EP2331007A1

EP2331007A1 - Surgical tool, especially for machining bones for insertion of a dental implant

Info

Publication number: EP2331007A1
Application number: EP08758431A
Authority: EP
Inventors: Herbert Hatzlhoffer
Original assignee: Palti Ady
Current assignee: Palti Ady
Priority date: 2008-05-09
Filing date: 2008-05-09
Publication date: 2011-06-15
Also published as: WO2009135514A1; US20110208192A1

Abstract

The invention relates to a surgical tool (1) for preparing bones, especially for machining bones for insertion of a dental implant, for example a drilling device comprising a tool shank (2) having a channel (3) for guiding a cooling or drilling liquid therethrough, a rotatable machining part (4) and a guide element (5) which is arranged on the proximal end of the machining part (4), which can be axially moved relative to the machining part (4) and which is adapted to be introduced into a pilot bore and has drilling grooves (6) for guiding the cooling or drilling liquid. In order to be able to machine bone material by means of the tool (1) without the tool (1) suddenly deviating from the pilot bore or from penetrating the drill channel, while at the same time allowing an improved cooling effect and improved removal of bone chips, tissue fragments and blood, the outlet where the cooling or drilling liquid (3) exits the channel (3) towards the drilling grooves (6) is arranged in the region of the transition between the proximal end of the machining part (4) and the distal end of the guide element (5).

Description

Surgical tool, in particular for processing bones for inserting a dental implant

The invention relates to a surgical tool for preparing bones, in particular for processing bones for the insertion of a dental implant.

The tool according to the invention can be used in all areas of bone surgery. It is described below without restriction of generality by means of the example of implant bores for maxillofacial surgery.

Dental implants are foreign bodies inserted in the jawbone. The field of dentistry, which deals with the implantation of dental implants in the jawbone, is referred to as implantology. Due to their usefulness as carriers of dental prostheses, dental implants assume the function of artificial tooth roots. To drill the holes for placing the dental implants in the jaw, a drilling template is used.

In the meantime, the technique of replacing a lost tooth with a dental implant and a dental prosthesis or bridge attached to it has become established. One uses an implant made of ceramic material or metal, anchored in the bone, the implant root on which the artificial dental crown is fastened. For this purpose, a hole for the implant root must be inserted into the jaw at the site of the lost tooth. Since the If the implant root is to be integrated harmoniously into the row of teeth, the implant root should have the largest possible diameter for better fit, and the bone supply in the jaw is limited, the position and angular orientation of the bore must be precisely predicted and adhered to.

To ensure this, a drilling template is usually first created, which has at the predetermined location a angularly adjusted drill sleeve whose inner diameter corresponds to the diameter of a pilot drill for the jaw bore. The surgical template is worn by the patient drilling the pilot hole. This surgical guide can be made using a jaw model of the patient or purely from radiographic or computed tomographic data. Furthermore, the information necessary for determining the direction of drilling information about the extent of the jawbone are obtained by means of computed tomography, wherein different sectional views are possible through the jaw. Other methods used to measure the jaw for making a surgical jig are e.g. So-called bone mapping, bone measurement with a probe or other measuring methods.

Surgical templates are thus auxiliary devices in order to make it easier for the implantologist to introduce a bore into the jawbone of a patient into which the implant is to be inserted. The drilling template has a hole created on the jaw model, which serves as a guide for the drill when inserting the bore or pilot hole in the jawbone. The drill hole should have the correct position and angular position.

Before introducing an implant into a bone, the bone material is first processed with special surgical tools. Frequently, a pilot hole, the so-called pilot hole, is first made with a relatively thin drill, in which the depth of preparation is ensured by depth-limiting elements. Thereafter, with the help of a so-called Formbohrers the Drilled boring channel and thereby receives the necessary shape for the implant. In a next step for the preparation of the bone, the mold bore is threaded. For this purpose, a tap is screwed into the hole.

The form drill thus serves to drill the hole in the jaw, after the pilot hole was performed with a pilot drill (and possibly the guide sleeves of a drilling template). When drilling with the form drill usually no guide sleeve is used.

