U.S. patent application number 13/387146 was filed with the patent office on 2014-08-14 for holding piece for an implant.
This patent application is currently assigned to Straumann Holding AG. The applicant listed for this patent is Rainer Bammerlin, Frederic Blason, Guillaume Bugnard, Daniel Guenter, Frank Kenk. Invention is credited to Rainer Bammerlin, Frederic Blason, Guillaume Bugnard, Daniel Guenter, Frank Kenk.
Application Number | 20140227661 13/387146 |
Document ID | / |
Family ID | 41421982 |
Filed Date | 2014-08-14 |
United States Patent
Application |
20140227661 |
Kind Code |
A2 |
Guenter; Daniel ; et
al. |
August 14, 2014 |
HOLDING PIECE FOR AN IMPLANT
Abstract
A housing (35) for an implant (25), a holding piece (1) to
connect the implant (25) to the housing (35), and an insertion tool
(20) for inserting the implant (25) into an implant site. The
holding piece (1) includes at least one resilient element (45) for
detachably connecting to the implant (25) with a first retentive
force and a tool retention means to connect to the insertion tool
(20) with a second retentive force which is greater than the first
retentive force. In between the two ends the holding piece (1)
features a housing connection segment (30) for connecting the
holding piece (1) to the housing (35). On a distal end the
insertion tool (20) comprises torque transmission means, which
transmit torque directly to the holding piece (1) and/or to the
implant (25).
Inventors: |
Guenter; Daniel; (Basel,
CH) ; Bammerlin; Rainer; (Basel, CH) ; Kenk;
Frank; (Basel, CH) ; Bugnard; Guillaume;
(Basel, CH) ; Blason; Frederic; (Basel,
CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Guenter; Daniel
Bammerlin; Rainer
Kenk; Frank
Bugnard; Guillaume
Blason; Frederic |
Basel
Basel
Basel
Basel
Basel |
|
CH
CH
CH
CH
CH |
|
|
Assignee: |
Straumann Holding AG
Basel
CH
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20120171638 A1 |
July 5, 2012 |
|
|
Family ID: |
41421982 |
Appl. No.: |
13/387146 |
Filed: |
March 27, 2012 |
Current U.S.
Class: |
433/163 |
Current CPC
Class: |
A61C 2202/00 20130101;
A61C 8/0087 20130101; A61C 8/0089 20130101 |
Class at
Publication: |
433/163 |
International
Class: |
A61C 13/225 20060101
A61C013/225 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 27, 2009 |
EP |
09 009 674.4 |
Jul 27, 2010 |
WO |
PCT/EP2010/004583 |
Claims
1. Holding piece for an implant comprising a first end and a second
end, both ends arranged on a longitudinal axis, and in between the
two ends a housing connection segment for connecting the holding
piece to a housing for the implant, wherein the first end comprises
at least one resilient element for connecting to an implant, said
at least one resilient element adapted to retain the implant with a
first retentive force the holding piece further comprising tool
retention means adapted to directly connect the holding piece to an
insertion tool with a second retentive force that is greater than
the first retentive force.
2. Holding piece as claimed in claim 1 wherein the at least one
resilient element is an integral part of the holding piece.
3. Holding piece as claimed in claim 2 wherein the at least one
resilient element is a flexible arm bendable in a direction
perpendicular to the longitudinal axis of the holding piece.
4. Holding piece as claimed in claim 3, wherein the arm comprises a
catch feature shaped to engage a complementary feature of an
implant such that a snap fit connection can be formed between the
holding piece and the implant.
5. Holding piece as claimed in claim 4 wherein the catch feature is
positioned on the radially outer side of the at least one flexible
arm for engagement with an internal complementary feature of an
implant.
6. Holding piece as claimed in claim 4 wherein the catch feature is
positioned on the radially inner side of the at least one flexible
arm for engagement with an external complementary feature of an
implant.
7. Holding piece as claimed in claim 3, wherein the at least one
flexible arm further comprises, at its proximal end, an abutment
surface for contacting the implant.
8. Holding piece as claimed in claim 1 wherein the first end
further comprises a support collar arranged for abutment with the
implant.
9. Holding piece as claimed in claim 8 wherein the support collar
consists of a plurality of longitudinally extending struts, said
struts forming an abutment surface for contacting the implant.
10. Holding piece claimed in any preceding claim 1, wherein the
tool retention means is an integral part of the holding piece.
11. Holding piece as claimed in claim 10, wherein the tool
retention means comprises at least one flexible arm bendable in a
direction perpendicular to the longitudinal axis of the holding
piece.
12. Holding piece as claimed in claim 11 wherein the at least one
flexible arm comprises a catch feature shaped to engage a
complementary feature of an insertion tool so as to create a snap
fit connection with an insertion tool.
13. Holding piece as claimed in claim 1 wherein the second end
defines an interior space for housing the distal end of an
insertion tool.
14. Holding piece as claimed in claim 13, further comprising
lateral openings in the exterior surface of the holding piece which
connect to the interior space defined by the second end.
15. Holding piece as claimed in claim 1 wherein the holding piece
is hollow.
16. Holding piece as claimed in claim 14 wherein the holding piece
does not comprise a force transmission element for transmitting
torque to the implant.
17. Insertion tool for cooperation with a holding piece as claimed
in claim 1, the insertion tool comprising a distal end having
torque transmission element and a shank, the shank comprising a
securing portion for engagement with the tool retention means of
the holding piece.
18. Insertion tool as claimed in claim 17 wherein the securing
portion comprises a complementary feature formed on the exterior
surface of the tool, said complementary feature being shaped to
engage a catch feature of the holding piece to form a snap
connection.
19. Insertion tool as claimed in claim 17, wherein the torque
transmission element is arranged to protrude through the holding
piece for direct engagement with an implant
20. Insertion tool as claimed in claim 19 wherein the torque
transmission element is arranged to protrude through lateral
openings in the holding piece.
21. Insertion tool as claimed in claim 20 wherein the force
transmission element comprises at least one longitudinally
extending groove configured to engage protrusions formed in the
interior bore of an implant.
22. Housing for an implant comprising a holding piece according to
claim 1.
23. Housing as claimed in claim 22 further comprising a pin element
inserted through the holding piece.
24. A holding piece in combination with an insertion tool, said
holding piece comprising a first end and a second end, both ends
arranged on a longitudinal axis, and in between the two ends a
housing connection segment for connecting the holding piece to a
housing for the implant, tool retention means adapted to directly
connect the holding piece to the insertion tool, the first end
comprising at least one resilient element for connecting to an
implant said insertion tool comprising a distal end, having a
torque transmission element, and a shank, the shank comprising a
securing portion for engagement with the tool retention means,
wherein said holding piece is at least partially hollow such that
the torque transmission element of the insertion tool can be
inserted into and protrude from the holding piece for direct
engagement with the implant.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a holding piece for a
medical tool, in particular a dental implant.
BACKGROUND
[0002] Prior to application or implantation medical tools must be
sterilized. In order to reduce the risk of contamination the number
of handling steps of sterilized products should be kept to a
minimum. Therefore medical tools are often sterilized together with
the housing in which they are delivered or stored. The housings
should allow easy access of the sterilizing agent (vapour, liquid
or radiation) to the product to be sterilized. Furthermore, the
housing should protect the medical tool from physical damage. Some
medical products are very sensitive to abrasion due to contact with
other surfaces, especially in combination with vibration, which
often occurs during transportation.
[0003] This is particularly true in relation to dental implants,
which are inserted into the jaw bone to replace one or more teeth.
