WO2009046896A1 - Depth stop and removal device for such a depth stop - Google Patents

Abstract

The invention relates to a depth stop for a dental instrument (80), comprising a working part (82) and a shank (84), with a first and a second ring-shaped longitudinal section (12, 14). According to the invention, the inside diameter of the first longitudinal section (12) is larger than the one of the second longitudinal section (14), such that a stop surface (16) is formed, which is designed to stop at the transition from the shank to the working part of the dental instrument (80). In the region of the second longitudinal section (14), at least one radially acting detent element (18, 20) is provided, which latches into a recess (88) in the shank (84) of the dental instrument (80) and is configured to expand for removal from the detent position.

Description

 Depth stop and puller for such a depth stop

The present invention relates to a depth stop for a dental instrument, which has a working part and a shaft, with a first and a second annular longitudinal section. The invention further relates to a puller for such a depth stop.

In the field of dental implantology, drills are used to introduce the necessary holes for dental implants in the jawbone. With such a treatment, it is important for the dentist to exactly maintain the drilling depth required for the selected dental implant and thus not to drill too deep. A previously proposed solution to comply with the required drilling depth is to attach certain markers on the drill, which are visually perceived by the dentist. The disadvantage of these markings, however, is that they are not perceptible to the dentist in every case, for example because blood obscures the markings.

BeSTÄTIGUNGSKOPlE Another solution to limit the drilling depth is to provide so-called depth stops or deep stops on the drill. A solution is given for example in DE 20 2004 020 516 Ul. These depth stops are mechanical means that ensure that the dentist does not drill too deep. Typically, these mechanically acting depth stops are pushed over the drill section of the drill on the shaft and fastened there.

However, this always results in the problem that the depth stop is released from its attachment and slips into the area of the drill section. An effective function of the depth stop is then no longer given. It is even worse if the depth stop slides away from the drill section, so that the set drilling depth increases, which is by no means desired.

Another disadvantage of the previous solutions is the fact that the mechanical depth stop rotates with the drill, so that there may be damage to tissue when the depth stop comes into contact with the jaw.

Against this background, one of the objects of the present invention is to refine a depth stop of the type mentioned above so that it no longer adheres to the aforementioned disadvantages. In particular, a secure attachment of the depth stop should be ensured so that the set depth can not accidentally change to larger values.

This object is achieved by the above-mentioned depth stop in that the inner diameter of the first longitudinal portion is greater than that of the second longitudinal portion, so that there is a stop surface, which is adapted to strike at the transition from shaft to working part of the dental instrument, and that in At least one radially acting locking element is provided in the region of the second longitudinal section, which engages in a recess in the shaft of the dental instrument and is designed expandable for unlatching. In other words, that the depth stop according to the invention is not - as usual - pushed over the working part (drill section) of the dental instrument in its position, but instead is plugged from the shaft end on the dental instrument. The stop surface ensures that the depth stop does not get into the working part under any circumstances. The expandable locking element ensures on the one hand that the depth stop is held securely in the longitudinal direction and holds its position, and on the other hand that a slight removal from the dental instrument is made possible by the locking element is widened and pulled by the shaft.

The detachable fastening of the depth stop according to the invention makes it possible to work with very high fastening or holding forces, so that it is reliably ensured that the fastening does not come loose during operation. On the other hand, allows the solution according to the invention that the depth stop can be easily removed from the dental instrument despite the large holding forces.

According to a preferred refinement, the at least one latching element is designed to permit a rotation of the depth stop relative to the dental instrument in the latched state.

The advantage of this solution is the fact that a relative movement between the depth stop and dental instrument is possible, so that the depth stop no longer rotates with the dental instrument when in contact with the patient's jaw so that damage to the tissue can be avoided.

According to a preferred embodiment of the depth stop is made of metal. Preferably, two locking elements are provided in the region of the second longitudinal section, which are arranged distributed uniformly in the circumferential direction of the longitudinal section. This embodiment has the advantage that the protection against longitudinal displacement on the dental instrument significantly better than with a single locking element.

According to a preferred embodiment, the locking elements each have a resilient tongue in the radial direction, provided at the free end of the tongue locking lug and a widening portion, wherein the widening portion at latched detent has a distance from the shaft of the dental instrument.

That In other words, that the locking elements are formed so that in the locked state, a space between the shaft and latching tongue remains, which is designed so that can be solved by inserting a puller, the locking lugs from their catch.

