Note: Descriptions are shown in the official language in which they were submitted.
W0 95135069 - I - PCIIDE95100714
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
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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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WO 9S/35069 - 8 - 21 9 2 7 0 0 PCT/DE9S/00714
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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