Patent Description:
Thanks to advances in the technical field of dental restorations, these dental restorations did not only become aesthetically more pleasing but have also evolved in relation to their biocompatibility and biomechanical functionality. To achieve this, today's dental restorations are in general an assembly of multiple dental components such as dental implants, abutments, bridges, spacers, superstructures, a single prosthetic tooth or multiple prosthetic teeth to allow for a patient specific adaptation of the dental restoration. For the assembly of these modular dental components, the interfaces enabling the connection between these components play a vital role in the assembly of a dental restoration and, thus, a successful treatment.

So far, the primary objective in developing interfaces of dental components has been flexibility for a patient specific adaptation. In this respect, it is an aim to provide dental professionals with modular systems that allow for selecting and arranging dental components to achieve a desired geometry for supporting a prosthetic tooth or prosthetic teeth. The connection between adjacent dental components requires interfaces for a stable connection between these components. These interfaces should preferably also provide multiple options to position or align the individual dental components to each other. As a result, these dental components include so-called indexing features that allow for an assembly of the dental components in a predetermined number of orientations in relation to each other.

For example, <CIT> discloses an inlay for connection to a dental implant, the inlay comprising an implant connection geometry for connecting the inlay to the implant and, coronal of the implant connection geometry, a post portion extending along a longitudinal axis. The post portion has a circular symmetric external surface and comprises at least one protrusion extending radially beyond said external surface. The inlay is used in combination with an overlay comprising an accommodation cavity for housing the post portion of the inlay. The accommodation cavity has a circular symmetric cavity wall and at least one groove dimensioned such that the one or more protrusion of the inlay can be housed in the one or more groove of the overlay in order to inhibit relative rotation between the components.

Further, <CIT> relates to a dental fixture for insertion into a jawbone, said fixture comprising a holding portion which is configured for holding an engagement portion of a dental component. The holding portion is provided with an indexing section, wherein the shape of the mating contour of the indexing section in a first plane differs from the shape of the mating contour of the indexing section in a second plane at a different height as seen in the apical-coronal extension of said fixture. These shapes of the mating contours of the indexing section at said first and second planes together allow a received dental component to be positioned in only one or two positions in relation to the fixture.

<CIT> suggests an implant comprising two internal anti-rotational features. One anti-rotational feature is adapted to engage a driving tool while the other anti-rotational feature is adapted to engage an abutment. An implant-abutment system is provided with an angled abutment adapted to mate with one of the anti-rotational features. A second, straight, abutment is adapted to engage with the other anti-rotational feature. An abutment is provided with resilient fingers to interface with the implant and provide tactile and audible feedback indicating when the abutment is properly seated.

The utility model <CIT> discloses a two-part dental implant with a distal and a proximal implant part, wherein a sealing body is provided between facing surfaces of the distal and the proximal implant part. The sealing body has sealing surfaces facing the surfaces which, in the finally connected state of the two implant parts, lie tightly against their facing surfaces. In addition, abutment surfaces facing each other are provided between the distal and proximal implant parts, which abut each other when the dental implant is completely assembled and which limit the degree of approach of the two facing surfaces of the implant parts between which the sealing body is arranged.

<CIT> presents a dental implant which comprises a dental component having first and second indexing elements and a fixture having third and fourth indexing elements, wherein the first and third indexing elements can only engage with each other after the second and fourth indexing elements have engaged with each other.

<CIT> discloses a two-piece dental abutment having a cuff portion that is removable from an upper portion. The cuff and the upper portion are two separate pieces that connect together to form the abutment. The upper portion has a base that connects to the top of the cuff. Once the upper portion and cuff are connected, the abutment is used in a conventional fashion with the cuff attaching to the implant and the upper portion attaching to the prosthesis. Further, <CIT> suggests a two-part tooth implant with a distal implant part and a proximal implant part which, when connected to each other, adjoin each other at a connection point and preferably have surfaces directed towards each other in the area of the connection point.

However, in particular when installing dental components to each other in the mouth of a patient, where space and visibility is rather limited, these indexing features make it harder to install dental components. On the one hand, having a high number of orientations available too easily results in mating of the two components in position, while these components are brought close to each other. This relative position is likely incorrect. In order to correct this mistake, the two components have to be moved away from each other, reoriented and brought together again. On the other hand, having only few options for orientations makes it harder for the dental professional to turn one of the dental components into the right direction against the other dental component to arrive at a final position or mating relationship between the two components that has the desired radial and rotational orientation.

Yet another problem of known indexing features is the lack of feedback for the dental professional that indicates if an assembly of dental components is complete. Instead, the dental professional has to rely on testing such as trying to rotate a dental component to see, if it is in an indexing position. This testing applies additional strain to the assembly and bears the risk to prematurely put too much load on an implant since this testing is normally done without torque control.

Based on the above, the inventors realized that although there is a need for flexibility in mounting a dental prosthesis on an implant or implants, this flexibility results in a higher complexity making the installation of these dental components harder.

This resulted in the inventors having the idea to provide the interfaces of these dental components with structures that help in finding a predetermined relative position or orientation between dental components during assembly. In other words, these features should assist a dental professional in finding the mating position of these components during treatment of a patient or in a dental lab.

Another objective of the present invention was to provide dental components with features that provide feedback to a dental professional during assembly in order to register if dental components are correctly installed or not. Part of this objective was also to prevent the dental components from being damaged during early fixation, in particular when being fastened with a dental screw.

Moreover, ease of dismantling the dental assembly for a correction or revision of a dental component was also identified as a desired property as well as having preventive measures against the ingress of detrimental substances or organisms into the dental assembly.

The present invention resulting from these objectives is defined by the subject matter of the independent claims. The claims dependent thereon specify preferred embodiments.

The present invention provides a dental component that includes a coronal end, an apical end, and a longitudinal axis extending between the coronal end and the apical end. The dental component also includes an interface for assembly to another dental component, the interface comprising at least one indexing section for rotationally locking the dental component to the other dental component and at least one guiding section for guiding the other dental component about the longitudinal axis towards the next indexing section. The at least one guiding section and the at least one indexing section alternate about the longitudinal axis, wherein the guiding section can include an apically facing or coronally facing guiding surface.

The interface of the dental component as defined above provides both, guidance for a correct assembly as well as feedback that the installation of the dental component is completed. This is achieved by the alternating arrangement about the longitudinal axis of the at least one guiding section and the at least one indexing section. In other words, the guiding section and indexing section are spatially separated. In this respect, the at least one guiding section and the at least one indexing section extend so as to at least partially and preferably completely surround the longitudinal axis.

Further, there is guidance provided by the at least one guiding section, which is configured to guide a dental component with a correspondingly designed interface towards the next indexing section. More specifically, the guiding section provides guidance and extends over a predetermined angle about and along the longitudinal axis towards the next indexing section, i. towards an assembled position. Thus, in contrast to the prior art, the dental professional is assisted in finding the indexing position. At the indexing section, rotational locking occurs and the dental component arrives at its final position in relation to the other dental component, i. the dental components are axially, radially and/or rotationally aligned and the distance between the apical and dental coronal component is minimal.

Once an indexing position is reached while relatively rotating the dental component, the dental component gets rotationally locked in relation to the other dental component as the indexing sections of the two components cooperate with each other. This locking action, which prevents any further relative rotation of the dental component against the other dental component about the longitudinal axis, also gives haptic feedback to the dental professional by the movement trajectory of the dental component that the assembly of the dental components is completed. In other words, the movement trajectory of guiding differs from the movement trajectory of indexing, which results in haptic feedback for a dental professional.

The rotational locking can be achieved by a form fit or self-locking friction as will be explained in more detail below. It has the advantage that once the desired final position is established, the dental component cannot rotate out of the position, such as during fastening a dental screw or implant screw. Thus, it is easier to keep the dental component in position once rotational locking is obtained even without using a dental screw.

The guiding surface defines the geometry and dimensions of the recess or protrusion of the interface part of the interface forming the guiding section. The slope(s) of each point(s) along the guiding surface forms a surface profile as the surface extends about the longitudinal axis. This surface profile can be identified by following the inner or outer edge of the guiding surface or any line in between. The surface profile extends about the longitudinal axis and due to its slopes also along the longitudinal axis. In other words, the surface profile of the apically or coronally facing guiding surface forms a linear and/or curved line on a surface, for example a cylindrical surface, about the longitudinal axis of the dental component. The width of the guiding surface, i.e. the extension of the guiding surface in a radial direction, is preferably perpendicular to the longitudinal axis.

