Patent Description:
In particular, the handpiece is used for a powder jet device, which ejects a stream, formed by a powder-gas-mixture being surrounded or sleeved by a fluid, in particular water. For such a nozzle head, the handpiece needs to provide both the powder-gas-mixture and the fluid to the nozzle head.

For enhancing reliability and for avoiding plastic cracking, a monoblock screwing assembly has been developed for realizing a connection between the nozzle arrangement and the handpiece. A connector including the monoblock screwing assembly is part of the handpiece. The screwing assembly establishes a screwing mechanism for screwing the nozzle arrangement into the connector, the connector forming a kind of nut for the nozzle arrangement, being screwed into the connector by a rotational movement.

This rotational movement for connecting the nozzle arrangement to the connector makes it necessary that a channel, being realized in the interface region between the handpiece and the nozzle arrangement and being intended to transport the fluid to the supply line of the nozzle element, is formed such that a rotational movement is possible. As a result a funnel like or conical shape has been established for the part of the channel transporting the fluid in the region directly upstream to the supply line of the nozzle arrangement.

Therefore, a comparably big amount of fluid is collected in the interface region between the nozzle arrangement and the connector. When the nozzle arrangement is removed from the connector or handpiece, this results in a comparably high risk of a droplet formation in said interface region. This droplet, in turn, could get into a channel or line, transporting the powder-gas-mixture, when the nozzle arrangement is reconnected to the connector. However, such an interaction between water and the powder-gas-mixture increases the risk of clogging the channel, along which the powder-gas-mixture is transported through the handpiece and/or the nozzle arrangement.

<CIT> discloses a construction that tries to separate a connection for an air-powder and a connection of water in order to avoid mixing of water and powder.

<CIT> discloses a dental blasting machine including a housing in which an inner frame is provided. The inner frame has a water inlet and a through hole. The water inlet and the through hole are spaced apart in the radial direction of the inner frame.

<CIT> discloses a handpiece for cleaning tooth surfaces comprising a grip body equipped, at one end, with a fitting for conduits that supply an air and powered mixture and water, respectively.

<CIT> discloses a nozzle for a dental handpiece. The handpiece is composed of a connector portion to be connected to a handpiece body, and a nozzle body, which is provided near its end with a notch of a substantially rectangular section cut-out from the front face into the lateral faces.

Considering the prior art, it is an object of the present invention to provide an assembly or a handpiece, which improves handling of the handpiece, in particular by reducing a risk for clogging. Furthermore, it is desirable to simplify the handling of the handpiece, for example by incorporating new functionalities into the handpiece.

The object is achieved by a handpiece including the features of claim <NUM>, a system including the features of claim <NUM> and a method including the features of claim <NUM>.

Further embodiments are described in the dependent claims, the description and the figures.

An aspect of the present invention is a handpiece, for a powder jet device, which in operation is used for treating a tooth,the handpiece being configured to be connected in a mounted state to a nozzle arrangement having a first supply line for transporting a powder gas-mixture and a second supply line for transporting a fluid,the handpiece comprising- a connector having a first side for connecting the connector to a supply system and a second side for connecting the connector to the nozzle arrangement, the powder-gas-mixture and the fluid being transported from the supply system to the nozzle arrangement through the connector via a transport direction during operation, wherein the connector comprises a sleeve like first component and a sleeve like second component, the first component being made from a metal and the second component made from plastic, in particular a polymer, and the first component and the second component are connected to each other via a form-fitting and/or a non-positive locking connection.

According to preferred embodiment of the present invention, a handpiece for a powder jet device, which in operation is used for treating a tooth, is provided, the handpiece being configured to be connected in a mounted state to a nozzle arrangement having a first supply line for transporting a powder-gas-mixture and a second supply line for transporting a fluid, preferably water,.

