Note: Descriptions are shown in the official language in which they were submitted.
CA 02672363 2011-10-19
Arrangement for Insertion of Implants
The invention relates to an arrangement for insertion of implants, in
particular dental implants,
the arrangement comprising an implant and a screwing tool, with the implant
having a male
thread to facilitate fastening into a bone by the screwing tool.
Such an arrangement is known from FR 2 853 828 Al, including an implant having
a male
thread and including a tool with which the implant can be screwed into a bone
for insertion. The
implant includes a receiving opening having an at least partially conical
interior surface, and the
tool includes a pin, with a conical exterior surface, that engages in the
receiving opening of the
implant, the aforesaid conical surfaces being adjacent to one another.
Provided for connecting
the tool to the implant is a sleeve that in the connecting region surrounds
the tool and the implant
radially on the exterior and has catch elements oriented radially inward that
engage with
associated catch elements on both the tool and on the implant. At least part
of this connection
sleeve is deformable and comprises for instance plastic or metal with slits
such that after
insertion the tool and the connection sleeve can be removed from the implant.
US 2004/0 175 673 Al describes a dental implant system, the implant of which
includes a male
thread for screwing into a bone and furthermore includes a female thread for
fixing a prosthesis.
The female thread possesses a number of notches or recesses that extend
axially in which a
complementarily embodied pin for the tool engages. Provided in the receiving
opening of the
implant is a conical interior surface against which a conical exterior surface
of the tool is
positioned, a pre-tension being =introduced via the tool for insertion.
Moreover, known from DE 94 18 182 Ul is an arrangement having an implant with
a male
thread. The implant is embodied as a dental implant and includes a receiving
opening that
extends apically from the coronal end area and that is for a pin of an
attachment part that can be
connected to the implant after it has been inserted into a bone, in particular
a jaw bone. The
receiving opening includes a conical interior surface that opens towards the
coronal end and
apically adjacent a first indexing element in the form of a polygonal
receiving element and a
threaded bore. Analogously, the pin of the attachment part includes a conical
exterior surface
and a second indexing element in the form of a polygonal element that can be
inserted into the
CA 02672363 2011-10-19
2
polygonal receiving element in the implant. Provided for connecting the
attachment part to the
implant is a tension or retaining screw that passes through a through-hole in
the attachment part
and can be screwed into the threaded bore of the implant by means of a male
thread. Provided
for inserting the implant into the bone is a tool having a polygonal element
that conforms to the
polygonal receiving element in the implant and can be inserted therein. The
torque for inserting
the implant is transferred only via the polygonal receiving element and
consequently during
insertion or screwing-in there is a risk that the polygonal receiving element
of the implant that is
embodied as the indexing element will be damaged and thus the proper
connection of the
attachment part to the implant, and above all the exact orientation of the
attachment part with
respect to the implant in a pre-defined rotational angle position, is called
into question. The first
indexing element is disposed in an area in which the implant does not have any
external thread.
The male thread is arranged spaced apart from the indexing element in the
axial direction, and it
extends approximately from the center of the longitudinal extension of the
implant to its apical
end. Since the aforesaid indexing element is then provided axially adjacent to
the conical
interior surface of the implant, the conical interior surface of the implant
body extends only
across a portion of its entire length so that for the conical connection to
the attachment part only
a very small or axially short connecting surface is available, there being a
comparatively large
takeout angle for the aforesaid conical surfaces.
Furthermore, known from EP 0 707 835 B1 is a dental implant with a central
receiving opening
that has a conical interior surface that opens toward the coronal end and in
the interior end region
has a female thread for anchoring a tension screw. It is possible to insert
into the receiving
opening a pin of an attachment part, the tension screw passing through the
through-hole thereof,
the through-hole being provided, in a head area of the attachment part that
faces the oral cavity,
an extension for receiving a head of the tension screw. The aforesaid pin of
the attachment part
includes an exterior surface that conforms to the conical interior surface of
the receiving
opening. The conical interior surface of the receiving opening and the conical
exterior surface of
the pin are embodied such that there is a self-locking conical connection
between the implant and
the attachment part connected by means of the tension screw. This form-fit and
press-fit conical
connection provides the attachment part continuous anti-rotational resistance
against the high
loads with regard to the implant. For placing the implant in the jawbone, the
implant has, in its
coronal region or the coronal end surface, engaging elements for a tool, such
as for instance slits
that open in the occlusal direction for a screwdriver. The attachment part can
be positioned in a
CA 02672363 2011-10-19
3
stepless manner relative to the implant in terms of the longitudinal axis in
any desired rotational
angle position, special measures for conforming transfer or orientation of the
attachment part
with respect to the implant being necessary in particular in the dental
laboratory and/or when the
impression is taken that is necessary for preparing a superstructure.
