 in the middle. Its legs protrude on the side facing away from the catch 6. The retention part 5 is inserted into a corresponding recess in the inner wall of the secondary crown 3, on the side walls of which

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the legs 10 are supported, the bottom of which is at a distance from the base 9 of the retention part 5 corresponding to the spring travel of the catch 6, so that when the secondary crown 3 is pushed onto the primary crown 2, the catch can completely disappear into the alignment of the inner wall of the secondary crown 3, as can be seen from Figure 4.

The side walls of the recess for receiving the retention part 5 are undercut, with the legs 10 being designed in such a way that they engage under the undercut. In this way, the retention part is held securely in the recess. The cross-sectional shape of the recess is preferably dovetail-shaped, with the legs 10 being inclined at the same angle. In the exemplary embodiment, the retention part 5 together with the catch 6 is made in one piece from a suitable plastic. The recess 11 receiving the retention part 5

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The basic structure can be seen in drawings 2, 4 and 6. In the drawings

tion parts are shown on a greatly enlarged scale. The recess 11 that accommodates the retention part has, for example, a height of 0.7 mm and a width of 1.4 to 1.45 mm. The retention part 5 has a total height of 0.95 mm according to drawing figure 7, with the catch 6 being designed as a hollow hemisphere, so that the desired spring effect can be achieved not only via the legs 10 and the base 9, but also by additional deformation of the hemisphere 6. The legs 10 protrude on the side facing away from the catch 6 by approximately 0.35 mm measured in the normal direction, with the catch 6 projecting beyond the base by approximately 0.3 mm. The diverging legs 10 of the retention part 5 have a narrow edge 12 running parallel to the base 9, which is shown in Figure 7 on an enlarged scale of 40:1. The outer legs 10, which are connected to the edge

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adjoining leg surfaces 13 form an angle of approximately 50° with one another. Their inner surfaces 14, adjoining the edge 12, form a flat angle of 140° with one another and change to a more acute angle of approximately 80°, from where they merge into the base 9. The width of the retention part 5 is approximately 1.3 to 1.35 mm. When producing the telescopic crown, the recess 11 for the retention part 5 and the locking recess 7 are each formed by a lost molded part 15 with the same contour, which molded parts are shown in the drawing figures 5 and 6. The molded part 6 for forming the recess 11 for the retention part 5 is essentially cuboid-shaped with an open cover surface, whereby the narrow side surfaces 17 for forming the undercut are designed to converge towards the cover surface. The undercut thus formed ends laterally shortly before the connection to the longer side surfaces 18. The molded part 16 for forming

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The recess 7 for the catch 6 of the retention part 5 is formed by a rectangular plate with a central depression, as can be seen in Figure 5. On the short edges of the plate, retaining webs 19 are formed which protrude at right angles from the ^plate and extend towards the top thereof and can be broken off via sole break points 20. The molded parts 15 are modeled into the inner surface of the secondary crown 3 or the outer surface of the primary crown 2 and embedded together with the crown. The modeled material is removed by heat, and the molded parts 15, 16, which consist of plastic that burns without residue, are also completely removed. Metal is then poured into the mold, thereby producing the primary crown 2 and the secondary crown 3 with their contours shown in Figure 1. The free space between the undercut and the side walls 18, which can be seen in Figure 6, serves to prevent the formation of air bubbles during

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To avoid embedding the crown. The retaining bars 19 of the molded part 16 serve to ensure that this molded part can be modeled and positioned correctly using an auxiliary tool.

The invention is not limited to the embodiment, but is variable in many ways within the scope of the disclosure. All new individual and combination features disclosed in the description and/or drawing are considered essential to the invention.

Claims (15)

1. Telescopic crown, consisting of a primary crown which can be placed on a tooth stump and a secondary crown which can be pushed onto the latter, characterized in that a resilient retention part (5) is held in the inner wall of the secondary crown (3), which is inserted in the desired position with a catch (6) projecting beyond the wall towards the outer wall of the primary crown (1) into a catch recess (7) of the same shape in the outer wall of the primary crown (2). 2. Telescopic crown according to claim 1, characterized in that the catch (6) and the catch recess (7) are hemispherical. 3. Telescopic crown according to claim 1 or 2, characterized in that the retention part (5) is U-shaped, the base (9) of which carries the catch (6) at least approximately centrally and the legs (10) of which protrude to the side facing away from the catch (6), and ¹ 1Jl Cool 9803/89 - 17 - that the retention part (5) is inserted into a recess (H) in the inner wall of the secondary crown (3), on the side walls of which the legs (10) can be supported and the bottom of which has a distance from the base (9) of the retention part (5) corresponding to the spring travel of the bracket (6). 4. Telescopic crown according to claim 3, characterized in that the side walls of the recess (11) are undercut and the legs (10) are arranged to engage under the undercut. 5. Telescopic crown according to claim 3 or 4, characterized in that the cross-sectional shape of the recess (11) is dovetail-shaped and the legs (10) are inclined at the same angle. 6. Telescopic crown according to one of claims 1 to 5, characterized in that the catch (6) of the retention part (5) consists of metal. at· < Cool 9803/89 - 18 - 7. Telescopic crown according to one of claims 1 to 6, characterized in that the retention part (5) consists of metal. 8. Telescopic crown according to one of claims 1 to 6, characterized in that the retention part (5) consists of plastic. 9. Telescopic crown according to one of claims 1 to 8, characterized in that the retention part (5) has an integrally formed catch (6). 10. Telescopic crown according to one of claims 1 to 9, characterized in that the retention part (5) receiving recess (11) has a height of approximately 0.7 to 1.1 mm, the retention part (5) can be inserted flush into the recess (11), wherein its legs (10) have a free length of approximately 0.3 to 0.5 mm and the catch (6) protrudes by approximately 0.2 to 0.4 mm, in particular 0.3 mm. «I · * ■ ft* Cool 9803/89 - 19 - 11. Telescopic crown according to one of claims 1 to 10, characterized in that the diverging legs (10) of the crown part (51) have a narrow edge (12) running parallel to the base, their outer leg surfaces (13) adjoining the edge (12) enclose an angle of 50° with one another, their inner surfaces (14) adjoining the edge (12) enclose a flat angle of in particular 140° with one another and extend into a more acute angle of approximately 80° with the base (9). 12. Telescopic crown according to one of claims 1 to 11, characterized in that the width of the retention part (5) is approximately 1.1 to 1.5 mm, in particular 1.3 mm. 13. Telescopic crown according to one of claims 1 to 12, characterized in that the recess (11) for Knhl 9803/89 - 20 - the retention part (5) and the locking recess (7) are each formed by a lost mold part (i 5 or iö) with the same contour, in particular made of non-flammable plastic. 14. Telescopic crown according to one of claims 1 to 13, characterized in that the molded part (15) for forming the recess (11) for the retention part (5) is cuboid-shaped with an open cover surface, the narrow side surfaces (17) for forming the undercut being designed to converge towards the cover surface and the undercut ending shortly before the connection to the longer side surfaces (18). 15. Telescopic crown according to one of claims 1 to 14, characterized in that the molded part (16) for forming the locking recess (7) is a rectangular plate with a central depression, with retaining webs (19) extending towards the top being molded onto the short edges of the plate, which are connected to the plate in particular via predetermined breaking points (20).