WO2025176731A1

WO2025176731A1 - A coping, a coping kit, and a method for preparing a fixed denture

Info

Publication number: WO2025176731A1
Application number: PCT/EP2025/054460
Authority: WO
Inventors: Ruben ZIMMERMANN; Boris MARTIN VILLAREJO
Original assignee: Institut Straumann AG
Current assignee: Institut Straumann AG
Priority date: 2024-02-19
Filing date: 2025-02-19
Publication date: 2025-08-28
Anticipated expiration: 2026-08-19

Abstract

Disclosed is a two-piece coping for preparing a fixed, e.g. screwed, denture. The two-piece coping comprises a coping housing and an intermediate insert. The coping housing is hollow and comprises an inner coupling element on its inner surface. The intermediate insert is hollow and comprises an outer coupling element on its outer surface configured to engage with the inner coupling element of the coping housing in order to connect the intermediate insert to the inner surface of the coping housing. The intermediate insert further comprising a seating surface on its inner surface for engagement with a securing element for securing the intermediate insert to a dental implant component. The outer coupling element of the intermediate insert is configured to disengage from the inner coupling element of the coping housing upon a first force being applied to the coping housing.

Description

A COPING, A COPING KIT, AND A METHOD FOR PREPARING A FIXED DENTURE

The present disclosure pertains to the field of restorative dentistry. In particular, the present disclosure relates to a two-piece coping for preparing a fixed denture, a coping kit for preparing a fixed denture, and a method for preparing a fixed denture.

BACKGROUND

A traditional denture is a removable dental appliance that replaces missing teeth and surrounding tissue. It is typically made of acrylic resin and can be either complete or partial, depending on the number of teeth being replaced. A traditional removable dental appliance, such as a denture, is held in the mouth through a combination of suction and the underlying soft tissues and gums. The denture is custom fitted to the individual's mouth and gums, creating a seal that helps hold it in place. Additionally, denture adhesive can be used to improve the stability and retention of the denture.

While such traditional dentures can restore the appearance and function of missing teeth, they have several disadvantages compared to implant borne prostheses. Traditional dentures can be uncomfortable and may slip or shift in the mouth, causing difficulty with speaking and eating. Such shifting or slipping of the denture can occur as, over time, the shape of the gums and underlying bone can change, causing the denture to become loose. Traditional dentures therefore require regular maintenance and adjustment, or replacement. Gum-borne dentures can also accelerate bone loss in the jaw, as these dentures rest on the gums and do not provide the stimulation to the jawbone that natural teeth do. Without this stimulation, the jawbone can begin to resorb, or shrink, leading to bone loss.

In contrast, implant borne prostheses are anchored securely to the jawbone, providing a stable and comfortable fit. They also help to preserve the jawbone by stimulating this in a similar manner to natural teeth, and hence prevent or reduce further bone loss. Overall, implant borne prostheses offer a more permanent and natural-looking solution for replacing missing teeth.

For this reason, many people with traditional dentures may wish to switch to a fixed, implant borne denture. In order to reduce the expenses involved with such a conversion, it is beneficial if the patient’s existing acrylic denture can be adapted for connection to implants, rather than the need to create a new denture.

However, conversion of an existing gum retained dental prosthesis, such as a denture, into a fixed, such as screwed in, dental prosthesis is work-intensive and time consuming and thus an annoyance to the patient. Known conversion procedures may for example require a large number of drilling steps, such as burling of wells in the dental prosthesis for receiving a coping, drilling a pilot hole for a screw channel in the dental prosthesis, step wise drilling for expanding the pilot hole, and pin vice drilling for removing remains from the conversion procedure from the screw channel, to allow for a final fixation of the converted denture to an implant. These drilling procedures may typically be performed in a freehand manner, or by using difficult to use drill guides, which may reduce the precision of the drilling procedures. This may lead to oversized screw channels, which may increase the risk of the dental prosthesis breaking. Known conversion procedures can thus be an annoyance to both a patient and a user of the conversion procedure, such as a dentist.

One example of a known denture conversion system is found in US 11 ,311 ,354. This system comprises a dental coping with an outer surface for permanent bonding to a denture and an inner surface for connection to a dental abutment. The system further comprises a separable screw, with a screw head that is separable from the screw shaft upon application of a predefined force. The separable screw allows the coping to be fastened to the abutment, after which the coping can be bonded to the prosthesis. The prosthesis and coping are then jointly removed from the abutment through the application of a pull-off force that matches or exceeds the predefined force, causing the screw head to separate from the shaft. While this system provides a method of fixing the coping to the prosthesis in correct alignment with the abutment, it does not solve the above-described problem of a complex drilling procedure.

SUMMARY

Accordingly, there is a need for a coping, which mitigates, alleviates, or addresses the shortcomings of existing systems and provides a denture conversion procedure which is easier and less time consuming to use. According to one aspect of the present invention a two-piece coping for preparing a fixed denture is provided. The two-piece coping comprises a coping housing and an intermediate insert. The coping housing is hollow and comprises an inner coupling element on its inner surface. The intermediate insert is hollow and comprises an outer coupling element on its outer surface which is configured to engage with the inner coupling element of the coping housing in order to connect the intermediate insert to the inner surface of the coping housing. The intermediate insert further comprises a seating surface on its inner surface for engagement with a securing element for securing the intermediate insert to a dental implant component. The outer coupling element of the intermediate insert is configured to disengage from the inner coupling element of the coping housing upon a first force being applied to the coping housing.

According to a second aspect of the present invention a coping kit for preparing a fixed denture is provided. The coping kit comprises the two-piece coping according to the first aspect of the present invention and a final insert. The final insert is hollow and comprises a second outer coupling element on its outer surface which is configured to engage with the inner coupling element of the coping housing in order to connect the final insert to the inner surface of the coping housing. The second outer coupling element of the final insert is configured to prevent a disengagement from the coping housing upon the first force being applied to the coping housing. The final insert further comprises a second seating surface on its inner surface for engagement with a securing element for securing the final insert to a dental implant component.

According to a third aspect of the present invention a method for preparing a fixed denture is provided. The method comprises the step of securing a two-piece coping according to the first aspect onto a dental implant component, using a securing element, the outer coupling element of the intermediate insert being engaged with the inner coupling element of the coping housing such that the intermediate insert is connected to the inner surface of the coping housing, and the securing element being engaged with the seating surface of the intermediate insert. The method further comprises the steps of joining a dental prosthesis to the outer surface of the coping housing and subsequently separating the coping housing from the intermediate insert through application of a first force onto the inner coupling element of the coping housing, so that the outer coupling element of the intermediate insert disengages from the inner coupling element of the coping housing. The method preferably comprises the further subsequent step of drilling a hole through the dental prosthesis guided by the coping housing. More preferably, prior to the drilling step, the method comprises the additional step of connecting a drill guide to the coping housing, preferably by engaging an outer coupling element of the drill guide with the inner coupling element of the coping housing, such that during the drilling step the drilling is guided by the drill guide. The method preferably further comprises the steps of removing the drill guide, where used, from the coping housing and removing the intermediate insert and securing element from the dental implant component. The method preferably further comprises the step of connecting a final insert to the inner surface of the coping housing by engaging the second outer coupling element of the final insert with the inner coupling element of the coping housing. The method preferably further comprises the step of securing the dental prosthesis to the dental implant component using a securing element which engages the second seating surface of the final insert. Preferably the same securing element is used to secure both the intermediate insert and final insert to the dental implant component.

The two-piece coping of the present invention is intended for attachment to a dental implant component by means of a securing element. The dental implant component may be a dental implant, abutment, or any other component of a dental implant system that is fixedly placed in the mouth. By placing a dental prosthesis on top of the two-piece coping while this is secured to the dental implant component, the coping housing can be joined to the dental prosthesis in the correct position in one step. Once the dental prosthesis has been fixedly joined to the coping housing, the dental prosthesis together with the coping housing can be separated from the intermediate insert by applying a first force to the coping housing. Because the coping housing is joined to the prosthesis while being secured to the dental implant component, the coping housing is aligned in relation to the dental implant component, which allows an access hole, such as a screw channel, to be drilled into the prosthesis with a high precision. Further, as the seating surface for engagement with the securing element is located in the intermediate insert and not in the coping housing, the access hole can be drilled through the coping housing in a single step without fear of damaging or destroying the seating surface. The final insert comprising a second seating surface can then be connected to the coping housing after the drilling procedure is finished. Hence, the solution of the present invention enables an access hole to be drilled using a single drilling step. The solution disclosed herein thus reduces the workload and the time requirements for converting the denture, which may increase comfort for both the user of the procedure and a patient. Once the coping housing has been separated from the intermediate insert, the inner coupling element of the coping housing can also be used for connecting a drill guide to the coping housing, for assisting with the drilling procedure.

In the following passages, different features of the invention are defined in more detail. Each feature so defined may be combined with any other feature or features unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

The present invention provides a two-piece coping for preparing a fixed denture, such as for converting a traditional, gum retained denture into a fixed, screwed denture, and a kit for producing a fixed, screwed, denture.

A coping can herein be seen as an element that may be placed over a dental implant component, usually an abutment or an implant, in order to connect a dental prosthesis, such as a denture, to the dental implant component.

A fixed denture can herein be seen as a denture which is secured to one or more implant by a securing member, such as a screw, via a coping, the coping being fixedly retained in the denture. Typically, the denture is a full arch denture, and thus replicates the entire upper or lower dentition of a patient, as well as the surrounding soft tissue. However, a denture may also replicate a smaller number of teeth, in which case it may be referred to as a bridge. As the denture replaces several or all of the teeth in a jawbone, this is typically attached to the bone using two or more, usually four, implants. Thus, a fixed denture will typically comprise a plurality of copings and access holes, one for each implant to which the denture should be fixed. The denture can be attached directly to the implant(s) inserted and osseointegrated into the bone, or it can be attached to the implant(s) by way of intermediary component(s), such as abutments, which are screwed, bonded or otherwise fastened to the implant(s).

The two-piece coping according to the first aspect of the present invention comprises a coping housing and an intermediate insert. The intermediate insert can herein be seen as an insert used during preparation of the fixed denture, which is not used for final fixation of the denture to the dental implant component(s). The coping housing is hollow and comprises an inner coupling element on its inner surface. Preferably the coping housing comprises a hollow body extending from a coronal end of the coping housing to an apical end of the coping housing along a central longitudinal axis, the body having an inner surface facing towards the central longitudinal axis and an outer surface facing away from the central longitudinal axis, the inner surface defining a through bore through the coping housing. The intermediate insert is hollow and comprises an outer coupling element, such as a first outer coupling element, on its outer surface which is configured to engage with the inner coupling element of the coping housing to connect the intermediate insert to the inner surface of the coping housing. The intermediate insert further has a seating surface, such as a securing element seating surface, on its inner surface, for engagement with a securing element for securing the intermediate insert to a dental implant component. Preferably the intermediate insert comprises a hollow body extending from a coronal end of the intermediate insert to an apical end of the intermediate insert along a central longitudinal axis, the body having an inner surface facing towards the central longitudinal axis and an outer surface facing away from the central longitudinal axis, the inner surface defining a through bore through the intermediate insert.

In accordance with conventional dental terminology, “apical” refers to the direction towards the bone and “coronal” to the direction towards the occlusal surface of the teeth. Therefore, the apical end of a component is the end which, in use, is directed towards or into the jawbone and the coronal end is that which is directed towards or into the oral cavity.

According to the present invention the outer coupling element of the intermediate insert is configured to engage with the inner coupling element of the coping housing in order to connect the intermediate insert to the inner surface of the coping housing. Preferably, when the outer coupling element is engaged with the inner coupling element, the intermediate insert is connected to the inner surface of the coping housing such that the through bore of the intermediate insert is coaxial with the through bore of the coping housing.

While it is possible for the intermediate insert to be connected to the coping housing such that this extends apically and/or coronally of the coping housing, preferably, when the outer coupling element is engaged with the inner coupling element, the intermediate insert is fully accommodated within the coping housing. In particular, it is preferable that the apical end of the intermediate insert is located coronally of the apical end of the coping housing. In this way, the apical region of the inner surface of the coping housing may form an accommodation chamber for the coronal region of a dental implant component. Additionally, or alternatively, the coronal end of the intermediate insert is preferably located apically of the coronal end of the coping housing. In one preferred embodiment, the inner surface of the coping housing comprises an apically facing, preferably planar, stop surface, the stop surface being arranged to abut the coronal end of the intermediate insert when this is connected to the coping hosing. More generally, in one or more preferred examples, the inner surface of the coping housing comprises an apically facing, preferably planar, stop surface, the stop surface being arranged to abut a coronally facing, preferably planar stop surface of the intermediate insert, when the intermediate insert is connected to the coping housing. The stop surface of the intermediate insert can be formed by, e.g., a flange or other protrusion on the outer surface of the insert, or by the coronal end of the intermediate insert. Such cooperating stop surfaces on the coping housing and intermediate insert define a precise location of the intermediate insert relative to the coping housing, which ensures the seating surface is correctly positioned in the two-piece coping. The stop surfaces may be surfaces arranged in a plane perpendicular to the central longitudinal axis of each component.