Since the guiding section is for guiding the dental component towards a next indexing section and, thus, the final position upon contact to another correspondingly formed dental component, the guiding section is located in front of the indexing section in the general direction of assembly, i.e. it is closer to the extremity of the dental component, the guiding surface faces. In other words, if located at the coronal end of a dental component, the guiding section is located more coronally than the indexing section and vice versa. As a result, the guiding section protrudes in relation to the indexing section in the direction of the dental component's end.

When being in the final position, the guiding section of one dental component comes to rest in the indexing section of another dental component. Consequently, the geometry and size of a guiding section generally fits into the indexing section of another correspondingly designed dental component. Nonetheless, when looking at one dental component only, the guiding section and indexing section preferably have different geometries and dimensions. For example, the guiding section(s) of a dental component can have an allover extension about the longitudinal axis that is bigger or smaller than the allover extension of the indexing section(s).

In a preferred embodiment, a tangent to at least a portion of the guiding surface has a slope towards the next indexing section in a direction about the longitudinal axis.

This structural characteristic of the guiding surface in this preferred embodiment allows the guiding surface to guide the other dental component towards the next indexing section.

The guiding surface has a slope towards the next indexing section that is preferably monotonic and faces apically or coronally. Upon contact with another component, the movement of the components towards each other will be partly transformed by the guiding surface into a rotational movement about the longitudinal axis of the dental component and will lead to a rotational alignment and/or radial alignment of the dental component relative to the other dental component. This rotational movement will guide the other correspondingly designed dental component to the next indexing section, which is formed to receive a portion of another dental component.

The guiding surface is configured with at least one slope of a tangent along the guiding surface that guides another dental component to either of the next indexing sections located at both ends of the guiding surface (which will be the same indexing section if only one guiding section and indexing section is provided). Preferably, a guiding surface has two guiding surface portions with general slopes that have opposite signs. In this case, each guiding surface has an apex, where the two guiding surface portions meet. This apex is the location of the guiding section that is closest to or at the extremity of the dental component, where the interface is located. Even more preferably, the guiding surface is configured to guide another dental component to the closest indexing section. This results in the guiding surface having an apex midway between indexing sections.

According to the claimed invention, the interface of the dental component further comprises a mating surface for transferring forces in the direction of the longitudinal axis of the dental component, the mating surface facing in the same direction as the guiding surface and extending about the longitudinal axis, wherein at least a portion of the mating surface is arranged radially next to the guiding section and the indexing section.

By providing a mating surface that is configured to transfer forces in the direction of the longitudinal axis between dental components, it is possible to prevent any of these forces to be transferred through the indexing and guiding sections of the dental components. This has the advantage that the indexing and guiding sections do not lock in a longitudinal direction so that the dental component can be easily disassembled if necessary. In other words, this embodiment spatially allocates the functions of force transferal to different structures of the interface. Without a mating surface, the indexing and guiding sections may take over its functions and vice versa.

The rotational locking function of the indexing section is preferably resulting from a form fit as described further below. The mating surface has a width in the radial direction to the longitudinal axis. Preferably, it surrounds the longitudinal axis completely.

Assisted by the forces that are transferred through the mating surface, the mating surface also provides for a seal that prevents detrimental organisms or substances from entering and accumulating inside the dental component. In order to effectively seal off the dental component, the mating surface is located outwards in relation to the guiding and indexing sections and even more preferably extends to the outer circumference of the dental component, i. the outer edge of the dental component also forms the outer edge of the mating surface.

In another preferred embodiment, each indexing section is defined between two boundary lines, each of the boundary lines being adjacent to an end of the guiding surface, wherein the boundary lines form boundary points along the profile of the indexing section. A tangent to any one of the two boundary points has a larger absolute slope than any tangent to the profile of the guiding section. Further, the two tangents of the boundary points preferably have the same absolute slope.

The two boundary lines define the extension of each indexing section about the longitudinal axis and preferably its width in a radial direction in relation to the longitudinal axis. Accordingly, the two boundary points define the limits of each indexing section of the profile formed by the indexing section or along the allover profile formed by the indexing and boundary sections. Since the absolute slope of a tangent to any one of the two boundary points, i. boundary lines, is larger than the slope of a tangent at any point along the profile of the guiding section, i. guiding surface, the indexing section can act as a rotational lock in relation to another dental component. Moreover, the part of the indexing section that causes rotational locking of the dental component preferably has the tangent with the maximum slope along both sections.

The movement caused by the larger slope gives haptic feedback to a dental professional that the dental components have been guided to an indexing section. If the two tangents of the boundary points have the same absolute slope, the same feedback is provided for both directions of rotation.

Further, each of the two boundary lines is located directly at the end of an adjacent guiding surface. The tangent corresponds to the direction of assembly at this location, along which another dental component will move upon contact. Accordingly, if no indexing surface is present, the direction of assembly is basically parallel to the longitudinal direction of the implant so that the absolute slope of the tangent equals infinity.

In another embodiment, the tangent to each of the boundary points has an absolute angle to the longitudinal axis in a range of <NUM>° to <NUM>°, preferably in a range of <NUM>° to <NUM>°.

In this embodiment, a tangent to a boundary point of a boundary line can have a slope identical, i. parallel, to the longitudinal axis (<NUM>°) or can be inclined up to <NUM>°, preferably <NUM>°. In case of <NUM>°, the rotational locking is achieved by a form fit since the tangent to the boundary point is perpendicular to the direction of rotation about the longitudinal axis. Thus, if the dental component is in a final position, i.e. in an end position in relation to another dental component, a relative rotation about the rotational axis is prevented.

However, a slope at the boundary points in above noted ranges of inclination will also cause rotational locking since the friction force caused by the normal force resulting from an applied torque at the boundary lines is sufficient to prevent a transformation of this torque into a movement in the longitudinal direction of the dental component.

Although above noted ranges are preferred, the locking effect may still be achieved in a range up to <NUM>°. The skilled person will appreciate the influence of friction coefficients in this respect, i. the higher the angle the higher should be the friction coefficient between the components.

In a preferred embodiment, each boundary line is part of an indexing surface and preferably a linear indexing surface.

An indexing surface provides more support and a more reliable rotational locking. The locking is further improved in case of a linear indexing surface with a slope in aforementioned ranges. This result in the feedback provided to a dental professional when assembling the dental component also being improved.

In another particularly preferred embodiment, the guiding section and the indexing section form an undulating, preferably continuous, surface about the longitudinal axis of the dental component.

In this embodiment, both the indexing section and the guiding section comprise a surface. The indexing surface and the guiding surface form together an undulating surface generally extending about the longitudinal axis. Preferably, the surface is continuous, i.e. without any interruptions, so that viewed along the longitudinal axis, has a continuous extension about the longitudinal axis. This includes the indexing surface partly extending parallel to the longitudinal axis.

The profile of the undulating surface is defined by a continuous or discontinuous function. For the sake of explanation, an undulating surface defined by a continuous function has a tangent at each point along the profile of this surface, wherein each of these tangents has an absolute slope that is smaller than infinity. In contrast, if the undulating surface is defined by a discontinuous function, at least at one angle, the profile of the surface has more than one point at the same angle φ about the longitudinal axis of a cylindrical coordinate system, i. multiple coordinates at the same angle.

The guiding surface of the at least one guiding section has two guiding surface portions and a mounting contact surface situated between the two guiding surface portions, wherein the mounting contact surface is parallel to a plane perpendicular to the longitudinal axis.

The mounting contact surface as a part of the guiding section extends the at least one guiding section surrounding the longitudinal axis and forms aforementioned apex. As a result, during assembly of the dental component, a premature rotational locking of the dental component during assembly is avoided. Instead, if the dental component is initially not being installed with the right orientation or predetermined orientation, the mounting contact surface can first get in contact with a corresponding dental component. Once in contact, the dental components can be rotated towards one of the guiding surfaces. Thus, the mounting contact surface allows the dental professional to choose and change a direction. In other words, movement along the mounting contact surface does allows to select a guiding surface. The selected guiding surface then guides the dental component towards the corresponding indexing section. Consequently, the mounting contact surface is the part of the guiding section that is at the end or closest to the extremity of the dental component.

