Patent Description:
After an implant has been implanted in a patient's upper or lower jaw bone and is integrated in the bone tissue after a healing period or immediately after surgery, at least one dental component will be attached to this implant in order to install a dental prosthesis. The dental prosthesis may comprise a plurality of dental components such as an abutment, a multi-unit abutment, a spacer, and a replica of a at least one tooth. Generally, fastening elements such as dental screws are used for fixing these dental components to the implant.

Since dental components and dental screws are in general rather small in size, it is generally advantageous to use tools for handling and fastening these components to an implant. Originally, two separate tools have been used, one for handling the dental component and the other one for tightening the dental screw.

More recently, handles have been introduced that handle both a dental screw and a dental component. Such a handle is, for example, known from US <NUM>, <NUM>, <NUM> Bl. Here, a spacer and a screw are engaged with a holder in a rotationally fixed position with respect to the holder. More specifically, the spacer is engaged in a spacer engaging portion of the holder and the screw is engaged in a screw engaging portion of the holder. For fixing the spacer to an implant, the screw is brought into engagement with a thread of the implant and tightened by applying a rotational motion to the holder. During fastening, both the rotationally fixed spacer and the dental screw are rotated until the spacer abuts a coronal side of the implant.

Although the handle of <CIT> considerably facilitates the handling and attachment of the spacer, such a handle cannot be used if indexing means are present between the dental implant and the dental component. Indexing means are generally intended for preventing any relative rotation between two dental components in order to set a predetermined orientation of the dental prosthesis.

Applying the handle of <CIT> to a dental component such as an implant and an abutment that include an indexing means will, thus, not result in the dental components being fastened to the dental implant. As soon as the indexing means between the dental implant and the abutment are in engagement, the handle holding the screw and the dental component will start turning the implant, which is obviously undesirable since it may result in loosening the implant.

Further, <CIT> discloses a tool for affixing a component to a dental implant fixture with a screw passing through the component and threaded into the implant fixture and forms the basis for the two-part form of independent claim <NUM>. The tool has two parts telescopically interfitting one within the other, the outer part being tubular for carrying the component at one end, and the inner part fitted at one end for carrying the screw positioned within the component. The component and the screw within it can be carried together to the implant fixture where the outer part is used to hold the component in place while the inner part is used to drive the screw into the implant fixture.

<CIT> is the basis for the two-part form and discloses a device for retaining and delivering dental implant components including a retainer-delivery member. The retainer-delivery member has a plurality of multi-sized stepped down portions for hands-off insertion into, and frictional engagement with various dental implant components. By this frictional engagement, the retainer-delivery member can retain various components for delivery to the implant site and can be manipulated for initial connection to the implant.

Further tools for assembling dental components are disclosed in <CIT> and <CIT>.

Consequently, an objective of the present invention was to provide a tool that allows to handle as well as tighten a dental component to another dental component such as an implant, even if the dental components include indexing means that prevent any relative rotation between these dental components.

Another objective was to provide a handling tool giving a better tactile feedback about the installation process to a user. At the same time, it was an aim of the invention to give the option of a dental screw being preassembled to a dental component in order to facilitate handling and to reduce the risk of contamination.

The claimed invention addressing above-noted objectives is defined in the subject matter of the independent claims, wherein the claims dependent thereon specify preferred embodiments.

As a solution, the invention provides a dental set comprising a handling tool and a dental component, the handling tool having a distal end, a proximal end and a longitudinal axis. Further, the handling tool comprises a grip at the proximal end and a shaft located distally to the grip. The shaft comprises an engagement section for engaging an engagement feature of a fastening element and a retaining section for retaining the dental component to be fastened by the fastening element, wherein the retaining section of the handling tool is configured to allow for a rotation relative to the dental component.

The fastening element is rotationally fixed by being engaged with the engagement section of the handling tool, whereas the dental component is releasably retained by the retaining section of the handling tool in the longitudinal direction. Nonetheless, the retaining section is configured so that a relative rotation between the retaining section of the handling tool and the dental component in the circumferential direction relative to the handling tool can be caused by applying an external torque. The external torque can be applied by hand or a tool using the grip of the handling tool. The difference of the interaction between the retaining section and the dental component in the longitudinal direction on the one hand and the circumferential direction on the other hand is that pulling the handling tool and the dental component apart will result in the retainment between these two parts being released, whereas turning the handling tool relative to the dental component will not separate the retaining section of the handling tool from the dental component. Instead, the handling tool keeps the dental component retained.

Further, the fastening element is not rotationally fixed in relation to the dental component. As a result, the dental component can be fastened to another dental component such as an implant or an abutment without causing a relative rotation between these components. Consequently, the handling tool can be used for attaching dental components to each other even if there are indexing means present.