In other embodiments, when the outer coupling element of the intermediate insert is engaged with the inner coupling element of the coping housing, the intermediate insert extends apically of the coping housing. In such embodiments it is still preferable that the coronal end of the intermediate insert is located apically of the coronal end of the coping housing, in order to ensure there is no contact between the intermediate insert and the dental prosthesis that will be joined to the coping housing. Having an intermediate insert which extends apically of the coping housing is particularly beneficial when the insert is intended for securing to a dental implant. Dental implants often comprise a blind bore for accommodation of various components, and hence an intermediate insert extending apically of the coping housing may in use be inserted into such a bore in the dental implant. This can help to centre the two-piece coping and/or in some instances the intermediate insert may form a sealing engagement with a dental implant.

In certain embodiments therefore the intermediate insert comprises an apical portion which, when the intermediate insert is connected to the coping housing, extends apically of the coping housing. Preferably the apical portion comprises a section for insertion into a dental implant component, preferably for insertion into a dental implant bore. This section may be cylindrical and/or conical and may provide a guiding and centring function during placement of the two-piece coping on the dental implant component. Preferably the section for insertion comprises a conical surface which tapers radially inwards in the apical direction. In use this conical surface may provide the above guiding and centring function and/or a sealing function with respect to a dental implant component, e.g. a dental implant bore. Additionally or alternatively the apical portion may comprise an abutment surface for engagement with an external surface of a dental implant component. The abutment surface may taper radially outwards in the apical direction, e.g. to form a conical surface or, more preferably, the abutment surface may be an annular, planar surface extending perpendicular to the central longitudinal axis of the intermediate insert. In use the abutment surface engages a complementary surface of the dental implant component in order to provide a sealing engagement between the intermediate insert and the dental implant component.

When the intermediate insert comprises an apical portion which extends apically of the coping housing, the apical region of the inner surface of the coping housing may still form an accommodation chamber for the coronal region of a dental implant component. This is possible when a radial gap exists between the apical region of the inner surface of the coping housing and the outer surface of the intermediate insert. In this way, the apical portion of the intermediate insert may be inserted into the dental implant component, e.g. an implant bore, while the accommodation chamber of the coping housing surrounds the coronal end of the dental implant component.

When the intermediate insert comprises an apical portion which extends apically of the coping housing, the inner surface of the coping housing may still comprise an apically facing, preferably planar, stop surface, the stop surface being arranged to abut a coronally facing, preferably planar stop surface of the intermediate insert when this is connected to the coping housing, as already described above. However, it is alternatively possible that the apical end of the coping housing may comprise an apically facing, preferably planar, stop surface, the stop surface being arranged to abut a coronally facing, preferably planar stop surface of the apical portion of the intermediate insert when this is connected to the coping housing.

The apical portion of the intermediate insert may comprise a soft tissue contact surface, the soft tissue contact surface being located coronal of any section for insertion into a dental implant component and coronal of any abutment surface for engagement with an external surface of a dental implant component. The soft tissue contact surface preferably tapers radially outwards in the coronal direction at a constant or increasing angle and in use can assist in forming an aesthetically pleasing emergence profile within the gingiva. In certain embodiments the soft tissue contact surface is located between a coronally facing, preferably planar stop surface of the apical portion and a section for insertion or an abutment surface of the apical portion.

According to the present invention the intermediate insert comprises a seating surface. The seating surface is located on the inner surface of the intermediate insert for abutting or otherwise engaging with a securing element. The seating surface is preferably a coronally facing seating surface, such as a seating surface being configured to engage a securing element inserted from the coronal end of the intermediate insert. The coronally facing seating surface may be a planar surface perpendicular to the central longitudinal axis of the intermediate insert, thus forming a flat seating surface. Alternatively, it may be a conical surface which tapers radially inwards or outwards in the apical direction. The seating surface may also be formed by a combination of planar and conical surfaces. Preferably the seating surface is a coronally facing conical surface which tapers radially inwards in the apical direction.

Preferably the seating surface of the intermediate insert is formed by a reduction in diameter of the through bore when viewed from the coronal end of the insert. In other words, the seating surface of the intermediate insert is preferably formed by a reduction in the diameter of the inner surface relative to the diameter of the inner surface at the coronal end of the insert. This reduction in diameter may occur at a single axial location, thus forming a flat seating surface in a plane perpendicular to the central longitudinal axis of the insert, or it may occur over an axial length, thus forming a conical seating surface.

According to the present invention, the outer coupling element of the intermediate insert is configured to engage with the inner coupling element of the coping housing in order to connect the intermediate insert to the inner surface of the coping housing. Preferably the outer coupling element is configured to provide an axially fixed connection of the intermediate insert to the coping housing. In other words, when the outer coupling element is engaged with the inner coupling element, the intermediate insert is axially fixed relative to the coping housing. In some embodiments the connection may also provide rotational fixation between the insert and coping housing.

The inner and outer coupling elements may, for example, be configured to engage via a snap fit. For example, the inner coupling element may comprise an annular groove on the inner surface of the coping housing and the outer coupling element may comprise a resilient annular protrusion, or a plurality of radially extending resilient arms, on the outer surface of the intermediate insert for accommodation in the groove, or vice versa. Alternatively, the inner and outer coupling elements may be configured to engage via friction fit, or bayonet fit, or any other connection that connects the intermediate insert to the coping housing.

In preferred embodiments, the outer coupling element of the intermediate insert is an external thread, and the inner coupling element of the coping housing is an internal thread. In this way the insert can be threadedly connected to the coping housing. A threaded engagement between the intermediate insert and the coping housing is preferred as, in comparison to, for example, a snap fit engagement, the coupling elements take up less radial space within the two-piece coping, thus enabling the overall footprint of the two-piece coping to be minimised. In addition, the internal and external thread structure is relatively easy to manufacture and to adapt in order to accurately define the first force necessary to disengage the coupling elements.

According to the present invention, the outer coupling element of the intermediate insert is configured to disengage from the inner coupling element of the coping housing upon a first force being applied to the coping housing. The outer coupling element of the intermediate insert may be configured to disengage from the inner coupling element of the coping housing upon the first force being applied to the coping housing in a coronal direction. This is desired in order to easily separate the coping housing from the intermediate insert when the intermediate insert is secured to a dental implant component and the coping housing is joined to a dental prosthesis. By configuring the outer coupling element to disengage from the inner coupling element at a first coronally applied force, the coping housing can be separated from the intermediate insert without needing access to the securing element once the two-piece coping is attached to a dental implant component. This allows a dental prosthesis to be joined to the outer surface of the coping housing in a manner which covers the coronal end of the coping housing and hence the access to the securing element, while the two-piece coping is arranged on the dental implant component, while still allowing the coping housing to be removed from the dental implant component to provide access for drilling access holes through the dental prosthesis.

The first force may be equal to a disengagement threshold. In other words, the outer coupling element of the intermediate insert may be configured to disengage from the inner coupling element of the coping housing upon the first force meeting a disengagement threshold. In one or more examples, the disengagement threshold is in the range of 20-50 Newton (N), such as in the range of 25-40N, most preferably in the range of 28-35 N.

In embodiments in which the inner and outer coupling elements are cooperating internal and external threads, the external thread of the intermediate insert may have a smaller number of revolutions than the internal thread of the coping housing. By providing the external thread of the intermediate insert with a smaller number of revolutions than the internal thread of the coping housing, the threaded connection may be weakened, so that the intermediate insert disengages from the coping housing at a lower force compared to a threaded connection having a larger number of revolutions. In one or more example two-piece copings, the external thread of the intermediate insert extends one to three revolutions about the outer surface of the insert, where a single revolution is defined as 360° about the central longitudinal axis. The number of revolutions of the external thread may be dependent on the material of the intermediate insert, where a softer material may have more revolutions than a harder material. For example, when the material of the intermediate insert is PEEK, the external thread may extend less than two revolutions, e.g. a single revolution, and when the material of the intermediate insert is POM-C the external thread may extend up to three revolutions.

Additionally or alternatively, the external thread of the intermediate insert may have a smaller thread angle than the internal thread of the coping housing. In the context of the present invention the thread angle of a thread is defined as the angle between the coronally facing thread flank and apically facing thread flank, as measured in an axial plane from the thread root. In other words, the thread angle is measured between the opposing flanks of axially adjacent threads. By reducing the thread angle of the external thread of the intermediate insert in comparison to the internal thread of the coping housing, the external thread of the intermediate insert can be weakened to facilitate disengagement of the intermediate insert from the coping housing. By weakening the external thread, a controlled failure of the thread upon applying a first force onto the threaded connection can be introduced. In one or more example two-piece copings, the external thread of the intermediate insert has a thread angle of 15-30°, such as 20°, and the internal thread of the coping housing has a thread angle of 50-70°, such as 60°.

Additionally or alternatively, the external thread of the intermediate insert may have a smaller thread pitch than the internal thread of the coping housing, the pitch of a thread being defined as the distance between adjacent thread peaks measured parallel to the longitudinal axis of the screw. By making the thread pitch of the external thread of the intermediate insert smaller than the thread pitch of the internal thread of the coping housing, the force required to disengage the coping housing from the intermediate insert can be reduced. In other words, by making the thread pitch of the external thread of the intermediate insert smaller than the thread pitch of the internal thread of the coping housing, the connection between the intermediate insert and the coping housing is weakened, which facilitates disengagement of the intermediate insert and the coping housing. Preferably, in such embodiments, the pitch of the external thread of the intermediate insert lies within the range of 80-90% of the pitch of the internal thread of the coping housing. Additionally or alternatively, the pitch of the external thread of the intermediate insert is between 0.02 and 0.08mm less than the pitch of the internal thread of the coping housing, most preferably approximately 0.05mm less. In a particular example, the thread pitch of the external thread of the intermediate insert may be in the range of 0.23 to 0.27mm, such as 0.25mm and the thread pitch of the internal thread of the coping housing may be 0.3mm.

Additionally or alternatively, the outer diameter of the external thread of the intermediate insert has a smaller dimension than the outer diameter of the internal thread of the coping housing, the outer diameter of both threads being measured relative to the central longitudinal axis of the intermediate insert and coping housing respectively. In this way, the external thread of the intermediate insert can be weakened to facilitate disengagement of the intermediate insert from the coping housing. In one or more example two-piece copings, the outer diameter of the external thread of the intermediate insert is in the range of 0.1 to 0.3 mm, such as 0.2 mm, smaller than the outer diameter of the internal thread of the coping housing. The above paragraphs demonstrate the advantage of forming the outer coupling element and inner coupling element as cooperating threads. Numerous options exist for adjusting the design and dimensions of the threads in order to control the force necessary to disengage the intermediate insert and coping housing. These options can all be used independently or in various combinations.

In certain preferred embodiments, the coping housing is formed of metal, for example titanium, a titanium alloy, such as Ti-6AI-7Nb (TAN), or stainless steel. Preferably the coping housing is formed of TAN. Forming the coping housing from a durable material such as metal is preferred as the coping housing will in use form a part of the fixed denture, and thus must be strong enough to withstand the chewing and other forces that will be transmitted to it during the lifetime of the prosthesis. Alternatively, the coping housing may be formed of another durable biocompatible material, such as ceramics. Preferably the coping housing is a single piece, monobloc component.

The material of the intermediate insert is preferably softer than the material of the coping housing, so that the intermediate insert deforms before the coping housing when the connection between the coping housing and the intermediate insert, such as the inner coupling element and the outer coupling element, is subjected to the first force. In certain preferred embodiments, the intermediate insert is formed of polymer, for example one or more of polyetereterketon (PEEK), polytetrafluoroethylene (PTFE) and polyacetal copolymer (POM-C). Most preferably the intermediate insert is formed of PEEK. Preferably the intermediate insert is a single piece, monobloc component.

