FR3063426A1 - DENTAL SURGICAL DEVICE COMPRISING AN INSTRUMENT DOOR AND A DENTAL ROTARY INSTRUMENT, THE INSTRUMENT DOOR PRINTING A BEND WITH A FLEXIBLE PORTION OF THE ROTARY INSTRUMENT - Google Patents

Abstract

The invention relates to a dental surgery device (1) comprising: - a rotary dental instrument (2) having an active portion (20) at one end and a coupling portion (22) at the other end, as well as a flexible portion (21) located between the active portion and the coupling portion; - an instrument holder (3) comprising a main body (30) incorporating motor means (301) intended to drive the rotary instrument in rotation, and a secondary body (31) capable of receiving the rotary instrument, the secondary body being intended to be assembled on the main body and to impart at least one curvature to the flexible portion of the rotary instrument.

Description

The field of the invention is that of the design and manufacture of dental surgery instruments. More specifically, the invention relates to a dental surgery device of the angle return type.

In the field of the invention, the practice of endodontics involves the use of small rotary instruments, in particular for root treatment. The rotary instruments used resemble small diameter drills.

Conventionally, such instruments consist of two parts, namely:

- an active portion consisting of a blade, a drill or even a file;

- a coupling portion located in the extension of the active portion, constituting an interface of the instrument.

The interface of the instrument is adapted according to the type of setting in motion which can be manual or mechanized. Either the instrument has a structure intended to be handled directly by a practitioner (manual movement), or it has a structure intended to cooperate with an instrument holder (motorized drive of the instrument, with complete freedom of animation, for example in rotation, alternating or continuous, or in axial or radial displacement, or in vibration, these movements can be simple or combined).

In the case where the instrument is coupled to an instrument holder, it is possible that the instrument has an angle of rotation which is not aligned with the axis of rotation of the motor means located inside the instrument holder.

For example, when a dental surgeon seeks to perform a pulpectomy, he uses an instrument holder called a contra-angle and an instrument of the "channel instrument" type. In this configuration, the instrument has an angle facilitating the work of the dental surgeon.

The angle presented by the instrument involves mechanisms of angle transmission.

These angle transmission mechanisms are conventionally produced with high-precision metal members (gear, axis, allowing the transmission of the motorized drive at high speed (in particular up to speeds of the order of tens of thousands of Rotations per minute).

According to standard practice, instrument holders with a bevel gear must be washed and sterilized. This characteristic is essential for these instruments intended to be used in the context of dental surgery. As a result, meticulous washing and sterilization methods have been devised for these instruments.

However, we note that, although these instruments were designed to be washed and sterilized, the presence of the angle return mechanisms creates places that are difficult to access for washing. Also, despite the washing and sterilization operations, the instrument holders may show significant fouling (for example by blood and other organic debris).

In addition, the instrument holders can also be designed to be able to inject an irrigant during a dental surgery operation. The disadvantage of these irrigators is that they crystallize inside the instrument holders. These crystals are extremely difficult to remove and increase the fouling of the instrument holders. In addition, metal instrument holders can be damaged by contact with the irrigant, which is generally a very corrosive fluid (diluted bleach, hydrogen peroxide, ...).

The object of the invention is in particular to overcome the drawbacks of the prior art.

More specifically, the invention aims to provide a dental surgery device, of the type comprising an instrument holder and an instrument inclined relative to the instrument holder, which does not present the fouling problems presented by the devices described in the prior art which include angle return mechanisms.

The invention also aims to provide such a device which is more suitable for the use of irrigants than the devices presented in the prior art.

