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Title:
RETAINING INTERFACE FOR DENTAL PARTS
Document Type and Number:
WIPO Patent Application WO/2020/058419
Kind Code:
A1
Abstract:
A dental part with an interface for a translational coupling along a longitudinal axis (L) of the dental part to another dental part is provided, wherein the interface is arranged about the longitudinal axis. The interface includes an interface surface section and a retaining element. The interface surface section extends along a portion of the perimeter of the interface. The retaining element is attached to the dental part, wherein a portion of the retaining element protrudes from the interface surface section to define an elongated engagement part, the engagement part having an elongation that extends transverse to the longitudinal axis.

Inventors:
RATIA GARCIA JAVIER (CH)
EGGIMANN FABIAN (CH)
Application Number:
PCT/EP2019/075200
Publication Date:
March 26, 2020
Filing Date:
September 19, 2019
Export Citation:
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Assignee:
NOBEL BIOCARE SERVICES AG (CH)
International Classes:
A61C8/00; A61C1/14; A61C5/30; A61C9/00; A61C13/265
Foreign References:
US20020049009A12002-04-25
US20090081614A12009-03-26
US6186785B12001-02-13
US4348181A1982-09-07
Attorney, Agent or Firm:
JENSEN, Olaf (CH)
Download PDF:
Claims:
CLAIMS

1. A dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910) with an interface (11; 111; 211; 311; 411; 511; 611; 711; 811; 911) for a translational coupling along a longitudinal axis (L) of the dental part to another dental part (20; 120; 220; 320; 420; 520; 620; 720), wherein the interface is arranged about the longitudinal axis and includes: an interface surface section (12a; 112a; 212a; 312a; 412a; 512a; 612a; 712a; 812a; 912a) extending along a portion of the perimeter of the interface, and

a retaining element (14; 114; 214; 314; 414; 514; 614; 714; 814; 914) attached to the dental part, wherein a portion of the retaining element protrudes from the interface surface section to define an elongated engagement part (14a; 114a; 214a; 314a; 414a; 514a; 614a; 714a; 814a; 914a), the engagement part having an elongation that extends transverse to the longitudinal axis.

2. The dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910) according to independent claim 1, wherein the interface surface section (12a; 112a; 212a; 312a; 412a; 512a; 612a; 712a; 812a; 912a) is curved and/or planar.

3. The dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910) according to claim 1 or 2, wherein the engagement part (14a; 114a; 214a; 314a; 414a; 514a; 614a; 714a; 814a; 914a) of the retaining element (14; 114; 214; 314; 414; 514; 614; 714; 814; 914) emerges gradually from the interface surface section at one or both ends in its longitudinal direction, (12a; 112a; 212a; 312a; 412a; 512a; 612a; 712a; 812a; 912a), and/or along its length substantially extends parallel to the interface surface section and/or extends with a slope in relation to the interface surface section, the engagement part preferably being substantially straight.

4. The dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910) according to any one of the preceding claims, wherein the retaining element (14; 114; 214; 314; 414; 514; 614; 714; 814; 914) is a separate part that comprises a polymer, in particular an elastomer, and/or a metal.

5. The dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910) according to any one of the preceding claims, wherein the interface (11; 111; 211; 311; 411; 511; 611; 711; 811; 911) is a male or female interface extending in the direction of the longitudinal axis (L) and the interface surface section (12a; 112a; 212a; 312a; 412a; 512a; 612a; 712a; 812a; 912a) forms part of the circumferential side of this male or female interface about the longitudinal axis.

6. The dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910) according to any one of the preceding claims, wherein the interface (11; 111; 211; 311; 411; 511; 611; 711; 811; 911) comprises at least along the interface surface section (12a; 112a; 212a; 312a; 412a; 512a; 612a; 712a; 812a; 912a) a reception recess (13; 113; 213; 313; 413; 513; 613; 713; 813; 913) .

7. The dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910) according to claim 6, wherein the retaining element (14; 114; 214; 314; 414; 514; 614; 714; 814; 914) is a plug that is molded into or is put into the reception recess (13; 113; 213; 313; 413; 513; 613; 713; 813; 913) .

8. The dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910) according to any one of the preceding claims, wherein the outer limits of the interface surface section (12a; 112a; 212a; 312a; 412a; 512a; 612a; 712a; 812a; 912a)in a circumferential direction about the longitudinal axis substantially limits the extension of at least the engagement part (14a; 114a; 214a; 314a; 414a; 514a; 614a; 714a; 814a; 914a) of the retaining element (14; 114; 214; 314; 414; 514; 614; 714; 814; 914) .

9. The dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910) according to claim 6, wherein the retaining element (14; 114; 214; 314; 414; 514; 614; 714; 814; 914) comprises a wire, in particular a curved wire, wherein the wire is arranged in the reception recess (13; 113; 213; 313; 413; 513; 613; 713; 813; 913) .

10. The dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910) according to claim 9, wherein the wire is held in place in the reception recess (13; 113; 213; 313; 413; 513; 613; 713; 813; 913) by extending from and into at least one positioning hole formed in the interface (11; 111; 211; 311; 411; 511; 611; 711; 811; 911), in particular the interface surface section (12a; 112a; 212a; 312a; 412a; 512a; 612a; 712a; 812a; 912a) .

11. The dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910) according to claim 10, wherein the wire is curved at an opening of at least one of the positioning holes, the opening preferably being on the side opposite to the side where the interface surface section (12a; 112a; 212a; 312a; 412a; 512a; 612a; 712a; 812a; 912a) is arranged.

12. The dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910) according to any one of the preceding claims, the dental part being a dental tool, such as an angle indicator or driver, or a dental component, such as a dental implant, an abutment, a part of a multi-piece abutment, a healing abutment, a healing cap, dental attachments, or a telescopic crown.

13. The dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910) according to any one of the preceding claims, wherein the engagement part (14a; 114a; 214a; 314a; 414a; 514a; 614a; 714a; 814a; 914a) is oriented in relation to the interface surface section and/or in relation to the longitudinal axis so that the first contact between the other dental part (20; 120; 220; 320; 420; 520; 620; 720) and the engagement part is a point contact.