Preferably, at least one of the dental component and the other dental component comprises a mounting contact surface to prevent above-noted premature locking of the corresponding interfaces.

In another embodiment, the two guiding surface portions each have at least one tangent, wherein the tangents of the two guiding surfaces at the same location along the longitudinal axis have the same absolute slope but different signs.

In this embodiment, the two guiding surface portions have basically the same but opposite profiles. As a result, on both sides guidance is provided in the same way to the next indexing section due to the slopes along this profile, which provides the same feedback to a dental professional for both guiding surface portions.

In another embodiment, the interface further comprises at least one radially facing support surface, the support surface preferably being located radially inwards in relation to the indexing section and guiding section and/or forms the extremity of the interface.

The support surface is cylindrical and/or conical with a circular profile as seen along the longitudinal axis. It may be located at or form the base of the interface. In this case, the guiding section and indexing section are located closer to the extremity of the dental component's interface side than the support surface. As a result, this radially facing support surface provides support for the transfer of radial forces between the dental components.

If the radially facing support surface extends along the longitudinal axis beyond the guiding section so as to form the interface's extremity. This allows the radially facing support surface to be in contact with another dental component during assembly before the guiding section. Consequently, it provides a facilitated initial axial alignment. Preferably, a chamfer is formed between the face side of the cylinder or cone at the extremity of the dental component and the support surface for further facilitating the initial assembly of the dental component. More specifically, such a chamfer helps inserting the dental component into another dental component. It also guides the rotation of the dental components about the longitudinal axis in relation to each other, similar to a bearing.

Locating the radially facing support surface radially inwards in relation to the indexing section and guiding section provides better visibility of these sections. Further, the support surface forming the extremity of the dental component and/or being inwards in particular support the structure of the guiding section.

In an embodiment not being according to the claimed invention, the mating surface is preferably frustoconical and/or undulates as a continuous periodic function along its entire extension about the longitudinal axis.

The mating surface being frustoconical results in its extension in the radial direction in relation to the longitudinal axis, i. width, being at an angle to the longitudinal axis other than <NUM>°. The frustoconical surface can be circular, trioval, or facetted. Preferably, the angle to the longitudinal axis is in a range of <NUM>° to <NUM>° and more preferably <NUM>° to <NUM>°. The frustoconical mating surface is self-centering and provides an efficient sealing surface for preventing above-noted ingress of detrimental organisms or particles that may threaten the success of the dental treatment.

In addition to the above embodiment, it has been found by the inventors that the desired effects for the dental component can be best achieved with an embodiment of the dental component having two to eight sections of each type, i.e. the guiding section and the indexing section, that alternate with each other. Even more preferably, the number of sections is three to six.

As already described above, the alternating arrangement of the at least one guiding section and at least one indexing section causes the guiding section and indexing section to be spatially separate. As a result, the sum of angular extension of all indexing sections and all guiding sections amounts to <NUM>°. In one embodiment, the ratio of angular extension between indexing section and guiding section is in a range of <NUM>,<NUM> to <NUM> and more preferably in a range of <NUM>,<NUM> to <NUM>.

If the mating surface, i. its profile, is defined by a continuous function, this uninterrupted surface provides an effective seal. If the function defining the mating surface is periodic, it further provides a better visual indication if two dental components are in a final position in relation to each other.

Further, in another embodiment, the at least one guiding section of the dental component may be formed as a protrusion or recess with a snap-fit feature. The snap-fit feature preferably faces in the radial direction of the dental component. In a final position of two dental components, each guiding section is situated within an indexing section. Consequently, the snap-fit feature of the other dental component will be formed at an indexing section. This enables the snap-fit feature of one dental component to engage the snap-fit feature of another dental component.

The invention also provides a dental component as described above, in particular an abutment or coronal part of a multi-piece, for example two-piece, abutment, a bridge, a dental bar, a healing abutment, a spacer, a superstructure, a single prosthetic tooth or multiple prosthetic teeth, an impression coping, a personalized implant abutment, a CAD/CAM personalized implant abutment, a manually customizable abutment assembly, healing cap, a cover screw, wherein the interface is formed at the apical end of the dental component so that at least part of the interface faces apically for being assembled to another dental component, in particular a dental component such as a dental implant, an abutment or an apical part of a two-piece abutment.

Further, the dental component can be a dental implant, an abutment or a coronal or apical part of a multi-piece, for example two-piece, abutment.

The invention further provides a dental assembly for mounting a prosthesis, the dental assembly comprising a dental component with at least a part of the interface facing apically as coronal dental component and a dental component with at least a part of the interface facing coronally as apical dental component.

The interfaces of the coronal dental component and the apical dental component correspond to each other so that in an assembled state they are in a mating relationship, i. at a final position in relation to each other. In this final position, the coronal dental component and apical dental component are rotationally locked in relation to each other.

In an embodiment, the dental assembly further comprises a dental screw for fixating the dental assembly, the dental screw having a predetermined length, wherein the apical dental component comprises an internal thread, the internal thread being arranged along a portion of the longitudinal axis of the apical dental component so that it can only be engaged by the dental screw if the apically facing interface of the coronal dental component and the coronally facing interface of the apical dental component are arranged at a final position.

Including a dental screw and an internal thread as defined above is another feature that assists a dental professional in correctly assembling the coronal dental component and apical dental component. Assuming, the two components are not at a final position, the dental professional will realize this since it is impossible to fixate these components to each other using the dental screw with the predetermined length.

In another embodiment, the guiding section of one of the coronal dental component and apical dental component is, in a final position, at a distance to the indexing section of the other one of the coronal dental component and apical dental component.

This distance between the guiding section of one of the components and the indexing section of the other one of the components, while these components are in a final position, prevents forces in the longitudinal direction to be transferred by this part of the interfaces. Instead, such forces are transferred by another part of the interfaces, preferably the previously described mating surface. Consequently, the distance between the two sections is along the longitudinal direction of the dental components. The part of the interface comprising the guiding section and indexing section will transfer torque as well as forces that act in a transverse direction in relation to the longitudinal axis.

The present disclosure also provides another type of a dental component that does not fall within the scope of the claimed invention. This dental component includes a coronal end, an apical end, and a longitudinal axis extending between the coronal end and the apical end, and an interface for assembly to another dental component. The interface comprises an apically or coronally facing mating surface. The mating surface extends about the longitudinal axis and undulates as a continuous periodic function, preferably a sine function, along its entire extension. Further, the interface comprises a radially facing support surface, which is preferably located radially inwards in relation to the mating surface.

In this embodiment of the dental component, the mating surface does not only transfer forces in a longitudinal direction but also forces acting in a circumferential direction of the dental component. Thus, the mating surface also acts as indexing feature when being in a final position in relation to another dental component. Preferably, this indexing is designed to prevent rotation without the dental components being fixated with a dental screw as described above in relation to the indexing and guiding sections of the previous type of a dental component.

The radially facing support surface preferably extends and forms the extremity of the dental component's interface side as described in relation to a previous embodiment of a dental component.

In one embodiment, the mating surface is frustoconical. Such a surface has the aforementioned advantages in relation to sealing a dental assembly from the ingress of detrimental organisms or substances.

Further, the disclosure provides a method of installing a coronal dental component to an apical dental component comprising the steps of providing a coronal and apical dental component having interfaces as described above; moving the coronal dental component towards the apical dental component in a longitudinal direction until the interfaces get in contact; if necessary, rotating the two dental components relative to each other, wherein the interface of one of the dental components guides the interface of the other one of the dental components to an indexing position so that the two dental components are in a final position in relation to each other, wherein guiding is performed by the guiding section of the first type of dental component or the mating surface of the second type of dental component; and fixating the two dental components using a dental screw.

In one embodiment, the apical dental component is a dental implant that has been previously implanted into the upper or lower jaw bone in a mouth of a patient. In another embodiment, the apical dental component is one of the other above-noted dental components that has been previously mounted on a dental implant, preferably with an interface according to this invention.

