CA2192700A1

CA2192700A1 - Device for cleaning cavities

Info

Publication number: CA2192700A1
Application number: CA002192700A
Authority: CA
Inventors: Jean Grosrey
Original assignee: Individual
Current assignee: Biovision GmbH and Co KG
Priority date: 1994-06-20
Filing date: 1995-05-26
Publication date: 1995-12-28
Also published as: JPH10501437A; EP0766535B1; DE4421503A1; DE4421503C2; EP0766535A1; AU2521895A; ATE175093T1; WO1995035069A1; DE59504699D1

Abstract

In a device for cleaning cavities, especially tooth cavities and tooth root channels, an alternating pressure generator is directly connected to the cavity to be cleaned via a connecting line. To the alternating pressure generator are connected a supply line and a discharge line having narrowed sections as flow resistors, through which a rinsing solution flows. As the rinsing solution flows through, the alternating pressure generator can give rise to cavitation in the cavity with the generation and implosion of gas bubbles so that microstructures in the cavity can also be cleaned. This device is distinguished by simple mechanical construction and small size.

Description

2~ 927~0 TRANSLATION
Device for Cleaning Cavities Ille invention relates to a device for cleaning cavities, notably tooth cavities and roo~
canals" ~ , at least one feed line to feed a rinse to the cavity and at least one 5 drain line to drain the rinse from the cavity, the 'dow of the rinse being caused by a pressure gradient from the feed line to the drain line, and comprising a device with which cavitation with generation and implosion of gas bubbles can be brought about in the cavity by way of a connecting component and an allenating pressure generator com-municating with the cavity.
Such a device is known from WO 92/12685; it allows feeding a rinse via an inlet line to a piston pump. The piston pump ~ witll the tooth cavity via a connecting component formed by a feed line and a connecting line hooked to the feed line by way of a fitting. The fitting features m the mouth area of the connecting line a suction section 15 with a diameter decreasing in the direction of 'dow after the fashion of a venturi nozzle.
The inlet line can be shut off by a valve in the I,o~;Vll phase of the piston pump, OO that the rinse can be fed via the connecting component to the tooth cavity with com-municating root canals. Raising the fiow velocity of the rinse in the a~ea of the suction section lowers the static pressure in the . ~ ~O;V.. phase, in the tooth cavity, below 20 the vapor pressure of a treatment solution fed to the tooth cavity, whereby gas bubbles form in the connecting line, tooth cavity and root canals.
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WO 95/35069 - 2 - 2 1 9 2 7 ~ O p~m~slnn7l4 The flow velocity of the rinse decreases in the retraction phase of the pigton and, conse-quently, the static pressure in the area of the suction section of ttle fitting increases, so that the gas bubbles formed in the ' , pllase implode as the vapor pregsure ise~ce~ded. Known as cavihtion, this 1' enhils a rinsing and cleaning, particu-S larly also of the ~llU~ lUl~i walls of the tooth cavity and root canals.
While with this device a high cleaning effect is achievable also on miniature- and micro-structures, nohbly in a root treatment, the (I;rn~nc;~mc of the gaid device are relatively large, due to the structure of the pumping device featuring a valve actuated at the clock 10 of the piston. r. , due to the relatively large length of the feed line to the tooth cavity, pressure losses occur which require I ~ by a relatively high output pressure of the piston pump. P~lh ukuly in cleaning root canals, however, the rinse and the treatment solution must be prevented from proceeding through the root canals into the systemic circulation, so that the high operating pressure of the piston pump must be lS controlled most accurately. For example, the length and diameter of the feed line must be sp~ci~ied exactly in order to obhin the required conditions of pressure in the area of the suction section. Adapting the device to specific conditions of use is thus relatively expensive, since structural changes affect the pressure conditions in the suction section relatively heavily and can adversely infiuence a proper ' 1~ of the device. Fur-20 thermore, working with two 1 - of solution is relatively expensive.
Known from CH oS7 520 AS is a device for cleaning tooth root canals where a rinse can be injected by way of a long feed tubelet allowing insertion deep into the root canal. The feed tubelet is enclosed by a shorter evacuation tubeiet, the end of which proceeds 25 through the crown of the tooth only little into the tooth cavity and is connected to a wo ss/3so6s - 3 - 2 1 9 2 7 0 0 PCI'IDE95100714 vacuum pump, for instance a water jet pump. The feed tubelet with a supply container filled with rinse.
Applying a vacuum to the end of tbe evacuation tubelet protruding out of the tooth cavity 5 causes rinse to be drawn through the feed tubelet into the root canal and thetooth cavity;
due to a complete separation of the suction space from the feed space, no mixing takes place between clean rinse and infected fiuid. While with this device good treatment results are achieved with smooth-walled root canals, due to the deep insertability of the feed tubelet into the root canal, only an insuffficient therapeutic result is sometimes 10 achieved, specifically with rough root canals, due to the low pressures applied on account of tbe treated patient's exposure to pain.
The objective underlying the invention is to create a device of the initially named type which, while providing a high cleaning ef~ect, is . I ,,. 1. .; ..1 by a small structure of 15 simple design and, thus, a nu..~.u~ handling as well as ~l~t~bilily to different conditions of use.
This objective is ~ ' according to the invention in that the fiow of the rinse is generated by a supply container which, to cause a pressure gradient, is with regard to 20 specific gravity arranged at a higher level than a collection container, the fiow of the rinse as well as the conditions of cavitation being adjustable in ~ " on the differ-ence in level between the containers, and in &t the feed line connected to the altemating pressure generator and the drain lille colltain l ' to fiow witb which, for one,the pressure difference for triggering cavitation can be generated by the altemating 25 pressure generator and, for another, the fiow of the rinse from the feed line to the drain line occurs at a difference in level between the containers.

