Dentist cannula for dental ejector for output medium

Abstract

A dentist's cannula (100) forms an attachment for a dental jet for discharging a fluid medium such as air and / or water, wherein the cannula (100) comprises a back-side connection area (80) designed to be connected to a dentist's handpiece for discharging the medium, a front end area (70) having at least one outlet (71, 72, 74) for discharging the fluid medium, and at least two elongated medium pipelines (11, 12) extending from the connection area (80) to the front end area (70), wherein the medium pipelines (11, 12) are at least partially formed by channels (51, 52) in a plastic body (50) composed of two respectively integral plastic parts (60a, 60b), and the plastic parts are sealed to each other along a connection plane in which the channels (51, 52) extend.

Description

[0001] The present invention relates to a dentist's cannula which is provided for delivering a fluid medium such as air and / or water. The cannula of the present invention is provided in this case for use with a so-called dentist's jet handpiece. In this case, the medical cannula of the present invention should be regarded as an attachment for a so-called dentist's jet handpiece as an attachment for a dental jet.

[0002] So-called jet handpieces or multifunctional handpieces are often used in the dental field and are used to support dentists in examinations or treatments. In this case, the jet handpiece is used to deliver air, water or perhaps an air-water mixture in the form of a jet to the area to be examined or treated in order to clean and perhaps dry it. This ensures good visibility of the area to be examined or treated at all times, which is why the normal use of such a jet handpiece is inevitable.

[0003] Typically, a jet handpiece of the type described above is connected via a supply hose, for example, to a so-called dental unit, which provides the medium output by the handpiece, namely air and water in the form of compressed air. With the help of corresponding buttons on the handpiece, the user can then select which medium is output by the handpiece.

[0004] The actual outflow of the medium takes place at the front end region of the cannula, which is arranged at the front end of the handpiece. The cannula is generally connected to the actual handpiece in such a way that it can be rotated relative to the handpiece about a rotation axis at least within a certain angle range. The medium is then transferred from the handpiece to the line extending in the cannula in the connection region. It leads to the front end region of the cannula, wherein a nozzle-like narrowing of the line cross section is generally provided, thereby ensuring a high outflow of the medium. As a result, the cleaning effect of the air or water output by the jet handpiece is improved.

[0005] For reasons of hygiene, cannulas need to be cleaned and disinfected after use. This so-called re-preparation requirement is limited to cannulas only if, due to their length, the actual jet handpiece is sufficiently far from the front end of the cannula and therefore does not come into contact with the patient. The corresponding standards stipulate that the cannula should have a minimum extension of at least 80 mm.

[0006] Different methods for realizing such a cannula are known from the prior art. Usually, it is a reusable component having an elongated, conically tapered sleeve-like body, which has a connection area for connecting to a dental handpiece at its back end and is provided with a nozzle-like medium outlet at the front end. A medium line in the form of a hose or a tube then extends inside the cannula, wherein a corresponding light conductor may also be passed through the cavity of the cannula, through which the area to be treated is illuminated. Such a cannula is known, for example, from EP 2 124 812 B1.

[0007] In the documents WO86 / 04247A1 and US4519385A, housing handpieces are described, which are designed to be used for housing flushing and suction applications. The handpiece disclosed here has a medium line, which is at least partially composed of a soft cannula, which can be closed by a trigger mechanism. In addition, the handpiece has areas for medium output and suction liquid respectively. However, the accessories are not designed for use with dental jet handpieces and are not suitable for outputting multiple media.

[0008] In the above-mentioned dental cases, the cannula is a relatively complex component that must be manufactured and installed at a relatively high cost. Another disadvantage is that the sleeve-like housing forms a cavity through which the lines and possibly the optical waveguide extend in a protected manner, but also forms a further unused cavity which can only be cleaned and / or sterilized with difficulty during reconditioning.

