DE29912643U1 - Medical device for supplying liquids to areas of tissue that are difficult to access - Google Patents

Description

PATENT ATTORNEYS

DR. ULRICH OSTERTAG DR. REINHARD OSTERTAG

EIBENWEG 10 D-70597 STUTTGART TEL.+49-71 1-766845 FAX +49-71 1-7655701

Medical device for supplying fluids too poor

accessible tissue areas

Applicant: 1. Dürr Dental GmbH & Co. KG Höpfigheimer Str. 17

74321 Bietigheim-Bissingen

2. Dr. Rainer Hahn
Schwabstr. 11

72 074 Tuebingen
Attorney file: 6638.6

TIT.02-054

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Medical device for delivering fluids to difficult-to-reach areas of tissue.

05

The invention relates to a medical device for supplying liquids to gaps, small-diameter channels, bores and similar poorly accessible tissue areas.

10

Sometimes it is necessary to supply fluid to tissue areas that are difficult to access. This particularly involves fluids containing pharmaceutical active ingredients, including those with a higher viscosity or gel-like or thixotropic media that become liquid under the influence of ultrasound. The use of viscous or gel-like media is of particular interest where the pharmaceutical active ingredients are to be kept at the application site even in the presence of body fluids.

Such liquids are difficult to apply in a controlled manner under physical conditions if the application site can only be reached via a small access point. Examples of this are gum pockets or the spaces in the furcation of tooth roots or small access holes through which diseased tissue areas inside a tooth are to be remineralized.

30

The present invention therefore aims to provide a medical device which allows liquids, in particular viscous liquids, to be supplied to tissue areas which are difficult to access.

35

AUN241-007 _ 2 -

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This object is achieved according to the invention by a liquid supply device having the features specified in claim 1.

The device according to the invention makes use of the fact that ultrasound facilitates the conveying of liquid in narrow spaces. The ultrasound is coupled into the liquid to be supplied via the transport part. The latter also serves to guide the liquid along a predetermined path to the application site.

Advantageous developments of the invention are specified in subclaims.
15

The invention is explained in more detail below using an embodiment with reference to the drawing. In this drawing:

Figure 1: a side view of a dental fluid supply handpiece placed on a shelf shown in section in the longitudinal center plane;

Figure 2: an axial section through the fluid supply handpiece according to Figure 1;

Figure 3: an axial section through a main housing part of the handpiece according to Figures 1 and

0 2;

Figure 4: a side view of a functional insert of the fluid delivery handpiece;

Figure 5: an axial enlarged section through the

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an end portion of the liquid supply handpiece adjacent to a liquid transport part,

Fig. 6: Various embodiments for ultrasonically actuated liquid transport parts,

which differ in their geometry;

Fig. 7: Various embodiments for different surface structures with which the liquid transport parts shown in Fig. 6

can be provided;

Fig. 8: The use of a fluid delivery handpiece to deliver fluid to the furcation area of a tooth root; and

Fig. 9: The use of a fluid delivery handpiece in the remineralization of a diseased tissue area inside a tooth.

In the drawing, a dental fluid supply handpiece is designated as 10. It comprises a main housing part 12, a rear plug-in housing end part 14 from which a supply hose 15 extends, and a front cover part 16 which surrounds a coupling body 18 which carries a fluid transport part 20.

The liquid supply handpiece 10 is placed on a support, designated as a whole by 22. The latter has the shape of a trough cut in a direction perpendicular to the plane of the drawing, which is slightly wider open than the circumferential curvature of the sonic handpiece 10. In the rear part, the support 22 has a support rib 24, which works together with an inclined support surface 26 of the housing end part 14. In a projecting section 28 of the

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An opening 30 is provided in the tray 22 through which the ultrasonic tool 20 projects and into which a container indicated by dashed lines at 32 can be inserted in order to collect liquid accumulating when rinsing the liquid supply handpiece.

Figure 2 shows details of the internal structure of the fluid supply handpiece 10.

The coupling body 18 is designed as a cylindrical ring and has at one end, which is located on the right in Figure 2, a connecting section 34 which is screwed onto the end of a sonotrode 36. Offset by 90° from the connecting section 34, a second connecting section 38 is provided which points downwards in the drawing and which carries a collet 40 in which a liquid transport part 20 can be clamped.

The sonotrode 36 has a longer sonotrode section 42 on the left in the drawing, which extends freely through the essentially conical space that is delimited by the main housing part 12 and the cover part 16. The sonotrode section 42 is followed by a sonotrode section 46 with a medium-larger diameter via a conical transition section 44, which is in turn followed by a sonotrode section 48 with a reduced diameter on the right in the drawing. The latter carries in its left section a package 50 of piezoelectric disks 52 that are axially clamped together. The sonotrode section 46 in the drawing

The right-hand section of the sonotrode section 48 is connected to a counter mass 54 which is screwed onto this sonotrode end and thus simultaneously generates the axial preload for the disk pack 50. 35

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A fluid channel 56 extends through the entire sonotrode 3 6 and the counter mass screwed onto it. This is connected at its end adjacent to the coupling body 18 to a nozzle body 58, the axis of which is inclined such that the fluid jet emitted by the nozzle body 58 strikes a central or front region of a liquid transport part inserted into the collet 40.