14. A dental assembly set comprising:

a first dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910), in particular according to any one of the preceding claims, which has an interface (11; 111; 211; 311; 411; 511; 611; 711; 811; 911) with a retaining element (14; 114; 214; 314; 414; 514; 614; 714; 814; 914) and an interface surface section (12a; 112a; 212a; 312a; 412a; 512a; 612a; 712a; 812a; 912a) extending along a portion of the perimeter of the interface, wherein the retaining element is positioned so as to partly protrude from the interface surface section forming an engagement part;

a second dental part (20; 120; 220; 320; 420; 520; 620; 720), which has an interface substantially corresponding to the interface of the first dental part, wherein the interface of the second dental part comprises an interface surface section, which, in an assembled state with the interface surface section of the first dental part, is arranged to be in contact with the retaining element of the first dental part.

15. A method for attaching a first dental part (10; 110; 210; 310; 410; 510; 610; 710; 810; 910) to a second dental part (20; 120; 220; 320; 420; 520; 620; 720), the method comprising the steps:

- providing the first dental part, in particular a dental part according to any one of claims 1 to 13, the first dental part having an interface (11; 111; 211; 311; 411; 511; 611; 711; 811; 911) with a retaining element (14; 114; 214; 314; 414; 514; 614; 714; 814; 914) and an interface surface section (12a; 112a; 212a; 312a; 412a; 512a; 612a; 712a; 812a; 912a) extending along a portion of the perimeter of the interface, wherein the retaining element is positioned so as to partly protrude from the interface surface section;

- providing the second dental part having an interface substantially corresponding to the interface of the first dental part; and

- relatively moving the first and second dental part towards each other so that the interface surface section of the second dental part slides over the retaining element of the first dental part and causes a friction and/or positive engagement fit between the first and second dental parts.

Description:
RETAINING INTERFACE FOR DENTAL PARTS

TECHNICAL FIELD

The present invention relates to a dental part with an interface for a translational coupling to another dental part so that the dental part retains the other dental part, a set of dental parts with a dental part having this interface and the other dental part having a corresponding interface, and a method for assembling two dental parts using these interfaces.

BACKGROUND

One dental treatment for replacing a tooth or multiple teeth is the insertion of a dental implant that acts as a support for a dental prosthesis. Generally, there are additional dental parts inserted in between the dental implant and the dental prosthesis. These intermediate dental parts form a dental assembly that facilitates or enables the attachment of the dental prosthesis. The need for intermediate dental parts arises since the direction of insertion of an implant often fails to coincide with a direction that allows for the installation of a dental prosthesis on top of an implant. As a result, it can be impossible or at least difficult to place the dental prosthesis in between existing teeth without an intermediate dental part.

Further, when assembling dental parts within the mouth of a patient, there is only a limited amount of space available for a dental professional to maneuver. This makes handling and correctly assembling dental parts challenging and may undesirably result in dental parts of the device moving freely in the mouth of a patient and even get lost. For example, this may occur after mounting a dental part on another dental part if these dental parts are to be fastened to each other with a dental screw. In order to achieve this, the dental professional has to correctly place the dental part on the other dental part and at the same time guide the dental screw into engagement. This can be particularly tedious when mounting a dental part in the region of the maxilla and/or mandibula of a patient.

Further, if the dental part is not part of a final dental restoration but is, for example, used to take a measurement, it is important to allow for a precise placement in relation to a dental component of a dental restoration. In particular in this case, it is advantageous if placing the dental part is fast and its removal after measurement easy. Moreover, a stable connection is required for a precise measurement. Also, if visually determining the measurement value, any obstruction should be avoided. Again, this is particularly challenging for a dental professional when assembling on the side of the maxilla and/or mandibula of a patient.

A dental part can also be a dental tool for assembling a dental restoration. For example, the dental part can be a driver for guiding and fastening a dental screw or inserting a dental implant. A stable connection between such a dental part and the other dental part is key to ensure proper placement as well as transfer of torque and/or force to the other dental part.

Further, a dental part in the form of a tool that is used during treatment in a mouth of a patient is preferably reused after cleaning. Thus, another requirement is ease of cleaning the dental part after use.

SUMMARY OF THE INVENTION

Resulting from the above, it was an objective of the present invention to provide a dental part with an interface that can be installed, retained and disassembled in a fast and easy manner during treatment. It has also been an objective to facilitate cleaning of the dental part, in particular if the dental part as part of a dental assembly is to be reused or is to be cleaned, disinfected and sterilized prior installation.

In response to these objectives a dental part with an interface for a translational coupling along a longitudinal axis of the dental part to another dental part is provided. The interface is arranged about the longitudinal axis and includes an interface surface section extending along a portion of the perimeter of the interface, in particular of the interface's profile along a cross-section perpendicular to the longitudinal axis, and a retaining element mounted to the dental part. A portion, in particular one portion, of the retaining element protrudes at least from the interface surface section to define a preferably elongated engagement part. More specifically, this engagement part preferably has an elongation that extends transverse to the longitudinal axis.

A dental part that employs such an interface can easily be coupled to and retained on another dental part. The coupling to another dental part is achieved by a translational movement of the two dental parts towards each other. As coupling means, the dental part comprises an interface that is arranged about the longitudinal axis. Thus, the interface extends circumferentially about the longitudinal axis and interacts with the other dental part. The coupling of the dental part is preferably performed by moving the dental parts relative to each other in the direction of the longitudinal axis.

The interface includes an interface surface section that extends along a portion of the perimeter of the interface, in particular the interface's profile. In other words, the interface surface section does not extend along the entire perimeter of the interface, wherein the interface surface section extends preferably along less than 50% and more preferably along less than 25% of the entire perimeter.

This interface surface section together with the remaining surface of the interface serves as guidance during coupling. As part of the interface and in relation to the body of the dental part, a retaining element protrudes at least from the interface surface section. In other words, the retaining element may protrude in a radial direction from the body of the dental part on the side of the interface as well on the side opposite to this side, i. e. it can extend through a through hole from one side to the other side. This protrusion is formed by a portion of the cross-section of the retaining element perpendicular to its longitudinal direction and defines an elongated engagement part. This elongated engagement part protrudes in its longitudinal direction at least at one, preferably at both ends from the surface of the interface and in particular from the interface surface section. The longitudinal direction of the elongated engagement part extends transverse to the longitudinal axis and the direction of assembly, which is in the direction of and preferably along the longitudinal axis.