Contrary to the state of the art, it is provided according to the present invention to use a fastening means, in particular a nut, for connecting the nozzle arrangement to the connector. Therefore, it is no longer necessary to screw the nozzle arrangement to the second side of the connector by a rotational movement. Instead it is possible, to plug the nozzle arrangement into the connector and to subsequently fix the nozzle arrangement to the connector by using the fastening means. As a result, there is no need for a rotationally symmetric shape of the second side, to which the nozzle arrangement is connected by a screwing mechanism otherwise. Instead of being rotationally symmetric to a central axis of the handpiece, the shape and location of the second interface section are freely selectable. The central axis is preferably defined by a course of a first channel in the connector, the first channel transporting the powder gas mixture. As a consequence, it is possible to space the first interface section and a second interface section such that the probability of transferring a droplet from the second interface section to the first interface section is reduced. Moreover, it is possible to reduce the cross section of a second channel, which transport the fluid in the handpiece to the second supply line, such that the amount of fluid at the second side is significantly reduced, when the nozzle arrangement is removed from the connector. In particular, the first interface section and the second interface section are separated from each other and the second interface section does not surround the first interface section.

As a consequence, the probability of a droplet being accidently moved into the first channel, in which the powder-gas-mixture is transported through the handpiece, in particular through the connector, is reduced as well as the probability of clogging the first channel and/or the first supply line. This makes the handpiece more reliable in operation, in particular in case of frequently separating and reconnecting the nozzle arrangement and the connector.

The fastening means is preferably moveable, in particular rotatable, relative to the connector. Furthermore, it is conceivable that the fastening means is non-integral with the connector. As a consequence, it is avoided that the connection between the nozzle arrangement and the connector is established by the nozzle arrangement and the connector itself, for example by a non-positive locking mechanism. As a result using a separate fastening means reduces the risk of damaging the nozzle arrangement and the connector during the mounting process, since otherwise residual stresses are generated, which lead to cracks. Preferably, the fastening means establishes a form fitting connection in a direction parallel to the transport direction or the central axis. Besides a nut, it is also thinkable that the fastening means is a clip.

In particular, the powder used in treatment of tooth is sodium bicarbonate, glycine, calcium carbonate, aluminum trihydroxide, erythritol, hydroxylapatite or threhalose. The handpiece has an extension along the handpiece axis that is larger than in any other direction. The handpiece has a substantially cylindrical shape extending along the handpiece axis. The handpiece axis is the axis of the cylindrical shape. Therefore, the handpiece is advantageously tangible for a user. The handpiece is a hollow body defining an accommodation space within the handpiece. As a result, the user's hand holding the handpiece is well separated from lines existing within the handpiece. Further, the handpiece is a separate element, which can be connected to a nozzle arrangement at a first distal handpiece side and to a supply system at a second proximal handpiece side. That is, the supply system communicates with the nozzle arrangement via the handpiece, in case the three elements are connected to each other. At the distal handpiece side, the handpiece has a smaller diameter than at the proximal handpiece side. As a result, the handpiece has a center of gravity which is located closer to the proximal handpiece side. Therefore, the operability of the handpiece is improved.

According to an aspect of the present invention, the nozzle arrangement is an elongated member. The nozzle arrangement is attachable or attached to the handpiece at the distal handpiece side. The nozzle arrangement has a first proximal nozzle arrangement side and an opposite second distal nozzle arrangement side. The nozzle arrangement is attached to the first distal handpiece side with the first proximal nozzle arrangement side. The nozzle arrangement has the first supply line configured to transfer powder mixed with air, and the second supply line configured to transfer water. At least a part of the first supply line protrudes from the first proximal nozzle arrangement side of the nozzle arrangement. The nozzle arrangement is configured to discharge powder mixed with air and water onto a tooth of a patient to be treated. Within the nozzle arrangement, the first supply line and the second supply line are merged into one discharge line. The discharge line is configured to discharge the powder mixed with air and water to the second distal nozzle arrangement side. The nozzle arrangement is configured to be a disposable product. Alternatively, the nozzle arrangement is an element that can be used several times. In this case, the nozzle arrangement is configured to be sterilized several times without being damaged. Therefore, the nozzle arrangement is made of metal.

According to a further aspect of the present invention, the tubular connector is accommodated within the handpiece. The connector has an elongated body. The connector includes an axis (e.g. a central axis or a rotational axis) that is aligned with the handpiece axis even though the handpiece is usually not symmetrical with regard to such axis. In other words, the connector is positioned inside the handpiece in a centralized manner (i.e. within the accommodation space of the handpiece). The first axial side and the second axial side of the connector are located at opposite sides of the connector. The connector is arranged within the handpiece such that the first axial side of the connector is closer to the second proximal handpiece side than the second axial side of the connector which extends towards the distal side of the handpiece. The connector has a smaller outer diameter at its second axial side as compared to an outer diameter at its first axial side. In other words, the connector has a tapered shape towards the second axial side of the connector. As a result, the space within the handpiece is effectively used.