In a preferred embodiment, the retaining section is shaped for retaining a dental component by means of a friction fit.

Using friction at the retaining section for retaining a dental component allows for above-mentioned longitudinal attachment of the dental component as well as relative rotation between the handling tool and the dental component. One of the advantages of a friction fit is the easy adjustment of the friction fit's strength by adjusting the geometric design and/or manufacturing tolerances of the retaining section.

The friction fit is configured to provide a releasable connection between the handling tool and the dental component. Thus, the dental component can be retained by the handling tool in a longitudinal direction for guiding the dental component to an attachment site. However, if pulled in a longitudinal direction away from each other, the handling tool and the dental component can be separated. This releasability of the friction fit also causes that a relative rotation between the handling tool and the dental component is possible.

In contrast to pulling the two parts apart, however, a rotation does not result in a disengagement of the dental component and the handling tool. Instead, rotation takes place against the friction fit and the handling tool keeps retaining the dental component while torque is applied. As a result, a user has an enhanced control over the fastening process. In other words, thanks to the friction fit, the connection between the handling tool and the dental component is stable so that a user has a good control and feedback while fastening the dental component to another dental component.

Since the rotation of the fastening element for tightening the fastening element and, thus, the dental component, to another dental component is effected about the longitudinal axis of the handle, the retaining section is preferably designed to be substantially rotationally symmetric. However, retaining elements may be provided on the face of the retaining section in order to adjust the strength of the frictional fit and / or form fit between the dental components.

The engagement section of the handling tool has a form fit geometry in order to enable a transfer of torque between the handling tool and a fastening element.

Using a form fit geometry provides an engagement section to the handling tool that allows for a high strength engagement in the rotational direction. In other words, the risk of any slippage between the handling tool and the dental component during tightening is minimized.

Further, a form fit ensures a defined behavior of the handling tool during its rotation while fastening the dental component to an apical dental component. More specifically, the rotation of the handling tool about its longitudinal axis will be fully transferred to the fastening element. As a result, there is no significant torque applied to the dental component during fastening of the dental component with the fastening element which otherwise could cause a relative rotation between the dental components. Also, there is no limitation on the transfer of torque from the handling tool to the fastening element so that a user will have a direct tactile feedback concerning the torque applied.

The engagement section of the handling tool has a friction fit geometry in order to limit the transfer of torque between the handling tool and a fastening element.

In this embodiment, the engagement section also has a friction fit geometry like the above described preferred embodiment of a retaining section mentioned above. However, the connection strength provided by the engagement section is higher than the connection strength provided by the retaining section so that any rotation of the handling tool about its longitudinal axis will be transferred to the fastening element.

However, if the fastening element is fastened up to a predetermined amount to an apical dental component, the continuous rotation of the handling tool will result in slippage of the handling tool in relation to the fastening element. Thus, slippage will occur at both sections, i.e. the engagement section as well as the retaining section. Consequently, this embodiment has the advantage that the amount of torque that may be applied by the handling tool is limited so that an overload of the dental assembly and in particular the dental implant can be prevented.

In another embodiment, the diameter of the grip is larger than any one of the diameter of the engagement section and the diameter of the retaining section.

Thus, on the one hand a user can easily grip the handling tool and control its rotation as well as the torque applied. On the other hand, the engagement section and the retaining section being smaller in diameter provides a good visibility of the site, where the dental component is to be installed, which enhances the guidance of the dental component in the oral cavity of a patient.

In a preferred embodiment, the handling tool further comprises an intermediate section. The intermediate section converges from the diameter of the grip down to the diameter of the engagement section and/or the diameter of the retaining section.

Consequently, the intermediate section is arranged between the grip on the one hand and the engagement section and the retaining section on the other hand. Since the handling tool has an intermediate section that converges instead of only having a simple step in diameter, the occurrence of visual obstructions at the site of fixation is prevented. Preferably, the intermediate section converges from the grip to the engagement section and/or the retaining section linearly or with a concave curvature towards the longitudinal axis of the handling tool in order to provide a smooth transition between the grip and the shaft of the handling tool.

In another preferred embodiment, the shaft includes a cutout, wherein the cutout preferably passes through the shaft or is formed by the engagement section.

Including a cutout in the shaft has the advantage that the elasticity of the shaft in a direction perpendicular to the longitudinal axis of the handling tool can be increased. As a result, the shaft is able to adapt to a larger range of manufacturing tolerances or even different dental components.

The cutout may be a recess on the circumferential side of the shaft transverse to the longitudinal axis or at the apical end of the shaft extending from an opening at the apical end of the shaft in a coronal direction along the longitudinal axis. Preferably, the cutout runs throughout the shaft forming a through hole. If the cutout is situated on the circumferential side of the shaft, it is preferably formed as a slotted or elongated hole.

