Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02360832 2001-11-O1
Apparatus For Filling A Cavity Of A Cavity Containing Member Such As
A Tooth Or A Restorative Dental Piece
Background Of The Invention
The present invention relates to an apparatus for filling a cavity
~s of a cavity containing member such as a tooth or a restorative dental
piece.
A cavity filling apparatus for filling teeth cavities has been
proposed which comprises a suction conduit communicable with the
cavity to thereby apply a vacuum to the cavity. A filling mass which is
io retained in a filling mass ready space between the suction conduit and
a lever positioned above the suction conduit is moved into the cavity
upon actuation of the lever.
This approach has not been comprehensively deployed in
practice for the reason that the filling mass ready space realistically
is must be practically located in the extension of the filling channel which
thus necessitates a correspondingly large assembled dimension.
Additionally, the actuation lever is still arranged above the filling mass
ready space so that only through skill can the dentist effect the desired
actuation of the lever. This arrangement also brings with it the
20 complication that there is a projecting lever which acts as an obstacle
and which is not well suited for the patient's mouth and, further, it
cannot be completely prevented that the tongue of the patient may
unintentionally and involuntarily prematurely actuate the actuation
lever.
CA 02360832 2001-11-O1
It has further been proposed in DE-OS 40 11 568 to fill, in
particular, a crown of a tooth via a cavity filling apparatus. This
approach is expected to insert the filling material to the deepest
possible extent into the root canals. This approach in fact sets the
~s filling inserter under a vacuum so that the filling mass can be inserted
in a non-air entraining manner. However, the cavity itself is merely at
the pressure of the surroundings so that it is very difficult to avoid
entrainment of air in the filling mass during the cavity filling process.
The filling inserter, in particular, must' be controlled as it is withdrawn
to from the root canal while, at the same time, the amount of the filling
material deposited must be precisely controlled in a manner
coordinated with the withdrawal movement of the filling inserter.
It is therefore not surprising that this just described approach is
not comprehensively deployed in practice.
is Summary Of The Invention
The present invention provides a cavity filling apparatus which
advantageously provides greater ease of use and is secured against
disturbances while nonetheless engendering an improved acceptance
of such an approach by the patients.
2o The cavity filling apparatus of the present invention offers the
particular advantage that it engenders improved acceptance by
patients because it provides a non-air entraining cavity filling process.
In order to make it possible that the adapter of the cavity filling
apparatus has only a relatively small height above the bore used for
2
CA 02360832 2001-11-O1
the filling, the cavity filling apparatus of the present invention permits
initially also filling the molars on their chewing surface side. Since a
special actuation of a projecting lever must be performed, the tendency
of the dentist to tilt or angle the adapter in actuating the mechanism
which switches between the suction and filling dispositions is strongly
reduced, whereby the danger that air is suctioned in and thereby
causes air entrainment in the filling material is practically foreclosed.
The cavity filling apparatus of the present invention permits
switching over from the suction disposition to the filling disposition with
1o a natural movement - namely, an increase of the force on the tooth or
the restorative dental piece to be filled without necessitating a special
hand disposition or an added hand movement of the dentist.
It is to be understood that while the force exerted on the cavity
filling apparatus during the evacuation phase of the filling process as
is well as the force exerted to effect switching between the suction and
filling dispositions is, in a wide range of situations, tailored to the
requirements of the task, these forces can also be tailored to the
preferences of the individual dentist. it is preferable to provided a
modest seating function for the switching mechanism which indicates
2o clearly that the switching has occurred. For example, the force
required for switching can be set as triple that of the normal force on
the adapter which is applied during the evacuation phase.
In an advantageous embodiment of the cavity filling apparatus of
the present invention, the switch over force is actuated automatically
3
CA 02360832 2001-11-O1
without other intervention by dimensioning the seating rings of the
working body portion which acts against the guide socket of the
working body portion. To place in readiness a large actuation force for
- effecting the switching over between the suction and filling dispositions,
's 'it is possible to use O-rings with an increased strength and, to place in
readiness a lower actuation force, to use O-rings with a reduced
strength. Moreover, the frictional force with respect to the seating force
can in any event be finely adjusted through corresponding
configuration of the seating groove. It is preferably provided that two
~o seals are disposed axially spaced from one another on a cylindrical
working body in the guide socket, each of which respectively seats in a
corresponding annular groove in accordance with the position of the
working body. The edge steepness of the annular groove determines
then the pure switch over force.