The engagement part forms a barrier in the direction of assembly of the dental part to the other dental part. During assembly a force is applied in the longitudinal direction to elastically deform the engagement part so that the other dental part can get past the engagement part. In the assembled state, the elasticity of the engagement part serves to retain the two dental parts together and prevents their accidental disassembly, for example during handling or an assembly. The elasticity can be adjusted by the shape and/or dimension of the engagement part's profile perpendicular to its longitudinal direction. The elasticity serves to preferably provide a friction fit and/or a positive engagement fit between the dental part and the other dental part. This combination of structural features of the dental part and in particular its interface provides for a simple and reliable, preferably detachable connection between two dental parts. The elongation of the engagement part provides for a stable connection between the two dental parts due to a point contact, a line contact or a surface contact between them.

In one embodiment, the interface surface section of the dental part is curved and/or planar.

In other words, the profile of the interface surface section in a cross-section perpendicular to the longitudinal axis is curved and/or linear. The curvature may be chosen to correspond to the curvature of the remaining interface surface of the interface about the longitudinal axis in order to allow for a relative rotation between the dental part and the other dental part about the longitudinal axis in an assembled state.

The curvature may also be defined in relation to the remaining interface surface so that the interface surface section forms an indexing means that prevents the aforementioned relative rotation. This functionality may also be provided by the profile of the interface surface section being at least partly planar. It should also be noted that it is likewise possible to achieve indexing between the dental parts by the design of the protruding portion of the retaining element .

In another embodiment, the engagement part of the retaining element emerges gradually from the interface surface section at one or both ends in its longitudinal direction. In other words, the cross section of the engagement part gradually increases where the retaining element surfaces from the interface surface section to form the engagement part. Additionally or alternatively, the engagement part along its length substantially extends parallel to the interface surface section and/or extends with a slope in relation to the interface surface section. Preferably, the engagement part extends substantially straight in its longitudinal direction, i. e. it is cylindrical and preferably cylindrical with a circular cross-section.

By gradually protruding from the interface surface section, the engagement part of the retaining element is supported in a manner that prevents damage of the engagement part during coupling.

Preferably, the engagement part gradually protrudes at both ends in its longitudinal direction. As a result, deformation of the engagement part is higher in the intermediate portion of the engagement part in comparison to the deformation occurring at the ends of the engagement part. This prevents damage to the engagement part during assembly of the dental part since stress concentrations at the ends of the protruding engagement part are reduced.

Since the interface of the dental part extends about the longitudinal axis, a gradually protruding engagement part may be achieved by the engagement part being substantially straight along its longitudinal direction. In other words, the engagement part geometrically forms a secant in relation to the profile of the interface in a cross-section perpendicular to the longitudinal axis of the dental part.

The engagement part protruding parallel to the interface surface section provides for a uniform point contact, line contact or surface contact between the dental parts during assembly .

The slope of the protruding engagement part results in the protrusion to increase in relation to the interface surface section along the longitudinal direction of the elongated engagement part, preferably from one end to the other end of the engagement part . The engagement part protruding in a sloped manner in relation to the interface surface section has the advantage that the dental part is retained in the direction of the longitudinal axis and at the same time biased in the direction about the longitudinal axis. In a coupled state, the biasing about the longitudinal axis minimizes rotational play between the dental parts. More specifically, in case of the interface surface section acting as an indexing means, the slope of the engagement part relative to the interface surface section causes in an assembled state of the dental parts an increasing pressing force along the longitudinal direction of the engagement part. This results in a biasing of the dental part in a rotational direction about the longitudinal axis that locks the dental part in a rotational direction. Thus, any play in the rotational direction can be effectively overcome.

Further, the slope may also serve to provide for an increasing pressing force that is required to push the dental parts together past the engagement part to the assembled position. If the slope is a linear slope, the increase of the pressing force is linear, which makes the application of the retaining force more controllable for a user. This is particularly the case if the other dental part is tapered at the end facing the dental part during assembly.

All designs of the engagement part described above have in common that they cause the two dental parts to be biased against each other at least by a point contact in the assembled state .

In yet another embodiment, the retaining element is a separate part that comprises a polymer, in particular an elastomer, and/or a metal.

In this embodiment, the retaining element is attached by mounting it to the dental part. In other words, it is at least initially not an integral part of the dental part. Since it is a separate part, its elasticity, in particular of the protruding engagement part, can easily be adjusted by the choice of material. In addition, it may be replaced if broken or not properly functioning any more. The retaining element particularly comprises silicone due to its durability and biocompatibility .

In a further embodiment, the interface is a male or female interface extending in the direction of the longitudinal axis and the interface surface section forms part of the circumferential side of this male or female interface about the longitudinal axis.

In other words, the interface is formed by a surface extending about the longitudinal axis and facing radially outwards or inwards. A part of this interface surface forms the interface surface section. As described above, this interface surface section may be designed as a continuation of the remaining interface surface or may differ from the remaining interface surface. The latter is particularly employed to provide an indexing means to the interface in order to prevent relative rotation between the dental parts in an assembled state and to have a predetermined orientation about the longitudinal of the dental part in relation to the other dental part.

In another embodiment, the interface comprises at least along the interface surface section a reception recess.

This reception recess in the interface surface section that may also extend into the remaining interface surface about the longitudinal axis serves to receive the retaining element. Thus, in this embodiment, the retaining element is designed as a separate part. The reception recess provides support to the retaining element in order to prevent the retaining element from being damaged during assembly and deformation or to be accidentally removed. The latter may be achieved by providing the cross section of the recess perpendicular to its longitudinal direction with an undercut that prevents the engagement part from falling out.

In yet another embodiment, the retaining element is a plug that is molded into or is put into the reception recess.

This embodiment is particularly advantageous when using a polymer or elastomer as retaining element. In particular when placing the plug acting as retaining element in the reception recess, it can easily be replaced if it has been damaged. This may also be achieved when molding the engagement part into the reception recess. On the other hand, molding the engagement part may also result in the plug forming an integral part of the dental part. Preferably, the plug is completely occupying the reception recess for easy cleaning and disinfection. Nonetheless, it is also possible that the plug is placed only in a part of the reception recess, for example to facilitate placement or removal of the plug.