In one particularly preferred embodiment the intermediate insert is formed of PEEK, the outer coupling element being an external thread having less than two revolutions, preferably between three-quarters and 1.5 revolutions, and having a thread angle of between 18°-22° and the coping housing is formed of TAN, the inner coupling element being an internal thread having a larger number of revolutions than the external thread, preferably 2 to 3 revolutions, and a thread angle of between 57°- 63°.

In another embodiment the intermediate insert is formed of a polymer, such as PEEK, and is created by overmoulding on the inner surface of the coping housing. Overmoulding is a manufacturing process where a material, such as polymer, is moulded, such as injection moulded, over a surface of another component. In such embodiments, when the inner coupling element of the coping housing is an internal thread, the outer coupling element of the intermediate insert will be an external thread that exactly matches the internal thread. In such embodiments it is the relative softness of the intermediate insert in relation to the coping housing that allows this to disengage upon application of a first force.

In addition to the outer coupling element and seating surface, which may have any of the preferred features previously discussed, the intermediate insert preferably further comprises a retaining member for retaining a securing element, such as a screw, in the intermediate insert. The retaining member is preferably arranged to prevent removal of the securing element in the coronal direction relative to the intermediate insert and may comprise a radially extending protrusion formed on the inner surface of the intermediate insert. For example, the retaining member may comprise an internal thread formed on the inner surface of the intermediate insert and located apical of the seating surface. In use a securing element in the form of a screw can be threaded through the internal thread of the retaining member, after which the retaining member acts to prevent removal of the screw from the intermediate insert in the coronal direction. Alternatively, the retaining member may be a resilient radially extending protrusion located coronal of the seating surface, which the coronal end of a securing element must be pushed past in order to retain this in the insert. Such retaining members may retain a securing element in the intermediate insert during transportation of the intermediate insert, to ensure that the securing element stays in the intermediate insert.

Additionally or alternatively, the intermediate insert may have a drive socket having a non- circular-symmetric cross-section in a plane perpendicular to the central longitudinal axis of the insert. The cross-section may be, for example, polygonal, e.g. square or hexagonal, or it may comprise one or more radially extending groove and/or protrusion, e.g. hexalobular, cross- or star-shaped. The drive socket can be used to transmit torque to the intermediate insert, using a suitable driving tool, and hence is particularly beneficial when the outer coupling element is configured to engage with the inner coupling element of the coping housing via rotational movement, for example a threaded or bayonet connection. Preferably the drive socket is formed at the apical end of the intermediate insert, in order to be easily accessible for the cooperating driving tool. The drive socket is preferably formed in the apical region of the inner surface, also the apical region of the through bore, of the intermediate insert and is located apical of the seating surface. In embodiments in which the intermediate insert also comprises a retaining member, the drive socket may be located apical of the retaining member or it may axially overlap, either partially or totally, with the retaining member. Overlapping the drive socket and retaining member allows the length of the intermediate insert to be kept to a minimum. Preferably the drive socket has a rectangular or hexalobular cross-section.

The coping housing of the present invention preferably comprises, on its outer surface, surfacing structuring for cement retention. For example, the outer surface of the coping housing may comprise radially and/or longitudinally extending grooves and/or ridges. Such surface structuring improves the retention of cement on the outer surface, thus assisting with the joining of the coping housing to a dental prosthesis.

Additionally or alternatively, the apical end region of the coping housing is preferably shaped for sealing engagement with a dental implant component. For example, the apical end of the coping housing may comprise an apically facing planar surface perpendicular to the central longitudinal axis of the coping housing for engagement against a planar surface of a dental implant component. As mentioned above, in certain embodiments the apical region of the inner surface of the coping housing, also the apical region of the through bore, may form an accommodation chamber for the coronal region of a dental implant component. Such an accommodation chamber can be formed both when the apical end of the intermediate insert is located coronally of the apical end of the coping housing or when the intermediate insert comprises an apical portion which extends apically of the coping housing, as discussed above. Preferably, at least a section of the accommodation chamber has an apically facing conical surface which tapers radially inwards in the coronal direction. This conical surface can be arranged for engagement with a complementary conical surface of a dental implant component. In addition, or alternatively, such a conical surface may perform a guiding function, as will be explained further below.

In one or more example two-piece copings, the intermediate insert and the coping housing are pre-assembled. Pre-assembled can herein be seen as the intermediate insert being inserted into the coping housing, or overmoulded within the coping housing, so that the outer coupling element of the intermediate insert engages the inner coupling element of the coping housing.

According to the second aspect of the present invention a coping kit for preparing a fixed denture is provided. The coping kit comprises the two-piece coping disclosed herein, and a final insert. The final insert may be used for final attachment of the dental prosthesis to the dental implant component. The final insert is hollow and comprises an outer coupling element, such as a second outer coupling element, on its outer surface which is configured to engage with the inner coupling element of the coping housing in order to connect the final insert to the inner surface of the coping housing. Preferably the final insert comprises a hollow body extending from a coronal end of the final insert to an apical end of the final insert along a central longitudinal axis, the body having an inner surface facing towards the central longitudinal axis and an outer surface facing away from the central longitudinal axis, the inner surface defining a through bore through the final insert.

The second outer coupling element of the final insert is configured to prevent a disengagement from the coping housing upon the first force being applied to the coping housing. In other words, the final insert is configured to withstand higher forces than the intermediate insert without disengaging from the coping housing. The final insert may be configured to withstand a second force being applied to the coping housing, such as to the coupling elements of the coping housing and the final insert. For example, the second outer coupling element may be configured to withstand at least 100N, preferably at least 150 N, without disengaging from the coping housing. Preferably, the second outer coupling element is configured to withstand a greater force than the joint between the coping housing and the prosthesis. In such embodiments therefore the prosthesis will disengage from the outer surface of the coping housing before the final insert disengages from the coping housing.

To enable the final insert to withstand higher forces than the intermediate insert, the material of the final insert is preferably harder than the material of the intermediate insert. Preferably the final insert is formed of metal, for example titanium, a titanium alloy, such as Ti-6AI-7Nb (TAN), or stainless steel. In a particularly preferred embodiment, the final insert is formed of TAN. Preferably the final insert is a single piece, monobloc component. In one or more example final inserts, it is particularly advantageous that the final insert is formed from the same material as the coping housing. For example, the material of the final insert and coping housing may be TAN.

As discussed above, in preferred embodiments the inner coupling element of the coping housing is an internal thread. In such embodiments, the second outer coupling element of the final insert is preferably an external thread. In this way the final insert can be threadedly connected to the coping housing.

In one or more preferred example final inserts, the external thread of the final insert has a higher number of revolutions than the external thread of the intermediate insert. By providing the final insert with a higher number of revolutions the strength of the threaded connection between the coping housing and the final insert can be increased compared to the threaded connection between the intermediate insert and the coping housing, since more of the internal thread of the coping housing is used for the connection. In preferred embodiments, the external thread of the final insert extends at least two revolutions about the outer surface of the final insert, such as two to three revolutions. In one or more preferred embodiment, the external thread of the final insert has a same number of revolutions as the internal thread of the coping housing. In this way, the whole of the internal thread of the coping housing is used for the connection.

Additionally or alternatively, the external thread of the final insert preferably has the same thread angle as the internal thread of the coping housing. By providing the external thread of the final insert with the same thread angle as the internal thread of the coping housing, the strength of the threaded connection between the coping housing and the final insert can be increased compared to the threaded connection between the intermediate insert and the coping housing. In one or more example final inserts, the external thread of the final insert has a thread angle of 50-70°, such as 60°.

Additionally or alternatively, the external thread of the final insert preferably has the same thread pitch as the internal thread of the coping housing. Providing the external thread of the final insert with the same pitch as the internal thread of the coping housing strengthens the threaded connection between the components. It is particularly beneficial to provide these threads with the same pitch in embodiments in which the final insert is formed of a metal material.

Additionally or alternatively, the outer diameter of the external thread of the final insert preferably has substantially equal dimensions to the outer diameter of the internal thread of the coping housing, the outer diameter of both threads being measured relative to the central longitudinal axis of the final insert and coping housing respectively. In this way, the external thread of the final insert can engage with the internal thread of the coping housing over the full depth of the internal thread, and thus provide a strong connection between the components. By “substantially equal” it is meant within the manufacturing tolerances necessary to ensure the components can be connected together.

In one particularly preferred embodiment the final insert is formed of TAN, the outer coupling element being an external thread having between 2 and 3 revolutions and having a thread angle of between 57°-63°.

According to the present invention, the final insert has a second seating surface on its inner surface for abutting or other engagement with a securing element for securing the final insert to a dental implant component.

The second seating surface of the final insert may have any of the shapes and configurations previously described in relation to the seating surface of the intermediate insert. In particular, the second seating surface is preferably a coronally facing second seating surface, such as a seating surface being configured to engage a securing element inserted from the coronal end of the final insert. The coronally facing second seating surface may be a planar surface perpendicular to the central longitudinal axis of the final insert, thus forming a flat seating surface. Alternatively, it may be a conical surface which tapers radially inwards or outwards in the apical direction. The second seating surface may also be formed by a combination of planar and conical surfaces. Preferably the second seating surface is a coronally facing conical surface which tapers radially inwards in the apical direction.

In the same manner as the intermediate insert, preferably the second seating surface of the final insert is formed by a reduction in diameter of the through bore when viewed from the coronal end of the insert. In other words, the second seating surface of the final insert is preferably formed by a reduction in the diameter of the inner surface relative to the diameter of the inner surface at the coronal end of the insert.

It is particularly preferred that the second seating surface of the final insert corresponds to the seating surface of the intermediate insert, such that the second seating surface and seating surface can engage with the same securing element for securing the intermediate insert and final insert to a dental implant component. This simplifies the use of the system by reducing the number of parts necessary. Preferably the second seating surface has the same shape and dimensions as the seating surface. Preferably both the second seating surface and the seating surface are located at the same axial location within the coping housing when their respective inserts are connected to the coping housing. In alternative embodiments however the second seating surface of the final insert may have a different shape to the seating surface of the intermediate insert in order to enable engagement with a different securing element.

Further preferred features of the final insert may be the same as those described in relation to the intermediate insert.

For example, when the second outer coupling element is engaged with the inner coupling element, the final insert is preferably connected to the inner surface of the coping housing such that the through bore of the final insert is coaxial with the through bore of the coping housing.

Preferably, when the second outer coupling element is engaged with the inner coupling element, the final insert is fully accommodated within the coping housing. In particular, it is preferable that the apical end of the final insert is located coronally of the apical end of the coping housing. In this way, the apical region of the inner surface of the coping housing may form the above-described accommodation chamber for the coronal region of the dental implant component. Additionally, or alternatively, the coronal end of the final insert is preferably located apically of the coronal end of the coping housing. In one preferred embodiment, the inner surface of the coping housing comprises an apically facing, preferably planar, stop surface, the stop surface being arranged to abut a coronally facing, preferably planar stop surface of the final insert when this is connected to the coping hosing. The final insert stop surface can be formed by, e.g., a flange or other protrusion on the outer surface of the insert, or by the coronal end of the final insert.

In other embodiments, when the second outer coupling element of the final insert is engaged with the inner coupling element of the coping housing, the final insert extends apically of the coping housing. In such embodiments it is still preferable that the coronal end of the final insert is located apically of the coronal end of the coping housing.

In certain embodiments the final insert comprises an apical portion which, when the final insert is connected to the coping housing, extends apically of the coping housing. This apical portion can have any of the features described above in relation to the apical portion of the intermediate insert, either in isolation or in combination.

It is preferable that when the intermediate insert comprises an apical portion which, when the intermediate insert is connected to the coping housing, extends apically of the coping housing, the final insert of the coping kit also comprises such an apical portion. While it is not necessary for the apical portions of the intermediate and final insert to be identical in design, it is preferable that parts of the apical portion intended to contact the dental implant component, e.g. the abutment surface, have the same design in both the intermediate and final inserts in order to ensure correct seating and sealing of the two piece coping and hence also the dental prosthesis. Further, when the intermediate insert comprises a soft tissue contact surface it is preferable that the final insert comprises a soft tissue contact surface having the same height, i.e. extension along the central longitudinal axis, and more preferably also the same shape as the soft tissue contact surface of the intermediate insert. This ensures correct placement of the dental prosthesis once the final insert is connected to the coping housing. For ease of design and manufacturing, the apical portion of the intermediate insert and apical portion of the final insert may be, within the limits of manufacturing tolerances, identical.