The surface of these implants, particularly those parts of the
implant which will, in use, be positioned within the bone, are
often treated to enhance tissue adhesion. Such treated surfaces are
very sensitive to abrasion or deterioration when placed in contact
with other surfaces.
[0004] To minimize abrasion and other deteriorating interactions
with any surface, housings have been developed in which the medical
tools, such as implants, can be firmly attached to the body of the
housing for transportation and storage. Housings are known which
firmly hold the implant at specified areas in such a way that the
majority of the implant is held away from the interior of the
housing.
[0005] US-B1-6 261 097 discloses a housing including a holding
device which comprises a sleeve and a carrier screw, one end of
which can be screwed into the internally threaded bore of an
implant. The sleeve of the holding device serves to fix the implant
inside an ampoule such that the implant itself does not contact the
ampoule walls. The opposing end of the screw is shaped for
connection to a screwing-in, or insertion, tool for removal of the
implant from the housing and implantation.
[0006] The sleeve is in contact with the body of the housing during
transportation. Prior to insertion of the implant the carrier screw
is connected to an insertion tool. The arrangement consisting of
implant/sleeve/carrier screw/insertion tool is then removed from
the housing. With the aid of the insertion tool the implant is then
screwed into a cavity in the bone. The carrier screw therefore
provides means to transmit torque from the insertion tool to the
implant. After the implant has been screwed into the bone the
carrier screw is detached from the implant. For this step the
practitioner reverses the direction of rotation of the insertion
tool.
[0007] A disadvantage of this system is that the carrier screw
might not easily be removed from the implant as force is applied to
the carrier screw during insertion of the implant, which connects
the carrier screw tightly to the implant. Therefore, special care
has to be taken when unscrewing the carrier screw from the implant
not to loosen the connection of the implant to the bone. This
requires the use of an additional tool to steady the implant during
initial loosening of the carrier screw. The need to unscrew the
carrier screw to remove the holding element presents an additional,
undesirable step in the implantation procedure.
[0008] Furthermore, a holding piece comprising two components
creates greater manufacturing costs and complexity.
[0009] EP-A1-1 749 501 describes a holding element for a dental
implant including an engagement section for connection to an
insertion tool, a retention section adapted for engagement with a
housing and a clamping member for connecting the holding element to
the dental implant. The clamping member lockingly engages the
implant when the clamping member is in a non-compressed position.
The holding element can thus be removed from the implant after
insertion simply by compressing the clamping member without the
need for an unscrewing motion. However the holding element must
still be connected to a separate insertion tool in order to insert
the implant. Therefore after insertion both the insertion tool and
the holding piece must be removed from the implant.
[0010] The holding element further comprises a force transmission
element, which co-operates with the internal structure of the
implant in order to transmit a torque to the implant. The holding
element must therefore be strong enough to withstand the torque
placed on it during use and to transmit this effectively to the
implant. Therefore the holding element is often made from titanium
or another metal material via machining.
[0011] The cost of production of this type of holding element is
therefore high. As the holding element is used to hold the implant
within the packaging a separate holding element must be
manufactured for each implant. This increases the cost of
production of each implant.
[0012] Insertion tools which connect directly to the implant are
also known. These can be multiple use tools which are provided to
the surgery separately from the implant or single use tools
supplied within the implant housing. Although this overcomes the
problem of having two separate elements connected to the implant
during insertion, the use of a directly connecting insertion tool
results in new problems. When the insertion tool is provided in the
packaging the above discussed problem of high manufacturing expense
remains. When the tool is provided separately an alternative
solution to the problem of securely holding the implant within the
packaging must be found.
SUMMARY OF THE INVENTION
[0013] The problem of the present invention is to provide a holding
piece for an implant, which simplifies the insertion procedure for
the implant and reduces the cost of the holding piece, as well as a
housing and insertion tool in connection with said holding
piece.
[0014] The holding piece according to a first aspect of the present
invention comprises a first end and a second end, both ends
arranged on a longitudinal axis, and in between the two ends a
housing connection segment for connecting the holding piece to a
housing for the implant. The first end comprises at least one
resilient element for connecting to an implant, said at least one
resilient element adapted to retain the implant with a first
retentive force. The holding piece further comprises tool retention
means adapted to directly connect the holding piece to an insertion
tool with a second retentive force that is greater than the first
retentive force.
[0015] The tool retention means of the holding piece is adapted to
directly cooperate with an insertion tool, that is no further
pieces or tools, such as carrier screws, are required to connect
the insertion tool to the holding piece. Typically, the insertion
tool is temporarily connected to the holding piece for the process
of removing the implant from the housing, transferring the implant
to the implant site and inserting the implant into the bone. In
this way the insertion tool can be a multiple use tool which is
supplied separately from the implant.
[0016] The holding piece has a dual connection function. The at
least one resilient element connects to an implant and the tool
retention means connects to an insertion tool. Therefore, in one
sense, the holding piece acts as an adaptor, which allows an
implant to be connected to an insertion tool. The holding piece
provides all the necessary features to firmly connect to an implant
and to an insertion tool at the same time. No carrier screw or
other additional items are needed to form the two connections.
Therefore, the production of the holding piece according to the
present invention is greatly simplified. In addition the holding
piece enables the implant to be indirectly held within the housing,
via the housing connection segment. The holding piece can therefore
be used to hold the implant within a housing during sterilisation,
transportation and storage.
[0017] When the implant is to be used, the insertion tool can be
connected to the holding piece via the tool retention means and the
implant, together with the holding piece, can be removed from the
housing. The at least one resilient element provides a firm
connection between the holding piece and implant during transfer of
the implant with the insertion tool to the implant site. At the
implant site the implant is inserted into the bone with the aid of
the insertion tool. After insertion of the implant into the bone
the insertion tool is pulled back. The holding piece is designed
such that the retentive force of the connection between the holding
piece and the insertion tool is greater than the retentive force of
the connection between the holding piece and the implant. This
characteristic causes the connection between the implant and the
holding piece to disconnect first when the practitioner pulls back
the insertion tool after having inserted the implant into the
implant site. The holding piece remains connected to the insertion
tool. In effect therefore, once the insertion tool has been
connected to the holding piece these two components function as a
single element throughout the implantation procedure. In this way
removal of the holding piece from the implant is facilitated and
the practitioner can immediately continue with the surgical
procedure. Only a single, simple step is required to remove both
the holding piece and the insertion tool. The holding piece can
later be removed from the insertion tool, which can then be
reused.
[0018] The retentive force of a specific connection is the minimal
force required to disconnect said connection. The at least one
resilient element is adapted to provide a retention force of
preferably between 1 and 10N, more preferably between 1 and 5N. The
retentive force provided by the tool retention means is greater
than the chosen retentive force of the resilient element but is
preferably no greater than 20N. Preferably the difference between
the first and second retentive forces is at least 1N, more
preferably at least 5N.
[0019] The one or more resilient elements firmly connect the
implant to the holding piece during the course of various events
such as sterilisation, packing, transportation, storage and
insertion.
[0020] A resilient element is one whose shape can be distorted or
otherwise adjusted but which returns to its original shape after
removal of the distorting force. This quality allows the element to
be bent, compressed or otherwise displaced in order to enable
relative movement between the implant and holding piece, but then
to spring back to, or at least towards, its original position in
order to hold the implant on the holding piece until the element is
again distorted to allow removal of the implant.
[0021] An example of a suitable resilient element is an o-ring or
other elastic, compressible component. The use of an elastic
component is however less preferred as the high flexibility of such
components renders them an unsuitable material from which to
manufacture the whole of the holding piece. Therefore a holding
piece comprising an o-ring or other elastic resilient element must
necessarily be composed of two separate components. This increases
the cost and complexity of the holding piece.