Preferably, it is provided that the nozzle arrangement includes a nozzle head, the first supply line and the second supply line, being at least partially included inside the nozzle head. Furthermore, the nozzle arrangement further includes tubes, in particular solid tubes, as first supply line and/or as second supply line, wherein the tubes for the first supply and/or the second supply line protrude from a side of the nozzle head facing to the connector in the mounted state. The protruding parts of the tubes are inserted into the handpiece in the mounted state.

The nozzle arrangement is preferably connected to the connector by a translation movement during a mounting process, preferably in a direction parallel to this central axis of the handpiece, and subsequent to this translation movement, the inserted tube of the first supply line and/or the tube of the second supply line is fixed to the connector by using the fastening means. Preferably, the fastening means is a nut being mounted by using a tool, which is inserted at the first side of the connector, wherein the tool passes through the inside of the connector up to the fastening means. Subsequently, the tool is used for rotating the fastening means.

The supply system being connected to the first side of the connector preferably comprises a hose or cord, which connects the handpiece and a stationary unit or base station. The base station or stationary unit provides the powder-gas-mixture, in particular by mixing powder and gas to form the powder-gas-mixture, and further provides the pressure for delivering the powder-gas-mixture to the handpiece and for ejecting the powder-gas-mixture from the nozzle head. Furthermore, it is provided that the first side of the connector is profiled such that the end of the hose or cord of the supply system can be plugged into the first side, in particular fixed to the first side in a non-positive locking and/or a form fitting manner. Preferably, the supply system supplies the handpiece with both the powder-gas-mixture and the fluid.

According to a preferred embodiment, in the mounted state the connector and the nozzle arrangement are fixed to each other in a non-rotatable manner. In particular, the skilled person understands the term "non-rotatable manner" such that there is no screwing possible or no rotational movement between the connector and the nozzle arrangement is possible without destroying the handpiece or the nozzle arrangement, in particular after the nozzle arrangement being inserted into the connector during the mounting process. As a result, the orientation of the connector and the nozzle arrangement to each other is always the same in the mounted state. This allows a proper connection between the nozzle arrangement and the connector, as well as inserting additional components that connect the connector with the nozzle arrangement, such as wires or fibers. This can increase the functionality of the handpiece, since new components can be included into the handpiece.

Preferably, in the mounted state the first supply line is plugged into the first interface section and of the second supply line is plugged into the second interface section. In particular, the first interface section and/or the second interface section includes a hole, in particular a through hole, or a recess into which the first supply line and/or the second supply line are respectively inserted along a inserting direction being preferably parallel to the central axis and/or transport direction. Thus, it is possible that by inserting or plugging the first supply line into the first interface section and or/the second supply line into the second interface section a non-rotatable fixation between the connector and the nozzle arrangement is established.

Preferably, the first interface section includes a receiving section, preferably in form of a socket, wherein in the mounted state the first supply line passes or extends through the receiving section and the fastening means is connected to the first supply line at a side of the receiving section facing away from the nozzle arrangement. Preferably, the fastening means is located such that a free access to the fastening means is possible from the first side of the connector. As a consequence, it is possible to use a tool, which passes through the connector for fixing the fastening means and consequently allows fixing the nozzle arrangement to the connector.

Preferably, the handpiece comprises a first channel for transporting the powder-gas-mixture and a second channel for transporting the fluid through the connector. Preferably, the second channel is located radially offset to the first channel with respect to the central axis, the first channel being located essentially at the central axis of the handpiece and/or the connector.

Preferably, the first cross section of the first channel, in particular directly upstream to the first supply line, is greater than a second cross section of the second channel, in particular directly upstream to the second supply line. The cross section of the second channel, in particular of the part of the second channel being located directly upstream to the second supply line, mainly corresponds to the cross section of the second supply line. As a result, in the second interface section less fluid is collected, and consequently the risk for formation of fluid droplets is reduced in the interface region between the nozzle arrangement and the connector.