Additionally or alternatively, the final insert preferably comprises a drive socket having a non-circular-symmetric cross-section in a plane perpendicular to the central longitudinal axis of the insert. The drive socket may have any of the shapes discussed above in relation to the intermediate insert. Preferably the drive sockets of the final insert and intermediate insert have substantially identical cross-sections such that these can cooperate with the same driving tool in order to provide torque to both inserts. The drive socket is preferably formed in the apical region of the inner surface, also the apical region of the through bore, of the final insert and is located apical of the second seating surface.

In preferred embodiments of the coping kit of the present invention, the axial length of the intermediate coping and the final coping are substantially equal. This eases the design of the coping kit.

In certain embodiments, the final insert may comprise a guide portion located at the coronal end of the final insert and coronally of the second outer coupling element. Such a coronally located guide portion assists with the insertion of the final insert into the coping housing. The outer surface of the guide portion may be cylindrical or conical. Preferably the outer surface of the guide portion is cylindrical. It is also possible for the intermediate insert to have such a guide portion. However, it is preferable that any guide portion present at the coronal end of the intermediate insert has a shorter axial length than the guide portion of the final insert. This eases removal of the intermediate insert from the coping housing during the step of separating the coping housing from the intermediate insert after joining of the dental prosthesis.

In contrast to the intermediate insert however, it is preferred that in certain embodiments the final insert does not comprise a retaining member for retaining a securing element, such as a screw, in the final insert. In other words, the inner surface of the final insert is free from protrusions and other structures which would prevent removal of the securing element in the coronal direction relative to the final insert. This is because, when used according to the method of the present invention, the securing element will only be introduced into the final insert upon fixation of the prosthesis to the dental implant component(s). There is therefore no need for the final insert to retain the securing element and indeed any retaining member may interfere with the insertion of the securing element through the final insert.

The coping kit of the present invention comprises an intermediate insert, coping housing and final insert, as discussed above. In preferred embodiments, the coping kit further comprises a drill guide. The drill guide comprises a hollow shaft extending from a coronal end of the drill guide to an apical end of the drill guide along a central longitudinal axis, the drill guide having an inner surface facing towards the central longitudinal axis and an outer surface facing away from the central longitudinal axis, the inner surface defining a through bore through the drill guide. The coronal end region of the drill guide is configured for insertion into the apical end of the through bore of the coping housing, wherein, when the coronal end region of the drill guide is housed within the through bore of the coping housing, the through bore of the drill guide is coaxial with the through bore of the coping housing. In this manner, the drill guide can be used to receive and guide a drill along the longitudinal axis of the coping housing for drilling a hole through a dental prosthesis.

The through bore of the drill guide may have the same or a smaller diameter than the diameter of the coronal end of the through bore of the coping housing. In this way the guided drill will not damage the coping housing.

The drill guide preferably comprises an outer coupling element on its outer surface configured to engage with the inner coupling element of the coping housing. In this way the drill guide can be easily and securely fastened to the coping housing during the drilling step. This greatly improves the ease and precision of the drilling step. In embodiments in which the inner coupling element of the coping housing is an internal thread, it is preferred that the outer coupling element of the drill guide is an external thread configured to engage with the internal thread of the coping housing. The external thread of the drill guide may for example correspond to the external thread of the final insert. In other embodiments however the drill guide may be fastened to the coping housing via a snap fit, friction fit, bayonet or other connection.

In certain preferred embodiments, discussed above, the apical region of the through bore of the coping housing forms an accommodation chamber, at least a section of the accommodation chamber having an apically facing conical surface which tapers radially inwards in the coronal direction. In such embodiments, it is preferred that the outer surface of the drill guide comprises, in the coronal end region, a complementary conical surface arranged for engagement with the conical surface of the accommodation chamber when the coronal end region of the drill guide is housed within the through bore of the coping housing. In this way, the conical surface of the coping housing acts as a guide surface during insertion of the drill guide to ensure centring of the drill guide relative to the through bore of the coping housing. These features improve the accuracy of the drilled access hole.

Additionally or alternatively, the drill guide may comprise a guide portion located at the coronal end of the drill guide. In embodiments in which the drill guide comprises the above described outer coupling element, for example an external thread, the guide portion is located coronally of the outer coupling element. Such a coronally located guide portion assists with the insertion of the drill guide into the coping housing. The outer surface of the guide portion may be cylindrical or conical. Preferably the outer surface of the guide portion is cylindrical.

In one or more example coping kits, the coping kit comprises a drill for drilling the hole through the dental prosthesis using the drill guide. The outer diameter of the drill in such embodiments is substantially equal, i.e. taking into account manufacturing tolerances, to the inner diameter of the through bore of the drill guide.

In one or more example coping kits, the coping housing is pre-assembled with the intermediate insert.

In one or more example coping kits, the coping kit comprises a securing element for securing the intermediate insert and/or the final insert to a dental implant component. The securing element preferably comprises a stop surface configured for engagement, such as abutment, with the seating surface of the intermediate insert and/or the second seating surface of the final insert for securing one or both of these inserts to a dental implant component. In other words, the stop surface is preferably complementary to the seating surface of the intermediate insert and/or the second seating surface of the final insert. In certain preferred embodiments therefore the stop surface is preferably an apically facing stop surface complementary to the coronally facing seating surface of the intermediate insert and/or the coronally facing second seating surface of the final insert. Depending on the configuration of the seating surface of the intermediate insert and/or the second seating surface of the final insert, the stop surface may be a planar surface perpendicular to the central longitudinal axis of the securing element, thus forming a flat stop surface. Alternatively, it may be a conical surface which tapers radially inwards or outwards in the apical direction. The stop surface may also be formed by a combination of planar and conical surfaces. Preferably, the stop surface is an apically facing conical surface which tapers radially inwards in the apical direction. In preferred embodiments, the stop surface of the securing element is configured for engagement with both the seating surface of the intermediate insert and the second seating surface of the final insert for securing both of these inserts to a dental implant component.

The securing element preferably comprises a shaft extending along a central longitudinal axis from a coronal end to an apical end. The stop surface of the securing element may be formed by an increase in diameter of the shaft, where the coronal end of the securing element is wider than the apical end of the securing element. The stop surface may be a flat or conical outer surface of the securing element, such as a surface tapering outward towards the coronal end of the securing element.

In one or more example securing elements, the securing element is a screw, such as an occlusal screw. The screw preferably comprises an external thread configured to be threaded into a corresponding internal thread of the dental implant component. The securing element may be configured to be inserted into the intermediate insert and/or the final insert from a coronal end of the respective insert. The thread of the screw may be arranged on an apical part of the screw. BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present disclosure will become readily apparent to those skilled in the art by the following detailed description of exemplary embodiments thereof with reference to the attached drawings, in which:

Fig. 1 illustrates an example two-piece coping comprising a coping housing and an intermediate insert according to the first aspect of the present invention,

Fig. 1A illustrates the example coping housing of Fig. 1 in an unconnected state, such as without the intermediate insert being connected to the coping housing,

Figs. 2A-2C illustrate further views of the intermediate insert according to Fig. 1 ,

Figs. 3A-3C illustrate an example final insert which can be used with the two-piece coping of Fig. 1 to form a preferred embodiment of a coping kit according to the second aspect of the present invention,

Fig. 4A illustrates an example drill guide of a preferred embodiment of a coping kit according to this disclosure,

Fig. 4B illustrates an example driving tool of a preferred embodiment of a coping kit according to this disclosure,

Fig. 40 illustrates an example drill of a preferred embodiment of a coping kit according to this disclosure,

Fig. 5 is a flow chart illustrating an example method for preparing a fixed denture according to a preferred embodiment of the third aspect of the present invention, Fig. 6 illustrates an example step of securing the two-piece coping of Fig. 1 onto a dental abutment according to this disclosure,

Fig. 7 illustrates an example step of joining a dental prosthesis to a coping housing according to this disclosure,

Fig. 8 illustrates an example step of separating the coping housing of the two-piece coping from the intermediate insert according to this disclosure,

Fig. 9A-9B illustrates an example step of arranging the drill guide of Fig. 4A in the coping housing according to this disclosure,

Fig. 10 illustrates an example step of drilling a hole through a dental prosthesis guided by the drill guide according to this disclosure,

Fig. 11 illustrates an example step of removing the intermediate insert from the dental abutment according to this disclosure, Fig. 12 illustrates an example step of arranging the final insert in the coping housing according to this disclosure,

Fig. 13 illustrates an example step of securing the dental prosthesis to the dental abutment using the final insert according to this disclosure,

Fig. 14 illustrates a second example two piece-coping comprising a coping housing and an intermediate insert according to the first aspect of the present invention arranged on a tissue-level implant,

Figs. 15A-15C illustrate further views of the intermediate insert of FIG. 14 shown in isolation,

Figs. 16A-16B illustrate further views of the coping housing of Fig. 14 in an unconnected state, such as without the intermediate insert being connected to the coping housing, Figs. 17A-17C illustrate a second example final insert which can be used with the two- piece coping of Fig. 14 to form a second preferred embodiment of a coping kit according to the second aspect of the present invention,

Fig. 18 illustrates a third example two piece-coping comprising a coping housing and an intermediate insert according to the first aspect of the present invention arranged on a bone-level implant,

Figs. 19A-19C illustrate further views of the intermediate insert of Fig. 18 in isolation,

Figs. 20A-20B illustrate further views of the coping housing of Fig. 18 in isolation,

Figs. 21A-21C illustrate a third example final insert which can be used with the two-piece coping of Fig. 18 to form a third preferred embodiment of a coping kit according to the second aspect of the present invention,

Figs. 22A-22B illustrate a drill guide for use with the coping housing of Figs. 16A-16B, and Fig. 23 illustrates a drill guide for use with the coping housing of Figs. 20A-20B.

DETAILED DESCRIPTION

Various exemplary embodiments and details are described hereinafter, with reference to the figures when relevant. It should be noted that the figures may or may not be drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the disclosure or as a limitation on the scope of the disclosure. In addition, an illustrated embodiment need not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated, or if not so explicitly described.

The figures are schematic and simplified for clarity, and they merely show details which aid understanding the disclosure, while other details have been left out. Throughout, the same reference numerals are used for identical or corresponding parts.

Fig. 1 illustrates a cross-section view of an example two-piece coping 1 according to a preferred embodiment of the first aspect of the present invention, comprising a coping housing 10 and an intermediate insert 20. The coping housing 10 comprises a hollow body 10A extending from a coronal end 11 of the housing 10 to an apical end 12 of the housing 10 along a central longitudinal axis X . The body 10A has an inner surface 14 facing towards the central longitudinal axis XM and an outer surface 17 facing away from the central longitudinal axis XM, the inner surface 14 defining a through bore 18 through the coping housing 10. The through bore 18 of the coping housing 10 may be wider towards the apical end 12 than towards the coronal end 11 , to allow the intermediate insert 20 to be inserted into the coping housing 10 from the apical end 12. The apical end 12 of coping housing 10 is shaped for sealing engagement with a dental implant component, such as a dental implant or a dental abutment arranged on a dental implant, and the coronal end 11 is configured to face a dental prosthesis. The coping housing 10 comprises an inner coupling element 13 on its inner surface 14.

The intermediate insert 20 comprises a hollow body 20A extending from a coronal end 21 of the insert to an apical end 22 of the insert along a central longitudinal axis XL. The body 20A has an inner surface 24 facing towards the central longitudinal axis XL and an outer surface 27 facing away from the central longitudinal axis XL, the inner surface 24 defining a through bore 28 through the intermediate insert 20. The apical end 22 is configured in use to face a dental implant component such as a dental implant or a dental abutment arranged on a dental implant, and the coronal end 21 is configured in use to face a dental prosthesis. The intermediate insert 20 comprises an outer coupling element 23 on its outer surface 27. The outer coupling element 23 of the intermediate insert 20 is configured to engage with the inner coupling element 13 of the coping housing 10 in order to connect the intermediate insert 20 to the inner surface 14 of the coping housing 10. Fig. 1 illustrates the intermediate insert 20 in its connected position within the coping housing 10, with the outer coupling element 23 engaged with the inner coupling element 13. In this connected position, the through bore 28 of the intermediate insert 20 is coaxial with the through bore 18 of the coping housing 10 and the central longitudinal axis XM of the coping housing 10 is coaxial with the central longitudinal axis XL of the intermediate insert 20. Further, in this connected position, the intermediate insert 20 is fully accommodated within the coping housing 10. The apical end 22 of the intermediate insert 20 is located coronally of the apical end 12 of the coping housing 10 so that an accommodation chamber 150 is formed in the apical region of the inner surface 14, also the apical region of the through bore 18, of the coping housing 10. This accommodation chamber 150 is configured for accommodating the coronal region of a dental implant component (see, e.g. Fig. 7). A section of the accommodation chamber 150 has an apically facing conical surface 19 which tapers radially inwards in the coronal direction.

