Patent Description:
After installing an implant in a patient's mouth, the dentist must install/fix a component, onto which the dental prosthesis will be installed.

However, as each patient has a different anatomy, the dentist must test various types of prosthetic components until finding the most suitable for the treatment case.

Thus, when carrying out tests, the dentist must use a capture tool (wrench) to transport the prosthetic component from the component case to the patient's mouth. It is essential that this transport occurs safely, mainly because these components are extremely small and easily lost should they fall. Furthermore, for hygienic reasons, if the component is found, it can no longer be used for testing, as it must be sterilized again.

Thus, there is a need for a wrench that can safely capture and transport the component.

To achieve this object, the tools available in the state of the art such as, e.g., the ones illustrated in <FIG> and <FIG> include a cone shape end, which allows for temporary fastening of the component for transport to the installation site.

After this testing process and finding the suitable component for fastening the implant located in the patient's mouth, the dentist needs to fix the screw. For such, a ratcheting torque wrench is used, which is different from the transport wrench, performing the torque necessary to hold the component in the implant.

It is often necessary to switch tools, as the cone in the torque wrench is used only to temporarily fasten the component to the wrench, preventing the tip of the wrench from fully penetrating the component, i.e. the tip of the wrench is not in contact with the entire internal surface of the component (see <FIG> and <FIG>).

Thus, when the dentist performs torque, the component will be deformed (dilation of the screw head).

Thus, in order to avoid this defect, the wrench used to fasten the component in the implant must have a straight end (tip), i.e., without the cone, allowing the whole tip of the wrench to fully penetrate the internal length of the screw. As a result, when torque is performed, said deformation will not occur.

However, the need to switch tools is cumbersome to dentists. Consequently, many professionals choose to use their own capture wrench to provide torque, deforming the screw.

Furthermore, torque wrenches are typically hexagonally shaped. Due to this shape, the wrench contact area with the component is reduced. If by mistake the dentist delivers more torque than necessary for fixing the screw, deformation of the ridges of the wrench and dilation of the screw head are likely to occur.

This constant deformation, dilating the head of the component and the ridges of the tool, causes the wrench to not fit properly to the component head at certain moments, making rotation impossible in order to tighten the prosthetic component/screw, i.e., the tool slips from the fitting area, spinning on its own. This problem is very common, especially in components with smaller diameters and that require less torque.

In order to prevent the above, there was an attempt to solve such problems, as can be seen in prior art <CIT>, which describes an arrangement to be used with a variety of dental screws.

Said document describes a tool (or wrench) with a circular cross section wherein the outer ends of the section widen slightly conically. At the same time, these conical outer ends are fastened to the component surface essentially in parallel.

Thus, the tool described in said document has two functions, the first function being the tightening function, i.e., the ability to provide torque to fasten the component, and the second function being the ability to fasten the tool in the component; the tool's capture ability. Furthermore, it is described that the first and second functions are mechanically separated.

However, although the tool, as presented, has both capture and fastening functions, it is clear from said document that said tool is not applicable to smaller prosthetic components/screws, i.e., usually smaller than <NUM> (ranging from <NUM> to <NUM>), such that components/screws smaller in diameter cannot benefit from using said tool. D1 (<CIT>) discloses a screw has a chamber conically formed and comprises alternating, downward tapered guide surfaces and opposite undercut, a tapering down guide surfaces which interacts with the corresponding antagonistic guide surfaces and another guide surfaces of the screwing tool in force-fit and form-fit manner. The guide surfaces of the chamber of a screw head define lateral force transmission surfaces, which interacts in force-fit and form-fit manner with the corresponding antagonistic force transmission surfaces of the screwing tool by using torque. D2 (<CIT>) discloses a threaded implant intended to be screwed into bone, preferably into jawbone, and for tightly fitting a prosthesis, including a spacer portion, in the screwed-in position, the implant body has an internal connection arrangement for rotationally locking said spacer, said arrangement also co-operating during positioning and insertion of the implant body with a tool and said arrangement having a low vertical height. D3 (<CIT>) discloses a threaded dental implant assembly is provided for insertion into a pre-drilled bore in the jawbone is disclosed. The threaded dental implant assembly includes a threaded implant body to which is attached a healing cap for covering the central socket in the implant body during the initial healing period. The healing cap is mechanically coupled to the implant body before the insertion procedure by a coupling screw extending through a bore in the healing cap into the central socket of the implant body. A recess in the bottom of the healing cap mates with a protrusion on the top of the implant body such that the healing cap is prevented from rotating relative to the implant body and can transmit torque thereto. A tool engages the top of the healing cap for easy manipulation of the implant body/healing cap during the insertion procedure. The tool is disengaged from the heating cap after the insertion procedure thereby leaving the implant body and healing cap in the jawbone. D4 (<CIT>) discloses an implant which can be cooperate with an installation tool and a spacer member and which is arranged with an internal recess which extends from the upper parts of the implant and opens upward, the recess being arranged with first tracks and/or ridges which, seen in cross section of the recess, extend outward from the main periphery of the recess, in which first surfaces of said first tracks and/or ridges can cooperate with corresponding (opposite) second surfaces on second ridges and/or tracks arranged on the tightening member.