In a particularly preferred embodiment, the position of the cutout along the longitudinal axis of the handling tool coincides at least partly with the position of the retaining section and/or engagement section along the longitudinal axis.

In this preferred embodiment, the cutout does not only provide more compliance in terms of manufacturing tolerances but also allows for an adjustment of the connection strength that the retaining section and/or the engagement section provide to the dental component and the fastening element, respectively.

Also, it is possible to form one of the retaining section and the engagement section as a cutout for the other one of the retaining section and the engagement section. This provides for an even more compact design of the handling tool since the cutout is not formed as an additional feature but by an advantageous placement of the retaining section and/or the engagement section along the shaft of the handling tool and relative to each other.

In another preferred embodiment, the circumference of the cutout is preferably rounded.

The rounded circumference prevents the occurrence of high stresses caused by the torque applied to the handling tool when fastening the fastening element. As a result, the risk of material failure is reduced. Further, the risk of an adverse effect on the patient due to failure of the handling tool is significantly reduced.

In another preferred embodiment, the handling tool further comprises at least one cavity that is located in the handling tool so that deviations in material thickness are minimized.

In this embodiment, the material thicknesses at different sections of the handling tool are kept in a relatively small range so that the handling tool can be efficiently produced, in particular using molding techniques such as injection molding.

In a particularly preferred embodiment, the handling tool is at least partly made out of a solid polymer or solid polymer composite, in particular PEEK or a PEEK composite.

Polymers are cheap in production so that their application offer a more cost efficient treatment. Also, polymers such as PEEK are known to be biocompatible and have sufficient material strength to be used for forming the handling tool. Further, it is possible to enhance material properties, in particular material strength, by using solid polymer composites. For example, a PEEK composite may be used that combines PEEK with a filler material such as TiO2 and/or a fiber, for example a glass fiber or a carbon fiber.

Further, the invention provides a dental set comprising a handling tool, in particular a handling tool as described above, and a dental component, the handling tool having a longitudinal axis and a retaining section for retaining the dental component in a longitudinal direction, i. in a fixed position along the longitudinal axis, but allowing a rotation between the handling tool and the dental component about the longitudinal axis.

The handling tool and the dental component are preferably delivered to a user such as a dentist as a preassembled dental set. Preferably, the dental set is provided as a sterilized package. As described above, the retaining section has the advantage to provide a connection between the handling tool and the dental component that is sufficient to retain the dental component in a longitudinal direction an at the same time allows for a relative rotation between these two parts. Further, by retaining the dental component in longitudinal direction, the control during application of torque to the fastening element by the handling tool is enhanced.

In a preferred embodiment, a circumferential contact between the retaining section of the handling tool and a contact section of the dental component is configured to be discontinuous.

Since the circumferential contact between the retaining section of the handling tool and a contact section of the dental component is discontinuous, the friction fit between the handling tool and the dental component can be easily adjusted to a desired value. Using a discontinuous contact particularly allows for adjusting the friction fit to a level ensuring that the strength of the fit caused at the retaining section is less than the strength of the fit caused at the engagement section.

Preferably, the discontinuous contact between the retaining section and the contact section is achieved by the surface of one of the sections having an undulating geometry.

The retaining section of the handle is an outer circumferential surface having a generally circular configuration as described above, whereas the contact section of the dental component surrounds the retaining section and has an undulating configuration or vice versa. As a result of the undulating geometry, the contact section of the dental component is in contact with the retaining section only at predetermined, preferably regular, intervals.

In another preferred embodiment of the dental set, a fastening element having a thread that is in engagement with a thread of the dental component, where said thread is out of engagement with the thread of the dental component when being fastened to a thread of an apical dental component.

The thread of the fastening element being engaged with a thread of a dental component that is to be fastened to another dental component is particular advantageous for a preassembled dental set. More specifically, such a threaded engagement fixes the position of the fastening element relative to the handling tool and the dental component. Also, the thread of the dental component at least initially guides the fastening element when mounting the dental component to an apical dental component by rotating the fastening element further.

The fastening element is fixed during preassembly so that any play is prevented that may cause the handling tool to go out of engagement with the dental component due to inertial forces caused by, for example, transporting the preassembled dental set. Consequently, providing a thread in the dental component for receiving the fastening element also supports a retaining section with a low strength friction fit in order to provide less connection strength at the retaining section than at the engagement section.

The invention also provides a method for assembling a dental set comprising a handling tool and a dental component as described above. The method comprises the steps of bringing an engagement section of the handling tool into engagement with an engagement feature of a fastening element and coupling a retaining section of the handling tool to a contact section of a dental component by a friction fit, wherein the friction fit allows for a relative rotation between the handling tool and the dental component.