These objectives, as well as others which will appear subsequently, are achieved thanks to the invention which relates to a dental surgery device comprising:

- a dental rotary instrument having at one end an active portion and at the other end a coupling portion, the active portion having an axis of rotation R1 and the coupling portion having an axis of rotation R2;

- an instrument holder comprising a main body integrating:

- motor means;

- A coupling member intended to establish a rotationally integral connection with the coupling portion, in order to be able to drive the rotary instrument in rotation using the motor means;

characterized in that the rotary instrument has a flexible portion between the active portion and the coupling portion, and in that the instrument holder comprises a secondary body capable of accommodating the rotary instrument, the secondary body integrating:

- means of assembly on the main body;

at least one internal element for guiding the rotary instrument in rotation, the internal guiding element or elements being capable of imparting at least one curvature to the flexible portion of the rotary instrument so that the axis of rotation R1 and the axis of rotation R2 form a non-zero angle.

The expression "rotary instrument" means for example any file, milling cutter or drill bit which is mounted and presented at the end of an instrument holder.

In other words, compared to an instrument holder according to the prior art which has a body at the end of which couples a rotary dental instrument and from which protrudes the active portion of the instrument, the instrument holder according to the invention has a main body at the end of which the secondary body couples. Thus, the dental rotary instrument according to the invention is received inside the secondary body and is intended to be assembled with the coupling member located and presented by the main body.

The secondary body thus forms an independent and complementary structure of the main body of the instrument holder as well as of the rotary dental instrument, the active portion being intended to project from the secondary body.

It therefore follows that the dental rotary instrument according to the invention and the secondary body of the instrument holder form an alternative to the mechanism of the bevel gear of the instrument holders according to the prior art.

Thanks to the design of the dental surgery device according to the invention, the instrument holder is not or only slightly subject to a fouling phenomenon.

In fact, the dental surgery device according to the invention does not include a bevel gear mechanism comprising gears and axes articulated with gears. As a result, the dental surgery device does not have places that are difficult to access for cleaning and sterilization, which would form potential areas of bacterial retention.

According to another approach, due to the absence of such a conventionally designed angle transmission mechanism, the secondary body can be designed for single use. In fact, thanks to the dental rotary instrument which has the flexible portion, the secondary body does not have to include a precise mechanical mechanism which is expensive to design and which would allow the angular gear to be produced.

According to an advantageous solution, the internal element for guiding in rotation is a channel having at least one curvature, the channel being intended to receive the flexible portion of the rotary instrument.

Such a channel forms a simple solution to implement to form the guide element in rotation.

Such a channel also avoids the creation of places which are difficult to clean in the event that a cleaning operation is necessary.

Preferably, the dental rotary instrument is in one piece.

Such a design of the dental rotary instrument eliminates the need to assemble multiple small parts.

According to a preferred characteristic, the secondary body takes the form of a shell subdivided into at least two parts able to be assembled with each other to form the shell.

Such a secondary body is particularly easy to use by a dental surgeon who only has to assemble the different parts of the shell together in order to be able to use it in his dental surgery device.

The secondary body can also be assembled prior to its marketing. In this case, the dentist simply has to assemble the secondary body on the main body of his instrument holder.

Advantageously, the hull is subdivided into two half-shells.

Such a half-shell design offers an even simpler solution to be implemented by a dental surgeon.

Preferably, the half-shells are hinged together by means of a hinge link.

Half-hulls hinged together through a hinge link form a secondary body similar to a wallet in use.

Indeed, according to an example of application, it suffices to position the rotary dental instrument in the half-shells or in one of the half-shells, then to close and fix the half-shells one on the other . Then the dentist only has to assemble the secondary body on the main body.

According to a solution envisaged, the secondary body incorporates a system for supplying irrigation liquid at the active portion of the dental rotary instrument to perform irrigation.

Thanks to the design of the dental surgery device according to the invention and more specifically of its secondary body, the integration of a system for supplying irrigation liquid is particularly suitable.

The expression “irrigation liquid” is understood to mean in particular the liquid products used to perform canal treatment of a tooth, but also any type of liquid or semi-liquid product, more or less fluid, even pasty, capable of 'be used in the power supply system of the dental surgery device according to the invention.