Moreover, known from DE 10 2005 005 402 Al is a dental implant containing an
implant body
having a central receiving opening, an attachment part that has a pin that
engages in the aforesaid
receiving opening, and a tension screw that passes through a through-hole in
the attachment part
and that after the implant body has been inserted is screwed into a female
thread in the receiving
opening. So that it can be inserted in a jawbone, the implant body has
placement elements in the
region of its coronal end, whereby the screwing tool can be embodied for
instance as a
screwdriver and the placement elements can be embodied as slits for the tool
that can engage
with them. After the implant body has been inserted, the attachment part is
connected to it, the
rotational position of the attachment being determined relative to the implant
body by means of
indexing elements that are provided in the receiving opening of the implant
body and on the pin
of the attachment part.
Proceeding herefrom, the underlying object of the invention is to further
refine the aforesaid
arrangement such that the implant can be inserted in a simple manner that also
assures function.
It should be simple to produce the arrangement and it should also be possible
to employ the
arrangement even for very small filigree implants, such as for instance so-
called mini-implants.
Reliable insertion should be possible while damage to the indexing element is
prevented.
Moreover, the indexing should be very precise and/or damages and/or overloads
should be
prevented.
This object is attained in accordance with an embodiment of the invention
which provides an
arrangement for insertion of an implant, the arrangement comprising an implant
and screwing
tool, the implant having a male thread to facilitate fastening into a bone by
the screwing tool,
whereby said implant has a receiving opening with at least a partially conical
interior surface,
whereby a pin of an attachment part can be connected to the implant after
insertion of the
implant by placement into the receiving opening of the implant, wherein the
screwing tool has a
pin that has a conical exterior surface and that engages in said receiving
opening of said implant,
CA 02672363 2011-10-19
4
the conical exterior surface of the screwing tool is complementary to said
conical interior surface
of said implant and is maintained in pre-tension at least partially against
the conical interior
surface of said implant such that at least a pre-defined portion of the torque
required for screwing
in said implant can be transferred via a self-locking conical connection of
said screwing tool and
said implant.
The proposed arrangement is distinguished by a functionally appropriate
design, the torque being
at least partially transmitted via the self-locking conical connection between
the screwing tool
and the implant during insertion thereof. The exterior conical surface of the
pin that engages in
the receiving opening and the conical interior surface of the implant conform
to one another such
that a pre-defined portion of the torque to be introduced is transferred via
the adjacent conical
surfaces of the screwing tool and the implant onto the implant. Usefully, only
a pre-definable
partial region of the entire conical interior surface of the implant is used
for transferring torque.
This partial region is advantageously provided in the part of the conical
interior surface that is
adjacent to the coronal end of the implant. To this end, the takeout angle for
the conical exterior
surface of the screwing tool is slightly larger than the takeout angle of the
conical interior surface
of the implant, specifically such that at the aforesaid partial region the
aforesaid conical surfaces
in the apical direction are practically no longer adjacent to one another
and/or do not contribute
to transferring torque. Alternatively, the conical part of the pin, if the
latter engages in the
receiving opening, can be shorter than the total length of the conical
interior surface, the takeout
angles of the adjacent conus surfaces being essentially identical. Finally, in
accordance with the
invention the takeout angle of the conical exterior surface of the screwing
tool can be slightly
smaller than the takeout angle of the conical interior surface so that the
partial region of the
support is preferably spaced apart from the coronal end surface of the
implant. Thus there is a
pre-definable or adjustable portion of the torque transmission provided by
varying the clamping
surface in the aforesaid partial region or its size, the remainder of the
conical interior surface of
the implant remaining free or unclamped with the screwing tool or its exterior
conical surface.
The remainder of the torque to be applied is usefully absorbed by other
elements, in particular by
means of mutually engaging indexing elements for the screwing tool and the
implant or by
means of jamming or running up a corresponding stop face surface for the
screwing tool on the
upper edge or coronal end surface of the implant or by means of jamming or
clamping the
screwing tool with the implant by means of a screw thread.