This method according to the invention for assembling a dental set provides the advantages already described in relation to the handling tool and the dental component.

This method may particularly be used for preassembling the handling tool, the fastening element and the dental component. This preassembly may be done before the dental set is delivered to the dental office for treatment. Nonetheless, the method may also be applied at the dental office in preparation for inserting and fixing the dental component in the mouth of a patient. In any case, the possibility to prepare the dental set in such a manner reduces the chairtime of the patient necessary for installing the dental component.

Preferably, the fastening element is inserted into the dental component before the handling tool is coupled to the dental component by the retaining section of the handling tool and the contact section of the dental component.

In a particularly preferred embodiment, the method also comprises the step of bringing a thread of the fastening element into a threaded engagement with a thread of the dental component, and preferably the step of further rotating the fastening element relative to the dental component for bringing the thread of the fastening element out of engagement with the thread of the dental component and into engagement with a thread of an apical dental component.

This embodiment of the method has the previously described advantage of fixing the screw in a preassembled dental set as well as guiding the screw into engagement with an apical dental component.

The following figures illustrate preferred embodiments of the present invention. These embodiments are not to be construed as limiting but merely to enhance the understanding of the invention. In these figures, same reference signs refer to components throughout the drawings that have the same or an equivalent function and/or structure. This also applies to reference signs that are identical except for the first digit that denotes different embodiments. Consequently, a repetitive description of these components is generally omitted.

<FIG> show a first embodiment of a handling tool <NUM> according to the invention for attaching and fastening two dental components to each other. A dental component may be an implant <NUM>, a spacer, an abutment <NUM>, and/or a prosthetic tooth. The handling tool <NUM> is elongated and has a proximal end <NUM> and a distal end <NUM>. At the proximal end <NUM> is a grip <NUM>. The grip <NUM> may have a structured circumferential surface such as the longitudinal grooves shown in <FIG> to provide a better grasp to a user.

At the distal end <NUM>, the handling tool <NUM> comprises on its outer circumferential side a retaining section <NUM>. In between the retaining section <NUM> and the grip section <NUM>, the handling tool <NUM> may include an intermediate section, where the diameter of the handling tool <NUM> decreases down to the diameter of the retaining section <NUM> and/or engagement section <NUM>. As can best be seen in <FIG>, the decrease of the diameter is preferably formed as a linear or concave convergence in the distal direction of the handling tool <NUM> along the longitudinal axis L.

The retaining section <NUM> is for retaining a dental component <NUM>. In other words, a dental component <NUM> may be coupled to the retaining section <NUM> of the handling tool <NUM> so that the dental component <NUM> is detachably coupled to the handling tool <NUM>. The retaining function is achieved by a friction fit and/or a form fit. In both cases, the retaining section <NUM> allows for a rotation of the dental component <NUM> about the longitudinal axis L of the handling tool <NUM>. Thus, the retaining section <NUM> has a geometry that allows for a rotation of the handling tool relative to the dental component such as a generally circular geometry.

The retaining section <NUM> retains a dental component <NUM> with a friction fit. A friction fit can be achieved with a simple geometry such as a circular circumferential surface. In this manner, the friction fit allows for a rotation of the dental component <NUM> relative to the handling tool <NUM>. However, it is also possible to provide, for example, an increased connection strength of the friction fit by including retaining elements 67a, 67b, 67c on the retaining section <NUM> (cf. In other words, a friction fit can be adjusted to a desired connection strength that is to be provided by the retaining section <NUM> so that the dental component is securely retained in the longitudinal direction of the handling tool <NUM> but allows for a rotation about the longitudinal axis L.

Nonetheless, it is also possible to include a snap-fit geometry as retaining section <NUM>. This can be an alternative or complementary feature to the aforementioned friction fit. Such a snap-fit geometry also needs to provide the previously described retaining function in the longitudinal direction as well as the rotational function about the longitudinal axis L. This may be achieved by providing a continuous circumferential groove or ridge on the retaining section <NUM> of the handling tool <NUM> and/or the contact section <NUM> of the dental component <NUM>.

The handling tool <NUM> also comprises an engagement section <NUM>. In the embodiment of the handling tool <NUM> shown in <FIG>, the engagement section <NUM> is formed at the distal end <NUM> of the handling tool <NUM> as a recess extending along the longitudinal axis L into the shaft <NUM> of the handling tool <NUM>.