The position, inclination and especially the length of the nozzle body 58 is important. The jet emitted by it should not expand due to oscillations of the nozzle body.

The disk package 50 is encapsulated in an electrical insulating compound 60, which may be a silicone compound.

The counter mass 54 is surrounded by a cup-like insert 62. This is designed as a plug connector part in the part on the right in the drawing, which has a fluid plug contact for connecting the fluid channel 56 via a hose piece 64 and electrical contacts for applying voltage to the piezoelectric disk package 50.

The parts described above are held together by an injection-molded functional housing 66, which has a radially inwardly projecting flange 68 at its end facing the head of the handpiece.

A connector part 70 is integrated into the housing end part 14, which has complementary contacts that match the contacts of the connector part formed at the end of the insert 62. A

•k *· ·· ···· at »r

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The anti-kink part 72 carried at the end protects electrical conductors and fluid hoses not shown in the figure against strong kinking loads when exiting the
Fluid delivery handpiece.

As can be seen from Figure 3, the functional housing 66 has two essentially rotationally symmetrical
Housing sections 74, 76, which are connected by two parallel

axial arms 78, 80 are connected to form a unit.

The rear housing section 76 has a short threaded rib 82 which is provided with a complementary threaded groove 84
(see Figure 3) of the main housing part 12 to detachably connect the functional housing 66 to the main housing part 12. The removability of the main housing part 12 when the plug connection is removed makes cleaning the handpiece components much easier.

At the free end of the main housing part 12, a downwardly hanging cover lip 86 is formed, the inclination of which corresponds to the position of the axis of the nozzle body 58. The cover lip 86 serves to keep oral tissue, in particular the patient's lips, away from the coupling body 18 and/or the opening of the nozzle body 58. In this way, the nozzle body 58 is prevented from being accidentally blocked by movable oral soft tissue. The cover lip 86 also prevents the mist of the working fluid from moving sideways away from the nozzle outlet opening and at the same time serves as a drip strip.

As can be seen from Figures 2 and 5, the cover part 16 has a cap portion 88 which covers the annular

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Coupling body 18 surrounds and can have the shape of a ball flattened on both sides or the shape of a can with a domed peripheral wall. Flat end faces 90 of the cap section 88 are located at a small distance (in practice 0.2 to 0.8 mm, preferably 0.4 mm) in front of the annular end faces of the coupling body 18. The domed peripheral wall 92 of the cap section 88 surrounds the coupling body 18 at a larger distance, eg 1 to 4 mm, preferably about 2 mm.

Wall openings 94, 96 are provided in the peripheral wall 92 in the extension of the axis of the main housing part 12 or in the upper section. These serve, on the one hand, to ensure that no trapped gas and/or liquid volume (pressure cushion) builds up between the outer surface of the coupling body 18 and the inner surface of the peripheral wall 92, which could impair the vibrations of the coupling body. At the same time, the wall openings 94, 96 serve as drainage openings through which any working fluid that reaches the interior of the cap section 88 can flow out or be thrown off the coupling body 18.

At the end located at the bottom in the drawing, the cap section 88 has an angled recess 98 as shown, through which the lowermost section of the coupling body 18, the collet 40 and a liquid transport part 20 carried by the latter protrude outwards.

The size of the wall openings 94, 96 is such that under the working conditions occurring during operation, no soft tissue parts of the patient and no fingers come into contact with the outer surface of the coupling body 18.

As can be seen from Figures 2 and 3, the cover part 5 16 has a

·

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Neck section 100, which has the shape of a partial cone. Accordingly, the main housing part 12 has a neck section 102, which also has the shape of a partial cone and, together with the neck section 100, forms a tapered, conical end section of the liquid supply handpiece 10 when the cover part 16 is placed on the main housing part 12, which is advantageous both with regard to working in hard-to-reach places in the patient's mouth, as well as with regard to a good grip on the handpiece and with regard to good visual contact with the work site.

For detachable attachment of the cover part 16 to the main housing part 12, the neck section 100 has a positioning lug 104 at its end facing the main housing part 12, which cooperates with a complementary positioning recess 106 in the front end of the functional housing 66. Locking means (not shown in detail) are located along the abutting edge designated 108 in Figure 3 between the neck sections 100 and 102 or at the end of the neck sections 100, 102 adjacent to the cap section 88.