CA 02672363 2011-10-19
The screwing tool is connected to the implant at the plant and/or pre-
tensioned in a defined
manner, specifically by means of a tension screw that passes through a through-
hole in the
screwing tool and that with a thread is screwed into a female thread arranged
in the receiving
opening of the implant. The screwing tool is advantageously pre-mounted with
the implant
and/or embodied as a screw-in post and contains a head part provided outside
of the implant for a
different tool or instrument, such as elbow or ratchet brace. Moreover, the
screwing tool can be
embodied as a separate instrument for an elbow or when designed as a pre-
mounted screw-in
post with elbow connector. The head part of the screwing tool advantageously
possesses at least
one gripping surface for the appropriate tool or instrument, such as ratchet
or the like. Moreover,
the head part can be embodied in a preferred manner for a temporary structure,
such as a crown,
or can be used as such.
Due to the inventive embodiment and arrangement of the screwing tool combined
with the
implant and/or the at least partial transferability of the torque via the self-
locking conical
connection between the screwing tool and the implant, there is great certainty
that the highly
precise indexing element of the latter will not be damaged when it is screwed
in. The indexing
element can thus be embodied in a relatively space-saving manner, i.e. with
limited structural
volume, whereby it is useful that it is possible to prevent damage resulting
from overloading.
This is of particular significance given that the implant sizes and/or shapes
are growing
increasingly smaller and more filigreed. Due to the use of the conical
clamping between the
screwing tool and the implant, the indexing element is reliably protected, it
being possible to
match or divide the portion of torque to be transferred via the conical or
clamping surfaces with
no problem. The precision for the anti-rotation assurance of the attachment
part to be connected
to the implant after insertion is provided with great reliability since the
indexing element for the
implant is not damaged during insertion. It is noted here that the rotational
forces acting via the
attachment part and/or prosthetic are significantly less than the torque to be
introduced onto the
implant when it is inserted. Furthermore, it should be expressly noted that
the arrangement in the
framework of the invention includes implants with or without indexing elements
and furthermore
the screwing tool has corresponding indexing elements or does not have them.
If the screwing
tool has indexing elements, the latter can preferably be embodied and/or
arranged such that the
screwing tool can be used and/or caused to engage with implants that have
indexing elements or
contain no indexing elements.
CA 02672363 2011-10-19
6
Since inventively only a partial region of the conical interior surface of the
implant is used for
transferring torque, undesired "seizing up" of the screwing tool or its
conical exterior surface
relative to the implant is avoided in a particularly useful manner and thus
after the implant has
been inserted the necessary release and removal of the screwing tool from the
implant is assured
with no problem. Moreover, it has proved particularly useful to pre-tension
the screwing tool
with the implant at the plant with a pre-defined pre-tension during
production. If such a pre-
defined limit for the torque to be introduced is exceeded during insertion,
the screwing tool can
be turned relative to the implant such that it comes to be positioned against
other elements
explained in the foregoing. In addition, the self-locking concial connection
is preferably
embodied such that the conical surface of the implant is not damaged if the
pre-defined limit for
the torque is exceeded and/or if the adapter rotates relative to the implant.
Thus in particular the
friction coefficient and/or the roughness of the conical surface of the pin of
the screwing tool are
inventively embodied less by a pre-specified value than the friction
coefficient and/or the
roughness of the conical surface and/or the interior surface of the implant.
This value is in
particular 10% less, advantageously 25% less, preferably 35% less.
Furthermore, the value is in
particular maximum 90%, advantageously 70%, preferably 35%.
In accordance with the invention, the arrangement is an implant system,
including the implant,
the screwing tool, and the attachment part, the pin of the screwing tool and
in particular its
conical exterior surface being embodied in conformance with the pin of the
attachment part. In
this implant system, the pin of the attachment part is preferably embodied
essentially the same as
the pin of the screwing tool. Moreover, the tension screw for connecting the
screwing tool to the
implant is advantageously embodied conforming to the tension screw provided
for connecting
the attachment part to the implant, in particular the complexity for
production and/or provision of
the aforesaid tension screw being reduced. This applies likewise for the
threaded sleeve that is
connected or is to be connected to the free end of the tension screw. In the
inventive implant
system, the implant and the screwing tool are preferably connected to one
another at the plant
and/or with defined and/or pre-defined pre-tension. Once the implant has been
inserted into a
bone, the connection is released and then the attachment part with the pin is
inserted into the
receiving opening of the implant and finally the self-locking conical
connection between the
attachment part and the implant is produced by means of the tension screw.
CA 02672363 2011-10-19
7
Special designs and refinements of the invention are provided in the
subordinate claims and in
the following description of a preferred exemplary embodiment of the
arrangement.
The invention is described in greater detail in the following using a special
exemplary
embodiment; however, this shall not constitute a limitation.