This can lead to considerable difficulties with the conventional processing tools. There is always the risk that you leave the given drill hole during processing and affects surrounding bone material. This is especially true in the preparation of jawbone because the implant bore extends into the porous sponge-like bone material of the spongiosa and the tool may penetrate into the cavities of the bone tissue. As a result, the patient's jaw would be severely damaged and possibly even the use of implants would be impossible.

Another danger is that the work goes beyond the specified depth of the bore, breaking through the bore floor, affecting both jaw material and nerves.

In the prior art, EP 1 304 087 A2 discloses a surgical tool for preparing bones, in particular for processing bones for inserting a dental implant, which comprises a tool shaft which is designed to be clamped in a rotatable tool holder and a channel for passing a cooling or rinsing liquid, a rotatable about an axial axis of rotation machining part, which is drivable by the tool shaft and disposed at the proximal axial end of the tool shaft, and a guide element extending in the axial direction of the tool, which is arranged at the proximal axial end of the machining part, is axially movable relative to the machining part and is designed for insertion into a pilot bore and has one or more axially extending flushing grooves on its surface Conduction of the cooling or rinsing liquid comprises.

After the pilot drilling, the final bore (so-called "finish bore") takes place with such a shaping drill before inserting the implant body into the jaw. The form drill, which could also be referred to as a telescopic drill, has the property that it is guided by the attached to the active cutting, telescopically extendable and retractable in the axial direction guide element, which disappears under pressure into the interior of the drill head. In use, the drill bit is pushed into the pilot hole without tilting it. When the guide member reaches the bottom of the pilot hole, it pushes against the spring force into the drill head until it encounters a stop. If the guide element protrudes from the drill head in this stop position, for example by 0.5 mm, and is not cutting, the drill head remains in its drilling motion in the blind hole of the pilot bore and can no longer be actively guided. The "finish bore" is thus carried out.

While good results could be obtained with this known tool, it has been found in practice that both the cooling of the processing part by the cooling fluid and the removal of the bone chips, tissue and blood from the drilling site during processing are not optimal and improved should.

On this basis, the object of the present invention is to provide a surgical tool with which bone material can be processed without the tool breaking out of the bore channel or piercing the bore channel, with an improved serte cooling and improved removal of bone chips, tissue parts and blood are possible.

The object is achieved by a surgical tool with the features of claim 1. Preferred embodiments will become apparent from the dependent claims and the following description with accompanying drawings.

A surgical tool according to the invention for preparing bones, in particular for processing bones for inserting a dental implant, thus comprises a tool shank, which is designed to be clamped in a rotatable tool holder and has a channel for passing a cooling or rinsing liquid a machining member rotatable about an axial rotation axis drivable by the tool shank and located at the proximal axial end of the tool shank, and a guide member extending in the axial direction of the tool disposed at the proximal axial end of the machining member are axially movable relative to the machining member and

Is formed in a pilot bore and has on its surface one or more axially extending flushing grooves for conducting the cooling or rinsing liquid,

and has the peculiarity that the tool and the flushing grooves are formed such that the exit point at which the cooling or rinsing liquid exits the channel in the flushing grooves, in the region of the transition between the proximal axial end of the machining part and a distal axial Area of the guide element is arranged.

It has been found that optimal cooling and rinsing is possible with such a surgical tool. This is because the liquid used for cooling or rinsing in a tool according to the invention exits directly at the proximal cutting edge of the machining part, and not at the tip of the guide element at the bottom of the pilot hole as in the prior art. This has the advantage of better cooling of the cutting edge and thus of a jaw- and tissue-preserving machining or drilling operation, because the cooling fluid does not first emerge through an opening located at the proximal end of the guide element, through the narrow gap between the proximal end of the guide element and the bottom of the pilot bore adjacent thereto must flow and must flow back through the flushing grooves to the proximal end of the machining part, but can exit directly at the proximal end of the machining part. Better rinsing of bone chips, tissue parts and blood results from the fact that the flow is directed radially from the inside to the outside and thus transports the removed bone chips radially outward from the drilling site. As a result, clog the outlets of the cooling channels and the cooling channels or Spülnuten even less.