is In accordance with a particularly advantageous aspect of the
present invention, solely a single adapter channel is provided in the
adapter which is deployed as both a suction passage as well as a filling
material passage. This solution offers a markedly reduced frequency
of disturbances in comparison to solutions having two concentric
2o canals, although also a reduction in the production effort. In
accordance with the present invention, the working body itself forms a
switchover flank, whereby, in a first disposition of the working body (the
suction disposition of the cavity filling apparatus), a filling inlet of the
filling mass ready space is closed off by the working body or, more
4
CA 02360832 2001-11-O1
precisely, by the switchover flank. In contrast, in a second disposition
of the working body (the filling disposition of the cavity filling
apparatus), a working opening of the adapter channel can be oriented
toward the filling inlet in the most obstacle-free manner so that the
~s filling mass can enter the adapter channel in a blockage-free manner
and pass from there into the cavity.
In accordance with the present invention, it is particularly
advantageous if the viscosity of the filling mass is exploited for the
purpose of keeping the filling mass free from entrained air. Although
to as a basic premise the filling of the filling mass ready space would be
possible by pressing movement of an injector head, in accordance with
the present invention, an integral suctioning or drawing of the filling
mass is preferable. in this connection, a small yet nonetheless defined
gap is provided in the working area between the working body and the
is guide socket. Air is drawn into this gap from a suction coupling which
is immediately adjacent the filling mass ready space and extends
perpendicularly therefrom and the drawn in air then travels out of the
adapter channel and into the cavity of the tooth or the restorative dental
piece. At the same time, air is drawn through the gap between the
2o switch over angle and the filling inlet so that a vacuum is produced in
the filling mass ready space. Since the cavity forms an enclosed space
with the adapter channel when the channel is firmly communicated
therewith, further suctioning via the suction conduit produces a vacuum
in the filling mass ready space and this vacuum acts to draw in a filling
s
CA 02360832 2001-11-O1
mass which has been pre-positioned in an injector until the filling mass
borders on the filling inlet. As soon as this occurs, the vacuum in the
adapter channel increases and the vacuum increases as well in the
suction conduit so that it is possible to detect via a pressure detector
s when the adapter is ready for a switchover from the suction disposition
to the filling disposition.
In accordance with the present invention, it is particularly
advantageous if the vacuum produced in the cavity acts to draw the
adapter thereagainst. The seal between the adapter and the cavity is
io for this reason not critical, whereby it is advantageous if the angle of an
outer cone on the adapter is selected such that the adapter maintains
itself in communication with the tooth or the restorative dental piece
after it has initially been disposed thereon.
In an especially advantageous embodiment of the cavity felling
is apparatus of the present invention, a static mixer is provided through
which pass the two components which comprise the filling mass. In
accordance with the present invention, this occurs via the heretofore
described suction force so that the components are at the same time
free of entrained air. The static mixer can be configured as a spiral
2o threaded component which is received in a cylinder having an inner
diameter sized in correspondence with the outer diameter of the spiral.
An intensive mixing of the two components with one another occurs
due to the suctioning of the filing mass for the reason that the filling
mass, which tends to follow the spiral passage, is at the same time
6
CA 02360832 2001-11-O1
subject to shearing during its passage due to the fact that suitable
measures such as a rotation preventing securement member are
provided to ensure that the injector connecting component, in which the
spiral threaded component is disposed, does not rotate.
~s The cavity filling apparatus of the present invention lends itself
to an especially cost favorable manufacturing thereof. The guide
socket which collectively comprises the filling mass ready space and
the adapter body can also be manufactured as a single unit. It is also
possible to releasably dispose the adapter body in the guide socket so
io that a cleaning can be facilitated.
In a further particularly advantageous embodiment of the
invention, it is provided that an additional coupling is also located
adjacent the suction coupling on the guide socket for the purpose of
measuring the respective vacuum.
Is Additional advantages, details, and features are set forth in the
following description in connection with the figures of the drawings.
Brief Description Of The Drawings
Figure 1 is an exploded perspective view of one
embodiment of the cavity filling apparatus of the
2o present invention;
Figure 2 is a perspective view of the one embodiment of the
cavity filling apparatus shown in Figure 1 prior to
its assembled together condition;
CA 02360832 2001-11-O1
Figure 3 is another perspective view of the one embodiment
of the cavity filling apparatus shown in Figure 1 in
its assembled together condition;
Figure 4 is a perspective view of the one embodiment of the
~s ~ cavity filling apparatus shown in Figures 1- 3;
Figure 5 is an enlarged perspective view of portions of the
one embodiment of the cavity filling apparatus
shown in Figures 1- 3;
Figure 6 is an enlarged cross-sectional view of portions of
io the one embodiment of the cavity filling apparatus
shown in Figure 1;
Figure 7 is an enlarged sectional view of the working unit
portion of the one embodiment of the cavity filling
apparatus shown in Figure 1 and showing the
is working unit portion in the suction disposition of
the cavity filling apparatus; and
Figure 8 is an enlarged sectional view of the working unit
portion of the one embodiment of the cavity filling
apparatus shown in Figure 1 and showing the
2o working unit portion in the filling disposition of the
cavity filling apparatus.