[0009] Correspondingly, there is also an alternative approach to realize this cannula as a cheap plastic part, which may be used as a disposable product later. Two solutions to this are shown in US9,814,551 and DE69106138T2, in which it is a plastic injection molded part in this case, which can be simply and cheaply manufactured. However, the known disposable cannula has the following problem, and they can only be realized with a straight-line medium pipeline due to the difficulty in manufacturing technology. But it is preferred that the cannula is designed to be bent in its front end area, because the visibility during the use of the jet handpiece is improved thereby. In addition, the disposable cannula known from the prior art can only be manufactured with a relatively short length, so the shortest length of 80mm explained above can only be realized with difficulty. Finally, the cannula injection molding manufacturing also only conditionally allows the front end area of ​​the medium pipeline to be designed as a nozzle shape to realize the high-speed output of the medium. Although these known disposable cannula can be manufactured cheaply accordingly, they also involve a large number of shortcomings at the same time.

[0010] An improvement on these known solutions is shown in US2020 / 0290066 A1. Here a cannula is shown for detachably connecting to the front end of a dental jet handpiece, wherein a pressurized fluid such as air or water is transmitted with the help of the cannula. The cannula is formed by two plastic bodies with corresponding flat contact surfaces, on which the two plastic bodies are welded together, wherein during the production process a medium channel is formed extending along the cannula. Compared with the production according to US9.814.551 or DE 691 06 138 T2, this method increases the possibilities for designing the medium channel.

[0011] The present invention is based on the object of specifying a possible way of further improving a cannula for discharging a fluid medium which can be produced in a simple and inexpensive manner, while nevertheless avoiding the problems and disadvantages known from the prior art which exist there.

[0012] The invention is achieved by a dental cannula for discharging a medium having the features of claim 1 and a method for producing a cannula having the features of claim 15. Advantageous developments of the invention are the subject matter of the dependent claims.

[0013] The solution according to the invention is again based on the idea of ​​forming a cannula in the form of a plastic body that can be manufactured inexpensively, wherein, similar to the method of US 2020 / 0290066 A1, the medium line is at least partially formed by a plurality of channels extending through the plastic body. Unlike the disposable cannulas of US 9,814,551 or DE 691 06 138 T2, it is therefore initially provided that the plastic body is not present as a one-piece injection-molded part, but is formed from two plastic parts that are each one-piece and are sealed to each other along a joint plane in which the channels extend.

[0014] It is also provided that the two media lines merge in the front end region of the insert in a mixing chamber and open into the same outlet, wherein a nozzle for mixing the media conveyed through the two media lines is provided in the region of the mixing chamber and is formed by a separate insert.

[0015] Therefore, according to the invention, a dentist's cannula for outputting a fluid medium such as air and / or water is proposed, wherein the cannula is an accessory for a dental jet and has:

[0016] a back engagement zone designed to engage with a medical handpiece accessible to the medium,

[0017] a front end region having at least one outlet for discharging a fluid medium,

[0018] At least two medium lines extending from the junction area to the front end area for conveying a medium from the rear junction area to an outlet at the front end area of ​​the cannula.

[0019] In this case, the present invention provides that the medium pipeline is at least partially formed by a channel in a plastic body composed of two respectively integral plastic parts, which are sealed to each other along a joining plane in which the channel extends, and wherein the two medium pipelines merge in a mixing chamber in the front end area of ​​the insertion tube and open into the same outlet, wherein a nozzle for mixing the media transported through the two medium pipelines is provided in the area of ​​the mixing chamber, the nozzle being formed by a separate insert.

[0020] According to the invention, a method for producing a dentist's cannula for discharging a fluid medium such as air and / or water is also provided, wherein the cannula is an attachment for a dental jet and has:

[0021] A back engagement zone designed to engage with a medical handpiece accessible to the medium,

[0022] a front end region having at least one outlet for discharging a fluid medium,

[0023] At least two medium lines extending from the joining region to the front region for conveying a medium from the rear joining region to an outlet at the front region of the cannula.

[0024] The production method consists in producing two integral plastic parts in a first step, which are then connected to one another in a subsequent production step in a sealing manner along a joint plane, wherein a plurality of channels forming a media line in the assembled state extend along the joint plane in the resulting plastic body. The two media lines merge in the front region of the insert in a mixing chamber and open into a common outlet, wherein a nozzle for mixing the media conveyed through the two media lines is provided in the region of the mixing chamber, the nozzle being formed by a separate insert.