The coronal end 21 of the intermediate insert 20 is located apically of the coronal end 11 of the coping housing 10. The inner surface 14 of the coping housing 10 comprises an apically facing planar stop surface 160, the stop surface 160 being arranged to abut the coronal end 21 of the intermediate insert 20 when this is in its connected position. The stop surface 160 defines a precise axial location of the intermediate insert 20 relative to the coping housing 10.

In the example intermediate insert 20 of Fig. 1, the intermediate insert 20 has a seating surface 25 on its inner surface 24 for engagement with a securing element for securing the intermediate insert 20 to a dental implant component, e.g. an abutment. The seating surface 25 is a coronally facing seating surface configured to engage a securing element inserted from the coronal end 21 of the intermediate insert 20. The seating surface 25 is formed by a reduction in diameter of the through bore 28 of the intermediate insert 20, where the diameter of the through bore 28 at the coronal end of the seating surface 25 is wider than the diameter of the through bore 28 at the apical end of the seating surface 25. The seating surface 25 being wider at the coronal end than at the apical end can herein be seen as a diameter Die of the coronal end 21 being wider than a diameter DIA of the apical end 22. In other words, the seating surface 25 is a coronally facing conical surface which tapers radially inwards in the apical direction. The outer coupling element 23 of the intermediate insert 20 is configured to disengage from the inner coupling element 13 of the coping housing 10 upon a first force being applied to the coping housing 10 in a coronal direction, for example along the main axis XM.

Fig. 1A illustrates the example coping housing 10 of Fig. 1 in an unconnected state, such as in a state where no insert, such as neither the intermediate insert 20 nor the final insert 30, is connected to the coping housing 10. In the example coping housing 10 of Fig. 1A, the inner coupling element 13 is an internal thread 13A. The internal thread 13A of the coping housing 10 may have a thread angle a_Ch. The thread angle a of a thread is defined as the angle between a coronally facing thread flank, such as thread flank 13B of the thread 13A, and an apically facing thread flank, such as thread flank 13C of the thread 13A, as measured in an axial plane from the thread root. In other words, the thread angle a is measured between the opposing flanks of axially adjacent threads. The thread angle a_Ch may be in the range of 50-70°, such as 60°. As can be seen in Fig. 1A, the coping housing 10 is hollow, and comprises a through bore 18 defined by inner surface 14.

Fig. 2A to 2C illustrate further details of the intermediate insert 20 of Fig. 1. Fig. 2A shows a side view of the example intermediate insert 20. In the example intermediate insert 20 of Figs. 2A-2C, the outer coupling element 23, which may herein be referred to as a first outer coupling element, is an external thread 23A configured to engage the inner coupling element (not shown in Figs. 2A-2C), such as an internal thread, of the coping housing. In the example intermediate insert 20, the external thread 23A of the intermediate insert 20 has a smaller number of revolutions than a corresponding internal thread of the coping housing. By providing the external thread 23A of the intermediate insert 20 with a smaller number of revolutions than the internal thread of the coping housing, the threaded connection may be weakened, so that the intermediate insert 20 disengages from the coping housing when a first force acts on the external thread 23A. In this example, the external thread 23A of the intermediate insert 20 covers less than two revolutions. The intermediate insert 20 may for example disengage from the coping housing 10, by the external thread 23A flexing and/or collapsing, so that the external thread 23A disengages from the internal thread of the coping housing.

The external thread 23A of the example intermediate insert 20 has a thread angle Ou smaller than the thread angle a_Ch of an internal thread of the coping housing, and/or an external thread a_fi of the final insert. The thread angle Ou of the thread 23A is defined as the angle between the coronally facing thread flank 23B and the apically facing thread flank 23C as measured in an axial plane from the thread root. The thread angle Ou may be in the range of 15-30°, such as 20°. The thread angle a_Ch of the internal thread of the coping housing may herein be in the range of 50-70°, such as 60°.

Fig. 2B shows a longitudinal cross section view through the centre of the example intermediate insert 20, seen in a direction perpendicular to the central longitudinal axis XL. As can be seen in Fig. 2B, the intermediate insert 20 is hollow, and comprises a through bore 28 defined by inner surface 24.

The example intermediate insert 20 comprises a retaining member 26 for retaining a securing element, such as a screw, in the intermediate insert 20. In the example intermediate insert 20 the retaining member 26 comprises an internal thread formed on the inner surface 24 and located apical of the seating surface 25. In use a securing element in the form of a screw can be threaded through the internal thread of the retaining member 26, after which the retaining member 26 acts to prevent removal of the screw from the intermediate insert 20 in the coronal direction. By engaging with the securing element, the retaining member 26 retains the securing element in the intermediate insert 20 during transportation of the intermediate insert 20, to ensure that the securing element stays in place in the intermediate insert 20. This eases placement and connection of the two-piece coping 1 to a dental implant component by the user.

Fig. 2C shows a view of the apical end 22 of the example intermediate insert 20 seen along the central longitudinal axis Xi_ of the intermediate insert 20. The intermediate insert 20 comprises a drive socket 290 having a non-circular-symmetric cross-section, in this case rectangular, in a plane perpendicular to the central longitudinal axis XL of the intermediate insert 20. The drive socket 290 can be used to transmit torque to the intermediate insert 20, using a suitable driving tool, in order to engage the external thread 23A of the intermediate insert 20 with the internal thread of the coping housing 10. The driving tool may be part of the coping kit as disclosed herein and is shown in Fig. 4B.

The drive socket 290 is formed in the apical region of the inner surface 24, also the apical region of the through bore 28, of the intermediate insert 20 and is located apical of the seating surface 25. In this example intermediate insert 20, the drive socket 290 totally axially overlaps the retaining member 26 in order to minimise the length of the intermediate insert 20. Figs. 3A to 3C illustrate a final insert 30 according to one or more examples of the current disclosure and which can be used in combination with the two-piece coping 1 of Fig. 1. The final insert 30 is configured to be inserted into the coping housing 10 once the intermediate insert 20 has been removed.

Fig. 3A shows a side view of the example final insert 30. The final insert 30 comprises a hollow body 30A extending from a coronal end 31 of the insert to an apical end 32 of the insert along a central longitudinal axis XN, the body 30A having an inner surface 34 facing towards the central longitudinal axis XN and an outer surface 37 facing away from the central longitudinal axis XN, the inner surface 34 defining a through bore 38 through the final insert 30. The final insert 30 comprises a second outer coupling element 33, on its outer surface 37 which is configured to engage with the inner coupling element 13 of the coping housing 10 in order to connect the final insert 30 to the inner surface 14 of the coping housing 10. In the example final insert 30 of Figs. 3A-3C, the second outer coupling element 33 is an external thread 33A configured to engage an internal thread of the coping housing (not shown in Figs. 3A-3C).

The second outer coupling element 33 of the final insert 30 is configured to prevent a disengagement from the coping housing 10 upon the first force being applied to the coping housing 10. In other words, the final insert 30 is configured to withstand higher forces than the intermediate insert 20 without disengaging from the coping housing 10.

In the example final insert 30 of Fig. 3A-C, the external thread 33A extends more than two revolutions about the outer surface 37 the final insert 30. The external thread 33A of the final insert 30 thus has a larger number of revolutions than the external thread 23A of the intermediate coping 20 (as shown in Fig. 2A-2B). By providing the external thread 33A of the final insert 30 with a larger number of revolutions than the external thread 23A of the intermediate insert 20, the strength of the threaded connection between the coping housing 10 and the final insert 30 can be increased compared to the threaded connection between the intermediate insert 20 of Figs. 2A-2C and the coping housing 10, since a larger part of the internal thread of the coping housing is used for the connection.

In the example final insert 30 shown in Figs. 3A-C, the external thread 33A of the final insert 30 has a thread angle an in the range of 50-70°, such as 60°. The thread angle ctfi corresponds to the thread angle a_Ch of the internal thread of the coping housing 10. By providing the external thread 33A of the final insert 30 with the same thread angle a as the internal thread of the coping housing, such that a_fi = a_Ch, the strength of the threaded connection between the coping housing 10 and the final insert 30 is increased compared to the threaded connection between the example intermediate insert 20 of Fig. 2A-2C and the coping housing 10, for which the thread angles differ.

Fig. 3B shows a longitudinal cross section view through a centre of the example final insert 30, seen in a direction perpendicular to the central longitudinal axis XN. AS can be seen in Fig. 3B, the inner surface 34 of the final insert 30 is similar in configuration to the inner surface 24 of the example intermediate insert 20 of Fig. 2B.

The final insert 30 has a second seating surface 35 on its inner surface 34 for engagement with a securing element for securing the final insert 30 to a dental implant component, such as an abutment. As with the seating surface 25 of the intermediate insert 20, the seating surface 35 of the final insert 30 faces the coronal end 31 of the final insert 30. Thereby, the seating surface 35 can seat a securing element inserted from the coronal end 31 into the hollow final insert 30. The second seating surface 35 of the final insert 30 corresponds to the seating surface 25 of the intermediate insert 20, such that the second seating surface 35 and seating surface 25 can engage with the same securing element for securing the intermediate insert 20 and final insert 30 to a dental implant component. Therefore, in this embodiment the second seating surface 35 is a coronally facing conical surface which tapers radially inwards in the apical direction.

Fig. 3C shows a view of the apical end 32 of the example final insert 30 seen along the main axis XNOf the final insert 30. The final insert 30 comprises a drive socket 390 having a non-circular-symmetric cross-section, in this case rectangular, in a plane perpendicular to the central longitudinal axis XN of the final insert 30. The drive socket 390 has a substantially identical cross-section to the drive socket 290 of the intermediate insert 20, such that the sockets can cooperate with the same driving tool in order to provide torque to both inserts for inserting the intermediate insert 20 and the final insert 30 into the coping housing 10.

In contrast to the example intermediate insert 20, the example final insert 30 does not comprise a retaining member for retaining a securing element, such as a screw, in the final insert. The axial length of the final coping 30 of Figs. 3A-C is substantially equal to the axial length of the intermediate coping 20 of Figs. 2A-C. This eases the design of the coping kit as the final insert 30 can be accommodated in the same region of the coping housing 10 as the intermediate insert 20 (see, e.g. Fig. 13). In particular, when the second outer coupling element 33 is engaged with the inner coupling element 13, the final insert 30 is fully accommodated within the coping housing 10 such that the apical end 32 of the final insert 30 is located coronally of the apical end 12 of the coping housing 10. In this way, accommodation chamber 150 remains free to accommodate the coronal region of the dental implant component. Further, the coronal end 31 of the final insert 30 is located apically of the coronal end 11 of the coping housing 10 such that the apically facing planar stop surface 160 can abut the coronal end 31 of the final insert 30 when this in its connected position.

The example intermediate coping 20 and example final coping 30 are designed such that, when the inserts are connected to the coping housing 10, both the second seating surface 35 and the seating surface 25 are located at the same axial location within the coping housing 10. This is beneficial when it is desired to use the same securing element with both copings.

Figs. 4A-C illustrate various preferred parts of a coping kit according to one or more examples of the second aspect of the present invention. In addition to the coping housing 10 of Fig. 1 , the intermediate insert 20 of Figs. 2A-2C and the final insert 30 of Figs. 3A- 3C, the coping kit may further comprise one or more of a drill guide 40 (Fig. 4A), a driving tool 60 (Fig. 4B) and a drill bit 50 (Fig. 4C).

The drill guide 40 comprises a hollow shaft 40A extending from a coronal end 41 of the drill guide to an apical end 42 of the drill guide along a central longitudinal axis Xo, the drill guide 40 having an inner surface 44 facing towards the central longitudinal axis Xo and an outer surface 47 facing away from the central longitudinal axis Xo, the inner surface 44 defining a through-bore 48, such as a longitudinal through-bore, through the drill guide 40. The through-bore 48 may herein also be referred to a drill chamber. The through-bore 48 is configured to receive the drill bit 50 of Fig. 4C. The inner diameter of the through- bore 48 is substantially equal to the outer diameter of the drill bit 50 and may be in the range of 2-2,5 mm, such as 2,3 mm. The coronal end region 411 of the drill guide 40 is configured for insertion into the apical end of through bore 18 of the coping housing 10, wherein, when the coronal end region 411 of the drill guide 40 is housed within the through bore 18 of the coping housing 10, the through bore 48 of the drill guide 40 is coaxial with the through bore 18 of the coping housing 10 (see, e.g. Fig. 9B).