Fig. 1 depicts a side elevation of the arrangement;
Fig. 2 depicts the arrangement in cross-section along section line II-II
in Fig. 3;
Fig. 3 depicts a cross-section of the arrangement in the section line
in Fig. 1;
Fig. 4 is an exploded depiction of the arrangement;
Figs. 5, 6 depict a side elevation and perspective elevation of the
screwing tool;
Figs. 7, 8 depict the implant in the section plane in accordance with Fig.
2 and in a
perspective elevation.
In accordance with Figs. 1 through 3, the arrangement includes the implant 2
and the screwing
tool 4, the screwing tool 4 engaging in a receiving opening 6 of the implant
with a pin 8. The
screwing tool 4 is connected to the implant 2 by means of a tension screw 10
that is arranged in a
central through-hole 12 of the screwing tool 4 essentially coaxially with the
longitudinal axis 14
of the implant 2. The receiving opening 6 runs from a coronal end surface 16
of the implant 2
towards its apical end region 18 and is basically embodied as a blind hole.
The implant 2
furthermore includes a male thread 20 that is preferably embodied self-cutting
in the apical end
region 18 and/or that has a conical thread core 22, indicated by means of the
broken line, that
tapers toward the apical end region 18. In the coronal end region 24 of the
implant 2, the
receiving opening 6 includes a conical interior surface 26 that opens toward
the coronal end
surface 16. Moreover, the implant 2 includes apically adjacent a first
indexing element 28 that
engages in part in the conical interior surface 26. Provided in the end region
of the receiving
opening 6, which is in particular embodied as a blind hole, is a female thread
30 in which the
tension screw 10 engages or is screwed in using a male thread 32. The male
thread 32 is
advantageously arranged on a threaded sleeve 34 that is securely connected to
the interior end of
the tension screw 10, in particular by welding or gluing. As can be seen from
Fig. 2, the outer
diameter of the threaded sleeve 34 is provided larger than the diameter of the
through-hole 12 so
that the screwing tool 4 is correspondingly small or embodied with a
correspondingly small outer
diameter. Provided in the through-hole 12 is a preferably conically embodied
support surface 36
CA 02672363 2011-10-19
8
against which the screwhead 38 for the tension screw 10 is positioned. The
screwing tool 4 is
releasably connected to the implant with a pre-defined pre-tension by means of
the tension screw
10.
The screwing tool 4 contains a head part 40, an intermediate part 42 apically
adjacent or toward
the implant, and the aforementioned pin 8 adjacent thereto. The screwing tool
that partially
engages in the receiving opening 6 or its pin 8 contains a conical exterior
surface 44 that
conforms to and/or matches the conical interior surface 26 of the implant. The
takeout angles for
the conical surfaces 26 and 44 are in particular pre-defined, taking into
account their friction
coefficients and/or their surface quality and/or the roughness and/or the size
of the surface
regions adjacent to one another, such that the screwing tool 4 is fixed due to
conical self-locking
relative to the implant 2, a defined pre-tensioning of the screwing tool 4 to
the implant 2 being
provided by means of the tension screw 10. The screwing tool 4 and/or its pin
8 contains another
indexing element 48 that is embodied corresponding to the first indexing
element 28 of the
implant 2 and engages the latter, as can be seen in Fig. 3.
The screwing tool 4 or its pin 8 is preferably embodied such that only in one
partial region 50 is
the conical exterior surface 44 positioned against the conical interior
surface 26 of the implant 2
under pre-tension and/or in a self-locking manner. Advantageously the partial
region 50 is
arranged adjacent to the coronal end surface 16, while apically there is no
effective support for
the self-locking conical connection between the conical interior surface 26
and the pin 8. To this
end in particular the takeout angle of the conical exterior surface 44 of the
pin 8 can be pre-
defined as larger or smaller than the takeout angle of the conical interior
surface 26 by a pre-
defined value. Furthermore, as indicated with the broken line 52 and greatly
enlarged, the
diameter of the pin 8 can be reduced apically adjacent to the partial region
50. In the framework
of the invention, the partial region can alternatively be arranged adjacent to
the region of the
apical end or, if there are indexing elements there, can preferably be
arranged occlusally adjacent
thereto at the pin of the screwing tool. This is significant when, after the
implant 2 has been
inserted and the attachment part has been connected, the part of the conical
interior surface 26
adjacent to the coronal end surface 16 of the implant 2 is used and/or
provided for a tight seal
with the pin of the attachment part. Thus damage to the conical interior
surface of the coronal
end the implant is prevented during the insertion.