In a preferred development, the dental instrument is a drill, in particular an implant drill.

Especially in the field of dental implantology, the depth stop can be used particularly advantageously with implant drills.

The invention also relates to a puller for such a depth stop according to the invention, the puller having first, second and third annular longitudinal portions whose inner diameters are greater than or equal to the outer diameter of the stem of the dental instrument, the first longitudinal portion having a tapered outer diameter. whose smaller outer diameter is less than or equal to the inner diameter of the depth stop in the region of the expansion section.

In other words, that the puller is fitted onto the shaft of the dental instrument and is introduced with the first longitudinal portion in the widening portion of the depth stop. Due to the conical tion, the locking elements are bent radially outward, so that the locking lugs release from their locked state. The depth stop can then be pulled over the shaft of the dental instrument by means of the puller.

Preferably, the third longitudinal section has a larger outer diameter than the second longitudinal section and serves as a handling aid. Preferably, the third longitudinal section is knurled on the outside. More preferably, a sleeve is provided, which is designed to be plugged onto the first longitudinal section and has an inner diameter which is greater than the outer diameter of the depth stop at least in the region of its second longitudinal section.

The above measures have the result that improves the ergonomics of the puller for the depth stop.

Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

The invention will now be described in more detail with reference to an embodiment. Showing:

1 shows several sectional views of a depth stop according to the invention;

2 shows several schematic sectional views of the puller for the aforementioned depth stop; and Fig. 3 shows two schematic sectional views showing a depth stop plugged onto a dental drill, wherein in one illustration, the puller expands the depth stop and releases from the catch.

In Fig. 1, a depth stop for a dental instrument is shown in several sectional views and generally designated by the reference numeral 10. The metal depth stop 10 is annular and has a bore 11 which completely penetrates the depth stop 10.

The depth stop 10 is divided into two functional sections seen in the longitudinal direction, namely a first longitudinal section 12 and an adjoining second longitudinal section 14. The first longitudinal section 12 has the function to specify the maximum drilling depth, while the second longitudinal section 14 has the function, a To allow attachment to the dental instrument.

The first longitudinal section 12 has a substantially uniform outer diameter, however, the inner diameter tapers from a diameter dl to a smaller inner diameter d2 at the transition to the second longitudinal section 14. Here, the smaller inner diameter d2 is at least as large as the outer diameter of the working part of the dental instrument. In a preferred implant drill as a dental instrument, the working part is the drill section of the implant drill.

The second longitudinal section 14, at least in the transition region from the first longitudinal section 12 to the second longitudinal section 14, has an inner diameter which is identified by d3 in FIG. 1 and is slightly smaller than the inner diameter d2 of the longitudinal section 12. This difference in inner diameter leads to a step is formed in the interior of the depth stop 10, which forms a stop surface 16 which is substantially perpendicular to the longitudinal axis. This abutment surface 16 is due to the rotational symmetry of the first longitudinal portion 12 an annular surface. The inner diameter d3 of the second longitudinal section 14 is chosen so that it is greater than the outer diameter of the shaft of the dental instrument, but smaller than the outer diameter of the working part, so for example, the drill section. This size selection of the inner diameter d2 and d3 ensures that the depth stop 10 with its second longitudinal section 14 can not be pushed onto the working part, ie, for example, the drill section, of the dental instrument. Instead, when the depth stop 10 is plugged from the shaft end of the dental instrument, the depth stop 10 with the abutment surface 16 strike the working part of the dental instrument. In this case, the first longitudinal section 12 projects into the working part of the dental instrument by a predetermined length (namely the length of the first longitudinal section 12), while the second longitudinal section 14 lies completely in the region of the shaft 84 of the dental instrument.

As already mentioned, the length of the first longitudinal section 12 determines the maximum drilling depth of the dental instrument. The longer the first longitudinal section 12, the lower the maximum drilling depth. This means in other words that depth stops 10 can be provided with differently long first longitudinal sections 12 as it were as a depth stop kit.

As already mentioned, the second longitudinal section 14 serves to secure the depth stop 10 on the dental instrument, namely the shaft 84, against displacement in the longitudinal direction. However, in a preferred embodiment, rotation of the depth stop 10 about the longitudinal axis relative to the dental instrument is still possible.