In a further embodiment, the outer limits of the interface surface section in a circumferential direction about the longitudinal axis substantially limits the extension of at least the engagement part of the retaining element.

If the extension of the engagement part is limited to the interface surface section it preferably extends along substantially the entire circumferential width of the interface surface section. As a result, the dental component is retained due to a reduced cross-section along this circumferential width. In other words, the dental part is retained due to a reduced distance between the engagement part at the interface surface section and the radially opposite site of the interface. In yet another embodiment, the retaining element comprises a wire, in particular a curved wire, wherein the wire is preferably arranged in a reception recess.

The use of a wire is a simple and effective means to form the engagement part. It also makes assembly and replacement of the engagement part easy. Further, the same dental part may be adapted by using different wires in order to be employed for different purposes that require different retaining forces. For example, the material and/or cross-section of the wire can be adjusted to result in a predetermined elasticity of the engagement part .

Further, the use of a curved wire provides for additional anchoring to the dental part alternatively or in addition to the placement within the reception recess. A wire curved along its longitudinal direction may be produced by bending the wire or by producing the wire with a curved geometry. The curved geometry also has the advantage of an engagement part without any sharp edges that may otherwise incur damage to the other dental part upon assembly. The wire may be made of a metal or a polymer and preferably has a squared or rounded, in particular circular, cross-section.

The wire can occupy the longitudinal extension of the reception recess fully or partially. In cross-section, a partial occupation of the reception recess may result in a higher elasticity of the wire since it is allowed to bend. A full occupation of the cross-section on the other hand results in an elasticity that substantially depends on the wire's material properties.

In another embodiment, the wire is held in place in the reception recess by extending from and into at least one positioning hole formed in the interface, in particular the interface surface section. In this embodiment, the wire is also anchored within at least one positioning hole. The wire may be curved in order to enter the positioning hole or may simply extend straight from the reception recess into the positioning hole. In the latter embodiment, the positioning hole is preferably formed in continuation to the reception recess.

The wire may be situated to face at least partly radially outwards and/or inwards in relation to the longitudinal axis. When facing radially outwards and/or inwards, the wire is preferably located within a recess of the dental part.

In a further embodiment, the wire is curved at an opening of at least one of the positioning holes, the opening preferably being on the side opposite to the side where the interface surface section is arranged.

This embodiment results in the wire being anchored by a change in direction of the wire. If the opening, where the wire is curved, is situated on the side opposite to the side where the interface surface section is arranged, the wire cannot be accidentally removed or fall out. For example, the wire is placed along the reception recess on the side of the interface surface section and enters at least at one of the ends of the reception recess into a positioning hole of the dental part's body in a curved or straight manner. The positioning hole preferably extends through a wall of the dental part and exits on the side opposite to the side where the interface surface section is arranged. When exiting, the wire is curved and subsequently extends along the opposite side resulting in an efficient and reliable fixation of the wire to the dental part. At the opposite side, the wire is preferably partly or fully arranged in a recess so that its position in relation to the body of the dental part is defined.

In yet another embodiment, the dental part is a dental tool, such as an angle indicator or driver, or a dental component, such as a dental implant, an abutment, a part of a multi-piece abutment, a healing abutment, a healing cap, dental attachments, or a telescopic crown.

Consequently, the dental part is in particular a dental tool or a dental component used in relation to a dental restoration or dental assembly.

In a further embodiment, the interface surface of the dental part extends parallel to the longitudinal axis of the interface .

Accordingly, the retaining element is the only feature at the interface in this embodiment and preferably of the dental part that retains the other dental part in an assembled state. As a result, the coupling force between the dental parts is defined and provides a reliable and stable connection.

In another embodiment, the engagement part is oriented in relation to the interface surface section and/or in relation to the longitudinal axis so that the first contact between the other dental part and the engagement part is a point contact.

Preferably, the longitudinal direction of the engagement part extends in an angle of substantially 90° (transverse) to the longitudinal axis when looking in a radial direction. Further, the amount of protrusion along the engagement part may be substantially constant, i. e. it may only differ at the ends as described above. In other words, the engagement part extends parallel to the interface surface section. This arrangement provides for optimal feedback to a user during assembly in terms of the point in time the other dental part abuts against the retaining element. As a result of the transverse orientation, the other dental part initially gets in contact with the engagement part along a line. In the following, a pressing force has to be applied in order to move the other dental part past the retaining element. However, in this embodiment the longitudinal direction of the engagement part may be oriented at an angle other than 90° to the longitudinal axis. Likewise, the engagement part may have a slope in relation to the interface surface section. As a result, the first contact between the engagement part and the other dental part is a point contact that increases to be a line or surface contact the more the two dental parts are pushed towards each other. This orientation in at least one of the above-noted directions makes the pressing force upon assembly increase gradually while moving the other dental part past the retaining element. This allows for a minimized load applied to the retaining element.

Further, a dental assembly set is provided that comprises a first dental part and a second dental part. The first dental part has an interface with a retaining element and an interface surface section extending along a portion of the perimeter of the interface, wherein the retaining element is positioned so as to partly protrude from the interface surface section, forming a preferably elongated engagement part. The second dental part has an interface substantially corresponding to the interface of the first dental part, wherein the interface of the second dental part comprises an interface surface section, which is arranged to be in contact with the retaining element of the first dental part in an assembled state with the interface surface section of the first dental part.

As described above, this arrangement provides for a reliable and stable coupling of the two dental parts so that they are retained in relation to each other. This coupling can be achieved by a friction fit and/or a positive engagement fit by configuring the corresponding interface of the other dental part accordingly. More specifically, in case of a friction fit, the corresponding interface of the other dental part does not require a structural feature that is only intended for coupling the dental part with the other dental part. In case of a positive engagement fit or form fit the other dental part may comprise a recess in order to engage the engagement part of the retaining element.

In addition, a method for coupling a first dental part to a second dental part is provided. The method comprises the steps of providing the first dental part, which has an interface with a retaining element and an interface surface section extending along a portion of the perimeter of the interface, wherein the retaining element is positioned so as to partly protrude from the interface surface section so as to form a preferably elongated engagement part; providing the second dental part having an interface substantially corresponding to the interface of the first dental part; and relatively moving the first and second dental parts towards each other so that the interface surface section of the second dental part slides over the retaining element and in particular the engagement part of the first dental part and causes a friction and/or positive engagement fit between the first and second dental parts.