[0022] It is therefore preferable for the at least one resilient
element to be an integral part of the holding piece. Most
preferably the at least one resilient element is a flexible arm
bendable in a direction perpendicular to the longitudinal axis of
the holding piece. This enables the arm to be flexed towards or
away from the longitudinal axis. Although the flexible arm may
simply provide a clamping fit with the implant, it is preferable
that the arm comprises a catch feature shaped to engage a
complementary feature of an implant. In this way the at least one
resilient element creates a "snap fit" connection with the
implant.
[0023] Snap fit connections are well known in the art and refer to
the displacement and subsequent release of a resilient element upon
alignment of the element with a complementary structure that allows
the element to return to its original, or near original, form. The
sudden release of the resilient element results in a physical and
sometimes aural feedback to the user that the connection has been
made.
[0024] The snap connection between the implant and the holding
piece is preferably designed in such a way that the holding piece
can again be connected to the implant after the connection was
initially disconnected. Reconnecting the holding piece to the
implant can be useful in case the implant was not correctly
inserted in the bone, e.g. positioned too high or deep. Therefore
the resilient element is preferably configured such that it can be
disconnected from the implant without permanent distortion or
damage. This is also beneficial from a safety perspective as it
prevents the possibility of parts of the holding piece breaking off
in the patient's mouth.
[0025] The at least one flexible arm of the holding piece may be
arranged to enagage the exterior or interior of a dental implant.
The chosen design of the flexible arm(s) will depend to a large
extent on the implant design with which the holding piece will be
used.
[0026] For example, many implants, in particular implants intended
for use with a separate abutment component, comprise an internal
bore extending longitudinally into the implant from the coronal
end. The bore can comprise a radial groove or rib, or undercut. A
holding piece designed to connect to such internal implant geometry
can therefore comprise at least one flexible arm comprising, on its
radially outer side, a catch feature shaped to engage this internal
complementary feature of an implant. The catch feature can comprise
either a complementary radially protruding nub or regressed indent
shaped to engage the internal feature of the implant. The bore of
the implant may also comprise an apical threaded portion and/or an
anti-rotation feature. This anti-rotation feature can be used to
prevent relative rotation between the implant and an abutment but
can also be used to transmit torque to the implant during insertion
into the bone. The complementary feature of the bore, for snap
connection to the holding piece, can be provided separately to
these features or may be a part of either of these structures.
[0027] Alternatively, an external snap connection can be formed. In
such cases the exterior of the implant must comprise an indentation
or protrusion for co-operation with the catch feature of the
flexible arm(s). In one advantageous configuration the implant is
formed with an undercut. For example, the implant may comprise an
outwardly tapering portion which extends to an outer perimeter,
thus forming a collar or shoulder. The flexible arm(s) can
therefore be shaped to complement this collar such that the arm
engages the implant below the outer perimeter. Alternatively the
implant may comprise an external anti-rotation feature, located on
the coronal end of the implant, or an integrally formed abutment
part. Either of these features may comprise an undercut, groove or
protrusion that can be complemented by the catch feature of the
flexible arm(s). In this embodiment therefore, the catch feature is
located on the radially inner side of the at least one flexible arm
for engagement with an external complementary feature of an
implant.
[0028] The holding piece preferably comprises two, more preferably
four flexible arms arranged to form a snap connection with the
interior or exterior of an implant, wherein the arms are arranged
in mutually opposing pairs. Furthermore, the retentive force
provided by the flexible arms should be sufficient to support the
implant without need of any additional elements. In this way, the
implant is preferably in contact only with the holding piece when
held in the housing and is not in direct contact with the housing
itself, whereby contamination of the implant by the material of the
housing is avoided and sterilization is facilitated. In order to
increase the retentive force provided by the flexible arms at least
two of these can be connected at their distal ends, such that a
partial or complete annular ring is formed.
[0029] Preferably the at least one resilient element is arranged to
connect to an area of the implant which will not be in direct
contact with the bone after insertion. This will of course always
be the case when the resilient element is arranged to connect to an
internal feature of the implant. When an external connection is
made this preferably occurs at the coronal end of the implant, e.g.
with the abutment part of a one-part implant, external
anti-rotation feature or neck portion of a two-part implant. Other
areas therefore, in particular more sensitive areas such as the
bone contact surface, experience no contact with the holding piece
or the housing.
[0030] The first end of the holding piece preferably further
comprises a support collar arranged for abutment with the implant.
This provides additional support to the implant and prevents
pivotal movement of the implant relative to the holding piece,
which may result in the disconnection of the resilient element(s)
from the implant. In order to reduce the contact between the
implant and holding piece the support collar is preferably
discontinuous in that it consists of a plurality of longitudinally
extending struts, the struts forming an abutment surface for
contacting the implant. These abutment surfaces do not provide any
axial retention, which is provided solely by the at least one
resilient element. The described construction allows a safe
retention of the implant, although only a small area of the implant
is in contact with the holding piece, thus allowing a thorough
sterilization of the implant. The holding piece is thus arranged in
such a way that the surface of the implant, which is in contact
with the holding piece, is reduced to a minimum while still
ensuring reliable holding properties.
[0031] In embodiments in which the arms are adapted for internal
connection to an implant, the struts are formed radially outwards
of the flexible arms. The struts and arms may however be located at
the same angular location, such that each arm has an associated
strut. It is also possible of course for the holding piece to
comprise differing numbers of flexible arms and struts.
[0032] In embodiments in which the arms are adapted for external
connection to an implant, the struts are preferably formed by the
flexible arms. Therefore, in one embodiment the at least one
flexible arm comprises, at its proximal end, an abutment surface
for contacting the implant. When the arm comprises a catch feature
the abutment surface should be proximal of this catch feature.
[0033] During the steps related to the insertion of an implant,
such as removing the implant from the housing, transferring the
implant to the implant site and inserting the implant into the
bone, an insertion tool is connected to the tool retention means of
the holding piece.
[0034] A firm connection between the insertion tool and the holding
piece is important, to prevent dropping of the implant. This is
clearly highly undesirable, as this can result in damage and
contamination of the implant or aspiration of the implant by the
patient. In accordance with the present invention the retentive
force between the holding piece and the insertion tool is greater
than the retentive force between the holding piece and the implant,
in order to enable the insertion tool and holding piece to be
jointly removed from the inserted implant.
[0035] Hence, the tool retention means of the holding piece is
adapted to interact with a securing portion of the insertion tool
in order to provide a secure connection. The holding piece acts as
a connector between the implant and the insertion tool and hence no
direct axial retention occurs between the insertion tool and the
implant.
[0036] In accordance with another aspect of the present invention
therefore there is provided an insertion tool for cooperation with
a holding piece as described herein. The insertion tool comprises a
distal end, having a torque transmission element, and a shank, the
shank comprising a securing portion for engagement with the holding
piece.
[0037] The engagement between the holding piece and the insertion
tool can be based on a thread, press fit, friction fit, snap
connections or the use of an o-ring or a griper.
[0038] Therefore, for example, the tool retention means of the
holding piece may comprise a male threaded shaft and the securing
portion of the insertion tool may comprise a complementary female
threaded cavity, or vice versa.
[0039] In an alternative embodiment the connection between the tool
retention means and insertion tool may comprise a bayonet fixture.
In such an embodiment the tool retention means or the securing
portion comprises one or more radially extending protrusions while
the other component comprises a cavity containing one or more
helically extending grooves. The insertion tool can thus be
connected to the holding piece by rotating the insertion tool such
that the protrusions are guided along the helical grooves. The
holding piece and insertion tool will then remain connected until
relative rotation occurs in the opposite direction.