A further feature which is advantageous in this context may be that the surgical tool and the flushing grooves are designed in such a way that the cooling or flushing liquid flows in the flushing grooves in the direction of the proximal end of the guide element. The guide element thus has one or more axially extending outer grooves, which may also be referred to as slots or grooves, in which the cooling fluid flows in the direction of the proximal tip of the guide element. On the other hand, in the prior art, the cooling liquid exits at the proximal tip of the guide member and returns to the outside of the guide member in the flushing grooves. In the invention, therefore, the flow of the cooling or rinsing liquid in the flushing grooves of the guide member is directed proximally, whereas it is directed distally in the prior art.

Accordingly, it can be provided in an advantageous embodiment that the guide element has no channel for passing the cooling or rinsing liquid and / or that the guide element at its proximal end has no opening from the cooling or rinsing liquid emerges.

According to a further advantageous feature, it is proposed that the machining part and the tool shank together form an integral part. In EP 1 304 087 A2 the drill head and the tool shank are two separate parts and the drill head is screwed by means of a threaded connection on the tool shank up to a stop. The threaded connection of the prior art is a weak point, namely in terms of hygiene, as can accumulate in the fine bone bone chips, tissue parts and blood, and also in mechanical terms, because this may represent a possible breakage or loosen the connection in particular if the drill has multiple holes in a patient, for example eight holes, whereby the drill is heavily loaded in the hard bone. The one-piece design of the machining body (e.g., drill bit or tapping shaft) with the tool shank (e.g., drill shank), where both parts are made together in one piece, avoids these disadvantages. In this case, the breakage of the construction is guaranteed even with very small dimensions.

One, several or all parts of the tool shaft, the machining part and the guide element may for example consist of industrial steel no. 1.4301, 1.4303 or 1.4305. The industrial steels no. 1.4034 and 1.4197 are also advantageous. The advantage of steel 1.4197 is that it is slightly more "flexible" than the 1.4034 steel, but it also has a slightly less hard / sharp finish. For thin drills, for example, a pilot drill for pre-drilling, you could therefore rather use the steel 1.4197, otherwise the steel 1.4034. A particularly advantageous embodiment, in particular with common one-piece design of the machining part and the tool shank, may be that one, several or all parts of the tool shank, the machining part and the guide element consist of titanium, titanium nitride, titanium nitride, zirconium, zirconium oxide or ceramic. These materials have the advantage that they are biologically neutral, unlike steel, against Many patients are allergic. Thus, even allergic patients can be treated.

An additional advantageous embodiment may consist in that the sum of the cross-sectional areas of the flushing grooves in the guide element is at least as large as the cross section of the channel in the tool shaft. The advantage here is that a reduction of the flow cross section for the flow of the cooling or rinsing liquid is prevented by a cross-section narrowed transition from the channel into the flushing grooves and thus a reduction of the coolant flow.

The invention will be explained in more detail with reference to embodiments shown in the figures. The features described therein may be used alone or in combination with each other to provide preferred embodiments of the invention. Show it:

1 shows a side view of a drill according to the invention with a cylindrical drill head,

FIG. 2 shows a basic axial section of the drill shank and the machining part of the drill of FIG. 1,

FIG. 3 shows a side view of the guide element of the drill of FIG. 1,

4 shows a section B to FIG. 2, FIG. 5 shows a section A to FIG. 3, FIG. 6 shows a side view of a drill according to the invention with a conical boring head,

FIG. 7 shows a principal axial section of the drill shank and the machining part of the drill of FIG. 6,

FIG. 8 shows a side view of the guide element of the drill of FIG. 6,

9 shows a section B to FIG. 7 and FIG. 10 shows a section A to FIG. 8. FIGS. 1 to 5 show a first exemplary embodiment of a tool 1 according to the invention in the form of a drilling device for drilling a hole in a jaw for the insertion of a dental implant. The drilling device comprises a tool shank 2, which is designed to be clamped in a rotatable tool holder and has a channel 3 for passing a cooling or rinsing liquid, and a machining part 4 rotatable about an axial rotation axis C, which can be driven by the tool shank 2 and at the proximal end axial end of the tool shank 2 is arranged. The machining part 2 is cylindrical in this embodiment and, for example, a drill, in particular a twist drill, or a countersink.

The machining part 4 preferably has an outer diameter between 1.8 mm and 15 mm, preferably between 2.0 mm and 12 mm, more preferably between 2.5 mm and 10 mm. The lower limit results from the requirement that due to the internal parts described below, the remaining wall thickness for the cutting edge must be large enough. The upper limit results from appropriate areas of general orthopedic applications.