For this purpose, the second longitudinal portion 14 at least one, preferably a plurality of fastening elements which cooperate with the dental instrument so that a displacement of the depth stop 10 is prevented in the longitudinal direction, however, a rotation about the longitudinal axis remains possible. In the present embodiment 18 locking tongues are provided as fastening elements, which are indicated in Fig. 1 by the reference numeral 20. Overall, the second longitudinal section 14 has two such latching tongues 20, which are arranged uniformly distributed in the circumferential direction. The locking tongues 20 are connected at their end facing the first longitudinal section 12 fixedly connected to the depth stop 10, while the opposite end, which faces the longitudinal end 22 of the depth stop 10, is free. By appropriate design of the material thickness of the locking tongues 20, thus, the free end can be deflected in the radial direction by applying a predetermined force. This force can be determined by the design of the locking tongue (eg. Material thickness, type of material, etc.). In particular, by this embodiment, very high forces acting in the radial direction can be achieved, which prevent unintentional release of a catch. In the "relaxed" state of the depth stop 10 (ie, the depth stop 10 is not attached to a dental instrument) protrudes the free end of the locking tabs 20 slightly inwardly towards the longitudinal axis, so that the inner diameter in this area is slightly less than the inner diameter d3.

Basically, the locking tongues 20 serve to engage in a corresponding depression in the dental instrument, in particular in the shaft region, and thus to prevent a longitudinal displacement at least in one direction. For this latching mechanism, the latching tongue 20 has at its free end a latching lug 24, which has a the end 22 facing, extending substantially perpendicular to the longitudinal axis surface 26. This can be seen particularly clearly in the enlargement representations in FIG.

To the surface 26 of the locking lug 24, a further region 28 connects, which is part of the latching tongue 20 and consequently also in the radial direction is deflectable. This region 28 extends in the longitudinal direction and forms a widening portion, which is designated in FIG. 1 by the reference numeral 30. This widening section 30 is essentially characterized in that its inner diameter is greater than the inner diameter in the region of the latching lug 24. The inner diameter of the expansion portion 30 is selected so that - in the mounted state of the depth stop 10 - a sufficiently large distance between the shaft and the inner region of the expansion portion 30 remains to plug a removal aid, which will be described later, in this gap can.

From the detailed drawings of FIG. 1, it is also apparent that the widening section 30 extends inwardly towards the longitudinal axis towards the end 22, so that the end region, which is designated by the reference numeral 32, has a smaller inner diameter than the region between the latching lug 24 and End area 32.

In Fig. 3, the depth stop 10 is shown in the attached state. The dental instrument is a dental or implant drill 80, which has a drill section 82 and a shaft 84. Since the outer diameter of the drill section 82 is greater than the outer diameter of the shaft 84, an edge 86 is created in the transition region, which cooperates with the abutment surface 16 of the depth stop 10 and prevents displacement of the depth stop 10 in the longitudinal direction of the drill section 82.

In the shaft 84 of the drill 80, an annular groove 88 is provided, in which the detent 24 of the depth stop 10 engages, thus preventing longitudinal displacement of the depth stop 10 to the shaft end. This state can be clearly seen in the upper illustration of FIG. 3. Furthermore, it can be clearly seen here that the widening section 30 of the depth stop 10 leaves open an annular gap between the shaft 84 and the widening section 30.

In order to release the depth stop 10 from this locked position and to pull it over the shaft 84, there is a removal aid, which is shown in detail in FIG. 2 and is identified by the reference numeral 40. The removal aid 40 has three longitudinal sections 42, 44, 46, wherein the first longitudinal section 42 can still be seen in FIG. 3. This first longitudinal section 42 has at its end an annular region 50 which lies between two conical regions 54 and 56. This means that the outer diameter of this annular region increases from the end 52 to the annular region 50 and then again decreases and merges into a straight region 58 in which the outer diameter is constant. Adjoining this straight region 58 is a latching section whose outside diameter is greater than that of the straight section 58 and which has a recess 62.

The second longitudinal section 44 has a uniform outer diameter and merges into the third longitudinal section 46 whose outer diameter is significantly greater than that of the second longitudinal section 44. This third longitudinal section 46 serves to handle the peel-off aid 40 and, for this purpose, has a knurling 70 on its outer side.

The removal aid 40 is rotationally symmetrical in its structure and has a bore 41 which extends with a uniform inner diameter over the entire length of the removal aid 40 and is adapted to receive at least the shaft 84 of the dental instrument.