Detailed Description Of The Preferred Embodiment
As seen in Figure 1, the cavity filling apparatus 10 of the present
invention includes a working unit portion 12, an injector connecting
s
CA 02360832 2001-11-O1
component 14, a static mixer 16, an injector cylinder component 18
and a double injector plunger 20. When deployed, these components
are in the assembled together disposition shown in Figure 3 and these
components are shown in the exploded unassembled disposition in
s Figure 1 for the sake of clarity of understanding.
The working unit portion 12 comprises a working body 22, a
guide socket 24 in which the working body 22 is slidably received, and
a filling space 26. .
The working body 22 further includes an actuation cap 28 which
io retains the working body in the guide socket 24. The working body 22
forms together with the actuation cap 28 an adapter 30 and includes on
its lower end an adapter cone 32. The adapter cone 32 is configured
for insertion into a bore in a tooth or restorative dental piece which can
itself be comically shaped with a cone angle corresponding to that of
Is the adapter cone 32.
The guide socket 24 is configured of minimal length and is
integrally built as a single unit with the filling space 26, whereby the
filling space 26 is formed substantially as a pipe which extends
outwardly from the guide socket.
2o A suction coupling 34, whose function will be described in more
detail below, and a pressure measurement coupling 38 are disposed
below the filling space 26.
As can be readily seen in Figure 2, the injector connecting
component 14 can be partially inserted into the pipe 38 which forms the
9
CA 02360832 2001-11-O1
filling mass ready space 26. A rotation preventing securement member
40, provided on the outer periphery of the injector connecting
component, engages corresponding tabs 42 of the injector cylinder
component 18. A static mixer 16, which is in the shape of a spiral
~s threaded component, is disposed in the injector connecting component
14 before the assembling together of the injector connecting
component. The injector cylinder component 18 includes two
cylinders, shown in Figure 1, which are each filled with a material
component to be mixed and injected. The filling mass in the filling
to mass ready space 26 is formed by the intensive mixing of the two
material components with one another.
The working unit portion 12 is shown in an enlarged view in
Figures 4 and 5. Figure 4 shows the suction position of the adapter 30
in the guide socket 24 and Figure 5 shows the filling position of the
is adapter in the guide socket. In the suction position of the adapter 30,
the actuation cap 28 is in a flat contact position on the top side of the
guide socket 24. In this position, the working body 22 is projected
clearly downwardly.
In contrast, the working body 22 extends outwardly above the
20 guide socket 24 in the filling position while solely the adapter cone 32
projects downwardly.
In connection with the transition between the suction position
shown in Figure 4 and the filling position shown in Figure 5, it is
sufficient if the dentist exerts from above a total downward force on the
to
CA 02360832 2001-11-O1
pipe 38 of the filling mass ready space 26. A transformer device 35 is
configured for this purpose.
As can be seen in particular in Figure 5, the pressure
measurement coupling 36 and the suction coupling 34 extend in
~s differing vertical planes as well as at an offset from one another.
These couplings can be disposed at the smallest possible assembled
height and, to ensure that the two couplings 34 and 36 each extend
sideways adjacent the pipe 38, the two couplings can be conducted
parallel to the pipe 38 out of the mouth of the patient.
to Conduits which are not illustrated form a connection to a supply
unit.
The pipe 38 includes - as can be seen in particular in Figure 5 -
a rotation preventing securement member 40 which receives and
supports therefrom the injector connection body 14. It is to be
is understood that a coupling without free play and, as desired,
corresponding sealing members can be provided.