The following figures illustrate preferred embodiments of the present invention. These embodiments are not to be construed as limiting but merely to enhance the understanding of the invention together with this description. The first digit of the reference signs refers to the number of the figure. For the remaining digits, same reference signs refer to features throughout the drawings that have the same or an equivalent function and/or structure. Consequently, a repetitive description of these components has been avoided.

<FIG> show a three-dimensional illustration of a dental assembly <NUM>. The dental assembly comprises a dental implant <NUM>, an implant screw <NUM>, a two-piece abutment with a coronal dental component <NUM> and an apical dental component <NUM>, and a dental screw <NUM>. In the figures, two-piece abutments are described as an example of dental components that can make use of the interface according to the present invention. This abutment can provide the support the placement of a dental prosthesis onto a dental implant with the desired orientation and position. Nonetheless, the invention can also be applied to any of the above listed dental components.

As shown in <FIG>, the apical dental component <NUM> of the two-piece abutment is fixed to the dental implant <NUM> using an implant screw <NUM>. The apical dental component <NUM> and the coronal dental component <NUM> are fixed to each other with a dental screw <NUM>. The interface between the coronal dental component <NUM> and the apical dental component <NUM> will be described in more detail further below.

As shown in the embodiment of <FIG>, the interface between dental implant <NUM> and the apical dental component <NUM> may differ from the interfaces between the two components <NUM> and <NUM> of the two-piece abutment. A skilled person will appreciate that the interface to the dental implant <NUM> may also be based on the features of an interface as the one acting between the dental components <NUM> and <NUM>.

As shown in <FIG>, the apical dental component <NUM> of the two-piece abutment may have an internal thread for engagement with the thread of the dental screw <NUM>. The placement of the internal thread <NUM> in the through hole <NUM> of the apical component <NUM>, the placement of the screw seat <NUM> along the longitudinal axis L of the coronal dental component <NUM>, and the length of the dental screw <NUM> are chosen so that the dental screw <NUM> can only be fastened if the coronal dental component <NUM> and the apical dental component <NUM> are in a final position in relation to each other.

Further, the coronal component <NUM> may also have an internal thread <NUM> that is arranged in the through hole <NUM> of the coronal dental component. This thread <NUM> is able to hold the dental screw <NUM> before assembly. This arrangement facilitates assembly in the mouth of a patient since the dental screw <NUM> does not have to be inserted separately. This avoids losing the screw during assembly. In particular during assembly in the mouth of a patient (in contrast to an assembly in a dental lab), the risk of the screw being swallowed or inhaled by the patient can basically be averted.

Turning to <FIG>, these figures show the coronal component <NUM> and the apical component <NUM>, respectively, in more detail. Both dental components <NUM> and <NUM> have a longitudinal axis L. In an assembled state, the longitudinal axes of the coronal dental component <NUM> and the apical dental component <NUM> form the longitudinal axis L shown in <FIG>. In other words, the longitudinal axes get aligned during assembly.

The coronal dental component <NUM> of <FIG> is shown in a three-dimensional view from below. At its apical end, the coronal dental component <NUM> includes an apical interface <NUM>. In the exemplary embodiments, the apical interface <NUM> comprises three guiding sections <NUM> that alternate with three indexing sections <NUM> so that they completely surround the longitudinal axis L of the coronal dental component <NUM>. As a result, there are three different relative orientations available between the dental components <NUM> and <NUM>.

The embodiments illustrated in any of the figures of this application show the same number of guiding sections for the apical and coronal dental components. However, it is also possible to configure an embodiment so that the number of guiding sections and/or indexing sections of one of these dental components is lower than the number of guiding sections and/or indexing sections of the other component. For example, the coronal dental component <NUM> shown in <FIG> may have only one or two guiding sections 123c as shown and one or two indexing sections <NUM>, respectively, that extend along the remaining angular extend about the longitudinal axis L. Such an apical interface <NUM> still corresponds to the coronal interface <NUM> of the apical dental component <NUM> shown in <FIG>. As a result, the two components <NUM> and <NUM> can be mounted to each other to take a final position, in which they are radially and rotationally aligned. Alternatively, the apical dental component <NUM> shown in <FIG> may only have one or two guiding sections <NUM> and/or only one or two indexing sections <NUM>, respectively. If there is only one indexing section, the accommodation surface <NUM> will simply extend further about the longitudinal axis L.

The interface <NUM> includes a radially facing support surface <NUM> that faces radially inwards and basically extends to the extremity of the coronal dental component <NUM> on the side of the apical interface <NUM>. The radially facing support surface <NUM> provides support for a rotation about the longitudinal axis during assembly and guidance to a next indexing section <NUM>. The interface <NUM> also comprises an apically facing mating surface <NUM>. Further, the coronal dental component <NUM> includes an internal thread <NUM> that is located within a through hole <NUM>. As described above, the internal thread <NUM> can hold a dental screw prior assembly.

Each guiding section <NUM> comprises and preferably consists of a guiding surface <NUM>. Like the mating surface <NUM>, the guiding surface <NUM> also faces in an apical direction. During assembly, the guiding surface <NUM> guides the apical dental component <NUM> to a next indexing section <NUM> in a rotational direction about the longitudinal axis L. As a result of its function, the guiding surface <NUM> consists of surface portions that face apically over their entire extension. The guiding surface <NUM> may be defined by two guiding surface portions 123a and 123b and a mounting contact surface 123c. The function of each of these surfaces will be described in relation to the assembly of the coronal dental component <NUM> to the apical dental component <NUM>.

Preferably, the guiding sections <NUM> are symmetrical to a plane crossing and extending along the longitudinal axis L. This results in the guiding surface portions 123a and 123b having the same surface profiles in a cylindrical coordinate system with the longitudinal axis L being the longitudinal axis h of this system (cf. In the cylindrical coordinate system, each of the guiding surface portions 123a and 123b has at least one slope, i.e. they have a linear and/or curved profile, wherein the corresponding slopes of the guiding surface portions 123a and 123b have opposite signs.

The indexing section <NUM> is preferably for rotationally locking the coronal dental component <NUM>. Since guiding sections <NUM> and indexing sections <NUM> alternate about the longitudinal axis L, each indexing section <NUM> is placed in between two guiding sections <NUM> and vice versa if there are at least two guiding sections <NUM> and two indexing sections <NUM> provided. Each indexing section <NUM> begins and ends with boundary lines 124a and 124b, respectively. The boundary lines 124a and 124b define boundary points 124a' and 124b' that mark the beginning and end of the profile of each indexing section <NUM>. By definition, these boundary points 124a' and 124b' of the surface profile or boundary lines 124a and 124b along the width belong to the indexing section <NUM>.

In the exemplary embodiment of a coronal dental component <NUM> shown in <FIG>, the indexing section <NUM> includes two linear indexing surfaces <NUM>. The indexing surfaces are limited by the boundary lines 124a, 124b, respectively, and extend substantially parallel to the longitudinal axis L. Consequently, the slope of the profile of the linear indexing surface <NUM> as well as the slope of a tangent at the profile of the boundary lines 124a and 124b, i. the boundary points 124a' and 124b', is infinite in above-mentioned cylindrical coordinate system. As a result, the indexing section <NUM> is configured for rotationally locking in relation to another dental component such as the apical dental component <NUM> by means of a form fit. Due to this form fit a rotation about the longitudinal axis L in a plane perpendicular to the longitudinal axis will be transferred to the other dental component but does not result in the two components being separated in a longitudinal direction. The latter can happen if the indexing surfaces <NUM> sufficiently taper along the longitudinal axis L towards the coronal end of the coronal dental component <NUM>. The tapering would then cause that above-noted torque is partly transformed into a force acting in the direction of the longitudinal axis and partly into a force acting in a circumferential direction. In order to result in a movement separating the two dental components, the longitudinal force, i. the taper, has to be large enough to overcome frictional forces that act due to the circumferential force.

As illustrated in <FIG>, for each dental component <NUM> or <NUM>, the geometry and dimensions of the guiding sections differs from the geometry and dimensions of the indexing sections, in particular their extension about the longitudinal axis L. However, due to the corresponding nature of the interface <NUM> of the coronal dental component <NUM> and the interface <NUM> of the apical dental component <NUM>, parts of the sections have corresponding geometries and dimensions in order to allow for a final position between these components.