The function of this removal aid 40 is now to release the latched on the dental instrument 80 depth stop 10 from the latch to pull it from the shaft 84 of the dental instrument 80. For this purpose, the annular region 50 is provided on the removal aid 40, which serves to penetrate through the conical region 54 into the widening section 30, ie the gap between the shaft 84 and the second longitudinal section 14 of the depth stop 10, thereby pressing the locking tongues 20 radially outward. Although the radially acting force of the latching tongue is very large in order to prevent accidental release of the latching, can be easily accomplished by means of the removal aid 40, the expansion. The deflection of the latching tongue 20 outwardly corresponds at least to the depth of the annular groove 88, so that the latching lug 24 comes out of the annular groove 88. Characterized in that in the expansion section 30, an inwardly projecting end portion 32 is provided on the depth stop 10, the locking tongues 20 behind the ring portion 50 quasi snap, so that a firm connection between depth stop 10 and Abziehhilfe 40 is present, which is at least sufficient to the depth stop 10 from the shaft 84 to pull.

3 that the removal aid 40 has in its first longitudinal section 42 a sleeve 90 whose inner diameter is greater than the outer diameter of the widened second longitudinal section 14 of the depth stop 10. The sleeve 90 also extends significantly in the longitudinal direction the end of the longitudinal portion 42 of the peel-off 40, so that almost the entire second longitudinal portion 14 of the depth stop 10 of the sleeve 90 - is covered - in the locked state.

In summary, it can be seen that the depth stop 10 according to the invention is easy to handle and can be securely fastened to the shaft 84 without the risk that it could enter the drill section 82 of the dental instrument 80 during operation. In addition, the attachment described on the shaft 84 ensures a relative rotation about the longitudinal axis between the depth stop 10 and the dental instrument 80. With the help of the described removal aid 40, the depth stop 10 can very easily be separated again from the dental instrument 80 and placed on another dental instrument.

Claims

claims A depth stop for a dental instrument (80) having a working part (82) and a shaft (84), having a first and a second annular longitudinal portion (12, 14), characterized in that the inner diameter of the first longitudinal portion (12) is greater than that of the second longitudinal portion (14), so that a stop surface (16) results, which is adapted to abut at the transition from shaft to working part of the dental instrument (80), and at least one radially acting locking element (18, 20) is provided in the region of the second longitudinal section (14), which engages in a recess (88) in the shaft (84) of the dental instrument (80) and is made expandable for unlatching. 2. depth stop according to claim 1, characterized in that the at least one latching element (18, 20) is designed to allow a rotation of the depth stop relative to the dental instrument (80) in the engaged state. 3. depth stop according to claim 1 or 2, characterized in that it is made of metal. 4. depth stop according to one of the preceding claims, characterized in that in the region of the second longitudinal portion (14) two locking elements are provided, which are arranged distributed uniformly in the circumferential direction of the longitudinal portion (14). 5. depth stop according to one of the preceding claims, characterized in that the latching elements (18) each one resilient in the radial direction Tongue (20), one at the free end of the tongue (20) provided latching nose (24) and a widening portion (30), wherein the widening portion (30) at latched detent (24) a distance from the shaft (84) of the dental instrument (80 ) having. 6. depth stop according to one of the preceding claims, characterized in that the dental instrument (80) is a drill, in particular an implant drill. A depth stop puller (10) according to any one of the preceding claims, including first, second and third annular longitudinal portions (42, 44, 46) having an inner diameter greater than or equal to the outer diameter of the stem (84) of the dental instrument (80 ), wherein the first longitudinal portion (42) has a tapered outer diameter (50, 54, 56) whose smaller outer diameter is less than or equal to the inner diameter of the depth stop (10) in the region of the expansion portion (30). 8. Pulling device according to claim 7, characterized in that the third longitudinal section (46) has a larger outer diameter than the second longitudinal section (44) and serves as a handling aid. 9. Pulling device according to claim 8, characterized in that the third longitudinal section (46) is knurled on the outside. 10. Pulling device according to one of claims 7 to 9, characterized in that a sleeve (90) is provided, which is designed to be attachable to the first longitudinal portion (42) and has an inner diameter which is greater than the outer diameter of the depth stop (10). at least in the region of its second longitudinal section (14).