SHORT DESCRIPTION OF THE DRAWINGS

The following figures illustrate preferred embodiments of the present invention. These embodiments are not to be construed as limiting but merely for enhancing the understanding of the invention in context with the following description. In these figures, same reference signs refer to features throughout the drawings that have the same or an equivalent function and/or structure. This particularly applies to reference signs that are identical except for the first digit which denotes different embodiments. It is to be noted that a repetitive description of these components is generally omitted for reasons of conciseness of the description . Figure 1 illustrates a dental part comprising a retaining element in the form of a plug and another dental part during assembly according to a first embodiment;

Figure 2 is a cross-sectional side view along the longitudinal axis of the dental parts shown in figure 1 in an assembled state that are retained by a friction fit;

Figure 3 is a cross-sectional view perpendicular to the longitudinal axis of the dental parts shown in figures 1 and 2 in an assembled state, wherein the dental parts are retained by a friction fit;

Figure 4 is a three-dimensional view of a dental part with a plug as retaining element and another dental part according to another embodiment during assembly using a positive engagement fit;

Figure 5 illustrates yet another embodiment of a coupling between two dental parts using a plug as retaining element for a friction fit;

Figure 6a is a cross-sectional view in a plane along the longitudinal axis of the two coupled dental parts illustrated in figure 5;

Figure 6b is a cross-sectional view in a plane perpendicular to the longitudinal axis of the two coupled dental parts illustrated in figure 5;

Figure 7 is a three-dimensional view of a dental part and another dental part of a further embodiment that are to be coupled using a positive engagement fit with a plug;

Figure 8 is a cross-sectional view along the longitudinal axis showing the coupled dental parts of figure 7; Figure 9 is a three-dimensional view of an assembly according to another embodiment of two dental parts by a friction fit that is caused by a wire;

Figure 10 is a three-dimensional view of another embodiment of an assembly between two dental parts that is achieved by a positive engagement fit using a wire;

Figure 11 is a cross-sectional view in a plane along the longitudinal axis of the coupled dental parts illustrated in figure 10;

Figure 12 is a cross-sectional view in a plane perpendicular to the longitudinal axes of the coupled dental parts illustrated in figures 10 and 11;

Figure 13 is a three-dimensional view of two dental parts of another embodiment to be assembled by a friction fit using a wire;

Figure 14 is a three-dimensional view of two dental parts to be assembled by a positive engagement fit of yet another embodiment ;

Figure 15 is a cross-sectional view in a plane along the longitudinal axes of the coupled dental parts illustrated in figure 14;

Figure 16 is a cross-sectional view in a plane perpendicular to the longitudinal axis of the coupled dental parts illustrated in figures 14 and 15;

Figure 17 is a three-dimensional view of another embodiment of a dental part in the form of a dental tool comprising a plug as retaining element; and Figure 18 is a three-dimensional view of another embodiment of a dental part in the form of a dental tool comprising a wire as retaining element.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

It should be noted that except for figures 17 and 18 the dental parts are merely shown in an abstract way since the focus of the description is on the interfaces of the dental parts and their function to couple or connect the dental parts to each other. In other words, the outer shapes of the dental parts with the exception of the interface regions do not represent the outer shapes of any specific dental parts but are instead merely showing arbitrary outer geometrical shapes for the purpose of illustration only. Thus, the outer shape may be configured according to any one of the dental parts listed above.

Figure 1 illustrates a first embodiment of a dental part 10 and another dental part 20. The dental parts may be coupled in order to form a dental assembly 1. The coupling between the dental parts is possible due to the first interface 11 of the first dental part 10 and the second interface 21 of the second dental part 20. The first interface 11 is formed about a longitudinal axis L. The same applies to the second interface 21 of the second dental part 20. In the embodiments described in the following, the longitudinal axis L of the first interface 11 coincides with the longitudinal axis L of the second interface 21 and is for this reason illustrated as one continuous longitudinal axis L.

Further, the first interface 11 of dental part 10 of this embodiment like the embodiments that follow are illustrated as a female interface. Correspondingly, the second interface 21 of dental part 20 is illustrated as a male interface. Nevertheless, as the skilled person will appreciate, the first interface 11 may also be configured as a male interface and the second interface 21 may be configured as a female interface .

The first interface 11 comprises an interface surface 12 that faces radially inward towards the longitudinal axis L. Accordingly, the interface surface 12 is a circumferential surface and, as shown in figure 1, preferably a continuous circumferential surface. In figure 1, the interface surface 12 is shown as a cylindrical surface about the longitudinal axis L with a circular cross-section. Accordingly, the first dental part 10 and the second dental part 20 may be rotated relative to each other. However, other shapes or geometrical configurations are conceivable such as a cross-section with a polygonal shape (cf. figure 5), an oval shape and/or a conical shape. In these cases, the interface is configured to provide indexing in a rotational direction about the longitudinal axis. The interface 11 may be formed as a recess or, as shown in figures 1 to 3, as a through hole.

The interface surface 12 of the dental part 10 includes an interface surface section 12a. The circumferential extension of the interface surface section 12a is defined by a retaining element 14 and more specifically an engagement part 14a of the retaining element 14 that protrudes from the interface surface 12. The engagement part 14a is preferably elongated. The circumferential extension of the interface surface section 12a is defined by the ends of the protruding engagement part 14a. The circumferential extension can be defined on the basis of an angle about the longitudinal axis L. This angle is preferably in a range of 5 to 60°, 15 to 50°, and preferably 20 to 45°. In figure 3, the angle is about 40°. As shown in the cross-sectional view along the longitudinal axis L in figure 2, the retaining element 14 is formed as a plug that is a separate part placed in a reception recess 13. The reception recess is defined in the interface surface 12 and in particular the interface surface section 12a. In reference to figures 1 to 3, the retaining element 14 has a cylindrical shape with a circular cross-section. The reception recess 13 corresponds to the shape of the retaining element 14 in order to receive this retaining element so that it preferably extends over the entire cross-section of the reception recess 13 including the space occupied by the elongated engagement part 14a. In other words, it preferably fills the space provided by the reception recess 13 at least at the level of the interface surface section 12a.