[0025] Since the cannula is not manufactured as a one-piece plastic injection-molded part, but is manufactured in the manner of the present invention, many advantages can be obtained. This is especially because the grooves or recesses of the plastic parts that ultimately form the channel are freely accessible before they are connected. Therefore, if the plastic parts are, for example, injection-molded, there will definitely be no problems in the so-called demoulding of the plastic parts compared to the solutions in the prior art, which ultimately opens up the possibility that the channel forming the pipeline can be designed with a large degree of freedom and at the same time with high precision. This not only means that the cannula that is finally formed can smoothly have the above-mentioned minimum length of 80 mm, but also this leads to the advantage that the bending implementation method of the channel can be smoothly realized. The narrowing of the channel in the front end area of ​​the cannula required for the optimal output of the medium can also be smoothly realized in this way, so although the manufacturing cost is slightly increased compared to the disposable cannula of the prior art, a large number of advantages are obtained at the same time.

[0026] The two plastic parts preferably form half shells respectively, in particular two half shells symmetrically configured about the joining plane. Here, as already explained, it is particularly preferred to provide that the two plastic parts are formed by injection molding, which is a very simple manufacturing method.

[0027] The sealing connection of the two plastic parts is preferably achieved by connecting them to each other in a material-bonded manner. A first possibility would be, for example, to glue the two plastic parts to each other. However, it is particularly preferred to weld them to each other, wherein laser welding can be used in particular. However, other welding methods such as so-called ultrasonic welding can also be used.

[0028] According to a preferred embodiment, it is further provided that at least one of the media lines is designed to be constricted in the front region of the cannula. As explained, this can be achieved without major problems in the method according to the invention for realizing the cannula. The constricted design of the media line then leads to an accelerated discharge of the medium in the form of a nozzle, which leads to a better cleaning effect when using the jet handpiece.

[0029] An improvement in handling and visibility with respect to the area to be treated is preferably achieved in that the cannula is designed to be angled in the front region.

[0030] At least two media lines extending along the cannula are preferably provided for discharging air and water. However, it can also be provided here according to a particularly preferred embodiment that a third media line extends along the cannula. The third media line is also provided in this case for conveying air, wherein one of the two air-media lines is used to discharge a so-called jet together with the media line for water as required. The additional separate media line for air is then provided only for discharging air, which has the advantage that pure air without any residual water can be immediately discharged as required.

[0031] According to the invention, as already explained, two media lines are provided to merge in the front end region of the cannula in a so-called mixing chamber and to lead into the same outlet. It can be provided in particular for media lines which output mixed air and water in a jet mode.

[0032] Another preferred embodiment of the cannula according to the invention is that it has an optical conductor which extends from the junction area to the front area of ​​the cannula for light output, wherein the optical conductor is then preferably formed by a separate component which is inserted into another channel of the plastic body. It is also easy to implement in terms of manufacturing technology, since only measures need to be taken within the scope of the production of the plastic parts to realize another channel, wherein the optical conductor is then inserted into this channel and is fixed in the cannula within the scope of the mutual connection of the two plastic parts. In this case, it can be provided that the optical conductor end provided for light output is arranged in the area of ​​at least one outlet for outputting the medium. However, as an alternative, the optical conductor end provided for light output can also be arranged at the peripheral area of ​​the plastic body and oriented in such a way that the air is directed to a position arranged in front of the at least one outlet.

[0033] The connection area provided for connection to the handpiece preferably has a substantially hollow cylindrical receiving area for receiving the connection shaft head of the handpiece, wherein a plurality of annular channels are particularly preferably formed on the inner wall of the receiving area, each annular channel being a channel connected to a connection line in a flow manner. The connection area design allows the cannula to be rotatable or at least partially twistable about the rotation axis compared to the handpiece, which ultimately simplifies the handling of the jet handpiece.

[0034] Here, according to a particularly preferred first variant, it can be provided that the joining zone is formed by these two interconnected plastic parts and is therefore a component of the plastic body. Leaving aside the possibly provided insert for the nozzle and / or the inserted optical conductor, the cannula of the present invention is therefore only composed of two interconnected plastic parts in this case. However, as an alternative, it is also conceivable that the two interconnected plastic parts form a roughly hollow cylindrical area on their back side, in which an insert forming a receiving area for accommodating the joint shaft head is arranged. In this case, it can be a sleeve of corresponding design, made of metal, which is then responsible for the actual medium transfer. Finally, it is also conceivable to form the joining zone by a separate component, which is then arranged on the back side of the plastic body forming the medium pipeline and connected to it.