Furthermore, the tool 1 comprises a guide element 5 extending in the axial direction of the tool, which is arranged at the proximal axial end of the machining part 4, is axially movable relative to the machining part 4 and is designed for insertion into a pilot bore and has one or more on its surface Has in the axial direction extending Spülungsnuten 6 for guiding the cooling or rinsing liquid. The outer diameter of the guide element 5 is as large as or slightly larger than the inner diameter of the pilot hole. Expedient values are between 0.5 mm and 6.0 mm, preferably between 0.8 mm and 4.0 mm, particularly preferably between 1.0 mm and 2.5 mm.

The tool 1 and the flushing grooves 6 are formed such that the exit point at which the cooling or rinsing liquid from the channel 4 in the flushing grooves 6 exits, is arranged in the region of the transition between the proximal axial end of the machining part 4 and a distal axial region of the guide element 5.

The tool shank 2, for example a drill head carrier, is set in rotation after being clamped in a drive (not shown), for example an angle piece, and transmits the rotational movement to the machining part 4, which rotates about the axis C as a rotating machining part. The machining part can be fastened on a carrier, for example a drill head carrier.

At the beginning of the machining, the guide element 5 or its tip is inserted into the pilot boring borehole bored by the pilot boring or, when tapping, into the still remaining rest of the pilot boring duct. The rotating processing parts, e.g. Form drills or taps, now work while editing the bone along the guide member 5 in the bone. Here they are defined axially displaced along the guide member 5 and there is no risk that they break out laterally.

Advantageously, it may be provided that the guide element 5 or at least the proximal part of the guide element 5 which can be inserted into a pilot bore is designed like a pin. Furthermore, it is advantageous if the guide element 5 or at least the proximal part of the guide element 5 which can be inserted into a pilot bore is not designed for machining bones, in particular is not designed for drilling, cutting or milling. A non-cutting guide element 5 ensures the user that he can drill a hole exactly round, without departing from the pilot hole in depth and / or angle.

A particularly advantageous embodiment may consist in that the maximum machining depth of the guide element 5 can be specified. This ensures that the machining parts can not penetrate into the bone beyond the predetermined bore. NEN. The processing space for the rotatable machining part 4 is specified exactly and there is no risk of lateral deflection or exceeding of the bore depth. Sources of error during processing are thus largely excluded.

If the guide element 5 specifies the maximum working depth, this brings many advantages. So do not have to be laboriously attached so-called depth stop rings above the drill. Furthermore, an automatic processing stop takes place at the desired processing depth and it is not necessary to measure the penetration depth on a length scale beforehand or during the entire processing operation. By the guide member 5, a maximum machining depth can also be specified when the machining part 4 is not fully penetrated into the hole. This is not possible when using conventional depth stop jumpers, as they usually have to be fastened above the machining part 4 and thereby would not come to a stop at the bore mouth.

The maximum machining depth can either be specified by the guide element 5 according to production or, if necessary, adjusted by the user according to his wishes on the tool itself. The maximum machining depth can be selected arbitrarily, so that, for example, only the upper part of the bone bore is machined or the machining takes place almost to the end of the bore.

If the maximum machining depth is predetermined by the guide element 5, it is conceivable, for example, that the machining depth can be predetermined by a stop. In this case, the rotatable processing part 4 can only be displaced axially on the guide element 5 up to this stop. An editing beyond the stop is then not possible.

In a first embodiment, the machining part 4 can rotate about the guide element 5, the guide element 5 without its own Rotary movements remains in its position and only the machining part performs rotational movements.

In a further embodiment of the tool 1 according to the invention, the machining part 4 rotates with the guide element 5, wherein the rotational movement can be transmitted from the guide element 5 to the machining part 4 or vice versa.

The transmission of the rotational movement can be effected for example by a positive connection in the direction of rotation. An axial movement along the guide element 5 can be forced in this case by a mutual wedge-shaped or conical taper of the positive connection. Due to this beveling, the machining part 4 is displaced in the direction of the bore during the working process, since the rotational movement is partially converted by the bevel into a movement with an axial component.