WO 95/35069 - 4 - 21 9 2 71:) 0 PCI/DE9S/Ol)714 The conditions of constant pressure causing the 'dow of the rinse are ~' ' in simple manner, so that the desired conditions of pressure are adjustable with a mechan-icaUy simple ~ r. ~, the design of the 1 ' to ~ow in the feed line and drain ]ine guarantee that, for one, a fiow of rinse from the feed line to the drain 5 line suffcient for removal of separated material occurs and, for another, the pressure difference required to cause cavitation with rinse circulation in the cavity is generated.
As a result, smallest amounts of rinso are sufficient for cleaning and, spccirlcally, only a single circulation of solution is re~uired.
10 ~ a preferred ~ t, the feed line and drain line connect to the alternating pres-sure generator by way of sections with a reduced cross section. The 'dow of rinse is caused by a constant pressure difference between 'a supply container arranged at a higher level in relation to a collecting container Tlle alternating pressure generator is formed by a piston pump driven by an electric motor and connected to the cavity via a short con-15 necting line emptying in a pump space. Adjustable in a simple manner in ~----'i ~,. ~ on the difference in level between the containers and on the speed of rotation of the electric motor, for one, are the dow of the rinse and, for another, the conditions of cavitation.
Further advantages and suitable i ' - " of tl~e invention are the object of the sub-20 claims and the following description of figures, which show in:
Fig. 1, a schematic illustration of a device for cleaning a tooth cavity and a root canal,where the feed line and drain line each feature a section of reduced cross section; 5 Fig. 2, partially sectioned and scaled up, a side elevation of an alternating pressure generator configured as a piston pump; and ' WO 95/35069 _ 5 _ 2 1 9 2 7 00 PCI/DE95100714 Fig. 3, partly sectioned, a scaled-up front view of the alternating pressure generator relative to Fig. 2.
Fig. 1 shows a schematic illustration of a device for cleaning a cavity formed by a tooth 5 cavity 1 and a root canal 2 of a tooth 3. In the illustration relative to Fig. 1, the root canal 2 is filled with pulp 4 that is still to be removed. A connecting line 7 surrounded hl the area of the tootll crown 5 by a sealant 6 is introduced in the tooth cavity 1 through a bore made in the crown 5. The connecting line 7 empties with its other end in a work-ing space 8 of an alternating pressure generator 9. In the ~ I~Q~ illustrated in Fig.
1, the alternating pressure generator 9 features a piston 11 running in a cylinder 10 and coMected by a connecting rod 12 to a crankshaft 13 driven by a motor not illustrated in Fig. 1.
Illustrated shortened in Fig. 1, a feed line 14 is connected to the working space 8 of the 15 dlternating pressure generator 9 and empties in a supply container 15 subjected to atmo-spheric pressure. Flled with a rinse 16, for e~ample a two- to three-percent NaOCI solu-tion, the supply cont~iner 15 is in the ~ ~ shown in Fig. 1 located, in the direc-tion of gravity, d~ at the level of the section of connecting line 7 that empties in the tooth cavity 1. The feed line 14 empties with a constricted section 17 of reduced 20 cross section in the working space 8.
Moreover, a drain line 19, illustrated shortened in Fig. 1, is via a constricted section 18 of reduced cross section connected to the working space 8, while emptying with its othff end in a collecting container 20. In the i ' ' illustrated in Fig. 1, the collecting 25 containff 20 is in the direction of gravity arranged below the cavity formed by the tooth cavity 1 and the root canal 2.