As particularly shown in figure 2, the reception recess 13 is provided with an undercut that prevents the retaining element 14 to be removed through the opening 13a defined by the reception recess 13 the elongated engagement part 14a is protruding from. In the exemplary embodiment illustrated in figures 1 to 3, the reception recess 13 is formed as a straight through hole. The through hole is placed so that a part of its cross-sectional shape intersects with the female interface 11 defined by the interface surface 12 (cf . figure 3) .

The retaining element 14 of the present embodiment is formed as a plug. This plug may be a preformed plug that is inserted into the reception recess 13. Alternatively, the plug may also be molded into the reception recess 13. As previously described, the retaining element 14 may be made of a metal or a polymer, in particular an elastomer, preferably silicone.

The elongated engagement part 14a protrudes from the opening 13a of the reception recess 13 that faces inward towards the longitudinal axis L. This results in the second dental part 20 being hindered to fully enter into the first interface 11 until a pressing force is applied to the second dental part in the direction of the longitudinal axis L towards the first dental part 10. This pressing force results in an elastic deformation of the elongated engagement part 14a of the retaining element 14. More specifically, the protruding engagement part 14a is compressed towards the reception recess 13 and, as a result, exerts a biasing force to the interface surface 22 of the second interface 21 of the dental part 20 in the assembled state.

In the embodiment of figures 1 to 3, the interface surface 22 of the second interface 21 is formed as a male interface that corresponds to the female interface 11 of the dental part 10. More specifically, the interface surface 22 is formed as a continuous cylindrical surface and may be inserted into the first interface 11 of the dental part 10 in any relative orientation in relation to the second dental part 20 about the longitudinal axis L.

During insertion, the interface 21 of the dental part 20 is guided by the interface surface 12 of the first dental part 10 into the space defined by the first interface 11. Since the elongated engagement part 14a of the retaining element 14 protrudes radially inward towards the longitudinal axis L, it provides resistance to further insertion of the second dental part 20. This is due to the face side 23 that faces the first dental part 10 during insertion and first contacts the protruding engagement part 14a. As described above, from this point further insertion requires a pressing force to be applied in the longitudinal direction. In order to facilitate insertion and to prevent damage to the retaining element 14, the transition between the face side 23 and the circumferential interface surface 22 may be designed smoother by providing a rounded or chamfered circumferential edge 22a. The final insertion depth can be marked by an abutment surface 25a of the second dental part 20 abutting an abutment surface 15a of the first dental part 10. Alternatively, the face side 23 can contact an abutment surface 15b.

In the assembled state shown in figures 2 and 3, the second dental part 20 is retained in the first dental part by a friction fit that is caused by the retaining force originating from the elastically compressed engagement part 14a.

This retaining force can be adjusted by the extent the engagement part 14a protrudes from the interface surface section 12a in a disengaged state, the shape and dimensions of the engagement part 14a in the disengaged state, and/or the material properties of the engagement part 14a, in particular its elastic modulus. Although the first dental parts in the illustrated embodiments only comprise one retaining element, the skilled person will appreciate that more than one retaining element may well be provided, in particular 2, 3, 4, or 5 retaining elements.

In order to disassemble the first dental part 10 and the second dental part 20, the dental part 20 can simply be pulled away from the interface 11 of the first dental part 10. The force needed for such a disengagement is larger than friction force generated by the retaining force caused by the engagement part 14a pressing against the interface surface 22 of the second dental part 20. This friction force can be adjusted according to the retaining force needed by setting the compressive force of the engagement part 14a as described above .

As particularly visible from the illustration in figure 3, the retaining element 14 is inserted into a through hole, which forms the reception recess 13 for the retaining element 14. The through hole extends along a secant in a cross section perpendicular to the longitudinal axis L in relation to the female recess formed by the interface surface 12. As a result, the reception recess 13 intersects the interface surface 12 within the interface surface section 12a and forms the reception recess opening 13a. On both sides of the reception recess opening 13a, the retaining element 14 is supported within the through hole of the reception recess 13.

Figure 4 shows a further embodiment of a first dental part 110 and a second dental part 120 that in an assembled state form a dental assembly. This configuration has the advantage of a higher retention force in comparison to the previous embodiment. In contrast to the previous embodiment illustrated in figures 1 to 3, the interface surface 122 of the second dental part 120 additionally comprises an engagement recess 122b. The exemplary engagement recess 122b of figure 4 is formed as a complete circumferential recess. However, the engagement recess 122b may also be formed as a recess that only extends along a portion of the circumference of the interface surface 122, in particular having a length corresponding to the length of the engagement part 114a.

Like in the previous embodiment, upon assembly of the dental assembly, the second interface 121 is inserted into the first interface 111. However, in the end position or assembled position of the second dental part 120 in relation to the first dental part 110, the engagement part 114a of the first dental part 110 that protrudes from the interface surface section 112a engages the engagement recess 122b of the second dental part 120. As a result, the retaining force keeping the first dental part 110 and the second dental part 120 mounted to each other is at least partly caused by a snap-fit (positive engagement fit) . Nonetheless, the engagement part 114a may still cause a friction force between the first dental part 110 and the second dental part 120 that assists in keeping these dental parts assembled. If the engagement recess 122b is a circumferential recess as illustrated in figure 4, relative rotation between the first dental part 110 and the second dental part 120 about the longitudinal axis L is possible. On the other hand, if the engagement recess 122b has an extension around the circumference of the second interface 121 that corresponds to the extension of the engagement part 114a along the circumference of the first interface 111, the engagement part 114a and the engagement recess 122b may act as an indexing means .

Now referring to figures 5 and 6 that show another embodiment of a dental assembly that comprises a first dental part 210 and a second dental part 220, the difference to the first embodiment of figures 1 to 3 is the shape of the first interface 211 of the first dental part 210 and the corresponding shape of the second interface 221 of the second dental part 220. Another difference is the shape of the protruding engagement part 214a of the retaining element 214. The skilled person will appreciate that either of these differences can be independently applied to modify the first embodiment .