According to the invention, it is provided that connector comprises a sleeve-like first component and a sleeve-like second component, the first component being made from a metal and the second component being made from plastic, in particular a polymer. By using a connector, having at least two components, namely the first component and the second component, allows using plastic for the second component. This reduce the weight of the handpiece and simplifies handling of the handpiece, advantageously.

According to the present invention, the first component and the second component are connected to each other by a form-fitting connection and/or a non-positive locking connection. Thus, the first and the second component are attached to each other. Preferably, the second component includes the second side of the connector and therefore is not rotatable against the nozzle arrangement about a central axis of the handpiece in the mounted state.

In particular, the second component includes a transmitter and/or a receiver. Using a plastic material, in particular a porous material, for realizing the second component allows sending or receiving signals, which were transmitted through the second component. As a result, it is possible to communicate with a transmitter and/or receiver being inserted into the supply system, in particular, into the cord or hose of the supply system, being connected to the first side of the connector. For example, this allows exchanging information about the state of the handpiece such as the number of treatments performed by the handpiece and/or type of the handpiece. As consequence, the transmitter and/or receiver of the connector can inform a stationary unit about the need of maintenance and/or specific configurations being needed for the handpiece, which is currently connected to the supply system, in particular the stationary system. Furthermore, it is possible to guarantee that the proper supply system is connected to the handpiece.

Preferably, the handpiece comprises a wire, the wire being preferably connected to the nozzle arrangement, more preferably to a light source being incorporated into the nozzle arrangement. The non-rotational fixation between the nozzle arrangement and the connector allows using a wire or fiber, which connects the connector and the component being incorporated inside the into no nozzle arrangement, since thus a twisting of the wire can be avoided, which otherwise occur when the nozzle arrangement is screwed into the connector.

Preferably, a housing is provided, the housing surrounding the connector and being at least partially spaced from the connector in a radial direction and/or in a direction being perpendicular to the transport direction. In particular, it is provided that the housing has mainly a tubular shape, being in particular completely rotationally symmetric. This simplifies gripping and therefore improves handling of the handpiece.

Preferably, the handpiece has an exhaust opening for ventilation of the first channel. Such a ventilation or exhaust opening suppresses a piston effect, which otherwise might occur at the second side of the connector. Such a piston effect would otherwise increase the risk of a droplet formation, the droplet getting inside the first channel. Therefore, by using a connector having such an exhaust opening the formation of a bundle inside the first channel and therefore a clogging of the first channel. The exhaust opening preferably represents an opening in the first channel, connecting the first channel to a space between the housing and the connector.

Another aspect of the present invention is an assembly of a nozzle arrangement and a handpiece according to the present invention. All specifics and benefits being discussed in context of the handpiece apply analogously for the assembly and vice versa.

Another aspect of the present invention concerns a method for connecting a nozzle arrangement and a handpiece according to the present invention, comprising.

Wherever not already described explicitly, individual embodiments or their individual aspects and features can be combined or exchanged with one another without limiting or widening the scope of the described invention, whenever such a combination or exchange is meaningful and in the sense of this invention. Advantages, which are described with respect to one aspect of the present invention are, wherever applicable also advantages of other aspects of the present invention.

In <FIG> an assembly of a handpiece <NUM> and a nozzle arrangement <NUM> according to the prior art is illustrated. Such an assembly is preferably part of a powder jet device, being used in operation for treating a tooth, in particular for removing coating, colorings and/or biofilms from the surface of a tooth. For effectively removing coverings, colorings and/or biofilms from the surface of the tooth an abrasive powder is used in the powder-gas-mixture, which in operation is directed to the tooth by using the handpiece <NUM>, wherein the nozzle arrangement <NUM> ejects the powder-gas-mixture towards the surface of the tooth.

In particular, it is provided the nozzle arrangement <NUM> comprises a first supply line <NUM> and a second supply line <NUM>. The first supply line <NUM> transports the powder-gas-mixture inside the nozzle arrangement <NUM> and/or the second supply line <NUM> transports a fluid through the nozzle arrangement <NUM>. In particular, the nozzle arrangement <NUM> includes a nozzle head <NUM>, through which the first supply line <NUM> and the second supply line <NUM> extend. Preferably, the nozzle head <NUM> is configured such that the ejected powder-gas-mixture is surrounded by the fluid being transported via the second supply line <NUM>. The handpiece <NUM> is used by an operator to orientate the nozzle arrangement <NUM>, in particular the nozzle head <NUM>.