[0040] However, preferably the connection between the holding piece
and insertion tool comprises at least one resilient element, which
can be positioned on either the holding piece or insertion
tool.
[0041] In a similar manner to the connection between the holding
piece and the implant, the resilient element of the tool retention
means may comprise an o-ring or other elastic element. However,
again this would require the elastic element to be provided
separately and hence increases the number of components
necessary.
[0042] Therefore preferably the tool retention means is an integral
part of the holding piece and more preferably comprises at least
one flexible arm bendable in a direction perpendicular to the
longitudinal axis of the holding piece. This enables the arm(s) to
be flexed towards or away from the longitudinal axis. Although the
resilient arm may simply provide a clamping fit with the insertion
tool it is preferable that the arm comprises a catch feature shaped
to engage a complementary feature of the insertion tool so as to
create a "snap fit" connection with the insertion tool.
[0043] Therefore preferred embodiments of the present invention
comprise snap connections between the holding piece and implant and
the holding piece and the insertion tool. Preferably, there is no
radial movement of the insertion tool necessary to form the snap
connections but only effort in the axial direction. In turn the
snap connections are preferably disengaged by effort in the
opposite axial direction. In this embodiment no threads are
required and no tedious screwing is needed to form or break the
connection between the holding piece and the insertion
tool/implant.
[0044] Although it is possible to reverse the snap connection
between the holding piece and the insertion tool, such that the at
least one flexible arm is formed by the securing portion of the
insertion tool and the complementary feature by the tool retention
means of the holding piece, it is preferable for the flexible arm
to be located on the holding piece. This is particularly true when
both the resilient element and the tool retention means comprise
flexible arms, as this enables both elements to be integrally
formed on the holding piece. In addition, the holding piece can be
formed of a suitably flexible material while enabling the insertion
tool to be formed of a stronger, less flexible material.
[0045] Preferably the tool retention means is located at the second
end of the holding means, such that the housing connection segment
is located between the first end and the tool retention means. This
eases access to the tool retention means by the insertion tool when
the holding piece is held within the housing.
[0046] Providing an integral holding piece that enables a simple,
non-rotational connection to both an implant and insertion tool is
considered inventive in its own right and therefore, viewed from a
further aspect therefore the present invention comprises a holding
piece for an implant comprising a first end and a second end, both
ends arranged on a longitudinal axis, and in between the two ends a
housing connection segment for connecting the holding piece to a
housing for the implant. The first end comprises at least one
integrally formed flexible arm bendable in a direction
perpendicular to the longitudinal axis for connecting the first end
to an implant. The second end comprises at least one integrally
formed flexible arm bendable in a direction perpendicular to the
longitudinal axis and adapted to directly connect the holding piece
to an insertion tool.
[0047] Preferably, as mentioned previously, the at least one
flexible arm of the first end comprises a catch feature shaped to
engage a complementary feature of an implant and the at least one
flexible arm of the tool retention means comprises a catch feature
shaped to engage a complementary feature of an insertion tool such
that a snap fit connection can be formed between the holding piece
and an implant and the holding piece and an insertion tool.
[0048] In accordance with one aspect of the present invention, the
snap fit connection between the holding piece and the insertion
tool must have a greater retentive force than that between the
holding piece and the implant. This can be achieved in numerous
ways. For example, the flexible arm(s) of the tool retention means
may be shorter and/or thicker than the arm of the resilient
element(s). A greater force is therefore needed to displace these.
Alternatively, or in addition, the depth of the engaging feature
into which the flexible arm "snaps" can be greater in relation to
the tool retention means. This requires the flexible arm to be more
greatly displaced in order to disconnect the insertion tool and the
holding piece. The shape of the catch feature also influences the
retentive force. It is preferable that the catch feature of at
least the tool retention means comprises a barb. A barb is formed
by a tapered, curved or otherwise gradated surface which ends in an
abrupt step change in diameter such that an abutment surface is
formed. This enables the arm to flex with relative ease in order to
allow passage of the insertion tool in one direction (i.e. towards
the holding piece) but to resist movement of the tool in the
opposite direction once the catch has been engaged.
[0049] The connection between the holding piece and the insertion
to tool can be made either with the exterior or interior of the
insertion tool.
[0050] When the connection is to be formed with the interior of the
insertion tool the tool retention means is arranged for insertion
into a blind or thorough bore of the insertion tool. For example,
the at least one flexible arm of the preferred tool retention means
can be arranged for insertion into a blind bore of the insertion
tool and comprise a catch feature on its radially outer side. The
surface of the blind bore comprises a complementary feature for
engaging the catch feature of the flexible arms in a snap
connection.
[0051] In a preferred embodiment however the connection is formed
on the exterior of the insertion tool. Therefore, in this
embodiment the second end of the holding means defines an interior
space for housing the distal end of an insertion tool. This
interior space may be defined exclusively by multiple flexible arms
which form the tool retention means. Alternatively the second end
may comprise a closed annular ring, in which one or more flexible
arms are formed, for example by milling or injection moulding. The
flexible arms of the tool retention means may also be located away
from the second end, in which case the interior space must extend
far enough into the holding piece to allow the insertion tool to
reach and engage with the arms. The one or more flexible arms can
comprise, on their radially inner side, a catch feature. In this
embodiment the securing portion of the insertion tool comprises a
groove or other complementary feature formed on the exterior
surface of the tool which is shaped to engage the catch feature of
at least one flexible arm to form a snap connection.
[0052] In this embodiment the diameter of the interior space
defined by the second end is equal to the largest outer diameter of
the distal end of the insertion tool introduced into the holding
piece.
[0053] This embodiment is preferred as the introduction of the
insertion tool into the interior space of the holding piece
provides additional strength to the holding piece. This in turn
allows the holding piece to be made of a relatively soft material,
such as plastics. This reduces the cost of the component.
[0054] In a particularly preferred embodiment the holding piece
comprises lateral openings in the exterior surface of the holding
piece which connect to the interior space defined by the second
end. Preferably, when the first end comprises a plurality of
flexible arms the lateral openings are formed, at least in part,
between these arms.
[0055] Preferably the holding piece is hollow. This reduces the
weight of the holding piece and the material required to
manufacture this. This embodiment features free space in the
interior of the holding piece, which free space preferably is
available in the first and second ends for the construction of the
snap connections with the implant and the insertion tool. In other
words, the free space enables the flexible arms to bend inward.
[0056] In a preferred embodiment the holding piece has
substantially the shape of a cylinder, preferably the shape of a
circular cylinder, so that the shape of the holding piece is
designed substantially as a hollow cylinder.
[0057] Providing a holding piece having an at least partially
hollow interior with lateral openings and/or providing a hollow
holding piece enables the insertion tool, when connected to the
holding piece, to protrude from the holding piece.
[0058] This is beneficial as it allows parts of the insertion tool
to directly contact the implant. In the prior art discussed in
detail above, the insertion tool is not in direct contact with the
implant and hence torque must be transferred to the implant via the
holding element or carrier screw. This requires these components to
be manufactured such that a good force transmitting connection can
be achieved. In addition the components must be strong enough to
withstand the torque placed on them during use and to transmit this
effectively to the implant.
[0059] A hollow or partially hollow holding piece in accordance
with the present invention however allows the insertion tool to
pass through the holding piece for direct connection with the
implant. In this way, all or part of the torque can be transferred
directly to the implant by the insertion tool.
[0060] The insertion tool comprises, at its distal end, a torque
transmission element. Although this element may to arranged to
transfer torque to the holding piece, which in turn transmits this
to the implant, this element is preferably arranged to protrude
through the lateral openings or hollow first end of the holding
piece for direct engagement with the implant.