<FIG> illustrates the apical dental component <NUM>. The apical dental component <NUM> comprises a coronal interface <NUM> that corresponds to the apical interface <NUM> of the coronal dental component <NUM>. In other words, the coronal interface <NUM> and the apical interface <NUM> are designed so that they can be engaged in a final position in relation to each other.

The apical component <NUM> comprises a predetermined number of guiding sections <NUM> and indexing sections <NUM> that corresponds to the number of guiding sections <NUM> and indexing sections <NUM> of the coronal dental component <NUM>. In the embodiment shown in <FIG>, the dental components <NUM> and <NUM> are equipped with three sections of each type. As described previously, other numbers of sections can be incorporated into the structure of the interface that also facilitate assembly of the two dental components <NUM> and <NUM>.

Each guiding section <NUM> of the apical dental component <NUM> has a guiding surface <NUM>. The guiding surface <NUM> is in turn subdivided into two guiding surface portions 153a and 153b. In contrast to the guiding sections <NUM> of the coronal dental component <NUM>, the guiding sections <NUM> of the apical dental component do not have a mounting contact surface. Nonetheless any or both may include one.

Each end of the guiding surfaces <NUM> is adjacent to boundary lines 154a and 154b. The boundary lines 154a and 154b define the outer limits of the guiding sections <NUM>. At the opposite sides of the guiding lines 154a and 154b can be indexing surfaces <NUM>. In the first embodiment, the slope of the indexing surfaces is basically parallel to the longitudinal axis L, i.e. infinite. Nonetheless, other slopes may be applied such as the ones defined above.

Between the two indexing surfaces <NUM> of each indexing section <NUM> may extend an accommodation surface <NUM>. In the exemplary embodiment, the accommodation surfaces <NUM>, indexing surfaces <NUM>, and guiding surfaces <NUM> form an undulating surface that undulates along (or in the direction of) the longitudinal axis L while surrounding this axis, i. the amplitudes of the undulating surface extend in a longitudinal direction. This undulating surface is substantially coronally facing and has substantially an annular shape as seen from a perspective along the longitudinal axis L.

Within a through hole <NUM>, the apical dental component <NUM> includes an internal thread <NUM>. The thread <NUM> is for fixating the coronal dental component <NUM> to the apical dental component <NUM> using a dental screw <NUM> (cf.

The apical dental component <NUM> may further comprise a radially facing support surface <NUM>. For being arranged at a final position with the radially facing support surface <NUM> of the coronal dental component <NUM>, the radially facing support surface faces radially outwards. In contrast to the radially facing support surface <NUM> of the coronal dental component <NUM>, the radially facing support surface <NUM> is provided at the base of the corresponding coronal interface <NUM>. In other words, it is located before (or apically to) the indexing sections <NUM> and the guiding sections <NUM>, the latter forming the extremity of the apical dental component <NUM>.

The radially facing support surfaces <NUM>, <NUM> may both be tapered or cylindrical. When being engaged during assembly, the radially facing support surfaces <NUM>, <NUM> are in contact or support each other in a radial direction and allow for the transfer for forces in this direction. For this function, the radially facing support surfaces <NUM>, <NUM> preferably comprise at least a portion that completely surrounds the longitudinal axis L.

Further, the interface <NUM> of the apical dental component <NUM> may include a coronally facing mating surface <NUM>. The coronally facing mating surface <NUM> is preferably located at the outer periphery of the coronal interface <NUM> and has a ring shape. Once assembled, the coronally facing mating surface <NUM> is in contact with the apically facing mating surface <NUM> of the coronal dental component <NUM>. Due to this contact, the mating surfaces <NUM> and <NUM> preferably seal the inner portion of the assembled dental components <NUM> and <NUM> against ingress of detrimental organisms or other substances. In use of the dental assembly <NUM>, the mating surfaces <NUM> and <NUM> transfer forces acting in a longitudinal direction between the two dental components <NUM> and <NUM>.

The surfaces of the guiding sections <NUM> and indexing sections <NUM> define the coronal shape and width of an annular protrusion at the interface <NUM>. Correspondingly, the guiding sections <NUM> and indexing sections <NUM> of the coronal dental component <NUM> define the shape and form of an annular recess. As a result, the mating surfaces <NUM> and <NUM> are in contact if the dental components <NUM> and <NUM> are at a final position. It will be clear to the skilled person that it is also possible to form this part of the interface as protrusions at the apical interface <NUM> of the coronal dental component <NUM> and as recesses at the coronal interface <NUM> of the apical component <NUM>. Other configurations are also possible and envisaged (cf.

The structure of the coronal interface <NUM> defined by the guiding surface <NUM> and a part of the indexing surface <NUM> forms a finger-like protrusion <NUM> that tapers coronally in a radial direction. This taper is adjacent to the cylindrical radially facing support surface <NUM> and has an inclination in relation to this surface. This taper of the protrusion <NUM> facilitates insertion of the protruding part of the coronal interface <NUM> into the recessed part of the apical interface <NUM>.

An assembly of a coronal dental component <NUM> to an apical dental component <NUM> can be performed as follows.

After insertion of a dental implant <NUM> and generally a healing period, the apical dental component <NUM> and the coronal dental component <NUM> can be assembled to the dental implant <NUM> so as to form the dental assembly <NUM> shown in <FIG>. Alternatively, assembly can take place in a dental lab, for example for designing and/or fitting the prosthetic tooth. In the case of assembly in a lab, the dental implant <NUM> may be replaced by a dental implant analogue (not shown).

Assembly starts with mounting the apical dental component <NUM> to the dental implant <NUM> by means of the apical interface <NUM> and an implant screw <NUM>. When beginning the assembly of the coronal dental component <NUM> to the apical dental component <NUM>, a dental screw <NUM> is preferably already in threaded engagement with the inner thread <NUM> of the coronal dental component <NUM>. As mentioned above, the coronal dental component <NUM> and the apical dental component <NUM> are in this example parts of a two-piece abutment. The skilled person will appreciate that any other combination of the above-noted dental components applying the features of the invention may be used instead.

For installing the coronal dental component <NUM> against the apical dental component <NUM>, the longitudinal axes L of both components are substantially brought into alignment. This step is supported by the tapering portions of the fingerlike protrusions <NUM> if present. When the coronal interface <NUM> of the apical dental component <NUM> and the apical interface <NUM> of the coronal dental component <NUM> approach each other, the following steps in the assembly depend on the rotational orientation of the dental components <NUM> and <NUM> in relation to each other.

In a first scenario, if the coronal dental component <NUM> is already correctly aligned to the apical dental component <NUM>, the fingerlike protrusions <NUM> of the coronal interface <NUM> will readily enter the indexing sections <NUM> of the apical interface <NUM>. As a result, the indexing surfaces <NUM> of the coronal dental component <NUM> will face the indexing surfaces <NUM> of the apical dental component <NUM> in both rotational directions. This facing relationship will establish the rotational lock between the two dental components <NUM> and <NUM>. In the illustrated example, the rotational lock between the two dental components <NUM> and <NUM> is caused by a form fit due to the orientation of the indexing surfaces <NUM> and <NUM> parallel to the longitudinal axis L. As mentioned above, the indexing surfaces <NUM> and <NUM> may also be inclined in the above noted ranges so that a rotational lock is established by self-looking friction.

As illustrated in the cross-sectional view of <FIG>, the coronal dental component <NUM> and the apical dental component <NUM> are brought together until the apically facing mating surface <NUM> of the coronal dental component contacts the coronally facing mating surface <NUM> of the apical dental component <NUM>.

In the final position, i. a mating relationship, of the coronal dental component <NUM> and the apical dental component <NUM> relative to each other, the most apical part of the indexing sections <NUM> is preferably at a distance to the most apical part of the guiding sections <NUM>. In a corresponding manner, the most coronal part of the indexing sections <NUM> is preferably at a distance to the most coronal part of the guiding sections <NUM>. In the illustrated embodiment, the coronal portion of the guiding surfaces <NUM> of the apical dental component is at a distance to the coronal portion of the accommodation surfaces <NUM> of the coronal dental component <NUM>. Likewise, the apical portion of the guiding surfaces <NUM> of the coronal dental component <NUM> is at a distance to the apical portion of the accommodation surfaces <NUM> of the apical dental component <NUM>. This arrangement is preferred in order to ensure an annular contact between the mating surfaces <NUM> and <NUM> for achieving an effective seal for sealing off the inside of the dental components <NUM>, <NUM> on the level of the interfaces <NUM> and <NUM>.