A specification of the maximum machining depth is also possible in that the positive connection between the guide element 5 and the machining part 4 is solvable from a certain depth and the machining part 4 no longer rotates at this depth and, thereby remains in the bone. In this case, there is a hollow turning of the guide member 5, wherein no rotational movement is transmitted from the guide member 5 to the machining part 4.

It is possible that after the processing part 4 has remained in the bone and the rotational movement of the guide element 5 is stopped, a new positive connection with the guide element 5 is produced and the processing part 4 is thereby removed from the bone. For example, in this case the machining part 4, for example a thread cutter, can be turned out of the bore again in a rotational movement in the opposite direction.

For the surgical tool 1 according to the invention, it is possible to use different machining parts 4. To be particularly important proven for a drill, especially form drill, and the other thread cutter.

During the machining process, bone material is removed. In addition to the bone chips are also tissue parts and blood. These contaminants should be removed from the bore during the working process, otherwise smearing will occur. For this purpose, 2 cooling or rinsing liquid is supplied through the inlet opening 7 in the distal end face of the tool shank. The cooling or rinsing fluid passes through the shaft of the drill into the drill head and is discharged from the drill bit via the flushing grooves 6 mounted on the guide element 5. This ensures that the liquid emerges at the point where the proximal edge of the machining tool 4 is most active.

The cooling or rinsing liquid introduced during the machining process is, for example, an isotonic saline solution. The aqueous solution serves, on the one hand, to cool the processing tool; on the other hand, the worn bone parts are flushed out of the hole in the bone. In order to make this possible, the guide element 5 is provided with flushing grooves 6 in the device according to the invention. However, the saline solution does not emerge at the tip of the guide element 5 as in the prior art and runs out of the bore in the bone along the flushing grooves 6, but the liquid already occurs in the region of the transition between the proximal axial end of the machining part 4 and a distal axial region of the guide element 5, ie at the distal and not at the proximal end of the pilot hole. By the fluid, the bone material is swished out, so that it can not come to smearing the drilled hole from the tool 1.

The flushing grooves 6 on the guide member 5 may extend to the proximal end of the guide member 5 to also cool or rinse the guide member 5 and the pilot hole. It is difficult for saline solution to enter the pilot hole in the bone. inflow and escape from it, since the guide element 5 usually sits in the pilot hole only with little play. However, it has been found that the cooling or flushing of the pilot bore achieved in this way is sufficient because it is more important to cool and rinse the proximal end of the machining part 4 than the guide element 5 in the pilot bore. Nevertheless, in the case of the invention, pressure does not build up when passing through an aqueous solution, which in the worst case could lead to the tool 1 being pushed out of the bore or pilot hole or which may lead to the cooling channel not being in the tool 1 flows through more and it comes to an undesirable heating. In fact, overheating the tool could cause significant patient damage by severely damaging bone and embedded nerves.

Expediently, an axially acting spring element 8 is provided between the machining part 4 and the guide element 5, which pushes the guide element 5 out of the machining part 4. The tool 1 thus has in this case a spring element 8 which generates a restoring force, which moves the guide member 5 in the proximal direction relative to the machining part 4, wherein the guide member 5 is axially movable against the restoring force. The advantage of using the spring force to push out the guide element 5 is that the tool 1 is ready for use immediately. The guide element 5 does not first have to be pulled out of the tool 1, in order then to be introduced into the pilot hole. By the spring force, the guide element 5 is automatically led out to a stop and can be used directly in the pilot hole. Furthermore, there is no risk that the guide element 5 slips back into the tool 1, for example, during the machining process. Thus, the user can also work against gravity, without having to fear that the guide element 5 comes out of engagement with the pilot hole and thus its leadership function is disturbed. In the distal end of the tool shank 2, which is clamped in a tool holder, it is, for example, a DIN-standard part or finished part. The machining part 4 is fixed on the tool shank 2 via a thread or, according to a preferred embodiment, formed integrally with the tool shank 2. The machining part 4 can be screwed onto the tool shank 2 up to a stop. The end of the tool shaft 2 also abuts a stop in the interior of the machining part 4. In the inner bore 9 of the machining part 4, the guide element 5 is slidably mounted. Before using the tool, the abutment of the guide element 5 abut against a stop of the machining part 4. The guide element 5 is pressed by the spring element 8 to the stop.