[0035] The present invention will be explained in detail below with reference to the accompanying drawings, in which:

[0036] Figure 1a to Figure 1d A view showing a first exemplary variant of the cannula according to the invention, which does not fall within the scope of the claims, for the purpose of illustrating the manufacturing method;

[0037] Figure 2a to Figure 2e A view showing a first embodiment of a cannula according to the invention;

[0038] Figures 3a to 3e A view showing a second embodiment of a cannula according to the invention;

[0039] Figures 4a to 4e A view showing a third embodiment of a cannula according to the invention;

[0040] Figure 5a to Figure 5d A view showing a second example of a cannula;

[0041] Figures 6a to 6d A view showing a third example of a cannula.

[0042] in accordance with Figure 1a to Figure 1d , a first example of a cannula according to the invention should first be explained in detail. The variants shown in the other figures then differ first in the number of media lines extending along the cannula and in the design of the area for discharging the medium and for connecting to the medical handpiece.

[0043] The basic design of the cannula with reference numeral 100 in the figure can be seen from Figure 1a and Figure 1b As can be seen in FIG. 1 , the figure shows two perspective views of the cannula 100. Next, Figure 1c A cross section of the cannula 100 along the plane of engagement is shown, and Figure 1d The two plastic parts are shown prior to assembly into cannula 100 .

[0044] As already explained, the cannula 100 is provided for connection to a dentist's handpiece (not shown in the figure), which provides a medium to be discharged by means of the cannula 100. Typically, the medium is air and water, which may also be discharged together in the form of a jet. In principle, however, the cannula 100 according to the invention can also be used to discharge other liquid or gaseous media or, in general, to discharge fluid media.

[0045] The back area of ​​the cannula 100 forms a connection area 80, which is designed to be connected to a dentist's handpiece. The connection area 80 has a greater width or thickness than the front part of the cannula 100 and also serves as a grip of the cannula 100, which is why two mutually opposite ridges 89 are provided on the outer circumference of the connection area 80 (see Figure 1b ), thereby making it easier to hold the cannula 100.

[0046] The tubular region formed by the bend in the front third extends from the junction area 80, the design of which will be described in detail below, and opens into the front end area 70 for discharging the medium. Figure 1a to Figure 1d In the variant shown, it is provided that air and water are discharged via two separate lines 11, 12, which is why the front region 70 in this case has two separate outlets 71, 72 for each of the two media. The two outlets 71, 72 can be oriented parallel to each other in this case or designed and oriented in such a way that the discharged media meet or intersect at a certain distance in front of the cannula 100, so that a jet occurs here when air and water are discharged simultaneously. However, as shown in other variants, the discharge of the jet can also be achieved in other ways.

[0047] The main function of the coupling area 80 is to receive the medium provided by the handpiece. For this purpose, the handpiece has a correspondingly designed roughly cylindrical coupling shaft head, which is inserted into the hollow cylindrical receiving area 85 of the coupling area 80 and outputs air and / or water here according to the user's operation of the handpiece. Annular channels 81 and 82 are correspondingly provided on the inner wall of the receiving area 85 of the cannula 100, which cooperate with the output opening of the coupling shaft head and allow the cannula 100 to be wound around it due to its annular shape. Figure 1cThe annular channel 82 at the rear is formed by a circumferential groove approximately at the half height of the cylindrical receiving area 85, while the annular channel 81 at the front is formed by a correspondingly stepped design of the receiving area 85.

[0048] The annular channels 81, 82 are then connected to the medium lines 11, 12 extending in the longitudinal direction of the cannula 100 and leading to the outlets 71, 72. In particular, it can be provided that the medium lines 11, 12 have a reduced cross section in the front region 70 near the outlets 71, 72 or are designed to be continuously narrowed. Both measures result in an additional increase in the discharge speed of the corresponding medium and thus a better cleaning effect.