[0061] In preferred embodiments therefore the holding piece does
not comprise a force transmission element capable of transmitting
torque to the implant. The holding piece therefore does not
comprise a surface which, when an implant is connected to the first
end, engages this implant in such a way that torque can be
transmitted from the holding piece to the implant. In other words,
the first end of the holding piece is arranged only to provide
axial retention to the implant. All the torque is transmitted to
the implant via the insertion tool. In this embodiment therefore
the functions of axial retention and torque transmission are
separated. The holding piece provides axial retention while the
insertion tool transmits torque. As the holding piece does not need
to withstand and transmit rotational forces this can be made of a
lighter, weaker material than the insertion tool. Preferably the
holding piece is formed of a plastic material such as PEEK, POH,
PPSU, PSU, etc and can be manufactured via, for example, injection
moulding. The holding piece can therefore be manufactured simply,
more cheaply and with tighter tolerances than a holding piece
designed for torque transmission, as such a holding piece must be
formed of metal or metal alloy.
[0062] In accordance with this preferred embodiment, the single use
holding piece can be cheaply produced and provided with every
implant while a multiple use insertion tool is provided
separately.
[0063] The separation of the functions of axial retention and
torque transmission is considered inventive in its own right and
therefore, viewed from a further aspect, the present invention
provides a holding piece for an implant comprising a first end and
a second end, both ends arranged on a longitudinal axis, and in
between the two ends a housing connection segment for connecting
the holding piece to a housing for the implant. The first end
comprises at least one resilient element for connecting to an
implant and the holding piece further comprises tool retention
means adapted to directly connect the holding piece to an insertion
tool, wherein the holding piece does not comprise a force
transmission element for transferring torque to an implant.
[0064] Viewed from another aspect the present invention provides a
holding piece in combination with an insertion tool, said holding
piece comprising a first end and a second end, both ends arranged
on a longitudinal axis, and in between the two ends a housing
connection segment for connecting the holding piece to a housing
for the implant. The first end comprises at least one resilient
element for connecting to an implant. The holding piece further
comprises tool retention means adapted to directly connect the
holding piece to the insertion tool. The insertion tool comprises a
distal end, having a torque transmission element, and a shank, the
shank comprising a securing portion for engagement with the tool
retention means. The holding piece is at least partially hollow
such that the torque transmission element of the insertion tool can
be inserted into and protrude from the holding piece for direct
engagement with the implant.
[0065] Preferably the torque transmission means of the insertion
tool is arranged to provide all of the torque to the implant.
Preferably the holding piece is arranged to provide the sole means
of axial retention between the implant and insertion tool.
[0066] The holding piece is preferably hollow such that it forms a
hollow cylinder extending from the first end to the second end. In
this embodiment therefore the insertion tool can extend through the
holding piece such that, when the holding piece is connected to the
insertion tool, the torque transmission element is exposed and can
contact the anti-rotation means of the implant directly.
Alternatively the holding piece may be at least partially hollow
such that the second end defines an interior space, said interior
space connecting to lateral openings in the exterior of the holding
piece. In this embodiment the torque transmission element may be
arranged to extend through said lateral openings when the holding
piece is connected to the insertion tool.
[0067] The torque transmission element of the insertion tool is
shaped to engage an anti-rotation element of the implant. The
torque is usually applied by the practitioner to the insertion tool
with or without the aid of additional tools, such as a wrench,
ratchet, or dental handpiece which can be connected to the
insertion tool.
[0068] The torque transmission element may comprise, for example,
one or more polygon sections, such as hexagonal or octagonal
polygon sections. Said polygon sections interact with anti-rotation
means having a corresponding shape on the implant. In some
embodiments the torque transmission element may comprises a male or
female polygon shape for inserting into or receiving the
anti-rotation means of an implant.
[0069] In a preferred embodiment the torque transmission element
comprises at least one longitudinally extending groove, preferably
at least two, most preferably four. These grooves are configured to
engage protrusions formed in an interior bore of an implant.
Preferably, said at least one groove comprises two lateral faces
substantially parallel to the longitudinal axis. These faces are
arranged to transmit torque to the side faces of protrusions in the
implant. Alternatively the torque transmission element could
comprise at least one longitudinally extending protrusion
configured to engage a groove of the implant in a similar
manner.
[0070] In embodiments in which the holding piece comprises flexible
arms for connection to the interior of the implant the grooves of
the insertion tool are further shaped to house these arms when the
tool is inserted into the holding piece, the grooves extending
radially beyond these arms for direct engagement with the
implant.
[0071] In embodiments in which the holding piece comprises flexible
arms for connection to the exterior of the implant, the torque
transmission element of the insertion tool need not protrude
longitudinally past these arms but only through the main body of
the holding piece such that it can engage the anti-rotation feature
of the implant.
[0072] In an alternative embodiment both the insertion tool and the
holding piece are arranged to provide torque transmission to the
implant. In this embodiment the holding piece may comprise lateral
openings to allow protrusion of the torque transmission element of
the insertion tool and additionally comprise, adjacent to these
openings, at least one torque transmission surface for direct
engagement with the anti-rotation means of the implant. The torque
transmission elements of the holding piece and insertion tool in
this embodiment may comprise only fractions of polygon sections
which, when the holding piece and the insertion tool are connected,
form a complete polygon. Alternatively both the insertion tool and
the holding means may comprise longitudinally extending grooves for
engagement with protrusions in the implant or protrusions for
engagement with grooves in the implant.
[0073] According to this embodiment the rotational forces that must
be applied to the implant are distributed between the holding piece
and the insertion tool. In such embodiments the holding piece must
be made of a relatively strong material, for example TAN (titanium
aluminium nitride) or TAV (titanium aluminium vanadium), in order
to transmit toque to the implant. This allows the flexible arms to
be thicker and provide stronger retentive forces to the implant and
insertion tool. As the insertion tool must extend through the
holding piece at least until the torque transmission surface the
insertion tool adds strength to the holding piece.
[0074] The holding piece is preferably made of injection plastics,
or metal or metal alloy, such as titanium, TAN or TAV. A holding
piece made of plastics is preferable, particularly when the holding
piece plays no or a minimal part in torque transmission.
[0075] The holding piece according to the present invention is
preferably made completely of a single material. The production of
the holding piece is therefore facilitated as compared to prior
art. As a consequence production costs of the holding piece, which
is preferably shipped as a disposable article, are lower.
[0076] The holding piece according to the present invention is
preferably made of a single, integral piece. The production of the
holding piece made of a single piece is greatly facilitated as
compared to the production of a carrier screw and a transfer piece,
for example, or transfer piece and o-ring. Therefore the production
costs of said holding piece are reduced. Also, a single piece
holding piece allows a good sterilization.
[0077] According to another aspect the present invention provides a
housing comprising the holding piece as described herein, the
holding piece being removeably connected to the housing by the
housing connection segment.
[0078] The housing according to the present invention preferably is
of cylindrical or tubular shape, for example a cylinder with a
cuboid or a circular or elliptic base, and comprises a longitudinal
axis. The housing preferably has one or more lateral openings
and/or at least one face is at least substantially open
facilitating sterilization of the implant and the housing. The
housing is dimensionally stable and is preferably made of COC,
PEEK, PPSU etc. Thereby, the housing provides protection to the
implant from damage or contamination. The housing is provided with
a fixing section which is intended to cooperate with the housing
connection segment of the holding piece. The housing connection
segment is preferably fixed to the fixing section of the housing
via press fit, friction fit, snap connections or bayonet mechanism
or a combination thereof.