The radially facing support surface <NUM> of the apical interface <NUM> and/or the radially support surface <NUM> of the coronal interface <NUM> may be configured to assist in sealing off the inner portion of the two-piece abutment as described in more detail further below, in particular when the two dental components <NUM> and <NUM> are fixated using the dental screw <NUM>. In addition or alternatively, an O-ring, preferably in combination with at least one groove in at least one of the mating surfaces <NUM> and <NUM> and/or support surfaces <NUM> and <NUM> can be used to form a seal.

In another scenario, in which the coronal dental component <NUM> is not correctly aligned with the apical dental component <NUM>, the guiding sections <NUM> of the coronal dental component <NUM> will first get into contact with the guiding sections <NUM> of the apical dental component <NUM>. More specifically, at least one of the guiding surface portions 153a and 153b of the guiding sections <NUM> will get in contact with one of the guiding surface portions 123a and 123b or the mounting contact surface 123c of the guiding sections <NUM>.

In case first contact is established between the guiding surfaces <NUM> and the mounting contact surfaces 123c, a dental professional can then rotate the coronal dental component <NUM> and the apical dental component <NUM> in one of the rotational directions about the longitudinal axis L relative to each other, i.e. clockwise or counterclockwise. As described above, this rotation can be supported by the radially facing support surface <NUM>.

This rotation results in one of the guiding surface portions 153a and 153b of the coronal interface <NUM> getting into contact with one of the guiding surface portions 123a and 123b of the apical interface <NUM>. Since both guiding surface portions 123a and 123b have a surface profile that is directing towards the next indexing section, the guiding sections <NUM> of the apical dental component <NUM> will approach the indexing sections <NUM> of the coronal dental component <NUM> by moving in a rotational and a longitudinal direction. In other words, the configuration and cooperation of the guiding sections provoke a longitudinal motion of at least one of dental component relative to the other when a dental component is rotated relative to the other about the longitudinal axis. The same applies to the interaction between the guiding sections <NUM> of the coronal dental component <NUM> and the indexing sections <NUM> of the apical dental component <NUM>. Consequently, a dental professional mounting the coronal dental component <NUM> onto the apical dental component <NUM> will be guided towards engaging these components in a final position.

Doing so, the dental professional will receive haptic feedback of reaching the predetermined relative position between the coronal dental component <NUM> and the apical dental component <NUM>. This feedback is caused by the discontinuous change in slope between the guiding surface portions 123a, 123b and the indexing surface <NUM> at the boundary lines 124a, 124b of the coronal dental component <NUM>.

Once a final position is reached, a dental professional can fasten the dental screw <NUM> so that it disengages from the inner thread <NUM> of the coronal dental component <NUM> (if present) and engages the inner thread <NUM> located in the through hole <NUM> of the apical dental component <NUM>. This results in the dental components <NUM> and <NUM> being assembled.

However, if the two dental components <NUM> and <NUM> are not at a final position, they will not engage due to the location of the thread <NUM> and the predetermined length of the dental screw <NUM> in order to prevent fixation in an undesired relative position since the length of the dental screw <NUM> is too short. The skilled person will appreciate that the inner thread <NUM> may also be located within a blind hole of the apical dental component <NUM> if the apical interface <NUM> of the apical dental component <NUM> allows an attachment to a dental implant <NUM> without an implant screw <NUM>.

It should be noted that the inner thread <NUM> of the coronal dental component <NUM> may also be used for helping in dismantling the two-piece abutment, if necessary. As a first step, the dental screw <NUM> is loosened and removed using a tool that engages the engagement section <NUM> of the dental screw <NUM>. In the next step, a dismantling screw (not shown) is inserted and brought into a threaded engagement with the inner thread <NUM> until the tip of the screw that has a smaller diameter than the inner diameter of the inner threads <NUM> and <NUM> contacts either the head of the implant screw <NUM> or the bottom of above noted blind hole. Screwing further will then pull the coronal dental component <NUM> away from the apical dental component <NUM>.

Another embodiment of the present invention is shown in <FIG> illustrates a coronal dental component <NUM>. In difference to the previous embodiment illustrated in <FIG>, the guiding surface <NUM> of the coronal dental component <NUM> does not have a mounting contact surface. Instead, the apical dental component <NUM> is formed with a mounting contact surface 253c (cf.

Further, the fingerlike protrusion <NUM> defined by the guiding surface <NUM>, the indexing surface <NUM>, and a portion of the accommodation surface <NUM> (as described above) comprises a snap-fit feature <NUM>. This snap-fit feature <NUM> of the protrusion <NUM> is formed as a tapering protrusion that extends radially outwards (cf. A corresponding snap-fit feature <NUM> is formed in each of the indexing sections <NUM> as a tapered radial recess extending outwards into the surrounding wall of the coronal dental component <NUM>.

When being assembled, the fingerlike protrusions <NUM> of the apical dental component <NUM> bend inwards upon contact with the supporting surface <NUM> of the coronal dental component <NUM>. If the coronal interface <NUM> of the apical dental component <NUM> is inserted further into the apical interface <NUM> of the coronal dental component <NUM>, the protrusions <NUM> reach the recesses <NUM> of the indexing sections <NUM> and snap back, preferably to their initial position.

In this configuration, the dental screw <NUM> of the previous embodiment may be omitted alongside with the inner thread located in the through hole <NUM> of the apical dental component <NUM>. In other words, the snap-fit features <NUM> and <NUM> can replace the function of the dental screw <NUM>. This results in an easier way of installing the coronal dental component <NUM> on the apical dental component <NUM>.

Further, as a result of the arrangement of the snap-fit feature, the inner thread <NUM> of the coronal dental component <NUM> may assist during assembly by holding an implant screw (not shown) while positioning the coronal dental component <NUM> and the apical dental component <NUM> relative to each other. Once the snap-fit features <NUM> and <NUM> are in engagement, a dental screw (not shown) can be used to fasten the dental components <NUM> and <NUM> to each other (cf. Alternatively, an implant screw (not shown) can be inserted and be engaged with a thread of the dental implant to fasten the coronal dental component <NUM> to the apical dental component <NUM> and to a dental implant (not shown).

Another difference to the embodiment shown in <FIG> is the geometry of the mating surfaces <NUM> and <NUM>. Both, the mating surface <NUM> of the coronal dental component <NUM> and the mating surface <NUM> of the apical dental component <NUM> have an undulating configuration. In other words, the mating surfaces <NUM> and <NUM> undulate along (or in the direction of) the longitudinal axis L while extending about this axis. In contact, the mating surfaces <NUM> and <NUM> may act as a seal as described above. In addition, the undulating surface <NUM> can be adapted to the surrounding soft tissue of the gingiva in order to disguise the apical dental component <NUM> of the two-part abutment. Further, the undulation of the surface <NUM> provides a better visual indication if a final position between the coronal dental component <NUM> and the apical dental component <NUM> is reached.

A skilled person will appreciate that any or all of the different configurations in relation to this embodiment, namely of the mounting contact surface, the snap-fit feature, and the geometry of the mating surface may be applied to the first embodiment.

A third embodiment will be explained in the following under reference to <FIG>. The dental components <NUM> and <NUM> have a configuration of the guiding surface <NUM> that is basically the same as the configuration illustrated and described in relation to <FIG>. In the third embodiment, the mating surfaces <NUM> and <NUM> are formed as ring-shaped surfaces in a plane perpendicular to the longitudinal axis L and extend about said axis.

The coronal dental component <NUM> and the apical dental component <NUM> comprise in addition to the support surfaces 328a and 358a that have already been described in relation to the previous embodiments radially facing support surfaces 328b and 358b, respectively. These support surfaces 328b and 358b have a cylindrical shape. As shown in <FIG>, the radially facing support surfaces 328b and 358b are located radially inwards and adjacent to the guiding sections <NUM> and <NUM> as well as indexing sections <NUM> and <NUM>, respectively.