The spring 8 is seated at its one end on the spring seat 10 of the guide element 5. At its other end sits the spring 8 on the spring seat 11 of the tool shank 2, which also serves as a tool carrier on. In the tool shank 2, the spring 8 is guided in the inner bore 12 of the tool shank 3.

After a pilot hole was made with a drill that has only a slightly larger diameter than the guide element 3, the guide element 3 is inserted into this pilot hole. The machining part 4, which is fixed, preferably integrally connected to the tool shank 2, is set in rotation. The guide member 3 does not rotate with it, but remains immobile in the pilot hole. By applying a force, the rotating machining part 4 is pressed proximally in the direction of the pilot bore. In this case, the force applied by the spring 8 counterforce must be overcome. The spring 8 compresses during this process together. During the drilling operation, the machining part 4 shifts along the guide element 3 or the guide element 3 with respect to the machining part 4 until a stop is reached. This stop defines the maximum machining depth up to which the rotating bearing Beitungsteil 4 can penetrate into the pilot hole. The spring 8 is compressed in this process.

Through the interior of the tool shank 2 and the machining part 4 a cooling water channel 3 runs through this channel 4 an isotonic saline solution is passed through this channel 4 for cooling the tool 1 and for spitting out the removed bone parts. The isotonic saline solution exits at the proximal end of the processing part 4 during the machining process. Tip of the guide member 3 and then runs in the radial direction from the exit point laterally outward and along the flushing grooves 6 in the proximal direction on the guide element. 3

For securing the guide element 3, in particular in the one-piece design of tool shank 2 and machining part 4, a securing element may be provided with which the guide element 3 is held in the processing part 4 after insertion into the machining part 4. In the exemplary embodiment, a securing bolt 13 serves this purpose, which is inserted or screwed into a corresponding radial opening 14 and engages in a corresponding recess or step in the guide part 3. In other embodiments, as a securing element, for example, the guide member 5 has formed as a pivotable barb fastening parts that fold during assembly of the guide member 5 in the processing part 4 and provide for the fixing of the guide member 5 in the processing part 4.

In Figures 4 and 5 it can be seen that in the embodiment in the tool holder 2 has an inlet opening 7 and a bore for passing cooling or rinsing liquid through the surgical saw tool 1 was centrally introduced and a total of four Spülungsnuten 6 in the Guide element 4 were milled into it.

FIGS. 6 to 10 show a second exemplary embodiment of a tool 1 according to the invention in the form of a drilling device for drilling a hole in a jaw for the insertion of a dental implant. posed. It corresponds to the first embodiment of Figures 1 to 5, with the difference that the machining part 4 is not cylindrical, but conical. The machining part 4 may be, for example, a drill head.

In summary, the surgical tool 1 according to the invention is characterized in that the user is once set the pilot hole, which can perform subsequent operations without major sources of error. With the tool according to the invention, there is neither the risk of a lateral breaking out of the bore nor of a puncture of the bore downwards. This is ensured by virtue of the tool having a guide element 5 and the rotating machining part 4 being displaced axially relative to the guide element 5 during the machining process, thereby enabling improved cooling and improved removal of bone chips, tissue parts and blood. With the tool 1 according to the invention it is also possible for beginners to carry out the necessary processing steps for the preparation of bones, in particular for the insertion of dental implants.

LIST OF REFERENCE NUMBERS

1 surgical tool

2 tool shank

3 channel

4 processing part

5 guide element

6 flush groove

7 entrance opening

8 spring element

9 internal bore in 4

10 spring seat to 5

11 spring seat to 2

12 internal bore in 2

13 securing bolts

14 opening

C rotation axis

Claims

claims

1. A surgical tool (1) for preparing bones, in particular for processing bones for inserting a dental implant, comprising - a tool shaft (2) which is designed for clamping in a rotatable tool holder and a channel (3) for passing a cooling or rinsing liquid, a about an axial rotation axis (C) rotatable machining part (4) of the tool shank (2) drivable and at the proximal axial end of the tool shank (2) is arranged, in the axial direction of the tool (1 ) extending guide member (5) arranged at the proximal axial end of the machining part (4), axially movable relative to the processing part (4) and adapted for insertion into a pilot hole and on its surface one or more in the axial direction extending Spülungsnuten (6) for conducting the cooling or rinsing liquid, characterized in that the tool (1) and the Sp ülungsnuten (6) are formed such that the exit point at which exits the cooling or rinsing liquid from the channel (3) in the Spülungsnuten (6), in the region of the transition between the proximal axial end of the processing part (4) and a distal axial region of the guide element (5) is arranged.