[0049] The solution according to the invention now mainly lies in the following question, in what way the cannula 100 with the media lines 11, 12 extending therein is realized. In this case, the invention provides that the cannula 100 is formed by a plastic body 50, in which the channels 51, 52 corresponding to the lines 11, 12 extend. Unlike the prior art described in the introduction, the lines 11, 12 are therefore not formed by hoses or tubes laid separately in a cavity, but by longitudinal channels in the plastic body 50. This measure has the effect that the cannula 100, apart from the media lines 11, 12 and the receiving area 85 of the connection area 80, does not have other cavities in which liquids and / or bacteria can collect. In particular, for situations in which the cannula 100 is provided for reuse and corresponding cleaning, this leads to a significant advantage, because there are no cavities that are difficult to access and therefore difficult to clean.

[0050] However, the realization of the channels 51 , 52 forming the media lines 11 , 12 in the form shown (bent, narrowed and of suitable length, etc.) is only possible within the scope of a special inventive measure which will be explained in detail below.

[0051] Therefore, due to the design and orientation of the channels 51 and 52, the cannula 100 cannot be realized in the form of an integral injection molded part. Figure 1d The plastic parts 60a, 60b are shown in FIG. 1 , which are sealed to each other in a subsequent processing step.

[0052] The design of the plastic parts 60a, 60b corresponds to Figure 1c and Figure 1d, i.e., it is two half shells designed ideally symmetrically to each other, so that they each form a receiving area 85 with a surrounding channel 81, 82 with respect to the half body and in particular also form a channel 51, 52 extending from the receiving area 85 to the front side. That is, each plastic part 60a, 60b has a half groove, for example with a semicircular cross section, which is open to the joining plane and corresponds to the corresponding half groove of the other plastic part 60a, 60b and then forms a real channel 51 or 52 with a preferably circular cross section in the assembled state of the two plastic parts 60a, 60b.

[0053] With regard to the channels 51, 52, it is also conceivable in principle that one of the plastic parts is designed to be planar in the connection region and that the corresponding groove is provided only in the second plastic part. However, it is preferred that the two plastic parts 60a, 60b thus jointly form the channels 51, 52 and the other components of the cannula 100 in a symmetrical design.

[0054] It is important that the two plastic parts 60a, 60b are practically sealed to each other when they are joined to form the plastic body 50, so that the channels 51, 52 which are formed in this case can then practically without interference transfer the medium from the joining area 80 to the front end area 70 of the cannula 100. In this case, preferably a material-bonded connection between the two plastic parts 60a and 60b is provided, wherein a first variant may exist when the two plastic parts 60a and 60b are respectively bonded to each other. However, it is particularly preferred that the two plastic parts 60a and 60b are welded to each other, wherein laser welding methods are particularly considered. Finally, the two plastic parts 60a, 60b are inseparably connected to each other by the measures described, so that the cannula 100 shown in the figure is then formed.

[0055] The described approach results in numerous advantages over the solutions known from the prior art, in particular also over disposable cannulas realized in the form of a one-piece plastic body. The proposed measures therefore allow, unlike the prior art, the realization of the bent, i.e. non-linear, design of the cannula 100 shown. The constriction of the media lines 11, 12 in the front end region is also realized in a very simple manner with the aid of the measures of the invention. Finally, in the proposed approach for manufacturing the cannula 100, there are also no restrictions on the dimensions of the cannula 100. This means that the distance from the back-side joining area 80 to the front end region 70 with the outlet openings 71, 72 can be selected in any case in such a way that the dimensions set by the hygiene regulations can be obtained. This means in particular that the cannula 100 can have a length that reaches or exceeds the above-mentioned 80 mm.

[0056] Now combine Figures 2a to 6d Variations of the cannula of the present invention should be explained. They are based on the combination of Figure 1a to Figure 1dThe same basic principle is explained. Therefore, in each case, the medium line is at least partially formed by a channel in the plastic body, which is formed in such a way that two plastic parts, each of which is integral, are connected to each other in a sealing manner. The same parts of the cannula mentioned below also carry the same reference numerals accordingly.