Therefore, the present invention aims to solve the problems presented in the prior art by providing a dental tool (wrench) with both capture and fixation functions, and that can also be used with components/screws with reduced diameters (e.g., smaller than <NUM>).

The present invention relates to a dental tool for coupling to prosthetic components, specifically a wrench for capturing and fixing a prosthetic component in the form of a screw in a dental implant, comprising, at its lower end, a plurality of protrusions and a plurality of recesses, wherein the plurality of protrusions and the plurality of recesses are alternately arranged, each of the protrusions being divided into a first region, a second parallel region, and a third conical region.

The invention further presents a set comprising the dental tool and the prosthetic component, such that the plurality of protrusions fits the plurality of counterbores, and the plurality of recesses fits the plurality of projections.

The present invention will now be described in more detail based on an example implementation illustrated in the drawings.

<FIG> illustrate a hexagonal tool <NUM> commonly used in the prior art, more specifically, a hexagonal capture tool <NUM> cooperating with a prosthetic component <NUM>.

As seen in <FIG>, the tip <NUM> of tool <NUM> is unable to fully penetrate the length of the internal orifice of component <NUM> due to the conical portion <NUM>, such that the bottom region <NUM> of the internal orifice of component <NUM> does not contact the tip <NUM> of tool <NUM>. This limitation occurs in regions of interference <NUM> highlighted in <FIG>.

Thus, when a torque T is applied (see <FIG>) to fasten the component <NUM> in the implant (not shown), note that it is only applied in the upper portion <NUM> of the internal orifice of component <NUM>. The contact regions/points <NUM> are highlighted in said <FIG>. This difference in torque T application makes it so that component <NUM> experiences deformations and, should the dentist continue to perform the fastening movement, more deformations will occur until such deformations add up and result in the deformation of the tool ridges <NUM>, so that it will start to rotate on its own, no longer performing torque T.

Thus, the tool <NUM> with conical tip works only for the capture function and to provide only a first torque to lightly fasten the component <NUM> in the implant. In order to provide the optimal and necessary torque to fasten the component <NUM> in the implant, the use of a straight-tipped, non-angled tool is ideal, allowing the internal surface of component <NUM> to fully contact the tip <NUM> of tool <NUM>, whereby the application of torque T is made preferably uniformly throughout component <NUM>.

Furthermore, <FIG> shows in enlarged details that the hexagonal tool <NUM> has only a small contact region <NUM> actually in contact with the internal surface of component <NUM> for performing torque T. Thus, in addition to the deformations that occur through the use of tool <NUM> to tighten component <NUM>, should the dentist provide a torque T greater than necessary for fastening component <NUM> in the implant, component <NUM> tends to deform with the intensity of force applied to it, i.e., the head of component <NUM> tends to dilate. This deformation is very common in parts small in diameter (smaller than <NUM>) that use smaller tools, as such tools support less torque and tend to deform more easily.

This deformation is extremely harmful, especially if component <NUM> needs to be removed for any reason. When the dentist uses a tool to remove the deformed component <NUM> (dilated head), tool <NUM> will have difficulty fitting in and, as a result, removing component <NUM>.

Therefore, the present invention aims to provide a dental tool, which performs the function of capturing and fastening a prosthetic component <NUM> without the need to switch tools, reducing the possibility of defects in the component/screw <NUM> when applying torque T (dilation of screw head/component) and which can further be used on components with diameters smaller than <NUM>.

<FIG> illustrate three capture and fastening tool <NUM> embodiments of the present invention, wherein its lower end <NUM> has been modified so as to solve the problems presented by the prior art.

As best seen in <FIG>, the lower end <NUM> of the dental tool <NUM> comprises a plurality of protrusions <NUM>, preferably six axial protrusions distributed around its circular perimeter. Said protuberances <NUM> are divided, from the tip <NUM> of end <NUM>, into three subsequent regions; the first region <NUM> being equipped with a corner break with the function of facilitate fitting the tool in the component/screw <NUM>; a second region <NUM> parallel to the longitudinal axis of the wrench, which will be housed inside the component; and a third region <NUM> conical/angled in shape.

In the embodiment illustrated in <FIG>, <FIG> the recesses <NUM> extend into the region next to the center of the circular end <NUM>'of the tip <NUM> of the tool <NUM>.

In the embodiment as shown in <FIG>, which is not according to the claimed invention, the lower end <NUM> of the tool <NUM> further comprises, alternately with the protrusions <NUM>, a plurality of recesses <NUM> also axial in the circular axis of the tool <NUM>, said recesses <NUM> having no extensions. Thus, in the embodiment illustrated in <FIG>, the recesses <NUM> extend only up to an edge <NUM>" of the tip <NUM> of the tool <NUM>, not extending in proximity to the center of the circular end <NUM>'.