A cavity filling apparatus of the present invention is shown in
Figure 6 in a disposition in which the adapter 30 is disposed for
administering a filling dose. It can be seen that the static mixer 16
2o practically completely Ells a cylindrical inner volume 43 of the injector
connection body 14. The static mixer 16 is so configured that it rests
on the inner volume 43 under a resilient bias yet can be removed as
required for, for example, the purpose of cleaning.
n
CA 02360832 2001-11-O1
Figure 7 shows the individual elements of the adapter 30 as they
are assembled into assembled condition in the guide socket 24. The
working body 22 of the adapter 30 is substantially cylindrical but
nonetheless includes a not insubstantial annular groove 44 disposed
~s slightly above the middle of the working body. The working body 22
further includes a first seal 46, a second seal 48, and a third seal 50,
.each of which is configured as an O-ring seal. The seals 46, 48, and
50 seal off the guide socket 24. The rotational position of the working
body 22 within the guide socket 24 is set by a rotation preventing
to securement member {not illustrated). The working body 22 further
includes a working opening 52 which is communicated with the annular
groove 44 and extends toward the filling mass ready space 26 into
communication with an adapter channel 54. The adapter channel
extends through the entirety of the working body 22 as well as the
is adapter cone 32.
The filling mass ready space 26 terminates in a filling coupling
56 which extends toward the working body 22. As shown in Figure 7,
the filling coupling 56 in the suction position of the working body 22 is
closed off by the transformation edge58 of the working body while, as
2o shown in Figure 8, the filling coupling 56 in the filling position is open
to
the adapter channel 54.
A gap 60 of a predetermined width extends between the working
body 22 and the guide socket 24. ~ The suction coupling 62 is
communicated with the gap 60 such that a vacuum exists in the gap
12
CA 02360832 2001-11-O1
and from there into other regions. The vacuum extends into the
annular groove 44 and via the groove into the adapter channel 54.
Since the seal 50 in the suction position shown in Figure 7 is above the
filling coupling 56, the vacuum extends as well into the filling coupling
~s 56 and from there info the filling mass ready space 26. This leads to
the condition that a filling mass, which is not shown, is drawn in by the
vacuum condition to be disposed at the transformation edge 58. The
viscosity of the filling mass is sufficiently large that it cannot enter into
the gap 60 so long as the working body 22 remains in the suction
to position.
The suction position as shown in Figure 7 is maintained for a
predetermined period such as, for example, five minutes or more, to
permit the evacuation of the cavity or hollowed out space in the tooth or
the restorative dental piece. In this connection, the cavity and the
is adapter channel 54 are initially evacuated, whereby a remainder
pressure of from 10 to 15 mbar remains automatically without further
intervention. The vacuum propagates through the filling mass ready
space 26 and effects a drawing in of the filling mass from the injector
through the static mixer 16 into the filling mass ready space 26 until
2o this space is filled. As soon as the filling mass ready space 26 is filled,
no further air remains to be evacuated, ~rvhereby a suction occurrence
is precluded. The dentist then presses from above on the pipe 38 so
that the filling position shown in Figure 8 is achieved. The switch over
permits the filling mass to be injected from the filling mass ready space
13
CA 02360832 2001-11-O1
26 through the adapter channel 54 into the cavity in the tooth.
Thereafter, as a stronger vacuum ensues, the filling space is filled in a
complete and air entrapment-free manner.
An inventive seating apparatus 64 is provided to make available
~s a fixed transformation or switch over position. The seating apparatus
64 includes an annular groove 66 located in the interior of the guide
socket 24 which cooperates with the first seal 46 and the second seal
48. In the first position, which is the suction position as shown in
Figure 7, the first seal 46 is seated in the annular groove 66. In this
to position, the first seal 46 is freely positioned and the vacuum existing in
the gap 60 can be measured, whereby the measurement is conducted
via the pressure measurement coupling 36.
For the transformation or switch over of the adapter 30 into the
second position, which is the filling position, shown in Figure 8, initially
is the first seal 46 is displaced out of its seated position in the annular
groove and, upon further displacing movement, the second seal 48
seats in the annular groove 66.
The spacing between the seals 46 and 48 is selected such that
the spacing is greater than the width of the annular groove 66, whereby
2o a constant vacuum sealing is ensured in the interior of the working unit
portion 12.
The actuation cap 28 is -as shown in Figures 7 and 8 -
threaded into a corresponding threaded receiving portion of the
working body 22. To permit cleaning of the working body 22 and the
14
CA 02360832 2001-11-O1
working unit portion 12, the actuation cap 28 is released from its
threaded retention so that the working body 22 can be withdrawn
downwardly out of the guide socket 24. The actuation cap 28 is ball
shaped for ease of reconfiguring the cavity filling apparatus from the
~s filling position shown in Figure 8 into the suction position shown in
Figure 7 in preparation for the filling thereof for the next tooth filling
operation.
The specification incorporates by reference the disclosure of
German priority document 100 64 005.2.
to The present invention is, of course, in no way restricted to the
specific disclosure of the specification and drawings, but also
encompasses any modifications within the scope of the appended
claims.