The drill guide 40 further comprises an outer coupling element 43, such as an external thread, on its outer surface 47 which is configured to engage with the inner coupling element 13 of the coping housing 10. In this way the drill guide 40 can be easily and securely fastened to the coping housing 10 for aligning the drill guide 40 in the coping housing 10. Although the coupling element 43 of the example drill guide 40 is illustrated as an external thread, the coupling element may in one or more example drill guides be a coupling element configured for snap fit, friction fit, bayonet engagement etc.

The outer surface 47 of the drill guide 40 further comprises, in the coronal end region 411 , a complementary conical surface 49 arranged for engagement with the conical surface 19 of the accommodation chamber 150 of the coping housing 10, when the coronal end region 411 of the drill guide is housed within through bore 18 the coping housing 10. In this way, the conical surface 19 of the coping housing 10 acts as a guide surface during insertion of the drill guide 40 to ensure centring of the drill guide 40 relative to the through bore 18 of the coping housing 10. This improves the accuracy of the drilled access hole.

The driving tool 60 comprises a torque transfer member 61 configured to engage the drive socket 290 of the intermediate insert 20 (as shown in Fig. 2C) and the drive socket 390 of the final insert 30 (as shown in Fig. 3C). In one or more alternative driving tools (not shown), the torque transfer member may have an alternative configuration, such as a hexalobular cross-section, for engaging with the drive sockets of the example intermediate and final inserts shown in Fig. 15A-C, 17A-C, 19A-C or 21A-C.

Fig. 5 shows a flow diagram of a preferred embodiment of the method of the third aspect of the present invention. A method 100 for preparing a screwed denture is disclosed. The method 100 for preparing a screwed denture may use the coping kit comprising the two- piece coping 1 and final insert 30 as illustrated in the previous figures. The method 100 may also be performed using a coping kit comprising the intermediate insert 20’, the coping housing 10’, and the final insert 30’ of Figs. 14-17C, or may be performed using a coping kit comprising the intermediate insert 20”, the coping housing 10”, and the final insert 30” of Figs. 18-21C.

The method 100 comprises securing S102 the two-piece coping comprising the coping housing and the intermediate insert onto a dental implant component. In the case of the first example coping kit the dental implant component is an abutment. In the case of the second and third example coping kits the dental implant component is an implant. The two-piece coping may be secured to the dental abutment or other dental implant component by securing the intermediate insert to the dental implant component using a securing element, such as screw, such as an occlusal screw. Thereby the intermediate insert is fixedly arranged to the dental implant component, while the coping housing is secured to the intermediate insert via the inner coupling element of the coping housing and the outer coupling element of the intermediate insert.

The method comprises joining S104 a dental prosthesis to the outer surface of the coping housing. The dental prosthesis may be joined to the coping housing by, e.g. gluing.

The method comprises separating S106 the coping housing from the intermediate insert by applying a first force onto the inner coupling element of the coping housing, so that the outer coupling element of the intermediate insert disengages from the inner coupling element of the coping housing. The first force may be applied by pulling the dental prosthesis, and hence the joined coping housing, in a coronal direction. Since the intermediate insert is secured to the dental implant component, the first force will act on the outer and inner coupling elements and cause the coupling elements to disengage from each other. The disengagement may be caused by the outer coupling element of the intermediate insert deforming and/or breaking. Since the coping housing is joined to the dental prosthesis, the coping housing will remain attached to the dental prosthesis after separating from the intermediate insert. The intermediate insert remains fixedly attached to the dental implant component.

In one or more example methods, the method comprises connecting S108 a drill guide, such as drill guide 40, to the coping housing by engaging an outer coupling element of the drill guide with the inner coupling element of the coping housing. In one or more example methods, such as when the coupling elements are threads, the drill guide is threaded into the coping housing. The drill guide may be arranged in the coping housing by insertion from an apical end of the coping housing. By connecting the drill guide to the coping housing, the drill guide is aligned with the coping housing and thus the dental implant component to which the coping housing was arranged when being joined to the dental prosthesis.

In one or more example methods, the method comprises drilling S110 a hole through the dental prosthesis guided by the drill guide, such as using a drill having an outer diameter corresponding to an inner diameter of the drill guide.

In one or more example methods, the method comprises removing S112 the drill guide from the coping housing. The drill guide may be removed from the coping housing once the hole through the dental prosthesis has been drilled.

In one or more example methods, the method comprises removing S114 the intermediate insert and securing element from the dental implant component. This step may be completed at any point after step S106 and is not related to the steps S108-112 concerning drilling.

In one or more example methods, the method comprises connecting S116 a final insert to the coping housing by engaging a second outer coupling element of the final insert with the inner coupling element of the coping housing.

In one or more example methods, the method comprises securing S118 the dental prosthesis to the dental implant component via the final insert.

Fig. 6 illustrates the step S102 of securing the two-piece coping 1 comprising the coping housing 10 and the intermediate insert 20 onto a dental abutment 70 according to one or more example methods of the current disclosure, such as according to the method disclosed in Fig. 5. The two-piece coping 1 is secured to the dental abutment 70 by securing the intermediate insert 20 to the dental abutment 70 using a securing element 80. The example securing element 80 of Fig. 6 is a screw, such as an occlusal screw, comprising an outer thread 81. The securing element 80 may be screwed into the dental abutment 70, so that the outer thread 81 engages an inner thread 71 of the dental abutment 70. The securing element 80 comprises a stop surface 85 configured for abutting engagement with the seating surface 25 of the intermediate insert 20. Thereby the intermediate insert 20 is fixedly arranged to the dental abutment 70, while the coping housing 10 is secured to the intermediate insert 20 via the inner coupling element 13 of the coping housing 10 and the outer coupling element 23 of the intermediate insert 20. Fig. 7 illustrates the two-piece coping 1 arranged on the dental abutment 70. Here it can be seen that the coronal region of abutment 70 is accommodated in the accommodation chamber 150 of the coping housing 10. Further, an apically facing planar surface 12A perpendicular to the central longitudinal axis of the coping housing 10 and located at the apical end 12 of the coping housing 10 abuts against a planar surface of abutment 70 in order to sealingly engage the coping housing 10 with the abutment 70. Once the two- piece coping 1 has been arranged on the dental abutment 70, a dental prosthesis 90, such as a full arch denture, can be joined to the outer surface 17 of the coping housing 10, for example by gluing. This corresponds to step S104 of the method 100 of Fig. 5. The outer surface 17 of the coping housing 10 comprises a plurality of grooves 170 (as shown in Figs. 9A-B) in order to improve the retention of cement on the outer surface 17. Although only one two-piece coping 1 is shown, a full arch denture will typically be joined to a plurality of such two-piece copings, e.g. four, using the method, coping kit and two- piece copings of the present invention.

Fig. 8 illustrates the step of separating the coping housing 10 from the intermediate insert 20 according to step S106 of method 100 of Fig. 5. Upon a first force F1 being applied onto the coping housing 10 in a coronal direction, the inner coupling element 13 of the coping housing 10 and the outer coupling element 23 of the intermediate insert 20 disengage from each other, for example due to the outer coupling element 23 deforming or breaking. Since the coping housing 10 is joined to the dental prosthesis (not shown in Fig. 8), the coping housing 10 will remain attached to the dental prosthesis after separating from the intermediate insert 20. The intermediate insert 20 remains fixedly attached to the dental abutment 70 via the securing element 80.

Fig. 9A illustrates the step of arranging a drill guide 40 in the coping housing 10 by connecting an outer coupling element 43 of the drill guide 40 with the inner coupling element 13 of the coping housing 10 according to step S108 of method 100 of Fig. 5. When the coupling elements 13, 43 are threads, the drill guide 40 is threaded into the coping housing 10. The drill guide 40 is arranged in the coping housing 10 by inserting the drill guide 40 from an apical end 12 of the coping housing 10. The complementary conical surface 49 in the coronal end region 411 of the drill guide 40 engages during insertion with the conical surface 19 of the accommodation chamber 150 of the coping housing 10. In this way, the conical surface 19 of the coping housing 10 guides the drill guide 40 during insertion to ensure centring of the drill guide 40 relative to the through bore 18 of the coping housing 10.

Fig. 9B illustrates the drill guide 40 arranged in the coping housing 10. When the coronal end region 411 of the drill guide 40 is housed within the through bore 18 of the coping housing 10, the through bore 48 of the drill guide 40 is coaxial with the through bore 18 of the coping housing 10. The through bore 48 of the drill guide 40 has substantially the same diameter as the diameter of the coronal end of the through bore 18 of the coping housing 10. By arranging the drill guide 40 in the coping housing 10, the drill guide 40 is aligned with the coping housing 10 and thus also the dental abutment 70 to which the coping housing 10 was indirectly attached when it was joined to the dental prosthesis 90 in step S104 (Fig. 7). By arranging the drill guide 40 in the coping housing 10 using the outer coupling element 43, the drill guide 40 is secured to the coping housing 10 and hence to the dental prosthesis joined to the coping housing (not shown in Figs. 9A-B). Thereby, no manual holding of the drill guide 40 is required. This facilitates the drilling and ensures that the hole drilled in the dental prosthesis using the drill guide 40 will be aligned with the dental abutment 70 when the dental prosthesis is arranged onto the dental abutment 70.

Fig. 10 illustrates the step of drilling a hole through the dental prosthesis (not shown in Fig. 10) guided by the drill guide 40 according to step S110 of method 100 of Fig. 5. To drill the hole the drill bit 50 is inserted into the drill guide 40. The drill bit 50 has an outer diameter corresponding to the inner diameter of the through bore 48 of drill guide 40 so that the drill bit 50 is radially supported by the drill guide 40 and the through bore 18 of the coping housing 10. The drill bit 50 is then used to drill a hole in the dental prosthesis joined to the outer surface 17 of the coping housing 10. As the coping housing 10 does not comprise a seating surface for the securing element, the hole in the dental prosthesis can be drilled in a single step.

Fig. 11 illustrates the step of removing the intermediate insert 20 from the dental abutment 70 according to step S114 of method 100 of Fig. 5. The intermediate insert 20 is removed by releasing the securing element 80 from the dental abutment 70, such as unscrewing the screw from the inner thread 71 of the dental abutment 70.

Fig. 12 illustrates the step of arranging S116 the final insert 30 in the coping housing 10.

Upon removing the drill guide 40 from the coping housing 10, the final insert 30 can be inserted into the coping housing 10 by using the driving tool 60 of Fig. 4B. The torque transfer member 61 is brought to engagement with the drive socket 390 of the final insert 30. The final insert 30 is then inserted into the coping housing 10 and rotated by the drive tool 60 until the outer coupling element 33 of the final insert 30 engages with the inner coupling element 13 of the coping housing 10 to connect the final insert 30 to the coping housing 10.

Fig. 13 illustrates the step of securing S118 the dental prosthesis 90 to the dental abutment 70 via the final insert 30. The dental prosthesis 90 joined to the coping housing 10 with the connected final insert 30 is positioned on top of the dental abutment 70. The securing element 80 is inserted into the coping housing 10 and the final insert 30 through the hole drilled in the dental prosthesis 90 in step S110 (Fig. 10). The securing element 80 is inserted into the dental abutment 70 and screwed into the dental abutment 70 until the stop surface 85 of the securing element 80 is engaged with the seating surface 35 of the final insert 30 and secures the dental prosthesis 90 to the dental abutment 70. Due to the higher strength of the final insert 30 compared to the intermediate insert 20, the dental prosthesis 90 is safely secured to the dental abutment 70.

Two further example two-piece copings and their respective coping kits shall now be described. In these examples, like features will be referred to by like reference numerals and a detailed description thereof will be omitted to the extent of the overlap with the first example of the invention.

Fig. 14 illustrates a cross-section view of a second example two-piece coping T according to a preferred embodiment of the first aspect of the present invention, comprising a coping housing 10’ and an intermediate insert 20’. Figs. 15A-15C show the intermediate coping 20’ in isolation and Figs. 16A-16B show the coping housing 10’ in isolation.