[0079] In a preferred embodiment of the housing the fixing section
comprises a laterally open indent. Preferably the indent is in the
form of a slot, which widens in the radial direction towards the
lateral area and constricts towards the longitudinal axis. However,
at the approximate location of the longitudinal axis the indent
widens again to form a cut-out with a cross-section of about the
shape of the cross-section of the housing connection segment of the
holding piece. The holding piece can be laterally pressed into the
indent and after the cross-section of the housing connecting
segment has overcome the width of the constriction, the housing
connecting segment latches into the cut-out. In order to remove the
implant from the housing the insertion tool is usually connected to
the tool retention means of the holding piece. Then the implant
together with the holding piece is laterally pulled out of the
housing.
[0080] The housing connection segment of the holding piece
therefore comprises, in this embodiment, a cylindrical outer wall.
This can be bordered in the longitudinal direction by portions of
the holding piece which have a greater diameter. The housing
connection segment may have a diameter similar to that of the
implant, i.e. no greater than 5 mm.
[0081] In a preferred embodiment the fixing section of the housing
induces increased pressure on the at least one resilient element of
the holding piece, thus providing an increment of the retentive
force required to disconnect the connection between the implant and
the holding piece during transportation and storage. It should be
noted however that the first retentive force of the holding piece
refers to the inherent retentive force, i.e. that produced solely
by the at least one resilient element.
[0082] In another embodiment, in which the resilient element forms
an internal connection to the implant, the housing further
comprises a pin element. During transportation and storage the pin
element is inserted into the holding piece such that the pin
element is in contact with at least part of the resilient element
of the holding piece. The pin element either presses the resilient
element(s) towards the surface of the implant or simply prevents
these from flexing inwards. In this way the implant is more
securely held within the housing. The pin may be configured such
that it only contacts the holding piece, or this may also contact
the implant interior. When the implant is to be removed from the
housing, the pin element is removed. The insertion tool is then
connected to the holding piece and the implant is removed.
[0083] In a further preferred embodiment the pin element is part of
a closure cap for the housing.
[0084] The holding piece is usually provided to the practitioner as
part of a combination comprising a housing, the holding piece and a
dental implant. The implant is held within the housing by means of
the holding piece, the at least one resilient element connecting
the first end of the holding piece to the implant.
[0085] In a preferred embodiment, for inserting the implant to the
implant site the distal end of the insertion tool is inserted into
the holding piece such that the tool retention means engages the
securing portion of the insertion tool. Then, the implant together
with the holding piece is removed from the housing with the aid of
the insertion tool. Subsequently, the insertion tool together with
the implant and the holding piece is transferred to the implant
site followed by inserting the implant into the bone. For insertion
of the implant, torque is applied to the insertion tool, and the
torque is transmitted by the torque transmission element to the
implant, preferably directly. After complete insertion of the
implant into the implant site the insertion tool is usually pulled
back along the direction of the longitudinal axis. The connection
between the implant and the holding piece is disconnected and the
connection between the holding piece and the insertion tool
remains. The insertion tool finally is removed from the implant
site after which the holding piece can be separated from the
insertion tool. This can be done either by overcoming the retentive
force or by destroying the holding piece, e.g. by cutting.
[0086] In one embodiment as discussed above the insertion tool
transmits the torque directly to the implant.
[0087] According to a further aspect the present invention
comprises a combination of the holding piece and insertion tool
described above.
[0088] According to another aspect the present invention comprises
a holding piece in combination with an implant, said holding piece
comprising a first end and a second end, both ends arranged on a
longitudinal axis, and in between the two ends a housing connection
segment for connecting the holding piece to a housing for the
implant. The first end comprises at least one resilient element
connected to the implant, such that the implant is retained with a
first retentive force. The holding piece further comprises tool
retention means adapted to directly connect the holding piece to an
insertion tool with a second retentive force that is greater than
the first retentive force.
[0089] In one embodiment the implant comprises an internal bore,
the at least one resilient element being connected to said internal
bore.
[0090] In another embodiment the implant comprises an undercut on
its exterior, the at least one resilient element being connected to
the undercut.
[0091] Preferably the implant further comprises anti-rotation
means, wherein said holding piece does not engage said
anti-rotation means in a torque transmitting manner.
[0092] According to a further aspect the present invention
comprises a combination of the housing, holding piece, insertion
tool and implant as detailed above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0093] Further characteristics and advantages of the present
invention are described with the help of the accompanying drawings,
wherein
[0094] FIG. 1A shows a perspective view of a holding piece
according to a first embodiment of the present invention;
[0095] FIG. 1B shows a lateral view of the holding piece depicted
in FIG. 1A;
[0096] FIG. 2A shows a lateral view of an assembly consisting of an
insertion tool according to the present invention, the holding
piece of FIG. 1A and a dental implant;
[0097] FIG. 2B shows a cross sectional view along line A-A of the
assembly depicted in FIG. 2A;
[0098] FIG. 2C shows a detail B of the assembly depicted in FIGS.
2A and 2B;
[0099] FIG. 2D shows a cross sectional view along line C-C shown in
FIGS. 2A and 2B perpendicular to the longitudinal axis;
[0100] FIG. 3A shows a perspective view of a holding piece
according to a further embodiment of the present invention;
[0101] FIG. 3B shows a lateral view of the holding piece depicted
in FIG. 3A;
[0102] FIG. 4A shows a lateral view of an assembly consisting of an
insertion tool according to the present invention, the holding
piece of FIG. 3A and a dental implant;
[0103] FIG. 4B shows a cross sectional view along line A-A of the
assembly depicted in FIG. 4A;
[0104] FIG. 4C shows a detail B of the assembly depicted in FIGS.
4A and 4B;
[0105] FIG. 5 shows a perspective view of the holding piece and
insertion tool of FIGS. 4A-C in combination but separate from the
implant;
[0106] FIG. 6 shows a dental implant connected to a holding piece
according to the present invention inside a housing according to
the present invention;
[0107] FIG. 7 shows a perspective view of another embodiment of the
holding piece according to the present invention;
[0108] FIG. 8A shows a perspective view of a further embodiment of
the holding piece of the present invention; and
[0109] FIG. 8B shows a perspective view of a further embodiment of
an insertion tool according to the present invention, for use with
the holding piece of FIG. 8A.
DETAILED DESCRIPTION
[0110] FIGS. 1A and 1B show a preferred embodiment of a holding
piece 1 according to the present invention. The holding piece 1 has
a longitudinal axis 5 and substantially a circular cylindrical
shape. The holding piece 1 exhibits a through hole along the
longitudinal axis 5 and thus substantially has a shape of a hollow
cylinder. The holding piece 1 comprises a first end 10 and a second
end 15 opposite to the first end 10 along the longitudinal axis 5.
The second end 15 comprises a tool retention means adapted to
cooperate directly with an insertion tool 20 (not shown in FIG. 1)
with the aid of a securing portion. The first end 10 is intended to
be connected to a dental implant 25 (not shown in FIG. 1).
[0111] Between the first end 10 and second end 15 the holding piece
1 exhibits a housing connection segment 30, which is used to
connect the holding piece 1 to a housing 35 (not shown in FIG. 1)
for the dental implant 25. The housing connection segment 30 has a
circular cylindrical shape and is to be fixed to the housing 35 in
a press-fit manner.
[0112] The holding piece 1 shown in FIG. 1A and FIG. 1B is made of
a single, integral piece. No further pieces are required to connect
the holding piece 1 to the implant 25 or to the insertion tool. The
holding piece 1 shown in FIG. 1 is intended for single use and is
made of injection plastics.