[0057] exist Figure 2a to Figure 2e In the embodiment shown, compared to Figure 1a to Figure 1d In the example of the embodiment of the present invention, a third medium line 13 is provided, which in turn extends from the joining area 80 to the front end of the insertion tube. A corresponding further annular channel 83 is formed for the third medium line 13 on the inner wall of the receiving area 85, which is connected to an additional third channel 53 extending in the longitudinal direction. All channels 51, 52, 53 extend in this case, as already explained, in the joining plane of the two plastic parts 60a, 60b and therefore parallel to each other.

[0058] In accordance with Figure 1a to Figure 1d In the insert 51, 52, the two outlet openings 71, 72 are connected to one of the two medium lines 11, 12 respectively, while according to the embodiment of the invention, it is provided that the two medium lines 11, 12 are still merged before the actual outlet 74. More precisely, the two corresponding channels 51 and 52 open into a small, approximately cylindrical mixing chamber 20, in which the supply media are mixed with each other before their actual output. Correspondingly, it is preferably provided here that air, for example, is conveyed through one of the two medium lines 11 and water is conveyed through the other medium line 12, wherein the air and water are then mixed with each other in the mixing chamber 20 and are discharged in the form of a jet through the opening 74. The mixing of air and water is optimized in this case by the additional part 25 forming the nozzle, which is inserted into the chamber 20 as an insert and fixed there in the area where the two plastic parts 60a, 60b are joined. By the groove formed on the outer circumference of the insert 25, a better distribution of one of the two media is achieved, so that it can then be mixed more evenly with the second medium to form a jet discharged through the opening 74.

[0059] The additional third medium line 13 with the associated outlet 72 can be used to convey the air further. Thus, pure air is discharged through the opening 72 while the air-water mixture is discharged in the form of a jet through the outlet 74. A separate line 13 used only for air discharge has the advantage that, when the air discharge is started, it does not initially still contain a small amount of liquid, but directly provides dry air to blow away particles or other dirt.

[0060] like Figures 3a to 3e The variant of the cannula 100 according to the invention shown corresponds to the embodiment of the present invention with regard to the transfer and further transport of the medium. Figure 2a to Figure 2e The variant shown. In this case, three medium lines 11-13 are also provided, by means of which pure air or a jet can be selectively output at the front side of the cannula 100.

[0061] In the third embodiment, it is further provided that the optical waveguide 30 extends parallel to the lines 11-13, which in turn extends from the back-side connection area 80 to the front end area 70 of the cannula 100. The light available at the front end of the connection shaft head (not shown) of the handpiece is then coupled into the optical waveguide 30 at the back and is output like other media at the front end area of ​​the cannula 100. The orientation of the front end 31 of the optical waveguide 30 provided for light output is such that it is oriented parallel to the orientation of the output openings 72, 74, so that the light output from the optical waveguide 30 is directed to the same area as other media.

[0062] The optical conductor 30 is preferably formed by a separate component which is inserted into the corresponding longitudinal channel 55 of the plastic body 50. Thus, similar to the media lines 11-13, plastic parts 60a, 60b are provided which also have corresponding half grooves facing each other, which in the assembled state of the two plastic parts 60a, 60b form an elongated curved channel in which the optical conductor 30 is laid. In this case, the optical conductor 30 is also inserted into one of the two plastic parts 60a or 60b, like the insert 25 forming the nozzle, and is then connected to the other plastic part 60a, 60b by material bonding. This measure also serves to securely fix the optical conductor 30 in the cannula 100.

[0063] exist Figures 4a to 4e In the variant according to the invention shown, provision is also made for the use of an optical conductor 30. However, it now ends in a circumferential region of the cannula 100 extending in the longitudinal direction and is therefore set back compared to the output openings 72, 74 for the other media. In this case, however, the optical conductor 30 is oriented at the front end 31 in such a way that the light emitted by it is directed to the region to which the medium is also delivered. Since the optical conductor 30 now does not extend to the front end 70 of the cannula 100, it can be compared to the optical conductor 30 according to the invention. Figure 3a to Figure 3d The variant of is designed to be slightly more compact, which may result in a better view of the area to be examined or treated.

[0064] Note that it is obviously also possible to Figure 1a to Figure 1d The cannula shown is provided as a combination of Figures 3a to 3e and Figures 4a to 4e The use of the photoconductor is explained.