The two-piece coping T is designed for connection to a dental implant 120, which may be a tissue level dental implant, and is secured to the dental implant 120 by a securing element 80’. The dental implant 120 comprises a coronal end section 121 having a conical end surface 122 and a planar end surface 124. The implant 120 further comprises a blind bore 123 which extends into the dental implant 120 from the coronal end and which comprises an inner thread 125 configured to engage an outer thread 8T of the securing element 80’, to secure the intermediate insert 20’ to the dental implant 120. Fig. 14 illustrates the intermediate insert 20’ in its connected position within the coping housing 10’, with the outer coupling element 23’ engaged with the inner coupling element 13’.

Fig. 15A shows a side view of the example intermediate insert 20’ and Fig. 15B shows a longitudinal cross section view through the centre of the example intermediate insert 20’, seen in a direction perpendicular to the central longitudinal axis XL.

The intermediate insert 20’ comprises a hollow body 20A’ extending from a coronal end 2T of the insert to an apical end 22’ of the insert along a central longitudinal axis XL. The body 20A’ has an inner surface 24’ facing towards the central longitudinal axis XL and an outer surface 27’ facing away from the central longitudinal axis XL, the inner surface 24’ defining a through bore 28’ through the intermediate insert 20’. The intermediate insert 20’ comprises an outer coupling element 23’ on its outer surface 27’ in the form of a thread 23A’.

The intermediate insert 20’ has a seating surface 25’ on its inner surface 24’ for engagement with a securing element 80’ for securing the intermediate insert 20’ to the dental implant 120.

In contrast to the intermediate insert 20 of the first example, intermediate insert 20’ comprises an apical portion 220 which, when the intermediate insert 20’ is connected to the coping housing 10’, extends apically of the coping housing 10’. The apical portion 220 comprises a section 220A for insertion into the dental implant bore 123, this section comprising a conical surface 230 which tapers radially inwards in the apical direction. The conical surface 230 may facilitate correct placement of the insert 20’ on the dental implant 120 by providing a guiding and centring function.

Although intermediate insert 20’ extends apically of the coping housing 10’, an accommodation chamber 150’ is still formed in the apical region of the inner surface 14’, also the apical region of the through bore 18’, of the coping housing 10’. This is possible because a radial gap G exists between the apical region of the inner surface 14’ of the coping housing 10’ and the outer surface 27’ of the intermediate insert 20’. The accommodation chamber 150’ is configured for accommodating the coronal region of dental implant 120 (see Fig. 14), in particular conical end surface 122 and planar end surface 124. A section of the accommodation chamber 150’ has an apically facing conical surface 19’ which tapers radially inwards in the coronal direction and which in use engages a complementary coronally facing surface, namely conical end surface 122, of the implant 120.

The intermediate insert 20’ further comprises a circumferential flange 210 on its outer surface 27’. The circumferential flange 210 defines a coronally facing, planar stop surface 211 which is arranged to abut an apically facing planar stop surface 160’ on the inner surface 14’ of the coping housing 10’. The coronal stop surface 211 of the example intermediate insert 20’ is a surface in a plane perpendicular to the central longitudinal axis of the insert 20’. The stop surfaces 160’, 211 define a precise axial location of the intermediate insert 20’ relative to the coping housing 10’. In this way, the stop surface 211 of intermediate insert 20’ performs the same function as the coronal end 21 of the intermediate insert 20 of the first example.

Intermediate insert 20’ further comprises a cylindrical guide portion 213 located at the coronal end 2T of the insert 20’ and coronally of the outer coupling element 23’. Such a coronally located guide portion 213 assists with the insertion of the intermediate insert 20’ into the coping housing 10’.

Fig. 15C shows a view of the apical end 22’ of the example intermediate insert 20’ seen along the central longitudinal axis XL of the intermediate insert 20’. The intermediate insert 20’ comprises a drive socket 290’ having a non-circular-symmetric cross-section, in this case a hexalobular cross-section 290A’, in a plane perpendicular to the central longitudinal axis XL of the intermediate insert 20’. The intermediate insert 20’ further comprises a retaining member 26’ in the form of an internal thread for retaining a securing element, such as a screw, in the intermediate insert 20’. The retaining member 26’ totally axially overlaps with the drive socket 290’.

Figs. 16A-16B illustrate the coping housing 10’ of the second example in isolation. Fig. 16A shows a side view of the coping housing 10’ and Fig. 16B shows a longitudinal cross section view through the centre of the coping housing 10’.

The coping housing 10’ comprises a hollow body 10A’ extending from a coronal end 1 T of the housing 10’ to an apical end 12’ of the housing 10’ along a central longitudinal axis XM. The body 10A’ has an inner surface 14’ facing towards the central longitudinal axis XM and an outer surface 17’ facing away from the central longitudinal axis XM, the inner surface 14’ defining a through bore 18’ through the coping housing 10’. The coping housing 10’ comprises an inner coupling element 13’ on its inner surface 14’ in the form of a thread 13A’.

In contrast to the coping housing 10 of the first example, the example coping housing 10’ further comprises a lip 16, such as a push-down lip, arranged at the apical end 12’ of the coping housing 10’. The lip 16 may be configured with a radiused undercut in order to hold a rubber damming. The rubber damming may be a rubber damming for isolating and preventing bacterial contamination of a surgical site of the dental implant during arrangement of the dental prosthesis onto the coping housing 10’.

Figs. 17A-17C illustrate an example final insert 30’ configured to be inserted into the coping housing 10’ of Figs. 16A-16B once the intermediate insert 20’ has been removed. Fig. 17A shows a side view of the example final insert 30’, Fig. 17B shows a longitudinal cross section view through the centre of the example final insert 30’, and Fig. 17C shows a view of the apical end 32’ of the example final insert 30’.

The final insert 30’ comprises a hollow body 30A’ extending from the coronal end 3T of the final insert to 30’ the apical end 32’ of the final insert 30’ along the central longitudinal axis XN. The hollow body 30A’ has an inner surface 34’ facing towards the central longitudinal axis XN and an outer surface 37’ facing away from the central longitudinal axis XN. The inner surface 34’ defines a through bore 38’ through the final insert 30’. The final insert 30’ comprises a second outer coupling element 33’ in the form of an external thread 33A’ on its outer surface 37’, which is configured to engage with the inner coupling element 13’ of the coping housing 10’. The inner surface 34’ further comprises a seating surface 35’ for engagement with securing element 80’ for securing the final insert 30’ to the implant 120. The seating surface 35’ corresponds to the seating surface 25’ of the intermediate insert 20’.

In a similar manner to intermediate insert 20’, final insert 30’ comprises an apical portion 320 which, when the final insert 30’ is connected to the coping housing 10’, extends apically of the coping housing 10’. The apical portion 320 comprises a section 320A for insertion into the dental implant bore 123, this section 320A comprising a conical surface 330 which tapers radially inwards in the apical direction. The conical surface 330 may facilitate correct placement of the insert 30’ on the dental implant 120 by providing a guiding and centring function.

Also analogous to intermediate insert 20’, the final insert 30’ further comprises a circumferential flange 310 on its outer surface 37’. The circumferential flange 310 defines a coronally facing planar stop surface 311 which is arranged to abut the apically facing planar stop surface 160’ on the inner surface 14’ of the coping housing 10’. The coronal stop surface 311 of the example final insert 30’ is a surface in a plane perpendicular to the central longitudinal axis XN. The stop surfaces 160’, 311 define a precise axial location of the final insert 30’ relative to the coping housing 10’. In this way, the stop surface 311 of final insert 30’ performs the same function as the coronal end 31 of the final insert 30 of the first example.

The example intermediate coping 20’ and example final coping 30’ are designed such that, when the inserts are connected to the coping housing 10’, both the second seating surface 35’ and the seating surface 25’ are located at the same axial location within the coping housing 10’. Stop surfaces 211 , 311 assist in correctly positioning both inserts 20’, 30’ within the coping housing 10’.

The final insert 30’ is configured to withstand higher forces than the intermediate insert 20’ without disengaging from the coping housing 10’. In the final insert 30’ of the second example, this is achieved in a similar manner to that of the first example, namely the external thread 33A’ has a larger number of revolutions than the external thread 23A’ of the intermediate coping 20’ (as shown in Figs. 15A-15B) and the thread angle of thread 33A’ corresponds to the thread angle a_Ch of the internal thread 13A’ of the coping housing 10’ whereas the thread angle Oh of thread 23A’ is narrower. In addition however, the outer diameter Di of the external thread 23A’ of intermediate insert 20’ has a smaller dimension than the outer diameter De of the internal thread 13A’ of the coping housing 10’, while the outer diameter DF of the external thread 33A’ of the final insert 30’ has substantially equal dimensions to the outer diameter De of the internal thread 13A’. In this way the external thread 33A’ of the final insert 30’ can engage with the internal thread 13A’ of the coping housing 10’ over the full depth of the internal thread 13A’, thus providing a stronger connection between the components than is achieved between the coping housing 10’ and intermediate insert 20’. As shown in Fig. 17C, the apical end 32’ of the example final insert 30’ comprises a drive socket 390’ having the same hexalobular cross-section 390A’ as the drive socket 290’ of intermediate insert 20’. The final insert 30’ further comprises a retaining member 36’ in the form of an internal thread for retaining a securing element, such as a screw, in the final insert 30’.

The example final insert 30’ further comprises a cylindrical guide portion 313 located at the coronal end 3T of the insert 30’ and coronally of the outer coupling element 33’. Such a coronally located guide portion 313 assists with guiding the final insert 30’ into the coping housing 10’. The guide portion 313 may be configured with an outer diameter having a close fit with the inner surface 14’ of the coping housing 10’, such as with the internal thread 13A’ of the coping housing 10’. This facilitates installation of the final insert 30’ by aligning the external threads 33A’ of the final insert 30’ with the internal threads 13A’ of the coping housing 10’. In contrast to the guide portion 213 of the intermediate insert 20’, guide portion 313 has a longer axial length. The shorter axial length of guide portion 213 eases removal of the intermediate insert 20’ during separation step S106.

Fig. 18 illustrates a cross-section view of a third example two-piece coping 1” according to a preferred embodiment of the first aspect of the present invention, comprising a coping housing 10” and an intermediate insert 20”. Figs. 19A-19C show the intermediate coping 20” in isolation and Figs. 20A-20B show the coping housing 10” in isolation.

The two-piece coping 1” is designed for connection to a dental implant 130, which may be a bone level implant, and is secured to the dental implant 130 by a securing element 80”. The dental implant 130 comprises a coronal end section 131 having a conical end surface 132 and a planar end surface 134. The implant 130 further comprises a blind bore 133 which extends into the dental implant 130 from the coronal end and which comprises an inner thread 135 configured to engage an outer thread 81” of the securing element 80” to secure the intermediate insert 20” to the dental implant 130.

Figs. 19A-19C illustrate intermediate insert 20” in isolation, where Fig. 19A shows a side view of the example intermediate insert 20”, Fig. 19B shows a longitudinal cross section view through the centre of the example intermediate insert 20”, and Fig. 19C shows a view of the apical end 22” of the example intermediate insert 20”. The intermediate insert 20” is similar to the intermediate insert 20’ of Figs. 15A-15C, with like reference numerals referring to the same features.

The example intermediate insert 20” of Figs. 19A-19C comprises an apical portion 220” which, when the intermediate insert 20” is connected to the coping housing 10”, extends apically of the coping housing 10”. The apical portion 220” comprises a section 220A” for insertion into the dental implant bore 133, this section comprising a conical surface 230” which tapers radially inwards in the apical direction.

In contrast to the apical portion 220 of intermediate insert 20’, the apical portion 220” of intermediate insert 20” further comprises an annular, planar abutment surface 212 for engagement with the planar end surface 134 of dental implant 130 to provide a sealing engagement between the intermediate insert 20” and the dental implant 130. In other embodiments the abutment surface may taper radially outwards in the apical direction to form a conical surface for engagement with conical end surface 132.

Apical portion 220” of the intermediate insert 20” further comprises a coronally facing planar stop surface 211”. Stop surface 211” is arranged to abut the apical end 12” of the coping housing 10”, as will be described below. The apical portion 220” further comprises a soft tissue contact surface 240, the soft tissue contact surface 240 being located between the coronally facing stop surface 211” and the abutment surface 212. The soft tissue contact surface 240 tapers radially outwards in the coronal direction at increasing angle in order to form a flared shape. In use the soft tissue contact surface 240 may assist in forming an aesthetically pleasing emergence profile within the gingiva.

The soft tissue contact surface 240 has a height HG, such as an extension along the longitudinal axis XL. The height HG may vary depending on one or more of a length of the implant, a height of the gingiva of a patient, and a mounting depth of the implant in relation to a coronal surface of the gingiva of the patient.