Preferably, the handpiece <NUM> comprises a connector <NUM>, having a first side <NUM> for connecting the connector <NUM> to a supply system (not shown) and a second side <NUM> for connecting the connector <NUM> to the nozzle arrangement <NUM>. The supply system preferably includes a hose or cord (not shown), which transports the powder-gas-mixture and/or fluid to the handpiece <NUM>, preferably from a stationary station (not shown). Preferably, the connector <NUM> is configured such that the hose of the supply system can be inserted and/or plugged into the first side <NUM> of the component <NUM>. Furthermore it is provided that the powder-gas-mixture and the fluid are transported during operation along a transport direction T through the connector <NUM>.

The second side <NUM> is opposite to the first side <NUM> along the transporting direction T and preferably the connector <NUM> is arranged inside a housing <NUM>. Further, the connector <NUM> comprises a first channel <NUM> for transporting the powder-gas-mixture inside the connector <NUM> and/or a second channel <NUM> for transporting the fluid inside the connector <NUM> and/or the handpiece <NUM>. In particular, a part of the second channel <NUM>, preferably the part being directly upstream to the nozzle head <NUM>, in particular to the second supply line <NUM> of the nozzle arrangement <NUM>, is formed by the handpiece <NUM> and the mounted nozzle arrangement <NUM>, preferably by a clearance or free space between the handpiece <NUM> and the nozzle arrangement <NUM> in the mounted state in an interface region, in which a part of the nozzle arrangement <NUM> is inserted into the handpiece <NUM>.

According to the prior art the nozzle arrangement <NUM> is typically connected to the handpiece <NUM>, in particular to the connector <NUM>, by a screwing mechanism, wherein the nozzle arrangement <NUM> is screwed into a screwing arrangement <NUM> being formed at the second side <NUM> of the connector <NUM>. For connecting the nozzle arrangement <NUM> to the connector <NUM>, the nozzle arrangement <NUM>, in particular the nozzle head <NUM>, is rotated around a central axis C of the handpiece <NUM>. Due to the screwing, being necessary for connecting the nozzle arrangement <NUM> to the connector <NUM>, the assembly forms a part of the second channel <NUM>, being located directly upstream to the second supply line <NUM>. This part is shaped in a conical manner or funnel like.

This shape allows rotating the nozzle arrangement <NUM> relative to the connector <NUM> of the handpiece <NUM> to realize the screwing connection. As a result, a comparably large volume of water is formed at the end of the second channel <NUM> in the part, being located directly upstream to the second supply line <NUM> of a nozzle arrangement <NUM>, in particular in the interface region between the nozzle arrangement <NUM> and the handpiece <NUM>. As a result such a shape, however, has the disadvantage of droplets being left after removing the nozzle arrangement <NUM> from the hand piece <NUM>. Such droplets might, in turn, move inside the first channel <NUM> and/or the first supply line <NUM> of the nozzle arrangement <NUM>, increasing the risk of forming a bundle, which clogs the first channel <NUM> and/or the first supply line <NUM>, when interacting with the powder-gas-mixture, being transported through the first channel <NUM> and the first supply line <NUM>.