Concerning the modification of the first interface 211 of the first dental part 210 and the second interface 222 of the second dental part 220, the interface surface 212 and the interface surface 222 each have a polygonal shape about the longitudinal axis L in a cross-section perpendicular to the longitudinal axis L. The example of a polygonal shape shown in figure 5 is a hexagonal shape with six plane surfaces. Naturally, other polygonal shapes with a different number of plane surfaces forming the polygonal cross-section are conceivable. Also, other cross-sectional shapes as the ones listed above may be employed. All these non-circular cross- sectional shapes have in common that they provide indexing between the first dental part 210 and the second dental part 220, i.e. they do not allow any relative rotation about the longitudinal axis L but instead a predetermined number of angular positions of the first dental part 210 in relation to the second dental part 220.

Concerning the engagement part 214a, it has a slope relative to the interface surface section 212a, i.e. the level of protrusion of the engagement part 214a decreases along the circumference of the interface surface section 212a.

This slope is preferably defined by a slope angle b between the interface surface section and the engagement part 214a, i. e. the ridge formed by the engagement part in relation to the interface surface section (see figure 6b) . This slope angle b is substantially 0° to 15°, substantially 0° to 10°, substantially 0° to 5°, or substantially 0°.

In the exemplary embodiment of an engagement part 214a, this engagement part 214a also tapers in the circumferential direction as seen in a direction perpendicular to the longitudinal axis L. This is caused by both a constant cross- section of the retaining element 214 at least along the engagement part 214a and the slope of the engagement part 214a in relation to the interface surface section 212a. The same applies to the reception recess opening 213a.

As a result, the first contact between the engagement part 214a and the other dental part 220 upon assembly is a point contact. While pushing the dental parts 210 and 220 further towards each other, this point contact will become a line or surface contact due to increased contact of the other dental part 220 and the engagement part 214a. This line or surface contact will increase the closer the two dental parts 210 and 220 are to each other.

Instead or in addition to using a slope as described above, it is also possible to orient at least the engagement part 214a of the retaining element 214 on the interface surface section in an angle to the longitudinal axis other than 90° (transverse) . This way, the other dental part 220 will first get in point contact with the end of the engagement part 214a that is closer to the beginning of the interface as seen in the direction of assembly. The more the dental parts 210, 220 are moved towards each other, the more the engagement part 214a will get in contact with the other dental parts 220.

Preferably, the angle of inclination in relation to the transverse to the longitudinal axis is between 0° and 15°, more preferably between 0° and 10°, and most preferably between 0° and 5° .

Further, the engagement part 214a extends along a portion of one plane surface of the hexagonal interface 211 and a portion of an adjacent plane surface. Accordingly, the reception recess opening 213a in the interface surface section 212a extends along two adjacent plane surfaces of the plane surface forming the polygonal shape.

The shape of the protruding engagement part 214a results in a gradually increasing force needed to push the second dental part 228 towards the first dental part 210. This effect is enhanced due to the smooth circumferential edge 222a of the second dental part 210. As a result, the load acting on the engagement part 214a is only gradually increased, which reduces internal stresses and strains in the retaining element 214, in particular at the reception recess opening 213a. Further, in an engaged state with the second dental part 220, the sloped shape of the protruding engagement part 214a pushes the second dental part 220 via the interface surface 222 along the circumference of the interface surface section 212a of the first dental part 210, which results in an enhanced locking of the indexing feature. In other words, play in the circumferential direction between the two dental parts can be effectively prevented.

As illustrated in figures 6a and 6b, the dental assembly comprising the first dental part 210 and the second dental part 220 is mounted using a friction fit caused by the compression of the retaining element 214. In order to get the sloped and tapering shape of the engagement part 214a, the reception recess 213 is formed as a cylindrical hole that, like in the first embodiment, is a secant to the recess formed by the first interface 211 in a cross-section perpendicular to the longitudinal axis L. This secant is running in an angle in relation to one of the plane surfaces of the hexagonal shape of the interface 211, the angle corresponding to the slope of the protruding engagement part 214a.

As in the previous embodiments, the reception recess 213 may be designed as a cylindrical through hole or as a blind hole, preferably with a circular cross-section. The reception recess opening 213a is located at the circumference of the respective hole since it is defined in the first dental part 210 as a secant to the recess formed by the interface surface 212.

The reception recess 213 and the retaining element 214 may also be formed to have a conical or frustoconical shape in order to provide a protruding engagement part 214a that has already been described above in more detail.

The next embodiment illustrated in figures 7 and 8 differs from the previous embodiment in that the second interface 321 further includes an engagement recess 322b. As can best be seen in the cross-sectional view of figure 8, the second dental part 320 is in engagement with the retaining element 314 by a positive engagement fit. In other words, during assembly, the protruding engagement part 314a of the first dental part 310 snaps into the engagement recess 322b so that the second dental part 320 is retained to the first dental part 310. The engagement recess 322b is formed as a circumferential recess that is defined within the interface surface 322. Otherwise, the interface surface 322 corresponds to the interface surface 312 of the first dental part 310.

Figure 9 shows an embodiment that employs a wire 414 configured to establish a friction fit between a first dental part 410 and a second dental part 420 of a dental assembly 401. More specifically, the protruding engagement part 414a is configured to press against the interface surface 422 of the second interface 421, which in turn causes a friction force acting in the direction of the longitudinal axis L that prevents accidental removal of the second dental part 420 from the first dental part 410 along this axis.

As in the previous embodiment, the retaining element 414 is located within a reception recess, wherein the reception recess comprises a reception recess opening 413a at its circumference. Within this reception recess opening 413a, the engagement part 414a is protruding from the interface surface 412 and more specifically from the interface surface section 412a into the recess defined by the first interface 411 about the longitudinal axis L. The configuration of the reception recess 413 and the placement of the retaining element 414 within this reception recess 113 will be described in more detail further down below in relation to the embodiment shown in figures 10 to 12.

Turning to figures 10 to 12, the embodiment of a dental assembly 501 differs from the embodiment shown in figure 9 in that the second interface 521 of the second dental part 520 includes a circumferential recess 522b that is configured to be in engagement with the protruding engagement part 514a of the retaining element 514 by a positive engagement fit. This positive engagement fit is particularly visible in figures 11 and 12. In figure 11, the first dental part 510 is an engaged or assembled state with second dental part 520. In this state, the protruding engagement part 514a of the retaining element 514 is snapped into the circumferential groove 522 defined within the interface surface 522 of the second interface 521.