According to a first approach where the secondary body is designed to be reused, the washing of any crystals resulting from the passage of the irrigation liquid is optimized because the secondary body does not include a bevel gear mechanism integrating mechanical members whose integration is likely to create spaces that are difficult to clean.

According to a second approach, the secondary body can be designed for single use. The presence of crystals following an irrigation operation is therefore not problematic.

Advantageously, the irrigation liquid supply system comprises a distribution channel opening at one end to the flexible portion of the rotary instrument, and having at another end a connection element on a reserve of irrigation liquid.

This irrigation liquid supply system allows irrigation to be carried out by injecting the irrigation liquid directly onto the flexible portion of the rotary instrument which is received and guided in the secondary body.

According to a preferred embodiment, the reserve of irrigation liquid is a cartridge.

Such a cartridge of irrigation liquid makes it possible to simplify the performance of an irrigation operation during the act of dental surgery.

More precisely, when a dental surgeon wishes to carry out machining and irrigation at the same time, he simply has to assemble an irrigation liquid cartridge on the connection element of the integrated irrigation liquid supply system. in the secondary body of the instrument holder.

Advantageously, the dental surgery device comprises an element for guiding the irrigation liquid along the active portion of the dental rotary instrument.

Thanks to such an irrigation liquid guiding element, the application of said irrigation liquid during an irrigation operation is optimized.

In fact, the irrigation liquid spreads from the end of the instrument holder from where the active portion of the dental rotary instrument emerges. Therefore, if the active portion of the dental rotary instrument is not fully inserted or in contact with a tooth, then the irrigation fluid tends to disperse.

The irrigation liquid guide element avoids such a situation by allowing the irrigation liquid to be brought as close as possible to the place to be irrigated.

According to an advantageous characteristic, the guide element for the irrigation liquid takes the form of a sleeve intended to be coupled to one end of the secondary body from which emerges the active portion of the dental rotary instrument, the sleeve surrounding a section of the active portion.

Such a sleeve forms an economical and easy to implement solution for producing the element for guiding the irrigation liquid.

Preferably, the sleeve is designed to be adjustable in length and forms a stop limiting the driving capacity of the active portion of the dental rotary instrument.

Such a length-adjustable sleeve advantageously makes it possible to produce a stop for driving in the active portion of the dental rotary instrument.

The invention also relates to a rotary instrument having at one end an active portion and at the other end a coupling portion intended to be secured in rotation with a coupling member presented by an instrument holder, characterized in that the 'rotary instrument has a flexible portion between the active portion and the coupling portion, the flexible portion being capable of having a curvature impressed by a rotating guide element.

The invention also relates to a secondary body for an instrument holder comprising a main body which incorporates:

- motor means;

a coupling member intended to establish a rotationally integral connection with a coupling portion presented by a rotary instrument which has at one end an active portion and at the other end a coupling portion, the active portion having an axis of rotation R1 and the coupling portion having an axis of rotation R2, the secondary body integrating:

- assembly means capable of cooperating with the main body to produce an assembly of the secondary body and the main body;

at least one internal element for guiding in rotation of the rotary instrument, the internal guide element or elements being capable of imparting at least one curvature to a flexible portion of the rotary instrument, located between the active portion and the portion of coupling, so that the axis of rotation R1 and the axis of rotation R2 form a non-zero angle.

Other characteristics and advantages of the invention will appear more clearly on reading the following description of several preferred embodiments of the invention, given by way of illustrative and nonlimiting examples, and of the appended drawings among which:

- Figure 1 is a schematic representation along a longitudinal section of a first embodiment of the invention;

- Figure 2 is a schematic representation of a secondary body of the instrument holder and a complementary dental rotary instrument, according to a second embodiment;

- Figures 3a and 3b are schematic representations of two different secondary bodies;

- Figure 4 is a schematic representation of a dental rotary instrument according to the invention;

- Figure 5 is a schematic representation of the end of the secondary body from which the dental rotary instrument emerges;