In <FIG> an assembly of a handpiece <NUM> and a nozzle arrangement <NUM> according to a first embodiment of the present invention is illustrated in a cross sectional view. The connector <NUM> of <FIG> also includes a first side <NUM> and a second side <NUM>. Contrary to the assembly of <FIG> the embodiment of <FIG> uses another connecting mechanism for connecting the nozzle arrangement <NUM> to the connector <NUM>. Preferably, it is provided that the nozzle arrangement <NUM> comprises a first supply line <NUM> and a second supply line <NUM>. The first supply line <NUM> and the second supply line <NUM> protrude from a side of the nozzle head <NUM>, facing to the connector <NUM> in the mounted state. Preferably, the first supply line <NUM> and/or the second supply <NUM> line are tubes, which extends from the inside of the nozzle head <NUM> to the connector <NUM> of the handpiece <NUM>. Preferably, the tubes of the first supply line <NUM> and the second supply line <NUM> are made from a solid material, such as metal. Contrary to the screwing arrangement <NUM> illustrated in <FIG> it is provided that the second side <NUM> of the connector <NUM> includes a first interface section <NUM> for connecting the first supply line <NUM> to the connector <NUM> and a second interface section <NUM> for connecting the second supply line <NUM> to the connector <NUM>, the first interface section <NUM> and the second interface section <NUM> being spaced from each other, in particular in a direction perpendicular to the transport direction T and/or the central axis C of the handpiece <NUM>. By using a first interface section <NUM> and a second interface section <NUM>, it is advantageously possible to reduce a size of a cross-section of the second channel <NUM>, in particular directly upstream to the second interface section <NUM>, since the second channel <NUM> need no longer to be completely rotationally symmetric to the central axis C, being necessary for the screwing mechanism in the embodiment of <FIG>.

The reduced cross section of the second channel <NUM> in the part directly upstream to the second supply line <NUM> of the nozzle arrangement <NUM> automatically leads to a decrease of the water amount being possibly collected in the interface region at the second side <NUM>, in particular in the second interface section <NUM>. Further, it is possible to reduce the probability of a droplet getting into the first channel <NUM> and/or the first supply line <NUM> unintentionally, since the second interface section <NUM> is spaced from the first interface section <NUM>.

For realizing such an arrangement of the first interface section <NUM> and the second interface section <NUM>, it is provided that the nozzle arrangement <NUM> is connected to the connector <NUM> by means of a fastening means <NUM> instead of a screwing mechanism. Preferably, the fastening means <NUM> is a nut. In the embodiment of <FIG>, the first supply line <NUM> is inserted into a receiving section <NUM> during the mounting process, the first supply line <NUM> extending through the receiving section <NUM>. In particular, the receiving section <NUM> is formed as a hole in a socket, being located at the second side <NUM> of the connector <NUM>. In particular, the socket is located in a region of the central axis C in a mounted state, i. central in the handpiece <NUM> in a plane perpendicular to the transport direction T. The first supply line <NUM>, passing through the receiving section <NUM>, is fixed to connector <NUM> by means of the fastening means <NUM>, being screwed to the first supply line <NUM> at a site of the receiving section <NUM> facing away from the nozzle arrangement <NUM> in the mounted state. Using a fastening means <NUM> and inserting the first supply line <NUM> into the first interface section <NUM> and the second supply line <NUM> into the second interface section <NUM> guarantees that the connector <NUM> and the nozzle arrangement <NUM> cannot be rotated to each other around the central axis C of the handpiece <NUM>. The non-rotational arrangement of the connector <NUM> and the nozzle arrangement <NUM> allows a second interface section <NUM> being not formed completely rotationally symmetric to the central axis C. This, in turn, allows to select freely the shape and location of the second channel <NUM>, in particular of the part of the second channel <NUM>, being located directly upstream to the second supply line <NUM> and further allows the separation of the second interface section <NUM> from the first interface section <NUM>.

Furthermore, it is provided that the connector <NUM> is covered by a housing <NUM>. The housing <NUM> has a first front end <NUM> and a second front end <NUM>, being in a direction parallel to transport direction T opposite to the first front end <NUM>. At the first front end <NUM> the nozzle arrangement <NUM>, in particular the first supply line <NUM> and the second supply line <NUM>, are inserted into the handpiece <NUM>, in particular the housing <NUM>, until the nozzle head <NUM> abuts at the front end <NUM> of the housing <NUM>.

Furthermore, it is provided that the second interface section <NUM> includes a sealing means <NUM> and/or guiding means <NUM>. The guiding means <NUM> simplifies introduction of the second supply line <NUM> into the second interface section <NUM>, for example by a diameter of the hole in the second interface section <NUM>, which decreases along the insertion direction. By using the sealing means <NUM> it is possible to avoid that fluid droplets can leave the second interface section <NUM> in the mounted state, in particular during operation. Thus, the probability of an interaction between fluid droplet, on the one hand, and powder-gas-mixture on the other hand, further decreases.