As illustrated in <FIG>, the engagement section <NUM> has a geometry that brings a fastening element <NUM> in a rotational direction about the longitudinal axis L into engagement. However, the geometry of the engagement section <NUM> is also formed to allow for a translation of the fastening element <NUM> along the longitudinal axis L. As a result, the fastening element <NUM> moves distally in relation to the handling tool <NUM> while the handling tool <NUM> is rotated and the fastening element <NUM> increasingly engages the apical dental component <NUM> by means of its thread <NUM>.

In the exemplary embodiment shown in <FIG>, the engagement section <NUM> has a hexagonal geometry. However, any geometry that provides a rotational engagement about the longitudinal axis L and at the same time allows for a translation of a fastening element <NUM> along this longitudinal axis L is suitable to be used as engagement section <NUM>.

The handling tools <NUM>, <NUM> are preferably made from a polymer such as PEEK since polymers allow for a cheap high volume production so that the handling tool <NUM> may simply be provided as a disposable part.

As illustrated in <FIG>, the handling tool <NUM> comprises a cavity <NUM> on the level of the grip section <NUM> along the longitudinal axis L. In this manner, the handling tool <NUM> comprises less deviations in material thickness, which facilitates production, for example by injection molding. Preferably, the change in material thickness between adjacent cross sections of the handling tool, in particular at locations with a step change, is less than <NUM>%, preferably less than <NUM>% and even more preferably <NUM>% relative to the thinner section. The same applies to the handling tool <NUM> which includes the cavity <NUM> for the same purpose.

<FIG> illustrate the application of the handling tool <NUM> at the end of tightening a dental component <NUM> to an apical dental component <NUM> as a side view and a cross-sectional side view, respectively. In <FIG>, the apical dental component <NUM> is a dental implant and the dental component <NUM> is an abutment. It will be understood by the skilled person, that the dental components can be any suitable dental component to build up a dental prosthesis or superstructure. For example, in <FIG> described in further detail below, a sleeve or coronal abutment <NUM> is fastened to an apical abutment <NUM>.

As can be taken from <FIG>, the dental implant <NUM> comprises an inner thread <NUM> for engagement with an outer thread <NUM> of the fastening element <NUM>. The fastening element <NUM> in <FIG> is a dental screw including a screw head <NUM> and a shaft. The shaft comprises at its distal end the outer thread <NUM>. The screw head includes on its outer circumference an engagement feature <NUM> for engaging the engagement section <NUM> of the handling tool <NUM>. It also comprises an inner thread <NUM> for a threaded engagement with another fastening element <NUM> that will be described in more detail in relation to <FIG> below.

The dental component <NUM> comprises a through hole passing through the component along its longitudinal direction for insertion of the fastening element <NUM>. At the coronal end of the through hole, the dental component <NUM> includes a contact section <NUM> for coupling to the retaining section <NUM> of the handling tool <NUM>. The contact section is formed as an inner circumferential surface that is substantially parallel to the longitudinal axis L to allow for a translation when being in contact with the fastening element. Apically to the contact section <NUM>, the dental component <NUM> further comprises a screw seat so that the dental component <NUM> can be fixedly attached to the dental component <NUM>.

At the apical end of the through hole, the dental component <NUM> can be provided with an inner thread <NUM>. As illustrated in <FIG>, the inner thread <NUM> serves for an engagement with the outer thread <NUM> of the fastening element <NUM> in a preassembled state. As described above, the handling tool <NUM>, the dental component <NUM> and the fastening element <NUM> are preferably preassembled in order to provide a ready to use dental set to the patient and to reduce the chairtime of the patient during treatment.

The preassembly of the dental set in the exemplary embodiment shown in <FIG> is performed by rotating the fastening element <NUM> into a threaded engagement with the inner thread <NUM> of the dental component <NUM>. This is followed by moving the engagement section <NUM> of the handling tool <NUM> along the longitudinal axis L onto the screw head <NUM> into engagement with the engagement feature <NUM> of the fastening element <NUM> and subsequently bringing the retaining section <NUM> of the handling tool <NUM> in contact with the contact section <NUM> of the dental component <NUM>. In this exemplary embodiment, the dental component <NUM> also comprises indexing means to lock the dental component <NUM> and the dental component <NUM>, i. in the present embodiment the implant, in the rotational direction.

This preassembled dental set is then transferred into the oral cavity of a patient and guided to the dental component <NUM>.

The method of fixing the dental component <NUM> to the dental component <NUM> in the oral cavity of a patient does not form part of the claimed invention.

More specifically, the dental component <NUM> is guided into a corresponding recess of the dental component <NUM> for receiving the dental component <NUM>. This results in the situation illustrated in <FIG>.

Since in the embodiment shown in <FIG> the fastening element <NUM> is in threaded engagement with the dental component <NUM>, the fastening element does not loosely extend from the preassembled dental set. As a result, the fastening element <NUM> does not hinder guiding the preassembled dental set to the dental component <NUM> within the oral cavity of the patient.