The radially facing support surface 358b provides structural support for the protrusions <NUM> of the interface <NUM>. The radially facing support surfaces 328b and 358c also facilitate initial axial alignment during assembly of the dental components <NUM> and <NUM>. Further, the cylindrical radially facing support surfaces 328b and 358b have an additional sealing effect since they act as an obstacle and render the inside of the dental components <NUM> and <NUM> less accessible.

The coronal dental component <NUM> shown in <FIG> and the apical dental component <NUM> shown in <FIG> are illustrated alongside with cylindrical coordinate systems. Based on these cylindrical coordinate systems, <FIG> show the profiles of the guiding sections <NUM>, <NUM> and indexing sections <NUM>, <NUM> of the coronal dental component <NUM> and apical dental component <NUM>, respectively. In <FIG>, the different parts of the guiding sections <NUM> and the indexing sections <NUM> of the apical interface <NUM> are indicated and explained in detail below for a better understanding.

The profile of each indexing section <NUM> is located between boundary points 324a' and 324b'. Adjacent to each of these boundary points 324a' and 324b' is an indexing surface <NUM>. The indexing surfaces <NUM> are in turn connected by an accommodation surface <NUM>. As illustrated in <FIG>, the accommodation surface <NUM> preferably has a profile that primarily extends perpendicular to the coordinate axis h or parallel to the coordinate axis φ.

In the illustrated exemplary embodiment, the indexing surfaces <NUM> are extending parallel to the longitudinal axis L or coordinate axis h. Consequently, the slope of tangents at the boundary points 324a' and 324b' and at the indexing surfaces <NUM> is infinite, i. they represent slopes along a discontinuity of the profile. As already described above, such a slope results in a form fit between the apical interface <NUM> and the coronal interface <NUM> in a rotational direction about the longitudinal axis L.

Further, the same slopes are present if the profile is missing the indexing surfaces <NUM>. Here, the boundary points 324a' and 324b' of the profile, i. the boundary lines adjacent to the ends of each guiding surface <NUM>, act as a locking feature in a rotational direction about the longitudinal axis L.

Nonetheless, indexing surfaces with a surface profile that are inclined in relation to the axis h are also envisaged. Such indexing surfaces can be embodied as surfaces having a linear and/or curved profiles. In an embodiment, in which the profile of the guiding section <NUM> and the indexing section <NUM> is a curve defined by a continuous function such as a sine-function, the boundary points 324a' and 324b' are defined as points on the sine-function having the maximum absolute slope. In such an embodiment, the rotational locking function would be provided at least primarily by the boundary points. Due to the finite slope, the rotational lock would be caused by self-locking friction.

Between the boundary points 324a' and 324b' lies the guiding section <NUM>. Consequently, the boundary points 324a' and 324b' are not part of the guiding section <NUM>. Preferably, the guiding surface <NUM> of the guiding section <NUM> comprises two guiding surface portions 323a and 323b having slopes with opposite signs. Even more preferably, the guiding surface portions 323a and 323b are symmetrical in relation to the coordinate axis h of the graphs in <FIG>. The guiding surface portion 323a and 323b meet each other and form an apex at the apical extremity of the coronal dental component. The apex angle β formed is preferably in a range of <NUM>° to <NUM>° and more preferably in a range of <NUM>° to <NUM>°.

In the embodiment shown, the profiles of the indexing sections <NUM> and guiding sections <NUM> or their surfaces form a profile that undulates along (or in the direction of) the longitudinal axis while extending about the longitudinal axis L. Thus, moving along the profile about the longitudinal axis L will also cause an undulating movement along this axis. In other words, the profile may form a signal with at least one predetermined period that consists of an indexing section <NUM> and a guiding section <NUM>. Thus, the exemplary embodiment shown comprises for both the coronal dental component <NUM> and the apical dental component <NUM> three consecutive periods about the longitudinal axis L.

In <FIG>, the reference signs refer to parts of the profile that is defined by the guiding sections <NUM> and indexing sections <NUM> of the coronal interface <NUM>. Each guiding surface <NUM> is formed by guiding surface portions 353a and 353b as well as a mounting contact surface 353c in between. The outer ends of the profile of the guiding surface portions 353a and 353b are adjacent to the boundary points 354a' and 354b' that define the endpoints of each indexing section <NUM>. Adjacent to each boundary point 354a' and 354b' of the coronal interface <NUM> is an indexing surface <NUM> with a slope of the profile that corresponds to the slope of the indexing surfaces <NUM> of the apical interface <NUM>. In between the profiles of the two indexing surfaces <NUM> of each indexing section <NUM> is the profile of an accommodation surface <NUM>.

In <FIG>, the profile of the guiding sections <NUM> and the indexing sections <NUM> of the apical interface <NUM> is shown in a state, in which the apical guiding surface portions 323b of the apical interface <NUM> are in contact with the guiding surface portions 353a of the coronal interface <NUM>. The contact of these guiding surface portions during assembly results at least in an easier rotation of the profiles, i.e. the surfaces, relative to each other compared to a rotation in the opposite direction. In <FIG>, this contact will result in the profile of the apical interface <NUM> turning left in relation to the profile of the coronal interface <NUM>.

In <FIG>, the apical interface <NUM> and the coronal interface <NUM> are engaged at a final position. At this final position, the indexing surfaces <NUM> and <NUM> face each other to cause above noted form fit so that the interfaces <NUM> and <NUM> cannot rotate relative to each other.

Further, <FIG> illustrates that at a final position, the mounting contact surface 353c of the guiding sections <NUM> are at a distance to the accommodation surface <NUM> of the indexing sections <NUM>. Likewise, the guiding surface <NUM> of the guiding sections <NUM> is at a distance to the accommodation surface <NUM> of the indexing sections <NUM>. As already mentioned above, this results in the mating surfaces <NUM> and <NUM> to be in close contact with each other in order to form an effective seal.

As a non-limiting example and in particular this embodiment, the profile(s) of at least one, preferably both, of the guiding sections <NUM> and indexing sections <NUM> can have an angular extent (or angular length) preferably between <NUM> and <NUM>°, more preferably between <NUM>° and <NUM> and even more preferably of about <NUM>°. The profile(s) of at least one, preferably both, of the indexing sections <NUM> and/or guiding sections <NUM> can have an angular extent (or angular length) preferably between <NUM> and <NUM>°, more preferably between <NUM> and <NUM>° and even more preferably of about <NUM>°. As already described above, the ratio of the angular extent of the indexing section(s) and the angular extent of guiding section(s) of one dental component may differ. Even more preferably, they differ substantially, i.e. in a range of <NUM> to <NUM> or <NUM>/<NUM> to <NUM>/<NUM>, alternatively in a range of <NUM> to <NUM> or <NUM>/<NUM> to <NUM>/<NUM>.

Furthermore, the extent or depth of the indexing section <NUM> along the longitudinal axis L may be about substantially <NUM>.

In an assembled state, the distance along the longitudinal axis L from the extremity of the guiding section of one of the dental components, i. the apex of the guiding surface <NUM> or the mounting contact surface 353c, to the extremity of the other one of the dental components, i. the mounting contact surface 353c or the apex of the guiding surface <NUM>, is preferably larger than the interfering thread length between the dental screw (not shown) and the apical dental component <NUM> in a correctly assembled state. As a result, the thread of the dental screw cannot be engaged unless the apical dental component <NUM> and coronal dental component <NUM> are in a mating relationship.

Turning to <FIG> illustrates yet another embodiment of a coronal dental component <NUM> and a corresponding apical dental component <NUM>. Generally, the dental components shown in <FIG> correspond to the dental components illustrated in <FIG>, respectively. However, in contrast to the coronal dental component <NUM> of <FIG>, the coronal dental component <NUM> of <FIG> comprises a frustoconical alignment surface 458c at the coronal end of the support surface 458b instead of the rounded coronal edge at the coronal end of the cylindrical support surface 358b.