- Figure 6 is a schematic representation of a dental rotary instrument and a secondary body provided with a supply system for irrigation liquid;

- Figure 7a is a schematic representation of the secondary body without an irrigation liquid supply system;

- Figure 7b is a schematic representation of the secondary body with a sleeve adjustable in length, and without an irrigation liquid supply system;

- Figure 7c is a schematic representation of the secondary body with a sleeve adjustable in length, and with irrigation liquid supply system comprising a cartridge of irrigation liquid;

- Figure 7d is a schematic representation of the secondary body with a sleeve adjustable in length, and with an irrigation liquid supply system comprising a remote supply of irrigation liquid.

With reference to FIG. 1, the dental surgery device 1 according to the invention comprises:

- an instrument holder 3;

- a dental rotary instrument 2 intended to be carried by the instrument holder.

As illustrated in FIG. 1, as well as in FIGS. 2, 4 and 6, the dental rotary instrument 2 according to the invention has at one end an active portion 20 and at another end a coupling portion 22.

Similarly to the dental surgery devices according to the prior art, when the rotary instrument 2 is coupled to the instrument holder 3, only an active portion 20 of the rotary instrument 2 is intended to emerge from the instrument holder 3.

According to the principle of the invention, the dental rotary instrument 2 also has a flexible portion 21 located between the active portion and the coupling portion.

As illustrated in FIG. 1, the active portion has an axis of rotation R1 and the coupling portion has an axis of rotation R2. Thanks to this flexible portion 21, the axis of rotation R1 and the axis of rotation R2 can form a non-zero angle α.

More specifically, the rotary instrument 2 according to the invention may have one or more curvatures at the flexible portion intended to be received by the instrument holder. As will be detailed below, the curvature (s) presented by the flexible portion of the rotary instrument is printed by the instrument holder.

In a complementary manner and according to FIG. 4, the dental rotary instrument 2 has a flat 220 at its coupling portion 22.

The rotary instrument 2 is in particular of the monobloc type. This instrument is more precisely made of an alloy of titanium and nickel.

With reference to FIG. 1, the instrument holder 3 comprises a main body 30 and a secondary body 31.

The main body 30 incorporates:

- motor means 301;

- A coupling member 302 which is intended to establish a rotationally integral connection with the coupling portion 22 of the rotary instrument 2, in order to be able to drive said rotary instrument in rotation using the motor means.

By main body is meant the part of the instrument holder which is attached to the apparatus of the practitioner's station, and which is conventionally intended to receive, among other things, standard contra-angles.

The secondary body 31 is intended to accommodate the rotary instrument. More specifically, the secondary body 31 is intended to receive the coupling portion 22 as well as the flexible portion 21 of the dental rotary instrument 2. The active portion 20 of the rotary instrument is intended to emerge from the secondary body 31.

With reference to FIGS. 1 and 6, the secondary body 31 includes:

- means of assembly on the main body;

- At least one internal rotational guide member 310 of the rotary instrument.

As illustrated in FIG. 1, the assembly means on the main body make it possible to secure the secondary body to the main body 30. The assembly means of the secondary body are integrated into a standardized door assembly system -instrument. More specifically, the assembly means have female means 330 which are complementary to male means 331 presented by the main body. The male means are intended to couple with the female means to lock the secondary body on the main body.

With reference to FIGS. 1 and 6, the internal elements for guiding in rotation 310 of the rotary instrument make it possible to impart at least one curvature to the flexible portion 21 of the rotary instrument 2 so that the axis of rotation R1 and l the axis of rotation R2 form a non-zero angle a.

For example, according to the embodiment illustrated in Figure 1, the flexible portion 21 has a curvature. With reference to the embodiment illustrated in FIG. 6, the flexible portion 21 then has two curvatures.

As illustrated in FIGS. 1, 3a, 3b, and 6, the internal rotating guide element 310 is a channel 3100 which has at least one curvature. This channel is intended to accommodate the flexible portion 21 of the rotary instrument 2.