Moreover, it is provided in the embodiment of <FIG> that the connector <NUM> comprises a sleeve-like first component <NUM> and a sleeve-like second component <NUM>, the first component <NUM> being made from metal and the second component <NUM> being made from a plastic material, preferably a polymer. Realizing the second component <NUM> as a plastic component reduces the weight of the handpiece <NUM> significantly. Thus, the handling of the handpiece <NUM> by the operator is simplified.

In particular, it is provided that the second component <NUM> acts with the second front end <NUM> of the housing <NUM> in a form-fitting and/or non-positive manner, in particular such that the housing <NUM> is sandwiched between the second component <NUM> and the nozzle head <NUM> in the mounted state. In particular, the second component <NUM> has a collar section protruding radially, the collar section interacting with the second front end <NUM> of the housing <NUM> in a form-fitting manner.

Furthermore, it is preferably provided that the connector <NUM>, in particular, the second component <NUM> includes a receiver <NUM> and/or transmitter <NUM>, being preferably inserted into the second component <NUM> such that a receiver <NUM> and/or transmitter <NUM> can communicate with a transmitter <NUM> and/or receiver <NUM> being located inside the hose or cord of the supply system. By choosing a proper material for the second component <NUM>, in particular a material being porous and/or non-metallic, it is possible to establish a communication, in particular a wireless communication between the receiver <NUM> and the transmitter <NUM>. For example, a porous second component allows electromagnetic waves to pass through the second component <NUM> for interchanging information, i. signals, between the emitter and the receiver.

Such a communication might be used for guaranteeing that the proper cord/hose is used for the handpiece <NUM>, in particular for the connector <NUM>. It is also conceivable that certain settings of the handpiece <NUM>/stationary station or a type or model of the handpiece <NUM>/stationary station are transferred from the handpiece <NUM> to the supply system or vice versa. Furthermore, it is possible to inform the supply system about the number and duration of the previous treatments such that, for example maintenance recommendation can be given, for example by the stationary station.

In <FIG> an assembly of a handpiece <NUM> a nozzle arrangement <NUM>, according to a second embodiment of the present invention is illustrated. In particular, the embodiment of <FIG> mainly differs from the embodiment illustrated in <FIG> by using a wire <NUM> or fiber, being located inside the housing <NUM>, the wire <NUM> and/or fiber being connected to an electronic component, for example a light source <NUM> in the nozzle arrangement <NUM>, in particular in the nozzle head <NUM>. Due to the rotational fixed arrangement between the connector <NUM> on one hand and the nozzle arrangement <NUM> on the other hand, it is possible in an advantageous manner to use wires <NUM> to connect the connector <NUM> with the nozzle arrangement <NUM>. In contrast to such a non-rotational arrangement between the connector <NUM> and the nozzle arrangement <NUM>, the rotational arrangement between the nozzle arrangement <NUM> and the component <NUM> prohibits such a use of wire or fiber, since this would cause a twist of the fiber during the mounting process, which could even damage the wire <NUM> or the fiber. In particular, the rotational fixed arrangement between the connector <NUM> and the nozzle arrangement <NUM> prevents the wires <NUM> and/or fibers from being twisted due to a relative rotation of the connector <NUM> and the nozzle arrangement <NUM>.

Claim 1:
A handpiece (<NUM>), for a powder jet device, which in operation is used for treating a tooth,
the handpiece (<NUM>) being configured to be connected in a mounted state to a nozzle arrangement (<NUM>) having a first supply line (<NUM>) for transporting a powder gas-mixture and a second supply line (<NUM>) for transporting a fluid,
the handpiece (<NUM>) comprising
- a connector (<NUM>) having a first side (<NUM>) for connecting the connector (<NUM>) to a supply system and a second side (<NUM>) for connecting the connector (<NUM>) to the nozzle arrangement (<NUM>), the powder-gas-mixture and the fluid being transported from the supply system to the nozzle arrangement (<NUM>) through the connector (<NUM>) via a transport direction (T) during operation, characterized in that the connector (<NUM>) comprises a sleeve like first component (<NUM>) and a sleeve like second component (<NUM>), the first component (<NUM>) being made from a metal and the second component (<NUM>) made from plastic, in particular a polymer, and the first component (<NUM>) and the second component (<NUM>) are connected to each other via a form-fitting and/or a non-positive locking connection.