[0113] The production of the holding piece 1 shown in FIG. 1 is
greatly facilitated as it is made of only one piece, consists of a
single material and is preferably produced in one step.
[0114] The first end 10 of the holding piece 1 comprises four
resilient elements in form of four flexible arms 45 extending
parallel to the longitudinal axis 5. These arms 45 are bendable
towards and away from the longitudinal axis 5. The flexible arms 45
are intended to be inserted inside a blind bore 50 of the dental
implant 25. Near the distal end of each of the arms 45 is a snap
catch 55 intended to form a snap connection with the internal
connection of the implant 25.
[0115] The shown embodiment further comprises longitudinally
extending struts 42 near the lateral area of the first end 10. Said
struts 42 form a discontinuous support collar and are intended to
further stabilize the implant 25 when connected to the holding
piece 1. The struts 42 each comprise an abutment surface 43 which
is arranged, when the holding piece 1 is connected to the implant,
to abut against an outer surface of the implant. This prevents any
pivoting of the implant with respect to the holding piece 1.
[0116] The tool retention means comprises two mutually opposing
flexible arms 16. As with arms 45, the flexible arms 16 of the tool
retention means can bend towards and away from the longitudinal
axis 5.
[0117] Holding piece 1 is designed in such a way that torque can be
directly transmitted from the insertion tool 20 to the dental
implant 25. The hollow shape of the holding piece 1 allows the
insertion tool 20 to penetrate the holding piece 1 and to interact
with the implant 25 directly.
[0118] The interaction between the holding piece 1, implant 25 and
insertion tool 20 is demonstrated by FIGS. 2A-D.
[0119] These figures show an assembly 60 of a dental implant 25,
the holding piece 1 of FIGS. 1A-B and insertion tool 20. The
assembly 60 comprises the anchoring part (implant) of a two-piece
dental implant having internal connection means in the form of a
blind bore 50 extending into the implant 25 from the coronal end
65. This blind bore 50 comprises a thread at its apical end (not
shown) and, coronally of said thread, protrusions 95 which form an
anti-rotation means. Said assembly 60 for instance is formed after
the insertion tool 20 has been inserted into the second end 15 of
the holding piece 1, and the implant 25 was removed from the
housing 35 with the aid of the insertion tool 20. The assembly 60
is now to be transferred to the implant site, for example.
[0120] The insertion tool 20 comprises a shank 105. The shank 105
features, at one end, connecting means 110 for connecting the
insertion tool 20 to further tools such as a wrench or a ratchet.
The distal end 75 of the insertion tool 20 is inserted into the
second end 15 of the holding piece 1, which is itself attached to
the implant 25. For simplicity, FIG. 2B does not detail the
connections between the holding piece 1 and the implant and
insertion tool. These are instead shown in FIG. 2C.
[0121] In the connected state the flexible arms 45 of the first end
10 form a snap connection with the implant 25, wherein each snap
catch 55 engages with an annular groove 100 located inside the
blind bore 50 of the dental implant 25. Struts 42 contact the
external surface of the coronal end 65 of the implant 25. As can
clearly be seen in FIG. 2C, the abutment surfaces 43 are shaped to
match the outer contour of the coronal end 65 such that the
abutment surfaces 43 support the implant 25 but do not provide any
axial retention. The axial retention is provided solely by flexible
arms 45 and their snap connection to the internal bore 50. As can
be seen in FIG. 2A, the spacing between struts 42 allows easy
circulation of sterilising fluids. During transportation and
storage the implant is connected only to the holding piece 1, which
in turn is fastened within housing 35, as will be discussed in
relation to FIG. 6.
[0122] When the implant 25 is to be removed from the housing 35,
the distal end 75 of the insertion tool 20 is inserted through the
hollow second end 15 of the holding piece 1. Distal end 75
comprises a securing portion in the form of an annular groove 22.
This groove 22 co-operates with the flexible arms 16 of the tool
retention means in order to connect the insertion tool 20 firmly to
the holding piece 1. As can be seen in FIG. 2C, flexible arms 16
comprise, on their radially inner side, catch features 24 in the
shape of barbs. When the distal end 75 of the insertion tool 20 is
inserted into the second end 15 of the holding piece, flexible arms
16 bend outwards. When the barbs are aligned with groove 22, they
"snap" into this groove 22, providing a physical and aural feedback
that the insertion tool has been fully inserted. The barbed nature
of the catch features 24 increases the force necessary to
disconnect the insertion tool 20 from the holding piece 1. The
retentive force of the connection between the holding piece 1 and
the insertion tool 20 is greater than the retentive force of the
connection between the dental implant 25 and the holding piece
1.
[0123] The distal end 75 of insertion tool 20 has a circular
cylindrical shape and, in addition to annular groove 22, comprises
four grooves 80 substantially parallel to the longitudinal axis of
the insertion tool. These grooves form the torque transmission
element of the insertion tool 20, which in this embodiment forms
the only means of torque transmission to the implant 25.
[0124] The distal end 75 of the insertion tool 20 is inserted into
the holding piece 1. The grooves 80 of the torque transmission
element are aligned with the flexible arms 45 of the first end 10
such that, in the connected state, these arms 45 are partially
situated within the grooves 80. Arms 45 extend beyond the distal
end 75 of the insertion tool 20 however in order to co-operate with
the annular groove 100 of the implant 25, as discussed above. The
internal bore 50 of the implant 25 comprises, coronally above the
groove 100, anti-rotation means in the form of longitudinally
extending protrusions 95, or guide rails. This can be more clearly
seen in FIG. 2D.
[0125] Each groove 80 of the torque transmission element has two
lateral faces 85 substantially parallel to the longitudinal axis 5.
The grooves 80 have a greater depth than the height of the portions
of the flexible arms 45 which are situated within the grooves 80.
This means that the lateral faces 85 of the groove 80 protrude
beyond the flexible arms 45 such that the end portions 90 can
directly contact the anti-rotation protrusions 95 of the implant
25.
[0126] The lateral faces 85 of the grooves 80 thus act as torque
transmission means and transmit torque from the insertion tool 20
directly to the dental implant 25. In this way the plastic holding
piece 1 does not need to transmit the high torque forces to the
implant 25. Instead this component only provides an indirect axial
connection between the implant 25 and the insertion tool 20.
[0127] FIGS. 3A and 3B show an alternative holding piece 3. This is
identical to the holding piece of the previous figures in terms of
operation, except that this is designed to connect to the exterior
of the implant 25.
[0128] The holding piece 3 has a longitudinal axis 5 and
substantially a circular cylindrical shape. The holding piece 3
exhibits a through hole along the longitudinal axis 5 and thus
substantially has a shape of a hollow cylinder. The holding piece 3
comprises a first end 4 and a second end 6 opposite to the first
end 4 along the longitudinal axis 5. The second end 6 comprises a
tool retention means adapted to cooperate directly with an
insertion tool 23 with the aid of a securing portion. The first end
4 is intended to be connected to a dental implant 25.
[0129] Between the first end 4 and second end 6 the holding piece 3
exhibits a housing connection segment 30, which is used to connect
the holding piece 3 to a housing 35. The housing connection segment
30 has a circular cylindrical shape and is to be fixed to the
housing 35 in a press-fit manner.
[0130] The first end 4 of the holding piece 3 comprises eight
resilient elements in form of flexible arms 7 extending parallel to
the longitudinal axis 5. These arms 7 are bendable towards and away
from the longitudinal axis 5. The flexible arms 7 are intended to
connect to the exterior the dental implant 25. Near the distal end
of each of the arms 7 is a snap catch 8 intended to form a snap
connection with the implant 25.