[0065] Of the ones mentioned so far Figures 1a to 4e In the embodiment of FIG. 8 , the joining region 80 is also formed by means of two plastic parts 60 a, 60 b. The half shells 60 a, 60 b accordingly also have annular channels 81 - 83 provided for medium transfer or form the annular channels in the assembled state.

[0066] However, it is also conceivable to design the junction area 80 in other forms, wherein Figure 5a to Figure 5dFirst, a first example is shown, in which the coupling zone is formed by a separate component 95, which is designed as a cylinder and is provided for the actual connection to the medical handpiece. In this case, the separate component 95 also has a cylindrical receiving area 85 with corresponding annular channels 81, 82, which are designed for coupling to the coupling shaft head of the handpiece. The channel formed in the separate component 95, which can be formed in the form of a rotating part, for example, then leads to the corresponding output openings 91, 92 at the front end of the component 95, which are connected to the actual channels 51, 52 in the plastic body 50 of the cannula 100. The plastic body 50 itself is fixedly connected with its round end to the component 95 forming the coupling zone 80, which can be carried out, for example, by bonding or other suitable measures.

[0067] With regard to the realization of the longitudinally extending channels 51, 52, this example is also identical to the previous embodiment. Therefore, two half shells 60a, 60b are provided, which form the medium pipelines 11, 12 in the form of elongated channels 51, 52 in the joined state. This variant can also be used with Figures 1a to 4e The variants are similarly realized with a different number of channels and possibly with optical conductors and inserts 25 .

[0068] FIG. 6 finally shows a sixth variant, which again differs in the design of the connection zone 80. In this case, the plastic body 50 again extends over the entire length of the cannula 100, but here the region provided for the actual connection to the dental handpiece is now realized by an insert body 90, which is inserted into a purely cylindrical receptacle of the back plastic body 50 and fixed there, for example, by means of adhesive bonding or the like. The advantage of this variant is that the processing of the region of the cannula 100 required for the actual connection to the handpiece is again more precisely realized, so that perhaps a better and more reliable medium transfer can be achieved. Nevertheless, it is preferred Figures 1a to 4e embodiments, because they can be realized with as few components as possible.

[0069] The cannula can be realized both as a disposable product and as a reusable product, depending on the material selected. In the case of a disposable product, PE (polyethylene) can be used, for example. If the cannula is to be used multiple times and therefore also to be sterilized, it is advisable to use a more durable plastic material. In this case, PA (polyamide), PEEK (polyetheretherketone) or PSU (polysulfone) come into consideration in particular.

[0070] Therefore, a cannula for discharging a medium is provided by the present invention in general, which can be realized in a simple manner and nevertheless avoids the disadvantages known from the prior art. In addition, as mentioned above, there are different possibilities for correspondingly adjusting the cannula design in a simple manner in terms of the amount of medium to be conveyed.

Claims

1. A dentist's cannula (100), the dentist's cannula (100) forming an attachment for a dental ejector for outputting a fluid medium, wherein: The cannula (100) has: a back engagement zone (80) designed to engage with a dentist's handpiece providing a medium, a front end region (70) having at least one outlet (71, 72, 74) for outputting the fluid medium, and at least two elongated medium pipelines (11, 12), which extend from the junction area (80) to the front end area (70) and are used to transport the fluid medium from the back junction area to the outlet at the front end area of ​​the cannula, The medium pipeline (11, 12) is at least partially formed by channels (51, 52) in a plastic body (50), wherein the plastic body (50) is composed of two integral plastic parts (60a, 60b), the plastic parts are sealed and connected to each other along a joint plane, and the channels (51, 52) extend in the joint plane, and are characterized in that: The two media pipelines merge in a mixing chamber (20) in the front end area of ​​the insert (100) and open into the same outlet, wherein a nozzle (25) for mixing the media transported through the two media pipelines is provided in the area of ​​the mixing chamber (20), the nozzle (25) being formed by a separate insert.

2. The dental cannula as claimed in claim 1, characterized in that: The two plastic parts ( 60 a , 60 b ) are formed by half shells.

3. The dental cannula according to claim 1 or 2, characterized in that: The two plastic parts (60a, 60b) are formed by injection molding.

4. The dental cannula as claimed in claim 1, characterized in that: The two plastic parts (60a, 60b) are connected in a materially joined manner.