As in the previous embodiment of figure 9 and in contrast to the embodiments shown in figures 1 to 8, the retaining element 514 is embodied as a wire. This wire exerts a force directed inwards towards the longitudinal axis L and caused by an elastic deformation of the wire instead of an elastic compression as the case with the plugs shown in the previous embodiments. In other words, the retaining element 514 gets bent in an engaged state, in which the protruding part 514a is pushed back into the reception recess opening 513a. In order to provide the space needed for the elastic deformation of the retaining element 514, the reception recess 513 has a bigger cross-section than the retaining element 514 (cf. figures 11 and 12 ) .

Like in the previous embodiments, the reception recess 513 is formed as a secant to the recess defined by the circumferential interface surface 512 of the first interface 511 of the first dental part 510. However, the reception recess 513 continues to extend after the through hole as a circumferential reception recess 513b on the outside of the first dental part 510. More specifically, the reception recess 513 comprises a first part that is formed as a hole which forms a the reception recess opening 513a and opens up on at least one of its ends to the outside of the first dental part 510 and then defines along the outer surface 517 in a circumferential direction about the longitudinal axis L a reception recess 513 that is formed as a groove. The reception recess 513 configured in such a way preferably extends more than 180° about the longitudinal axis L. As a result, the wire acting as retaining element 514 and being placed in the reception recess 513 may also extend more than 180° about the longitudinal axis L so that the retaining element 514 is attached to the first dental part 510 by a positive engagement fit. Alternatively the reception recess 513 does not extend to the outside of the first dental part 510 or extends less about the longitudinal axis L. In this case, the retaining element 514 may be mounted by an adhesive or may be fixed on one side of the reception recess opening 513a by a press-fit.

The retaining element 514 can be produced, such as by milling or laser cutting, so as to have a final shape, such as the shape shown in figure 12, or can be made of a straight wire that is bent to get into such a shape. The wire may be made of a metal or a polymer.

The embodiment of a dental assembly 601 shown in figure 13 differs from the dental assembly 501 shown in figure 9 in that the second interface 621 comprises a circumferential interface surface 622 with a polygonal shape about the longitudinal axis L. Likewise, the first dental part 610 comprises a first interface 611 with an interface surface 612 that has a polygonal shape formed by plane surfaces that corresponds to the polygonal shape of the second interface 621 of the second dental part 620. As shown in figure 13, the interface surface section 612a extends completely along one plane surface of the hexagonal interface 611 and partly along the two adjacent plane surfaces in the circumferential direction on either side of the one plane surface. Consequently, the reception recess opening 613a is cut into three of the plane surfaces formed by the interface surface 612. This provides optimal support to the retaining element 614. Nonetheless, the reception recess may also be defined in the one plane surface and one of the adjacent plane surfaces or only in the one plane surface. In addition to the embodiment shown in figures 13 to 16, the interface 721 of the second dental part 720 includes a circumferential recess 722b within the interface surface 722 similar to the embodiments shown in figures 4, 7, and 10 to 12. As previously described, this circumferential recess 722b of the second interface 721 results in a positive engagement fit with the retaining element 714 and more specifically the engagement part 714a by a snap-fit. This snap-fit provides feedback (e.g. acoustic "click", change in physical resistance) to the person handling the dental assembly 701 of a proper assembly of the first dental part 710 and the second dental part 720. The snap-fit engagement is illustrated in more detail in figure 15.

Figure 16 further shows the interlock in a rotational direction of the hexagonal shapes defined by the first interface 711 and the second interface 721. As described above, the polygonal shape or any of the other non-circular shapes listed above results in an indexing feature acting between the first dental part 710 and the second dental part 720. This indexing feature may be used to limit assembly to a predetermined number of orientations or to transfer torque between the dental parts.

Figure 17 shows an embodiment of a first dental part 810 in the form of a dental tool and more specifically as an angle indicator. This indicator may be used for determining the angle of an angular abutment to be placed on a dental implant or spacer. It is to be noted that the angle indicated by the angle indicators 816a and 816b are merely exemplary angles and other angles can be chosen. Further, the first dental part 810 may also comprise 1, 3 or 4 angle indicators.

The interface 811 corresponds to the coronal interface of an implant or spacer (not shown) . In this embodiment, the interface 811 with the protruding engagement part 814a of the retaining element 814 provides a friction fit and/or positive engagement fit with the respective second dental part. The retaining element 814 is configured as a plug similar to the plug shown in the embodiments of figures 5 to 8.

The exemplary embodiment of figure 18 also shows a dental tool, in particular an angle indicator that is similar to the embodiment of an angle indicator shown in figure 17. In contrast to figure 17, the retaining element 914 with the protruding engagement part 914a is configured as a wire as previously described in relation to the embodiments illustrated in figures 9 to 16. The dental indicators 810 and 910 shown in figures 17 and 18, respectively, and their secure retaining mechanism to another dental part provides for an exact measurement or determination of angle that, for example, is required for choosing a dental part to be installed on the other dental part.

As described above, the unique combination of features allows the dental parts to be coupled and retained, which provides a provisional attachment. This provisional attachment particularly facilitates handling of the dental parts. Further, detachment of the dental parts is easily performed, which is advantageous for their reuse. In all embodiments, the retaining element can easily be replaced if damaged, which is particularly advantageous in the case of dental tools.

REFERENCE SIGNS

In the following, only the last two digits of the reference signs are listed. The first digit used in the detailed description and the drawings refers to the embodiment.

1 dental assembly

10 (first) dental part

11 (first) interface

12 interface surface

12a interface surface section

13 reception recess

13a reception recess opening

13b circumferential reception recess

14 retaining element

14a engagement part

15a abutment surface

16a, b angle indicator

17 outer surface

20 (second) dental part

21 (second) interface

22 interface surface

22a smooth circumferential edge

22b engagement recess

23 face side

25a, b abutment surface

L longitudinal axis

a angular extension of the interface surface section about the longitudinal axis

b slope angle of the engagement part in relation to the interface surface section