With reference to FIGS. 1,4 and 6, at least one narrowing 3101 of the channel has an internal diameter corresponding essentially to the external diameter of complementary parts 210, 221 of the flexible portion 21 and / or of the coupling portion 22, of the rotary instrument 2.

These constrictions each form an internal element for guiding the rotation of the rotary instrument. Indeed, they exercise a bearing function with respect to the complementary parts 210, 221 of the flexible portion.

As illustrated in FIG. 1 as well as in FIG. 6, the secondary body 31 also includes a driving member 32. This driving member 32 serves as an interface between the coupling portion 22 of the rotary instrument 2 and the member 302 coupling presented by the main body 30 of the instrument holder 3.

More specifically, this driving member 32 receives the coupling portion 22 of the rotary instrument 2, and in particular cooperate with the flat part of this coupling portion 22 having a flat part 220 (flat part illustrated in FIG. 4).

The driving member, the flat part of the coupling portion and the coupling member of the main body thus participate together in the establishment of a rotationally integral connection of the rotary instrument with the drive means of the instrument holder.

With reference to FIG. 1, the driving member 32 comprises:

- A first part 324 mobile in rotation in the secondary body, intended to be coupled in rotation with the coupling portion of the dental rotary instrument;

- A second part 322 having a coupling housing 323 complementary to the coupling member 302 of the main body 30

- an accordion part 321, located between the first part and the second part. ;

This accordion part acts as a spring and makes it possible to optimize the coupling of the driving member with the coupling member 302, during the assembly of the secondary body 31 on the main body 30. The accordion part allows in particular synchronization of the driving member with the coupling member.

Indeed, it is possible that the coupling member 302 is not aligned with the coupling housing 323 of the driving member when assembling the instrument holder. In this case, the coupling member of the main body comes to press on the second part of the driving member and causes, thanks to the compression of the accordion part of the driving member, a retraction of this second part. Following a rotation of the driving member and / or the coupling member, and when the coupling member and the coupling housing are aligned, the tension exerted by the accordion part causes the second part to return in its original position and thus the coupling of the driving member with the coupling member by fitting the coupling member into the coupling housing.

The driving member is in particular of flexible nylon.

With reference to FIGS. 2, 3a and 3b, the secondary body 31 takes the form of a shell 4. This shell 4 is intended to accommodate the rotary instrument 2.

The shell 4 is subdivided into at least two parts which are intended to be assembled with each other to form the shell. According to the embodiments illustrated in FIGS. 3a and 3b, the shell 4 is subdivided into two half-shells 40.

With reference to the embodiment illustrated in FIG. 3a, the demicoques 40 are completely independent of one another.

According to the embodiment illustrated in FIG. 3b, the half-shells 40 are hinged together by means of a link forming a hinge 400.

According to these two embodiments (Figures 3a and 3b), to implement the invention, the person carrying out the assembly must first couple the rotary dental instrument 2 with the drive member 32. He then positions the driving member 32 in a housing 320 formed by the shell 4 of the secondary body 31, as well as the flexible portion 21 of the rotary instrument 2 inside the channel 3100. Then it suffices for this person to close one on the 'other half-shells and to join them together.

The two half-shells can be joined together by welding (vibration), and / or by bonding, and / or by clipping.

This assembly can be carried out before the product is marketed, or directly by the user (a surgeon).

According to the embodiment illustrated in FIG. 6, the secondary body 31 integrates an irrigation liquid supply system 5. This irrigation liquid supply system makes it possible to bring said irrigation liquid up to the active portion 20 of the rotary dental instrument 2 for performing irrigation.

With reference to this FIG. 6, the irrigation liquid supply system 5 comprises a distribution channel 50 which opens at one end onto the flexible portion 21 of the rotary instrument 2. The distribution channel 50 presents at another end of a connection element 51 on a reserve of irrigation liquid. This connection element 51 takes the form of a striker to which the reserve of irrigation liquid can be connected.