In order to fix the dental component <NUM> to the dental component <NUM>, the fastening element <NUM> is rotated by turning the handling tool <NUM> about its longitudinal axis L. As a result, the outer thread <NUM> of the fastening element <NUM> advances in an apical direction out of engagement with the inner thread <NUM> of the dental component <NUM> and further into engagement with the inner thread <NUM> of the dental component <NUM>. In the fixed or tightened state, the outer thread <NUM> is completely out of engagement with the inner thread <NUM> so that a reliable fastening of the dental component <NUM> to the dental component <NUM> is achieved.

On the one hand, during rotation in a fastening direction, the fastening element <NUM> moves out of the engagement section <NUM> of the handling tool <NUM> in an apical direction. Consequently, the engagement between the engagement section <NUM> of the handling tool <NUM> and the engagement feature <NUM> of the fastening element <NUM> is present only in terms of rotation about the longitudinal axis L but not in terms of translation along this longitudinal axis.

On the other hand, the retaining section <NUM> of the handling tool <NUM> being in contact with the contact section <NUM> of the dental component <NUM> provides a friction fit that retains the dental component <NUM> in a fixed position relative to the handling tool <NUM> along the longitudinal axis L as long as no external force is applied along this direction but allows for a relative rotation of the handling tool <NUM> in relation to the dental component <NUM>. Although the friction fit transfers a minimal torque between the handling tool <NUM> and the dental component <NUM> while rotating the handling tool <NUM> during fastening of the dental component <NUM>, this torque does not affect the integrity of the dental implant <NUM> with the surrounding bone tissue of the patient.

Generally, the strength of the connection between a retaining section <NUM>, <NUM> of a handling tool <NUM>, <NUM> and a dental component <NUM>, <NUM> in a rotational direction about the longitudinal axis L of the handling tool <NUM>, <NUM> is less than the strength of the connection between an engagement section <NUM>, <NUM> of the handling tool <NUM>, <NUM> and the dental component <NUM>, <NUM>.

This difference in strength is provided in the embodiment of <FIG> by using a form fit between the fastening element <NUM> and the handling tool <NUM> and a friction fit between the handling tool <NUM> and the dental component <NUM>. As a result, slippage can only occur between the handling tool <NUM> and the dental component <NUM>.

However, this precondition can also be fulfilled in case of using a friction fit between the handling tool <NUM> and the fastening element <NUM> on the one hand and the dental component <NUM> on the other hand (cf.

After fastening the dental component <NUM> to the dental component <NUM> by means of the fastening element <NUM>, the handling tool <NUM> can easily be removed by pulling the handling tool <NUM> in an apical direction.

Turning to <FIG> illustrates three retaining elements 67a, 67b, 67c that may additionally be provided on the retaining section <NUM> of the handling tool <NUM>. These retaining elements <NUM> may be provided as protrusions 67a, 67b, 67c that locally increase the friction fit and / or provide a form fit between the handling tool <NUM> and a dental component <NUM>.

Additionally or alternatively, the retaining elements 67a, 67b, 67c may have elastic properties similar to a leaf spring for providing a defined local contact force between the handling tool <NUM> and the dental component <NUM> to obtain a predetermined friction fit and / or form fit.

The retaining elements <NUM> are preferably provided in an equidistant manner around the circumference of the retaining section <NUM>. Preferably, <NUM> to <NUM> protrusions and more preferably <NUM> to <NUM> protrusions are formed on the circumferential surface of the retaining section <NUM>.

<FIG> shows another embodiment of a handling tool according to the invention denoted with reference sign <NUM>. As can be taken from the first digit of the reference signs in relation to the embodiment of the invention described in the following, the basic structure of the handling tool <NUM> is similar to the previously described handling tool <NUM>. For example, like the handling tool <NUM>, the handling tool <NUM> comprises at its proximal end a grip <NUM> and at its distal end a shaft <NUM> including a retaining section <NUM> and an engagement section <NUM>. However, the retaining section <NUM> and the engagement section <NUM> are at least partly not provided on the same level as the retaining section <NUM> and the engagement section <NUM> of the handling tool <NUM> but instead one after the other. More specifically, the engagement section <NUM> is situated at the distal end <NUM> of the handling tool <NUM> and the retaining section <NUM> is located proximally thereof.