The diameter of a tool shaft is preferably 1.4 mm or 2.0 mm; values in the range of 1.3 to 1.5 mm (for elastic plastic composite and metal tool shafts) or 1.8 to 2.2 mm (brittle tool shafts, e.g. made of silicate ceramic, glass, glass ceramic, porcelain) are also suitable. On the one hand, this allows the use of a 0 axially short coupling body, which is desirable with regard to good visual contact with the work site, and on the other hand ensures sufficient mechanical strength of the tool shaft.

5 It is understood that using tool shanks,

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which satisfy the above requirements, and in addition, fluid transport parts can be realized in which the working tip is made of the same material as the tool shaft, or also those in which the working tip is made of a different material.

By screwing the clamping ring 122 onto the pin 110, the collet 40 can be closed or opened.

As can be seen from Fig. 5, the nozzle body 58, which is supplied with pressurized liquid via the fluid channel 56, emits a liquid jet 210.

Since the axis of the nozzle body 58 is positioned such that it intersects the axis of the liquid transport part 20 at an acute angle (approximately 30° in the embodiment shown), the liquid jet 210 strikes the outer surface of the liquid transport part 24 in a grazing manner, which, as described above, is driven via the coupling body 18 such that it is moved back and forth in the axial direction by a small distance (in practice approximately 30 μm).

Under these conditions, the liquid jet 210 forms a sleeve-shaped liquid layer 212 after hitting the outer surface of the liquid transport part 20, which is conveyed to the free end of the liquid transport part 20 by means of ultrasound. If the liquid to be conveyed is a viscous liquid or a thixotropic medium, the viscosity of the medium to be conveyed is reduced, which supports the conveying of the medium. The overall conditions are such that the liquid layer

- 10 -

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is also moved to the free end of the liquid transport part 20 when the liquid transport part is oriented upwards, i.e. against gravity.

Preferably, the liquid jet 210 is discharged intermittently by pulsing the liquid supply to the fluid channel 56 through a feed unit not shown in the drawing.

Fig. 6 shows various embodiments for the liquid transport part 20:

A first fluid transport part 20-1 is of slender conical shape. It has a cylindrical clamping section 214 which cooperates with the collet 40.

In a first embodiment, the liquid transport part 20-2 is designed to be plano-conical, as indicated by the cross section 216. Alternatively, the liquid transport part 20-2 can also be designed as a blade with a substantially rectangular cross section tapering towards the free end, as shown at 218.

The liquid transport part 20-3 has an angled end section 22 0, which is shown as a plano-convex section tapering towards the free end. Here, too, a double-sided flattened geometry can be used.

The liquid transport part 20-4 is designed as a curved rod tapering towards the free end.

The two liquid transport parts 20-3 and 20-4 are used to supply liquid to undercut

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tissue areas, e.g. the furcation area of a tooth root.

The liquid transport parts 20-1 to 20-4 described above have in common that they are solid and that the liquid to be transported is supplied to their outer surface and moved along it under the influence of ultrasound.

A further transport part 20-5 is designed as a hollow cylindrical part, and the liquid to be transported is fed to a central axial bore 222, as will be described in more detail below with reference to Fig. 9.

The liquid transport part 20-6, also shown in Fig. 6, is similar to the liquid transport part 20-5, only the free end of the liquid transport part 20-6 is closed and in the vicinity of the free end, a plurality of liquid outlet openings 224 distributed in the circumferential direction are provided in the peripheral wall of the liquid transport part 20-6.

Fig. 7 shows various surface structures 226 that can be provided on at least a portion of the outer surface of a liquid transport part 20.

A first surface structure 226-1 has, in an axial sectional view, axially successive ribs 228 with a sawtooth-shaped cross-section. These not only have a fluid-promoting property but can also remove tissue, e.g. on the inside of a periodontal pocket wall.

5 A second surface structure 226-2 has a plurality

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axially spaced annular ribs 228-2, each having a roof-shaped cross-section.

A third surface structure 226-3 consists of a plurality of desk-shaped projections 230 distributed in the axial and circumferential direction, which are preferably arranged in axially successive rings, wherein the projections 230 of successive rings are offset from one another in the circumferential direction by half a pitch. As can be seen from the drawing, the desk-shaped projections 230 have roof surfaces 232 which are alternately tilted in opposite directions relative to the tangential direction.

Another surface structure 226-4 is corrugated when viewed in axial section, so that convex ribs 228-4 running in the circumferential direction are obtained.

Fig. 8 shows the use of a liquid supply device as described above for supplying a liquid or gel-like medium into the space beneath the furcation of a tooth root 234. The liquid transport part 20-4 is guided tactilely through the adjacent tooth pocket 236 beneath the root furcation and the gel-like medium, made more liquid by the ultrasound, is conveyed along its outer surface to the end of the liquid transport part 20 and thus to the application site.