2. A surgical tool (1) according to claim 1, characterized in that the tool (1) and the flushing grooves (6) are formed such that the cooling or rinsing liquid in the flushing grooves (6) toward the proximal end of the guide member (5).

3. Surgical tool (1) according to one of the preceding claims, characterized in that the guide element (5) has no channel (3) for passing the cooling or rinsing liquid.

4. Surgical tool (1) according to any one of the preceding claims, characterized in that the guide element (5) has at its proximal end no opening from the cooling or flushing liquid exits.

5. surgical tool (1) according to any one of the preceding claims, characterized in that the Spülungsnuten

(6) extend to the proximal end of the guide element (5).

6. Surgical tool (1) according to one of the preceding claims, characterized in that the sum of the cross-sectional areas of the flushing grooves (6) in the guide element (5) at least as large as the cross section of the channel (3) in the tool shank (2 ).

7. Surgical tool (1) according to one of the preceding claims, characterized in that the guide element (5) or at least the insertable into a pilot hole proximal part of the guide element (5) is pin-shaped.

8. Surgical tool (1) according to one of the preceding claims, characterized in that the guide element (5) or at least the insertable into a pilot hole proximal part of the guide element (5) is not designed for machining bone, in particular not for drilling, Cutting or milling is formed.

9. surgical tool (1) according to any one of the preceding claims, characterized in that it comprises a spring element (8) which generates a restoring force which moves the guide element (5) in the proximal direction, wherein the guide element (5) against the restoring force is axially movable.

10. A surgical tool (1) according to any one of the preceding claims, characterized in that the machining part (4) and the tool shank (2) together form an integral part.

11. Surgical tool (1) according to the preceding claim, characterized in that it comprises a securing element (13) with which the guide element (5) after insertion into the machining part (4) in the machining part (4) is held.

12. Surgical tool (1) according to one of the preceding claims, characterized in that one, several or all parts of the tool shank (2), the machining part (4) and the guide element (5) made of industrial steel no. 1.4301, 1.4303, 1.4305, 1.4034 or 1.4197 exist.

13. Surgical tool (1) according to one of the preceding claims, characterized in that one, several or all parts of the tool shank (2), the machining part (4) and the guide element (5) made of titanium, titanium nitrite, titanium nitride, zirconium,

Zirconia or ceramic.

14. Surgical tool (1) according to one of the preceding claims, characterized in that it is designed such that by means of the guide element (5) a maximum machining depth can be predetermined.

15. Surgical tool (1) according to the preceding claim, characterized in that it comprises a stop for specifying the machining depth.

16. Surgical tool (1) according to one of the preceding claims, characterized in that the machining part (4) about the guide element (5) is rotatable.

17. Surgical tool (1) according to one of the preceding claims, characterized in that the machining part (4) with the guide element (5) is rotatable.

18. Surgical tool (1) according to one of the preceding claims, characterized in that the machining part (4) is designed as a drill, in particular as a twist drill, or as a countersink.

19. Surgical tool (1) according to one of the preceding claims, characterized in that the machining part (4) is designed as a tap.

20. Surgical tool (1) according to one of the preceding claims, characterized in that the machining part (4) is cylindrical.

21. Surgical tool (1) according to one of the preceding claims, characterized in that the machining part (4) is conical.

22. A surgical tool (1) according to any one of the preceding claims, characterized in that the machining part (4) has an outer diameter between 1.8 mm and 15 mm, preferably between 2.0 mm and 12 mm, more preferably between

2.5 mm and 10 mm.

23. Surgical tool (1) according to one of the preceding claims, characterized in that the guide element (5) has an outer diameter between 0.5 mm and 6.0 mm, preferably between 0.8 mm and 4.0 mm, more preferably between 1.0 mm and 2.5 mm.