According to the embodiment illustrated in FIGS. 6 and 7c, the reserve of irrigation liquid is a cartridge 52 intended to take place on the secondary body 31. This cartridge 52 is assembled on the secondary body 31 by interlocking.

The cartridge is preferably made of a flexible material. Such a flexible cartridge allows the triggering of irrigation by means of a simple pressure applied to the cartridge.

When the cartridge is put in place, the striker pierces the cartridge to allow the irrigation liquid to flow into the distribution channel towards the flexible portion of the rotary instrument.

According to the embodiment illustrated in FIG. 7d, the irrigation liquid supply system 5 uses a reserve of irrigation liquid remote from the instrument holder, using a liquid supply pipe 53 irrigation.

To allow proper application of the irrigation liquid and as illustrated in FIGS. 5, 6, 7b, 7c and 7d, the dental surgery device 1 comprises an element for guiding the irrigation liquid 6 along the portion active 20 of the dental rotary instrument 2.

This element for guiding the irrigation liquid 6 takes the form of a sleeve 60. This sleeve 60 is intended to be coupled to one end of the secondary body 31 from which the active portion 20 of the dental rotary instrument 2 emerges.

As illustrated in FIG. 5, a groove 54 allows the irrigation liquid to be conveyed at the end of the secondary body and the sleeve

60. In other words, the groove allows the passage of the irrigation liquid from the channel which guides in rotation the flexible portion 21 of the rotary instrument, to the end of the sleeve 60 from where the active portion 20 of the rotary instrument protrudes.

With reference to FIGS. 5 and 6, this sleeve surrounds a section of the active portion 20 of said rotary instrument 2. This sleeve 60 is also designed to be adjustable in length. Indeed, this sleeve can be sectioned at different predetermined heights by following the notches it presents.

Referring to Figure 1, a traditional push-in stopper 7 is inserted into the active portion 20 of the dental rotary instrument 2. This stop may disturb the application of an irrigating product.

According to the embodiment illustrated by Figures 5 and 6, as well as Figures 7b, 7c and 7d, the sleeve 60 according to the invention has a stop function which limits the driving capacity of the active portion 20 of the rotary 2 dental instrument.

Consequently, the sleeve 60 replaces a traditional stop inserted on the flexible portion while allowing and advantageously allowing good irrigation.

With reference to FIG. 6 and as explained previously, the irrigation liquid supply system 5 comprises the distribution channel 50 which opens onto the flexible portion 21 of the rotary instrument 2. According to this embodiment, the dental surgery device 1 comprises a seal 8 which surrounds the coupling portion 22 of the rotary instrument 2. This seal 8 is located between the transmitting member 32 and the portion of the channel 3100 where the distribution channel 50 opens. joint 8 thus makes it possible to avoid or limit the rise of irrigation liquid in the direction of the main body of the instrument holder.

As illustrated in FIG. 7a, the secondary body 31 is presented in a simplified form. Indeed, according to this design mode, the secondary body 31 has a shell 4 having only at its end a cap 61 from which emerges the active portion 20 of the rotary instrument.

According to the embodiments illustrated in Figures 7b, 7c and 7d, the secondary bodies 31 each have a shell 4 having at their end a sleeve 60 adjustable in length (breakable) from which emerge the active portions 20 of the rotary instruments.

As explained above, the embodiments illustrated in FIGS. 7c and 7d each include a system for supplying irrigation liquid 5.

In FIG. 7c, the irrigation liquid supply system 5 comprises a reserve of irrigation liquid in the form of a cartridge 52.

Referring to Figure 7d, there is the irrigation liquid supply system 5 with supply pipe 53 connecting the secondary body to a remote reserve (not shown).