CA 02672363 2011-10-19
9
The intermediate part 42 of the screwing tool 4 is preferably embodied as an
expansion of the
screwing tool 4 that is provided on the conical pin, a concave region 54 of
the intermediate part
42 being present essentially adjacent to the conical exterior surface 44 and
adjacent thereto a
convex region 56. The head part 40 has a reduced exterior diameter compared to
the expansion
42 and in particular its convex region 56, the expansion 42 preferably forming
an annular collar
with a support surface 58. The head part 40 of the screwing tool 4 contains
gripping surfaces 60
for an instrument, such as e.g. a ratchet, the gripping surface 60 here being
embodied for instance
as a hexagon. Because of the support surface 58, the aforesaid instrument is
securely guided and
fixed and the instrument is prevented from slipping and even injuring the
patient. Furthermore,
in the framework of the invention the head part 40 is embodied for the
arrangement of a
temporary structure, for instance a crown, that after the implant has been
inserted is joined to the
head part 40 in a suitable manner by means of the screwing tool 4 and is then
advantageously
arranged against and/or supported on the support surface 58 of the expansion
42. Moreover, it
has proved particularly useful to provide the preferably conical support
surface 36 for the
screwhead 38 at least approximately, usefully completely, in the expansion 42,
so that the
screwing tool is thick enough and thus the pre-tension force applied via the
screwhead 38 by
means of the tension screw 10 is introduced safely. In accordance with the
invention, the pre-
tension force is defined at the plant and the adapter 4 is releasably
connected to the implant 2 by
means of the tension screw 10.
The head part 40 of the screwing tool 4 in accordance with the invention is
embodied as a bolt,
the exterior surface of which has the at least one gripping surface for the
additional tool or
instrument. The head part and/or the bolt 40 exhibits a non-round exterior
surface and/or a
cross-section that preferably remains essentially the same across its entire
length. The bolt 40 is
embodied in particular as a polygon having the at least one gripping surface
60. The head part or
the bolt preferably has n + 1 gripping surfaces 60, n being a whole number,
and/or the gripping
surfaces 60 are arranged distributed uniformly around the circumference. The
embodiment of
the bolt 4 with a polygonal cross-section having at least three exterior
surfaces is advantageous
for using the additional tool or instrument, a square or, as depicted,
hexagon, having proved
particularly useful.
Fig. 4 is an exploded depiction of the arrangement with the implant 2,
screwing tool 4, and
tension screw 10 to which, after insertion into the screwing tool 4, the
threaded sleeve 34, which
CA 02672363 2011-10-19
has a male thread 32, is securely joined. The additional indexing element 48
provided adjacent
to the conical exterior surface 44 of the screwing tool 4 contains axial
grooves 62. As can be
seen in conjunction with Fig. 3, radial projections or tappets 64 of the first
indexing element 28
of the implant 2 engage in these axial grooves 62 of the screwing tool 4 or
its pin 8. The
indexing elements 28 and 48 are embodied like axial teeth that conform to and
mesh with one
another.
Figs. 5 and 6 are enlarged depictions of the screwing tool 4, which contains
the head part 40
having the gripping surfaces 60, the expansion 42, furthermore the pin 8
having the conical
exterior surface 44, and finally the additional indexing element 48 having
grooves 62 that run
radially. Thus present in the circumferential direction between the grooves 62
are bars 66 that
engage in corresponding grooves of the first indexing element of the implant
after the pin 8 has
been inserted.
Figs. 7 and 8 depict an axial cross-section and perspective elevation,
respectively, of the implant
2 having the receiving opening 6. In its coronal end region 24 the receiving
opening contains the
conical interior surface 26 and furthermore apically the first indexing
element 28 having the
tappets 64 oriented inward radially. The aforementioned grooves 68 are
disposed
circumferentially between the tappets 64.
CA 02672363 2011-10-19
11
2 Implant
4 Screwing tool
6 Receiving opening for 2
8 Pin for 4
Tension screw
12 Through-hole in 4
14 Longitudinal axis for 2
16 Coronal end surface for 2
18 Apical end region for 2
Male thread for 2
22 Conical thread core
24 Coronal end region for 2
26 Conical interior surface for 6
28 First indexing element
Female thread for 6
32 Male thread for 10
34 Threaded sleeve
36 Support surface for 12
38 Screwhead for 10
Head part of bolt for 4
42 Intermediate part/expansion of 4
44 Conical exterior surface for 8
48 Additional indexing element
Partial region for 44
52 Broken line/reduction in diameter of 8
54 Concave region of 42
56 Convex region of 42
58 Support surface
Support surface
62 Axial groove for 48
64 Radial tappet for 28
66 Bar for 48
68 Groove for 28