Like in the embodiment of the handling tool <NUM> of the previous figures, the engagement section <NUM> is configured for engagement with a fastening element <NUM> by at least a partial form fit in order to apply torque. As illustrated in <FIG>, the engagement section <NUM> may be formed by a plurality of engagement subsections 161a, 161b. These engagement subsections 161a, 161b are located on the circumference of the engagement section <NUM>. In the present embodiment, the engagement subsections 161a, 161b are planar and are separated by intermediate subsections 167a, 167b. In other words, the engagement subsections 161a, 161b alternate with intermediate subsections 167a, 167b around the circumference of the engagement section <NUM> in order to form a preferably regular pattern. The intermediate subsections 167a, 167b are formed so that they do not engage a corresponding engagement feature <NUM> of a fastening element <NUM>. The number of engagement subsections 161a, 161b is preferably equal to the number of intermediate subsections 167a, 167b. Further, the number of engagement subsections 161a, 161b is chosen according to an engagement feature <NUM> of a fastening element <NUM>. For example, if the engagement feature <NUM> is formed by a hexagonal geometry, there will be preferably six planar engagement sections 161a, 161b.

In longitudinal direction, the engagement section <NUM> is configured for engagement with the fastening element <NUM> by friction fit in order to retain the fastening element <NUM> on the handling tool <NUM>.

The skilled person will appreciate that the engagement subsections 161a, 161b do not necessarily have to be planar but can also have any other geometry as long as this geometry is able to at least partially engage an engagement feature <NUM> of a fastening element <NUM>. Nonetheless, these engagement subsections 161a, 161b are preferably formed to only partly engage an engagement feature <NUM>. In this manner it is possible to limit the amount of torque that is applied by the engagement section <NUM> of the handling tool. In other words, providing engagement subsections 161a, 161b to the handling tool that only partly engage an engagement feature <NUM> of a fastening element <NUM> allow for slippage between the handling tool <NUM> and the fastening element <NUM> if the torque applied by the handling tool <NUM> exceeds a predetermined amount.

Also, the handling tool <NUM> does not comprise an intermediate section <NUM>, where the diameter of the handling tool continuously converges down from the grip <NUM> to the retaining section <NUM> and the engagement section <NUM>. Instead, the grip section <NUM> is designed relatively shorter in the longitudinal direction of the handling tool <NUM> and comprises a step change to the smaller diameter of the shaft <NUM> in order to provide a good visibility of the attachment site, and in particular to facilitate larger prosthetic restorations. Preferably, the grip section <NUM> is formed at the proximal end <NUM> along about half of the length or less of the total length of the handling tool <NUM> in the distal direction.

Another difference to the handling tool <NUM> of <FIG> is a cutout <NUM> near the distal end <NUM> of the handling tool <NUM>. The cutout <NUM> extends in a transverse direction throughout the shaft <NUM>. As already described above, the recess forming the cutout <NUM> also enables the adjustment of the shaft's elasticity and, in particular, the retaining section <NUM>.

In case of the handling tool <NUM> of the previous embodiment, such a recess may also be formed by the engagement section <NUM>. Here, the location of the engagement section <NUM> also enhances the elasticity of the retaining section <NUM> since both sections are located on the same level along the longitudinal axis L of the handling tool <NUM>.

In the exemplary embodiment of <FIG>, the cutout <NUM> extends into the region of the retaining section <NUM> along the longitudinal axis L of the handling tool <NUM>. In this manner, the elasticity of the retaining section <NUM> is increased. Also, the cutout <NUM> extending further along the shaft <NUM> towards the proximal end <NUM> can ensure an easy rotation of the handling tool <NUM> within the through hole of a dental component <NUM> (cf.

As previously described in relation to an embodiment of the handling tool, the cutout <NUM> comprises a rounded circumference in order to prevent the occurrence of high stresses within the material of the handling tool <NUM>. Although the cutout <NUM> is formed as a slot or elongated hole extending throughout the transverse direction of the shaft <NUM>, it may well be sufficient to form the cutout <NUM> as a recess that does not form a through hole but has a bottom. In such an embodiment, the cutout <NUM> is preferably provided as more than one recess located in an equidistant manner around the circumference of the shaft <NUM>.

As can further be taken from <FIG> and <FIG>, the retaining section <NUM> is not formed as a continuous retaining section but instead comprises two retaining subsections that are opposed to each other and are separated by the cutout <NUM>.

Subdividing the retaining section into a plurality of subsections that may be separated by the cutout or are simply separated by sections between the subsections with a decreased dimension, i. a distance in a direction perpendicular to the longitudinal axis L. This is another option to adjust the strength of the friction fit to the desired value needed to retain the dental component <NUM> at a fixed position along the longitudinal axis L of the handling tool <NUM> while allowing for a rotation of the handling tool <NUM> in relation to the dental component <NUM> about that longitudinal axis L.

The application of the handling tool <NUM> is best described in relation to <FIG>. As previously described, the dental component <NUM>, the handling tool <NUM> and the fastening element <NUM>, which in the embodiment shown in <FIG> is formed as a dental screw, are inserted into the mouth of a patient in a preassembled state.