The frustoconical alignment surface 458c faces radially outwards. It helps achieving initial axial alignment between the two dental components during assembly upon contact of the frustoconical alignment surface 458c of the apical dental component <NUM> with the corresponding radially inwards facing frustoconical alignment surface 428c of the coronal dental component <NUM>. In accordance with the structure of the apical dental component <NUM>, the radially inwards facing frustoconical alignment surface 428c is adjacent to the coronal end of the radially inwards facing support surface 428b.

<FIG> show yet another embodiment of a dental assembly <NUM> and an apical dental component <NUM>, respectively. In this embodiment, the mating surfaces <NUM> and <NUM> are positioned like the mating surfaces of previous embodiments at the outer periphery of the coronal dental component <NUM> and the apical dental component <NUM>. However, the mating surface <NUM> of the coronal component <NUM> and the mating surface <NUM> of the apical dental component <NUM> are inclined in relation to the longitudinal axis L by an angle α. Due to this angle α, the mating surfaces <NUM> and <NUM> do not extend in a plane perpendicular to the longitudinal axis L. In other words, the angle α differs from <NUM>°. Instead, this angle preferably has one of the values in the ranges as defined above. These angled or frustoconical mating surfaces <NUM> and <NUM> can be applied to any of the previous embodiments as well as to the following embodiment.

Further, the angle αa of the mating surface <NUM> of the apical component <NUM> may differ from the angle αc of the mating surface <NUM> of the coronal component <NUM> so that a contact between these surfaces is generally a line contact about the longitudinal axis L. Still, both angles αa, αc have a value of above-defined ranges. The difference between these angles αa and αc is preferably in a range of <NUM>° to <NUM>°, more preferably in a range of <NUM>° to <NUM>°, and in particular <NUM>°. Preferably, in relation to the longitudinal axis L, the angle αa is greater than the angle αc. Moreover, the difference between these angles αa and αc preferably results in the line contact being established on the radially inner side of the mating surfaces <NUM> and <NUM> in relation to the longitudinal axis L or closer to the longitudinal axis than to the periphery or outer wall of the dental components <NUM> and <NUM>. This results in a better stress distribution for forces in the direction of the longitudinal axis of the coronal dental component <NUM> and the apical dental component <NUM>. Further, it can form a seal in an assembled state of these components.

Another difference to the previous embodiments is that the indexing sections <NUM> do not comprise an accommodation surface. Instead, the indexing sections <NUM> have the boundary lines 554a and 554b and adjacent to each of these an indexing surface <NUM>. Instead of the accommodation surface, the mating surface <NUM> extends radially further inwards than in the previous embodiments so that the guiding surface of the corresponding apical dental component <NUM> faces the mating surface <NUM> when being at a final position. As a result, only a portion of the mating surface <NUM> is located next, i. outwards, to the guiding sections <NUM> and indexing sections <NUM> as viewed along the longitudinal axis L, wherein the remaining portion of the mating surface <NUM> in the radial direction is located beneath the guiding sections <NUM> and indexing sections <NUM>.

As illustrated in <FIG>, the guiding surface <NUM> with the guiding surface portions 553a and 553b as well as the mounting contact surface 553c and the adjacent indexing surfaces <NUM> substantially define the geometry of a protrusion extending outwards from the cylindrical support surface 558b. The outer face of this protrusion forms the support surface 558a. Consequently and in contrast to the previous embodiments, the radially outwards facing support surface 558a does not extend until the mating surface <NUM>. Instead, a gap is present between the protrusion defined by of the above mentioned surfaces and the mating surface <NUM>.

As previously mentioned, it is also envisaged that the indexing section may solely have the boundary lines 554a and 554b as structural features. In this case neither an indexing surface nor an accommodation surface would be present. As defined above, the slope at the boundary lines would then be defined as being infinite and, thus, sufficient to provide a rotational locking function based on a form fit.

Further, the coronal components <NUM> illustrated in <FIG> corresponds to the apical component in <FIG>. The same applies to the indexing and guiding sections of the coronal dental component <NUM> shown in <FIG>.

Another embodiment of a dental component <NUM> is illustrated in <FIG> that is also based on the principles of the present invention. Although these figures show an apical dental component <NUM> with a coronal interface <NUM>, the skilled person will at least from the previous description be aware how to shape a corresponding interface for a coronal dental component that is intended to reach a final position in relation to the apical dental component <NUM>, in which the two components are radially and rotationally aligned.

The coronal interface <NUM> of the apical dental component <NUM> comprises at its peripheral edge a mating surface <NUM>. Adjacent to the edge of the mating surface <NUM> radially located inwards is a cylindrical outwardly facing support surface <NUM>. At the coronal end of the outwardly facing support surface <NUM> is a frustoconical sealing surface 658c. This sealing surface 658c and the support surface <NUM> have the same structure, function and advantages as described in relation to the embodiment shown in <FIG>.

In contrast to the previous embodiments, the mating surface <NUM> is an undulating ring-shaped surface that also has the functionality of the previously described guiding sections and indexing sections. More specifically, the guiding sections <NUM> and indexing sections <NUM> are embodied by the undulations of the mating surface <NUM>. Like in the previous embodiments, the surface of the guiding sections <NUM> are located closer to the coronal extremity of the apical dental component <NUM> than the surface of the indexing sections <NUM>.

The extension of the indexing sections about the longitudinal axis L is also defined by two boundary lines 654a and 654b traversing the width of the mating surface. Since the undulating mating surface <NUM> is defined by a continuous function, such as a sine function, the boundary lines 654a and 654b are located at the tangents to the mating surface <NUM> with the maximum absolute slope. Self-locking can be achieved by the surface properties of the mating surface <NUM> and the amplitude described by this function, which relates to the maximum slope at the boundary lines 654a and the 654b. In other words, if the amplitude is large enough, the slope at the boundary lines 654a and 654b will be sufficient for a self-locking effect of the dental component <NUM> in relation to another dental component.

In comparison to the previous embodiments, the structure of the dental component shown in <FIG> is simplified. Due to the missing discontinuity in the surface's profile, there may be less haptic feedback for a dental professional that indicates that the final position of the dental components is reached. However, by setting the amplitude and the surface roughness of the profile so that the dental components will slide against each other to the final position due to the weight of the upper component (in relation to gravitation), the dental assembly can find the mating relationship by itself.

In the different embodiments described above, the configurations of the different parts of the apical and coronal interfaces may be switched between dental components. In other words, the arrangement and/or configuration of the mating surfaces, guiding sections, indexing sections and/or radially facing support surfaces can be formed vice versa on the dental components. For example, the shape of the guiding sections and indexing sections of the coronal interfaces of the apical dental components shown above can be formed at the apical interfaces of the coronal dental components and vice versa.

Claim 1:
A dental component (<NUM>; <NUM>) for assembly to another corresponding dental component, including:
a coronal end, an apical end, and a longitudinal axis (L) extending between the coronal end and the apical end, and an interface, the interface comprising:
at least one indexing section (<NUM>) for rotationally locking the dental component to the other dental component, the indexing section comprising indexing surfaces (<NUM>; <NUM>) extending parallel to the longitudinal axis (L) and
at least one guiding section (<NUM>) for guiding the other dental component about the longitudinal axis towards a next indexing section (<NUM>), the guiding section (<NUM>) including an apically facing or coronally facing guiding surface (<NUM>; <NUM>), wherein the guiding surface (<NUM>; <NUM>) of the at least one guiding section (<NUM>) has two guiding surface portions (353a, 353b; 453a, 453b) and a mounting contact surface (353c; 453c) situated between the two guiding surface portions (353a, 353b; 453a, 453b), wherein the mounting contact surface is parallel to a plane perpendicular to the longitudinal axis (L),
wherein the at least one guiding section and the at least one indexing section alternate about the longitudinal axis (L),
wherein the interface (<NUM>; <NUM>) further comprises a mating surface (<NUM>; <NUM>) for transferring forces in the direction of the longitudinal axis (L) of the dental component, the mating surface facing in the same direction as the guiding surface (<NUM>; <NUM>) and extending about the longitudinal axis (L), and
wherein at least a portion of the mating surface is arranged radially next to the guiding section (<NUM>; <NUM>) and the indexing section (<NUM>), the mating surface (<NUM>; <NUM>) being located outwardly in relation to the guiding and indexing sections and being formed as a ring-shaped surface in a plane perpendicular to the longitudinal axis (L) and extending about said axis.