5. The dental cannula as claimed in claim 1, characterized in that: At least one of the medium pipelines (11, 12) is narrowed in the front end region of the cannula (100).

6. The dental cannula as claimed in claim 1, characterized in that: The cannula (100) is bent in the front section.

7. The dental cannula as claimed in claim 1, characterized in that: Three medium pipelines (11, 12, 13) extend along the cannula (100).

8. The dental cannula as claimed in claim 1, characterized in that: The cannula (100) has a light conductor (30) which extends from the joining region (80) to a front area of ​​the cannula (100) for outputting light.

9. The dental cannula as claimed in claim 8, characterized in that: One end (31) of the optical waveguide (30) which is provided for outputting light is arranged in the region of at least one outlet (71, 72, 74) for outputting the medium.

10. The dental cannula according to claim 8, characterized in that: An end (31) of the optical waveguide (30) provided for outputting light is arranged at the outer peripheral region of the plastic body (50) and is oriented such that the light is directed toward a location arranged in front of the at least one outlet (71, 72, 74).

11. The dental cannula of claim 1, wherein: The coupling region (80) has a substantially hollow-cylindrical receiving region (85) for receiving a coupling shaft head of a handpiece that is accessible to the medium.

12. The dental cannula of claim 1, wherein: The joining region (80) is formed by the two plastic parts (60a, 60b) connected to one another and is therefore a component of the plastic body (50).

13. The dental cannula of claim 11, wherein: The two plastic parts (60a, 60b) connected to each other form on their rear sides an approximately hollow cylindrical region (65), in which an insert (90) is arranged, which forms the receiving area (85) for receiving a joint shaft journal.

14. The dental cannula of claim 1, wherein: The joining region (80) is formed by a separate component (95) which is arranged on the rear side of a plastic body (50) forming the media line (11, 12, 13) and is connected to the plastic body.

15. The dental cannula of claim 2, wherein: The two plastic parts (60a, 60b) are formed by two half shells which are symmetrically designed with respect to the joining plane.

16. The dental cannula of claim 4, wherein: The two plastic parts (60a, 60b) are bonded or welded to each other in a materially joined manner.

17. The dental cannula of claim 4, wherein: The two plastic parts (60a, 60b) are connected in a material-joined manner by laser welding.

18. The dental cannula of claim 8, wherein: The optical waveguide (30) is formed by a separate component which is embedded in a further channel (55) of the plastic body.

19. The dental cannula of claim 11, wherein A plurality of annular channels (81, 82, 83) are formed on the inner wall of the accommodating area (85), and each annular channel is fluidically connected to a channel (51, 52, 53) forming a medium pipeline (11, 12, 13).

20. A method for manufacturing a dental cannula (100) having an attachment for a dental ejector for delivering a fluid medium, wherein: The cannula (100) has: a back engagement zone (80) designed to engage with a dentist's handpiece providing the medium, a front end region (70) having at least one outlet (71, 72, 74) for outputting the fluid medium, and at least two elongated medium pipelines (11, 12), which extend from the junction area (80) to the front end area (70) and are used to transport the medium from the junction area on the back side to the outlet on the front end area of ​​the cannula, The method comprises the following steps: Manufacturing two integral plastic parts (60a, 60b); The two plastic parts (60a, 60b) are connected along a joint plane to form a plastic body (50), wherein in the assembled state, a plurality of channels (51, 52) forming medium pipelines (11, 12) extend along the joint plane in the plastic body (50), Its characteristics are: The two media pipelines (11, 12, 13) merge in a mixing chamber (20) in the front end region of the cannula (100) and open into a common outlet, wherein a nozzle (25) for mixing the media transported through the two media pipelines is provided in the region of the mixing chamber (20), the nozzle (25) being formed by a separate insert.

21. The method according to claim 20, characterized in that: The two plastic parts (60a, 60b) are manufactured by injection molding.

22. The method according to claim 20 or 21, characterized in that: The two plastic parts (60a, 60b) are connected in a materially joined manner.

23. The method of claim 22, wherein: The two plastic parts (60a, 60b) are bonded or welded to each other in a materially joined manner.

24. The method of claim 22, wherein: The two plastic parts (60a, 60b) are connected in a material-joined manner by laser welding.

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