0 Fig. 9 shows the use of a modified liquid supply handpiece for supplying remineralization liquid to a diseased tissue area of a tooth 23 8. In this, an access 240 has been created from the chewing surface to a tissue area 242 which is carious, but in which the caries is still

- 13 -

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is not so advanced that the diseased tissue needs to be removed. Instead, the tissue should be given a remineralizing fluid.

A liquid transport part 20-5 is inserted into the access 240, which is inserted into the collet 40 of a liquid supply device that is similar to that according to Figs. 1 to 5. However, the nozzle body 58 is omitted in this embodiment, and the end of the fluid channel 56 is connected to the interior of the collet 40 via a schematically indicated channel 244. The channel 244 is preferably formed in the interior of the coupling body 18.

Alternatively, the fluid channel 56 can also be made to open into a connecting piece pointing towards the interior of the coupling body 18, which is then connected via a flexible hose piece to a further connecting piece pointing towards the interior of the coupling body 18, which is provided in the extension of the collet 40.

The liquid transport parts 20 described above each have a small dimension (less than 0.6 mm, preferably in the range between 0.1 mm and 0.3 mm) in at least one direction perpendicular to their longitudinal axis. In addition, the liquid transport parts are made of a material which has such a high internal attenuation for ultrasound that no significant abrasive effect is obtained on adjacent tissue sections due to ultrasound emitted by the liquid transport part to the environment.

These properties are particularly fulfilled by plastic materials such as polyetheretherketone and polysulfone. These plastic materials can also be

- 14 -

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particulate fillers or short fiber filler material (e.g. carbon fibers of 1 to 3 mm length).

Due to both the choice of material and the geometry, the transport parts described above also have a flexibility that allows them to adapt to the contour of hard tissues.

A treatment gel liquefied under ultrasonic influence and a remineralization liquid were given above as examples of a liquid supplied by a liquid supply device. Other examples of liquids for which the liquid supply handpiece described is suitable are, for example, liquids or gel-like media containing growth factors or liquids or gel-like media containing diagnostic substances, caustic liquids or gel-like media, sealing liquids or gel-like media. Another example is pure rinsing liquids.

Claims (16)

1. Device for supplying liquids to gaps, channels and similar poorly accessible tissue areas, characterized by an ultrasonic generator ( 50 ) and a liquid transport part ( 20 ) driven in a substantially axial direction by the latter, as well as a device ( 56 , 58 ; 56 , 244 ) for supplying liquid to the transport part ( 20 ). 2. Device according to claim 1, characterized in that the liquid supply device has a nozzle ( 58 ) supplied with liquid under pressure, the axis of which is adjacent to the axis of the transport part ( 20 ), preferably intersects it. 3. Device according to claim 2, characterized in that the axis of the nozzle ( 58 ) intersects the axis of the transport part ( 20 ) at an acute angle, which is preferably 20-40°, again preferably about 30°. 4. Device according to claim 1, characterized in that the liquid supply device comprises a flexible line ( 244 ) which is connected to the end of the hollow transport part ( 20-5 , 20-6 ) remote from the free end. 5. Device according to claim 4, characterized in that the transport part ( 20-6 ) is closed at the end and has at least one radial liquid discharge opening ( 224 ) in the vicinity of its end. 6. Device according to one of claims 1-5, characterized in that the transport part ( 20 ) is made of a material which has a small modulus of elasticity compared to metal. 7. Device according to claim 6, characterized in that the transport part ( 20 ) is made of a plastic material. 8. Device according to claim 7, characterized in that the plastic material comprises polyetheretherketone or polysulfone. 9. Device according to claim 7 or 8, characterized in that the plastic material contains filler particles. 10. Device according to one of claims 7-9, characterized in that the plastic material contains short fiber filling material. 11. Device according to one of claims 1-10, characterized in that at least a part of the outer surface of the transport part ( 20 ) has a surface structure ( 226 ). 12. Device according to claim 11, characterized in that the surface structure ( 226 ) is sawtooth-shaped, wave-shaped, roof-shaped, pyramid-shaped or dome-shaped when viewed in an axial sectional view of the transport part. 13. Device according to one of claims 1-12, characterized in that the transport part ( 20 ) has a dimension of less than 0.6 mm, preferably of between 0.1 mm and 0.3 mm, at least in a direction transverse to its longitudinal axis. 14. Device according to one of claims 1-13, characterized in that the transport part ( 20-1 to 20-4 ) tapers towards its free end. 15. Device according to one of claims 1-14, characterized in that the transport part ( 20-2 , 20-3 ) is flattened at least in its section adjacent to the free end. 16. Device according to one of claims 1-15, characterized in that at least one section of the transport part ( 20-3 , 20-4 ) adjacent to the free end is curved.