This configuration allows protrusions <NUM> and recesses <NUM> to have different mechanical functions when the tool <NUM> is used.

However, in order to apply the capture and fastening functions of tool <NUM>, it is necessary to modify the components/screws <NUM> to better adapt to the distinct shape of the tool <NUM>. Therefore, note in <FIG> that the internal surface of the component/screw <NUM> is comprised of a plurality of projections <NUM> which form counterbores <NUM>.

As seen in <FIG>, the counterbore <NUM> and projections <NUM> regions of component <NUM> are alternately distributed and equidistant around the inner surface of the circular section of component <NUM>. It should be noted that in the embodiment illustrated in <FIG> the internal surface of component <NUM> is further provided with a small settling platform <NUM>.

Thus, when the tool <NUM> is inserted into the component <NUM>, as seen in <FIG> and <FIG>, the recesses <NUM> will couple with the projections <NUM> while the protrusions <NUM> will couple with the counterbores <NUM>, as indicated by arrows A and A' in <FIG>, respectively.

It is important to note that such modification in the shape of both tool <NUM> and component <NUM> allows the tool <NUM> to fully penetrate the internal extension of component <NUM>, as the conical region <NUM> when fitting into counterbores <NUM> forms a flat axial fitting with the side walls of the projections <NUM>. This avoids any tendency of defects occurring in tool <NUM> or component <NUM> when torque T is applied.

With the tool <NUM> adequately fitted into component <NUM>, the conical region <NUM> will function as a (retention) capture region <NUM> of component <NUM>, as highlighted in <FIG>, due to the male/female coupling formed between the conical region <NUM> and the counterbores <NUM> of the internal region of component <NUM>, temporarily locking the component <NUM> in the tool <NUM>. This locking allows the transportation of the component package into the installation site.

After transporting the component <NUM> into the installation site, the dentist needs to perform the necessary torque T to fasten it in an implant (not shown) installed at the patient's mouth.

Due to the alternate combination of the protrusions <NUM> and the recesses <NUM>, side walls <NUM> (seen in <FIG> and <FIG>) substantially perpendicular to the longitudinal axis of the tool <NUM> are formed.

Thus, when the tool <NUM> contacts the component <NUM>, the side walls <NUM> align with side walls <NUM> substantially perpendicular to the axis of component <NUM>, which are formed due to the alternately combination of counterbores <NUM> with the projections <NUM> (see Fig. 15a).

Thus, when applying torque with rotation movement, the side walls <NUM> directly contact the entire length of the side walls <NUM> forming torque areas <NUM> as highlighted in <FIG>.

As seen in greater detail in Figs. 15a and <FIG>, the point of contact for applying torque between tool <NUM> and component <NUM> does not occur at a single point, but along the entire length of the surfaces of the side wall <NUM>, <NUM> of tool <NUM> and component <NUM>, respectively.

Thus, when the dentist performs torque T to fasten the component <NUM> in the implant, the chances of deforming the head of the component <NUM> or tool <NUM> are significantly reduced, which reduces the chances that tool <NUM> will dilate the head of the component. <NUM> and, consequently, spin on its own and deform its ridges.

Furthermore, since the tool <NUM> of the present invention does not have the tendency of dilating the head of the component <NUM>, it is possible to reduce the thickness of the wall of component <NUM>. This decrease in wall thickness increases the fitting area of the tool <NUM>, regardless of the size of the component <NUM> to be fixed.

Thus, the same tool <NUM> can be used for components/screws <NUM> of different sizes, including those with diameters smaller than <NUM>. This is because with the adopted geometry, the radial component of contact force between the parts is smaller, such that a smaller wall thickness is required for the same resistance with the same force applied.

Claim 1:
Wrench (<NUM>) for capturing and fixing a prosthetic component (<NUM>) in the form of a screw in a dental implant, the wrench comprising at its lower end (<NUM>):
a tip (<NUM>) with a circular end (<NUM>'),
a plurality of protrusions (<NUM>), and
a plurality of recesses (<NUM>);
wherein the plurality of protrusions (<NUM>) and the plurality of recesses (<NUM>) are alternately arranged, such that side walls (<NUM>) are formed substantially perpendicular to the longitudinal axis of the wrench (<NUM>); and
wherein each of the protrusions (<NUM>) is subsequently divided, from the tip (<NUM>) of the lower end (<NUM>), into a first region (<NUM>), a second region (<NUM>), and third region (<NUM>), characterized in that:
- the first region (<NUM>) is provided with a corner break, so as to facilitate fitting the wrench into the component (<NUM>) ;
- the second region (<NUM>) is parallel to the wrench longitudinal axis;
- the third region (<NUM>) is conical in shape; and
- the recesses (<NUM>) extend into the region next to the center of the circular end (<NUM>').