[0131] The arms 7 further comprise, proximal of the catch 8,
abutment surfaces 9. Said abutment surfaces 9 form a discontinuous
support collar and are intended to further stabilize the implant
25. It can thus be seen that, in effect, the struts 42 of the
previous embodiment have been incorporated into the flexible arms.
This is possible as, due to the external snap connection used in
this embodiment, the flexible arms 7 are positioned radially
outwards of the arms 45 of the previous embodiment.
[0132] The tool retention means of the second end 6 comprise two
mutually opposing flexible arms 36, identical to the tool retention
means of the previous embodiment.
[0133] The interaction between the holding piece 1, implant 25 and
insertion tool 23 is demonstrated by FIGS. 4A-C. In this
embodiment, the implant 25 is identical to that of FIG. 2.
[0134] As with FIGS. 2A-C, these figures show an assembly 60 of a
dental implant 25, the holding piece 3 and insertion tool 23.
[0135] The insertion tool 23 comprises a shank 205. The shank 205
features, at one end, connecting means 210 for connecting the
insertion tool 23 to further tools such as a wrench or a ratchet.
The distal end 31 of the insertion tool 23 is inserted into the
holding piece 3, which is itself attached to the implant 25. The
connections between the holding piece 3 and the implant and
insertion tool are best seen in FIG. 4C.
[0136] In the connected state the flexible arms 7 of the first end
4 form a snap connection with the exterior of the implant 25. The
coronal end 65 of the implant includes an undercut, formed by an
outwardly tapering section 26. The snap catches 8 are shaped in a
complementary manner to the undercut such that the flexible arms 7
form a snap connection to the implant 25. Abutment surfaces 9
contact the external upper surface of the coronal end 65 of the
implant 25 but do not provide any axial retention. As can be seen
in FIG. 4A, the spacing between arms 7 allows easy circulation of
sterilising fluids. During transportation and storage the implant
is connected only to the holding piece 3, which is fastened within
housing 35, as will be discussed in relation to FIG. 6.
[0137] When the implant 25 is to be removed from the housing 35,
the distal end 31 of the insertion tool 23 is inserted through the
hollow second end 6 of the holding piece 3. Distal end 31 comprises
a securing portion in the form of an annular groove 32. This groove
32 co-operates with the flexible arms 36 of the tool retention
means in order to connect the insertion tool 23 firmly to the
holding piece 3. As can be seen in FIG. 4C, flexible arms 36
comprise, on their radially inner side, catch features 34 in the
shape of barbs, which operate as described in relation to FIG. 2C.
The retentive force of the connection between the holding piece 3
and the insertion tool 23 is greater than the retentive force of
the connection between the dental implant 25 and the holding piece
3.
[0138] The distal end 31 of insertion tool 23 has a circular
cylindrical shape and, in addition to annular groove 32, comprises
four grooves 80 substantially parallel to the longitudinal axis of
the insertion tool. These grooves form the torque transmission
element of the insertion tool 23, which in this embodiment forms
the only means of torque transmission to the implant 25. The torque
transmission element is best seen in FIG. 5, which shows the
holding piece 3 attached to the insertion tool 23 but without the
implant 25. This figure shows therefore how the assembly would look
after the implant 25 has been inserted into the bone and
disconnected from the holding piece 3.
[0139] The distal end 31 of the insertion tool 23 is inserted into
and through the holding piece 3. The grooves 80 of the torque
transmission element protrude through hollow holding piece 3 to
enable direct engagement with the implant 25. Due to the lack of
internal flexible arms the grooves 80 of insertion tool 23 do not
need to be as deep as those of insertion tool 20. Each groove 80
has two lateral faces 85 substantially parallel to the longitudinal
axis 5 which in use contact the lateral edges of protrusions 95 of
the implant 25. Torque applied to the insertion tool 20 is thus
transmitted from the insertion tool 20 directly to the implant
25.
[0140] FIG. 6 shows a housing 35 according to the present
invention. The housing is preferably made of COC, PEEK, PPSU etc
and comprises a holding piece 1, 3 and a dental implant 25. The
housing 35 substantially has a tubular shape. The body 115 of the
housing 35 substantially is hollow for accommodating the body of
the implant 25, wherein one face of the housing 35 is open allowing
access to the implant 25. The open face facilitates sterilization
of the implant and the housing. On a front end the housing 35
further features a fixing section 120 for connecting the holding
piece 1, 3 to the housing 35.
[0141] The dental implant 25 is connected to the housing 35 via the
holding piece 1, 3. The dental implant 25 is connected to the first
end 10, 4 of the holding piece 1, 3 as discussed above. The housing
connection segment 30 is connected to the fixing section 120 of the
housing 35. The fixing section 120 preferably comprises a laterally
open indent 125 and, on both sides of the indent 125, cut-outs 130
on the front end of the housing 35. A flexible flap 135 is formed
between the indent 125 and the cut-outs 130. The indent 125 is in
principle in the form of a slot, which in radial direction widens
towards the lateral area and constricts towards the longitudinal
axis of the housing. The housing connection segment 30 of the
holding piece 1 is fixed in the indent 125 in a clamping manner
between the two flexible flaps 135.
[0142] The insertion tool 20, 23 about to be connected to the
implant 25 is shown in FIG. 6. The distal end of the insertion tool
20, 23 is being inserted into the second end 15, 6 of the holding
piece 1, 3. The holding piece 1, 3 is connected to the housing 35
in such a way that the implant 25 is accommodated inside the free
space of the housing 35 and that the second end 15, 6 is accessible
easily from the outside of the housing 35.
[0143] FIG. 7 shows a perspective view of another embodiment of the
holding piece 1b. The first end 10b of the holding piece 1b
comprises four flexible arms 45b. Alternatively these can be viewed
as eight flexible arms, with each second pair being connected at
their distal end, thus forming a discontinuous annular ring. Each
flexible arm 45b features catch feature 140a, for forming a snap
connection with the exterior of an implant. A one- or two-piece
dental implant can be to be supported and retained by this holding
piece 1b.
[0144] The second end 15b comprises flexible arms 140b, which
constitute part of the snap connection for connecting the holding
piece 18b to a insertion tool. The retentive force of the
connection between the tool receiving section 15b and the insertion
tool is greater than the retentive force of the connection between
the dental implant and the implant receiving section 10b.
[0145] In the above described embodiments it is the insertion tool
that transmits torque directly to the implant.
[0146] FIGS. 8A and 8B show a further embodiment in which torque
transmission is provided by both the insertion tool and the holding
piece.
[0147] Holding piece 11 is formed in the shape of a hollow
cylinder. First end 12 comprises two flexible arms 13 for snap
connection to the interior of an implant 25. Second end 14 once
again comprises arms 17 for connection to the groove 27 of
insertion tool 21 (see FIG. 8B). In a similar manner to the
previous embodiments holding piece 11 comprises a housing
connection segment 30. In addition to providing a snap connection
to the implant, flexible arms 13 also comprise, on their radially
outer sides, grooves 19.
[0148] The distal end 18 of the insertion tool 21 comprises torque
transmission element in the form of two mutually opposing grooves
80. The distal end 18 can be inserted through the hollow holding
piece 11 such that the arms 17 engage the groove 27 in a snap
connection. When the insertion tool 21 is connected to the holding
piece 11 in this way the force transmission element is aligned with
the flexible arms 13 such that grooves 80, 19 engage protrusions 95
of the implant 25. In this way, both the holding piece 11 and the
insertion tool 21 transmit torque to the implant 25.
[0149] The above described embodiments are for illustrative
purposes only and the skilled man will realize that many
alternative arrangements are possible which fall within the scope
of the claims.
* * * * *