wo ssl3so6s - 6 - 2 1 9 2 7 0 a PCI/DE95100714 The constricted sections 17, 18 form in with tlle otherwise constant cross section of the feed line 14 amd drain line 19 the major , ' to fiow in the feed line 14 and drain line 19. The rl" '- of the; `l~1- . ~ to f~ow in the feed line 14 and drain line 19 is such that, for one, the pressure differences arising upon i ' ~ or 5 reduction of the volume of the working space 8 and induced by the l~ ' to flow in the constricted seclions 17, 18 cause cavitation with generation and implosion of gas bubbles while, for another, the ~ ' of the supply cont3iner 15 at the level of the ~ line 7 and the provision of the collecting container 20 below the cavity formed by the cavity 1 and the root canal 2 produces a fiow of rinse 16 through the feed 10 line 14 amd drain line 19.
Due to the generation and implosion of the air bubbles in the tooth cavity 1 and root canal 2, a circulation of the rinse 16 takes place between the working space 8 and the tooth cavity I or root canal 2, in addition to a dissolution of the pulp 4 and deaning of u~Llu;lu-~ on the walls of the tooth cavity I and root canal 2, along with carrying the dissolved material of pulp 4 into the working space 8. The 'dow of rinse 16 from the supply container 15 to the collecting container 20 removes the dissolved material.
In treating a tooth 3, the difference in height between tl~e collecting container lS and the 20 tooth cavity 1 or root canal 2 is suitable kept relatively small, so as to avoid the issuance of rinse 16 from the root canal 2 into the systemic ~;~. ' In cleaning sealed cav-ities, for instance in the technical area aiming for a high cleaning effect within a short time, the supply container lS is favoMbly arr2nged above the cavity to be cleaned, in order to achieve a large fiow of rinse 16. When it is desirable to cause the flow of rinse 25 16 solely by the hydrostatic pressure in the fe~d line 14, the supply container lS is ar-ranged above the cavity while the collecting container 20 is set at the level of the cavity.