The method of inserting the handling tool fitted with the dental component <NUM> and the fastening element <NUM> does not form part of the claimed invention.

The dental component <NUM> comprises a through hole like the previously described dental component <NUM> but without an internal thread at its apical end.

During preassembly, the fastening element <NUM> is inserted into the dental component <NUM> followed by the retaining section <NUM> of the handling tool <NUM>. By pushing the fastening element <NUM> and the handling tool <NUM> into the through hole of the dental component in an apical direction until the fastening element <NUM> abuts the screw seat, the fastening element <NUM> is prevented from moving in the longitudinal direction during the insertion of the dental set into the mouth of the patient. Consequently, in this embodiment, the retaining section <NUM> of the handling tool also has the function of retaining the fastening element <NUM>, which in the previous embodiment is achieved by the inner thread <NUM> of the fastening element <NUM>.

During placement of the dental set and, i. the placement of the dental component <NUM> on the dental component <NUM>, the fastening element <NUM> is pushed back within the through hole in a coronal direction of the dental component <NUM>.

The dental component <NUM> may comprise an undulating contact section as described above for coupling the dental component <NUM> to the dental component <NUM>. This undulating contact section <NUM> may serve as an indexing means for preventing a rotation between these two components. If the circumferential contact section <NUM> of the dental component <NUM> has an undulating geometry, the friction fit between the handling tool <NUM> and the dental component <NUM>, previously described in relation to <FIG>, is established discontinuously around the circumference of the retaining section <NUM> of the handling tool <NUM>. As described above, this allows to manipulate the connection strength of the friction fit.

Once the dental component <NUM> is placed on the dental component <NUM>, the fastening element <NUM> can be advanced into a threaded engagement with the inner thread <NUM> of the previously described fastening element <NUM> located at the head of the fastening element <NUM> by rotating the handling tool <NUM>. Since the at least partial form fit engagement between the engagement section <NUM> of the handling tool <NUM> and the engagement feature <NUM> of the screw has a higher connection strength than the connection caused by the contact of the retaining section <NUM> of the handling tool <NUM> with the contact section <NUM> of the dental component <NUM>, slippage only occurs between the retaining section <NUM> and the contact section <NUM>.

However, as soon as the fastening element <NUM> is tightened to the inner thread <NUM> of the fastening element <NUM> up to a predetermined torque value, the geometry and/or dimensions of the engagement subsections 161a, 161b may be configured as previously described, to allow slippage to occur between the engagement section <NUM> and the contact section <NUM>. Thus, in such an embodiment, a better tactile feedback is provided to a user by the handling tool <NUM> in the form of slippage that occurs as soon as a maximum torque is reached. In this manner, any damage to the dental components or the interface between a dental component and the tissue of the patient can be prevented.

After tightening the fastening element <NUM>, the handling tool <NUM> can easily be removed by pulling the handling tool <NUM> in an apical direction. Thus, neither during insertion of the dental set nor during removal of the handling tool there is a risk that a component of the dental set gets lost within the oral cavity of the patient.

Claim 1:
Dental set comprising a handling tool (<NUM>; <NUM>) and a dental component (<NUM>; <NUM>), the handling tool (<NUM>; <NUM>) having a distal end (<NUM>; <NUM>), a proximal end (<NUM>; <NUM>) and a longitudinal axis (L), the handling tool (<NUM>; <NUM>) comprising:
a grip (<NUM>; <NUM>) at the proximal end,
a shaft (<NUM>; <NUM>) located distally to the grip (<NUM>; <NUM>), the shaft comprising an engagement section (<NUM>; <NUM>) for engaging an engagement feature (<NUM>; <NUM>) of a fastening element (<NUM>; <NUM>) and on its outer circumferential side a retaining section (<NUM>; <NUM>) for retaining the dental component (<NUM>; <NUM>) to be fastened by the fastening element (<NUM>; <NUM>),
wherein the retaining section of the handling tool (<NUM>; <NUM>) is shaped for retaining the dental component (<NUM>; <NUM>) by means of a friction fit and is configured to allow for a rotation relative to the dental component (<NUM>; <NUM>), and
characterized in that the engagement section (<NUM>; <NUM>) of the handling tool has a geometry to allow for a translation of the fastening element (<NUM>; <NUM>) along the longitudinal axis (L) and has a form fit geometry in order to enable a transfer of torque between the handling tool (<NUM>) and the fastening element (<NUM>) by at least a partial form fit so that slippage occurs only between the retaining section (<NUM>; <NUM>) and a contact section (<NUM>) of the dental component (<NUM>; <NUM>).