Figs. 20A-20B illustrate coping housing 10” in isolation. Fig. 20A shows a side view of the example coping housing 10” and Fig. 20B shows a longitudinal cross section view through the centre of the example coping housing 10”. The coping housing 10” is similar to the coping housing 10’ of Figs. 16A-16B, with like reference numerals referring to the same features. The example coping housing 10” differs from the previous example coping housings 10, 10’ in that it does not comprise an accommodation chamber for accommodating the coronal region of a dental implant component. Instead, the apical end 12” of the coping housing 10” comprises an apically facing planar stop surface 160” perpendicular to the central longitudinal axis XM of the coping housing 10”. The stop surface 160” is arranged to abut the coronally facing planar stop surface 211” of the apical portion 220” of the intermediate insert 20” when this is connected to the coping housing 10”. The stop surfaces 160”, 211” define a precise axial location of the intermediate insert 20” relative to the coping housing 10”. In this way, the stop surface 211” of intermediate insert 20” performs the same function as the coronal end 21 of the intermediate insert 20 of the first example and the stop surface 211 of the intermediate insert 20’ of the second example.

Figs. 21A-21C illustrate an example final insert 30” configured to be used with the two- piece coping 1” to form a third example of a coping kit according to the second aspect of the present invention. Fig. 21 A shows a side view of the example final insert 30”, Fig. 21 B shows a longitudinal cross section view through the centre of the example final insert 30”, and Fig. 21 C shows a view of the apical end 32” of the example final insert 30”.

The final insert 30” is similar to the final insert 30’ of Figs. 17A-17C, with like reference numerals referring to the same features.

In an analogous manner to the intermediate insert 20”, the example final insert 30” comprises an apical portion 320” comprising a section 320A” for insertion into the dental implant bore 133, this section comprising a conical surface 330”. The apical portion 320” also comprises an annular planar abutment surface 312 for enagagement with the planar end surface 134 of the dental implant 130, a coronally facing planar stop surface 311” arranged to abut the apically facing planar stop surface 160” of the coping hosing 10”, and a soft tissue contact surface 340, the soft tissue contact surface 340 being located between the coronally facing stop surface 311” and the abutment surface 312.

The apical portions 220”, 320” of the intermediate 20” and final 30” insert have a substantially identical design. In partcular, the abutment surfaces 212, 312, stop surfaces 211”, 311” and soft tissue contact surfaces 240, 340 have the same design in both the insertmediate insert 20” and final insert 30”. This ensures correct seating and sealing of the two piece coping 1” and hence also the correct position of the dental prosthesis. The apical end 32” of the example final insert 30” comprises a drive socket 390” having the same hexalobular cross-section 390A” as the drive socket 290” of intermediate insert 20”. The example final insert 30” further comprises retaining member 36” in the form of an internal thread for retaining the securing element 80” in the final insert 30”.

Figs. 22A-22B illustrate an example drill guide 40’ configured to be used with the example coping housing 10’ (see Fig. 16A-16B). The example drill guide 40’ of Figs. 22A-22B is similar to the example drill guide 40 of Fig. 4A, with like reference numerals referring to the same features. A detailed description thereof will be omitted to the extent of the overlap with the first example drill guide 40. The coronal end region 41 T of the drill guide 40’ is configured for insertion into the apical end of through bore 18’ of the coping housing 10’ (in the same way as described in e.g. Fig. 9B). The outer surface 47’ of the drill guide 40’ further comprises, in the coronal end region 41 T, a conical surface 49’ arranged for engagement with a complementary part of the inner surface 14’ of the coping housing 10’, when the coronal end region 41 T of the drill guide 40’ is housed within the through bore 18’ of the coping housing 10’.

The example drill guide 40’ of Figs. 22A-22B differs from the example drill guide 40 of Fig. 4A in that the drill guide 40’ comprises a cylindrical guide portion 412 located at the coronal end 4T of the drill guide 40’, coronal of the outer coupling element 43’. Such a guide portion 412 assists with the insertion of the drill guide 40’ into the coping housing 10’. The guide surface 412 may be configured with an outer diameter having a close fit with the inner diameter of the coping housing 10’, such as of the internal thread 13A’ of the coping housing 10’. This facilitates installation of the example drill guide 40’ by aligning the external threads 43A’ of the drill guide 40’ with the internal threads 13A’ of the coping housing 10’.

In addition the hollow shaft 40A’ comprises an evacuation hole 45 for evacuating removed material from the longitudinal through-bore 48’ during a drilling procedure. The example drill guide 40’ of Figs. 22A-22B further comprises a knurling 413. The knurling provides enhanced friction of the outer surface 47’ which improves the grip during handling, such as during screwing or unscrewing the drill guide 40’ in the coping housing 10’. Due to the rotational motion of the drill during drilling, the drill guide might tighten itself onto the coping housing 10’. This may lead to the drill guide 40’ not being able to be unscrewed by hand anymore. The example drill guide 40’ may thus comprise a release aid in the form of a second through-hole 46 extending through the drill guide 40’ perpendicular to the longitudinal through-bore 48’. The release aid provides a seat for a bar, which bar can be inserted into the second through-hole 46, to provide a lever for increasing the torque applied to the drill guide 40’ for unscrewing it from the coping housing 10’.

Fig. 23 discloses an example drill guide 40” configured to be used with the example coping housing 10” (see Figs. 20A-20B) of the third example. The drill guide 40” corresponds to the example drill guide 40’ of Figs. 22A-22B apart from that the coronal end region 411” does not comprise a complementary conical surface 49’ configured to be engaged with the inner surface 14” of the coping housing 10”. Instead an annular planar stop surface 490 is provided for engagement with the stop surface 160” at the apical end 12” of the coping housing 10”.

It shall be noted that the features mentioned in the embodiments described in Figs. 1-4 are not restricted to these specific embodiments. Any features relating to the coping kit and the components comprised therein and mentioned in relation to the coping housing, the intermediate insert, and the final insert of Figs. 1-3C, such as dimensions or shapes of the coping housing, the intermediate insert, and the final insert, are thus also applicable to the coping housing, the intermediate insert, and the final insert described in relation to Figs. 6-13, Figs. 14-17C, and Figs. 18-21C. Any features relating to the drill guide of Figs. 22A-22B are also applicable to the drill guides of Figs. 4A and Fig. 23, apart from the coronal end regions which are specific to the corresponding coping housing.

It shall further be noted that the method 100 of Fig. 5 and the workflow described in Figs. 6 - 13 can also be performed with the intermediate inserts, the final inserts, the coping housings, and/or the drill guides described in Figs. 14-23.

It shall further be noted that a central longitudinal axis, when referred to herein, relates to an imaginary line running from an apical end to a coronal end of a component, such as the coping housing, the intermediate insert, the final insert, the drill guide, and the dental abutment, and through its centre of gravity.

The above embodiments are described by way of example only and other variations are possible which fall within the scope of the claims. For example, the seating surfaces of the intermediate insert and final insert may be planar rather than conical. Further the seating surface of the intermediate insert and final insert may differ from one another, in order to engage with different securing elements. Inner and outer coupling elements other than threads may be used, for example cooperating snap fit elements.

The use of the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. does not imply any particular order, but are included to identify individual elements. Moreover, the use of the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. does not denote any order or importance, but rather the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. are used to distinguish one element from another. Note that the words “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. are used here and elsewhere for labelling purposes only and are not intended to denote any specific spatial or temporal ordering. Furthermore, the labelling of a first element does not imply the presence of a second element and vice versa.

It is to be noted that the word "comprising" does not necessarily exclude the presence of other elements or steps than those listed.

It is to be noted that the words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements.

Although features have been shown and described, it will be understood that they are not intended to limit the claimed disclosure, and it will be made obvious to those skilled in the art that various changes and modifications may be made without departing from the scope of the claimed disclosure. The specification and drawings are, accordingly to be regarded in an illustrative rather than restrictive sense. The claimed disclosure is intended to cover all alternatives, modifications, and equivalents.

Claims

1. A two-piece coping for preparing a fixed denture, the two-piece coping comprising: a coping housing and an intermediate insert, the coping housing being hollow and comprising an inner coupling element on its inner surface, and the intermediate insert being hollow and comprising an outer coupling element on its outer surface, the outer coupling element being configured to engage with the inner coupling element of the coping housing in order to connect the intermediate insert to the inner surface of the coping housing, the intermediate insert further comprising a seating surface on its inner surface for engagement with a securing element for securing the intermediate insert to a dental implant component, wherein the outer coupling element of the intermediate insert is configured to disengage from the inner coupling element of the coping housing upon a first force being applied to the coping housing.

2. The two-piece coping of claim 1 , wherein the outer coupling element of the intermediate insert is an external thread and the inner coupling element of the coping housing is an internal thread.

3. The two-piece coping of claim 2, wherein the external thread of the intermediate insert has a smaller number of revolutions than the internal thread of the coping housing.

4. The two-piece coping of claim 2 or 3, wherein the external thread of the intermediate insert has a smaller thread angle than the internal thread of the coping housing.

5. The two-piece coping of claim 4, wherein the external thread of the intermediate insert has a thread angle of 15-30° and the internal thread of the coping housing has a thread angle of 50-70°.

6. The two-piece coping of any of the previous claims, wherein the intermediate insert formed of polymer, preferably one of polyetereterketon (PEEK), polytetrafluoroethylene (PTFE) and polyacetal copolymer, POM-C.

7. The two-piece coping of any of the previous claims, wherein the coping housing is formed of metal, preferably TAN.

8. A coping kit for preparing a fixed denture, the coping kit comprising:

- a two-piece coping according to any one of claims 1-7; and a final insert, the final insert being hollow and comprising a second outer coupling element on its outer surface, the second outer coupling element being configured to engage with the inner coupling element of the coping housing in order to connect the final insert to the inner surface of the coping housing, the second outer coupling element of the final insert being further configured to prevent a disengagement from the coping housing upon the first force being applied to the coping housing, wherein the final insert further comprises a second seating surface on its inner surface for engagement with a securing element for securing the final insert to a dental implant component.

9. The coping kit of claim 8, wherein the final insert is formed of metal, preferably TAN.

10. The coping kit of any one of the claims 8 to 9, when dependent upon claim 2, wherein the second outer coupling element of the final insert is an external thread.

11. The coping kit of claim 10, wherein the external thread of the final insert has a higher number of revolutions than the external thread of the intermediate insert.

12. The coping kit of any one of claims 10 to 11, wherein the external thread of the final insert has the same thread angle as the internal thread of the coping housing.

13. The coping kit according to any one of the claims 8 to 12, wherein the kit further comprises a drill guide comprising a hollow shaft extending from a coronal end of the drill guide to an apical end of the drill guide along a central longitudinal axis, the drill guide having an inner surface facing towards the central longitudinal axis and an outer surface facing away from the central longitudinal axis, the inner surface defining a through bore through the drill guide, the drill guide comprising an outer coupling element on its outer surface configured to engage with the inner coupling element of the coping housing.

14. The coping kit according to any one of claims 8 to 13, wherein the coping kit further comprises a securing element for securing the intermediate insert and/or the final insert to a dental implant component, the securing element comprising a stop surface configured for engagement with the seating surface of the intermediate insert and/or the second seating surface of the final insert.

15. A method for preparing a fixed denture, the method comprising the steps of:

- securing (S102) a two-piece coping according to any one of the claims 1-7 onto a dental implant component using a securing element, the outer coupling element of the intermediate insert being engaged with the inner coupling element of the coping housing such that the intermediate insert is connected to the inner surface of the coping housing and the securing element being engaged with the seating surface of the intermediate insert,

- joining (S104) a dental prosthesis to the outer surface of the coping housing,

- separating (S106) the coping housing from the intermediate insert through application of a first force onto the inner coupling element of the coping housing, so that the outer coupling element of the intermediate insert disengages from the inner coupling element of the coping housing,

- connecting (S108) a drill guide to the coping housing by engaging an outer coupling element of the drill guide with the inner coupling element of the coping housing,

- drilling (S110) a hole through the dental prosthesis guided by the drill guide,

- removing (S112) the drill guide from the coping housing,

- removing (S114) the intermediate insert and securing element from the dental implant component, - connecting (S116) a final insert to the inner surface of the coping housing by engaging a second outer coupling element of the final insert with the inner coupling element of the coping housing, and

- securing (S118) the dental prosthesis to the dental implant component using a securing element which engages the second seating surface of the final insert.