WO 95/35069 7 _ 2 1 ~ 2 7 ~ Q PCr/DE95100714 When admixing solid substances, for example grains of sand, to the rinse 16 so as to achieve an abrasive effect on the walls of the cavity, it may be suitable to increase the , ~ ' to flow in the feed line 14 and drain line 19 by multiple bends instead of ~ sections 17, 18. In other, not illustrated C~ JC " ', an increase of the S , ' to flow may be provided for, e.g., by a roughened surface or by a sequence of ~u~ ~Liu..~ .. ,. c of short length. Especially with a feed line 14 and drainline 19 of relatively short Icngth each, it may be suitable for r ' ~, rcasons to provide a relatively small cross section across the entire length. To avoid scoring on the contact surface of the cylinder 10 and piston 11, an elastic diaphragm is provided in a 10 not illustrated ~ ' ' as a l of tlle working space 8, said diaphragm allowing periodic cllanges of the working space 8 volume upon stimulation of vibrations.
Fig. 2 shows in a scaled-up, partly sectioned side elevation an alternating pressure generator 9 driven by an electric motor 21. The speed of the electric motor 21 is adjust-able with a control unit not illustrated in Fig. 2. The shaft 22 of the electric motor 21 is fastened to a drive eccentric 23 with an axle 24 tllat is offset relative to the shaft 22.
The eccentric axle 24 is fitted in a slider mounting 25 which is mounted movably in a guide recess 26 of piston 11. With the shaft 22 rotating, the stroke established by the distance of the center axis 27 of e~centric axle 24 from the center axis 28 of shaft 22 can 20 be transmitted to the piston 11 by,' , ' of tlle slider mounting 25.
In the; ' ~ ' of the alternating pressure generator 9 illustrated in Fig. 2, the cylin-der 10 is integral with a base 30 comprising the connecting line 7 as well as fittings 29 for the feed line 14 and, not illustrated in Fig. 2, the drain line 19 with constricted 25 sections 17, 18.
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Scaled up, Fig. 3 shows a partly sectioned front view of the alternating pressure gen-erator 9 relative to Fig. 2. The slider mounting 25 is fitted in the guide recess 26 in a fasbion aL~vwing I Sr'~ transverse to the ~ direction of piston 11. The constricted sections 17, 18 empty in the area of the working space 8 adjacent to the con-5 necting line 7. The dimension of the guide recess 26 in the l~ direction of thecylinder 10 includes a slight allowance in relation to the stroke of the piston 11, so as to guarantee an unimpeded movelnent of the piston 11 also at maximum speed.
The following specifies for a specific ~ ' ' t, notably for application in the root 10 treatment of a tooth 3, the dimrnc;~n.c and parameters of the ~ r ' governing the flow and cavitation. In this specific ~...1,, ' t, the constricted sections 17, 18 have across a length of about 5 millimeters a diameter of about 0.8 ' The diameter of tbe feed line 14 and drain line 19 is about 1.2 ' for each. The diameter of piston 11 is about 3 " the stroke about 0.8 mill- ' The speed of Iotation is adjustable between about 10,000 revolutions per minute and about 15,000 revolutions per minute. Wltll these operating data, the fiow of rinse 16 is adjustable between 0 milli-liter per minute and 8 milliliters per minute by simply changing the distance between the supply container 15 arranged at the level of tooth cavity I and the collecting container 20 belweu~ nd SO .

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Claims

1. Device for cleaning cavities, notably tooth cavities and tooth root canals, comprising at least one feed line (14) for feeding a rinse (16) to the cavity (1, 2) as well as at least one drain line (19) for draining the rinse (16) from the cavity (1, 2), the flow of the rinse (16) being brought about by a pressure gradient from the feed line (14) to the drain line (19), and comprising a device with which by means of an alternating pressure generator communicating through a connecting component with the cavity (1,2) cavitation can be brought about in the cavity (1,2) with generation and implo-sion of gas bubbles, characterized in that the flow of the rinse (16) is generated by a supply container (15) which for producing the pressure gradient is with regard to gravity arranged higher than the collecting container (20), the flow of rinse (16) and the conditions of cavitation being adjustable depending on the height differencebetween the containers (15,20), and in that the feed line (14) and drain line (19) con-nected to the altemating pressure generator (9) feature impedances to flow where, for one, the pressure difference for causing cavitation is produced by the alternating pres-sure generator (9) and,for another,the flow of rinse (16) from the feed line (14) to the drain line (19) occurs at a difference in height between the containers (15,20).

2. Device according to claim 1, characterized in that the alternating pressure generator (9) features a movable piston (11) with which the volume of a pump space (8) is changeable periodically.

3. Device according to claim 1, characterized in that the alternating pressure generator features an elastic diaphragm with which the volume of a pump space (8) is change-able periodically.

4. Device according to one of the claims 2 or 3, characterized in that the frequency of volume change is adjustable with a control unit.

5. Device according to one of the claims 1 through 4, characterized in that the alter-nating pressure generator (9) is driven by an electric motor (21).

6. Device according to one of the claims 2, 4 or 5, characterized in that the shaft (22) of the electric motor (21) is fastened to a drive component (23) with which the rotary movement of the shaft (22) can be transmitted [sic] into a displacement of a piston (11).

7. Device according to one of the claims 2 through 6, characterized in that the alter-nating pressure generator (9) communicates with the cavity (1,2) via a connecting line (7) that is short as compared to the length of the feed line (14) and drain line (19) and hooked directly to the pump space (8), so that the alternating pressure gen-erator (9) is arranged near the cavity (1,2).

8. Device according to one of the claims 2 through 7, characterized in that the feed line (14) and drain line (19) empty in the pump space (8).