Claims (14)

1. Dental surgery device (1) comprising: - a dental rotary instrument (2) having at one end an active portion (20) and at the other end a coupling portion (22), the active portion having an axis of rotation R1 and the coupling portion having an axis of rotation R2; - an instrument holder (3) comprising a main body (30) integrating: - motor means (301); - A coupling member (302) intended to establish a rotationally integral connection with the coupling portion, in order to be able to drive the rotary instrument in rotation using the motor means; characterized in that the rotary instrument has a flexible portion (21) between the active portion and the coupling portion, and in that the instrument holder comprises a secondary body (31) capable of accommodating the rotary instrument, the body secondary integrating: - means of assembly on the main body; - At least one internal element for guiding in rotation (310) of the rotary instrument, the internal guide element or elements being capable of imparting at least one curvature to the flexible portion of the rotary instrument so that the axis of rotation R1 and axis of rotation R2 form a non-zero angle. 2. dental surgery device (1) according to claim 1, characterized in that the internal element of rotation guide (310) is a channel (3100) having at least one curvature, the channel being intended to receive the flexible portion (21) of the rotary instrument (2). 3. Dental surgery device (1) according to any one of the preceding claims, characterized in that the dental rotary instrument (2) is in one piece. 5 4. dental surgery device (1) according to any one of the preceding claims, characterized in that the secondary body (31) takes the form of a shell (4) subdivided into at least two parts capable of being assembled l 'with each other to form the shell. 5. A dental surgery device (1) according to the preceding claim, characterized in that the shell (4) is subdivided into two half-shells (40). 6. dental surgery device (1) according to the preceding claim, 15 characterized in that the half-shells (40) are articulated together by means of a link forming a hinge. 7. dental surgery device (1) according to any one of the preceding claims, characterized in that the secondary body 20 (31) integrates an irrigation liquid supply system (5) at the active portion (20) of the dental rotary instrument (2) to perform irrigation. 8. A dental surgery device (1) according to the preceding claim, 25 characterized in that the irrigation liquid supply system (5) comprises a distribution channel (50) opening at one end onto the flexible portion (21) of the rotary instrument (2), and having a at the other end, a connection element (51) on a reserve of irrigation liquid. 9. A dental surgery device (1) according to the preceding claim, characterized in that the reserve of irrigation liquid is a cartridge (52). 10. A dental surgery device (1) according to any one of claims 7 to 9, characterized in that it comprises an element for guiding the irrigation liquid (6) along the active portion (20) of the 'dental rotary instrument (2). 11. dental surgery device (1) according to the preceding claim, characterized in that the element for guiding the irrigation liquid (6) takes the form of a sleeve (60) intended to be coupled to one end of the body secondary (31) from which emerges the active portion (20) of the rotary dental instrument (2), the sleeve surrounding a section of the active portion. 12. dental surgery device (1) according to the preceding claim, characterized in that the sleeve (60) is designed adjustable in length and forms a stop limiting the driving capacity of the active portion (20) of the rotary instrument (2) dental. 13. Rotary instrument (2) having at one end an active portion (20) and at the other end a coupling portion (22) intended to be secured in rotation with a coupling member (302) presented by an instrument holder (3), characterized in that the rotary instrument has a flexible portion (21) between the active portion and the coupling portion, the flexible portion being capable of having a curvature imprinted by a rotating guide element. 14. Secondary body (31) for an instrument holder (3) comprising a main body (30) which integrates: - motor means (301); - a coupling member (302) intended to establish a rotationally integral connection with a coupling portion (22) presented by a rotary instrument (2) which has at one end a portion 5 activates (20) and at the other end a coupling portion (22), the active portion having an axis of rotation R1 and the coupling portion having an axis of rotation R2, the secondary body integrating: - assembly means able to cooperate with the main body 10 to achieve an assembly of the secondary body and the main body; - At least one internal guiding element in rotation (310) of the rotary instrument, the internal guiding element or elements being capable of imparting at least one curvature to a flexible portion of 15 the rotary instrument, located between the active portion and the coupling portion, so that the axis of rotation R1 and the axis of rotation R2 form a non-zero angle.