U.S. patent application number 15/080107 was filed with the patent office on 2017-11-16 for dental component and a dental implant.
This patent application is currently assigned to DENTSPLY SIRONA INC.. The applicant listed for this patent is DENTSPLY SIRONA INC.. Invention is credited to Daniel Magnusson, Josef Saltell.
Application Number | 20170325915 15/080107 |
Document ID | / |
Family ID | 45444381 |
Filed Date | 2017-11-16 |
United States Patent
Application |
20170325915 |
Kind Code |
A9 |
Magnusson; Daniel ; et
al. |
November 16, 2017 |
DENTAL COMPONENT AND A DENTAL IMPLANT
Abstract
The invention relates to a dental component, such as an
abutment, an abutment replica, an abutment blank, a customized
abutment, a scan abutment, a digital transfer coping, an impression
pick-up element, a healing cap or a driver, comprises a first
indexing element and at least two second indexing elements having
apical ends located apically of the apical end of said first
indexing element. The invention also relates to a dental implant
which comprises a dental component having first and second indexing
elements and a fixture having third and fourth indexing elements,
wherein the first and third indexing elements can only engage with
each other after the second and fourth indexing elements have
engaged with each other. The invention also relates to a
fixture.
Inventors: |
Magnusson; Daniel; (Hono,
SE) ; Saltell; Josef; (Goteborg, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DENTSPLY SIRONA INC. |
York |
PA |
US |
|
|
Assignee: |
DENTSPLY SIRONA INC.
York
PA
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20160199156 A1 |
July 14, 2016 |
|
|
Family ID: |
45444381 |
Appl. No.: |
15/080107 |
Filed: |
March 24, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13613118 |
Sep 13, 2012 |
9333056 |
|
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15080107 |
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61534521 |
Sep 14, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61C 8/0001 20130101;
A61C 8/008 20130101; A61C 8/0089 20130101; A61C 2008/0046 20130101;
A61C 8/0069 20130101; A61C 8/0068 20130101; A61C 8/0054 20130101;
A61C 8/0066 20130101 |
International
Class: |
A61C 8/00 20060101
A61C008/00; A61C 8/00 20060101 A61C008/00; A61C 8/00 20060101
A61C008/00; A61C 8/00 20060101 A61C008/00; A61C 8/00 20060101
A61C008/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 14, 2011 |
EP |
11181242.6 |
Claims
1. A dental component, comprising a fixture engagement portion
being provided with at least two radially projecting first indexing
elements, each having an apical end, wherein the at least two
radially projecting first indexing elements include a primary first
indexing element and a secondary first indexing element being
spaced from one another by a first cylindrical enveloping surface
portion therebetween and at least two radially projecting second
indexing elements being interposed between the primary first
indexing element and the secondary first indexing element, each one
having an apical end located apically of the apical ends of said
primary first indexing element and said secondary first indexing
element, wherein the first cylindrical enveloping surface portion
is free of additional radially projecting first indexing
elements.
2. The dental component as claimed in claim 1, wherein said at
least two second indexing elements are asymmetrically distributed
along the circumference of the fixture engagement portion.
3. The dental component as claimed in claim 1, wherein said at
least two radially projecting first indexing elements and said at
least two second indexing elements are asymmetrically distributed
along the circumference of the fixture engagement portion.
4. The dental component as claimed in claim 1, wherein said at
least two second indexing elements are symmetrically distributed
along the circumference of the fixture engagement portion.
5. The dental component as claimed in claim 1, wherein said at
least two radially projecting first indexing elements and said at
least two second indexing elements are symmetrically distributed
along the circumference of the fixture engagement portion.
6. The dental component as claimed in claim 1, wherein the axial
extension of the indexing elements is such that the first indexing
element and the second indexing elements are intersected by a
common geometrical plane which is perpendicular to the central axis
of the fixture engagement portion.
7. The dental component as claimed in claim 1, wherein following
the circumferential direction of the fixture engagement portion,
said at least two second indexing elements are interposed between
two of said first indexing elements.
8. The dental component as claimed in claim 1, wherein said at
least two radially projecting second indexing elements are arranged
as at least three radially projecting second indexing elements,
interposed between said at least two first indexing elements,
wherein each one of said three second indexing elements has an
apical end which is located apically of the apical ends of said at
least two first indexing elements.
9. The dental component as claimed in claim 1, wherein a radius
from said central axis to the centre of one of said at least two
second indexing elements and a radius from said central axis to the
centre of said first indexing element form a first angle .theta.,
wherein a radius from said central axis to another one of said at
least two second indexing elements and said radius from said
central axis to the centre of said first indexing element form a
second angle .phi., and wherein said second angle .phi. is
different from said first angle .theta. and from any angle being a
multiple of said first angle .theta., so that .phi..noteq.n.theta.,
where n is a positive integer.
10. The dental component as claimed in claim 1, wherein the number
of first indexing elements is greater than the number of second
indexing elements.
11. The dental component as claimed in claim 1, wherein each one of
said second indexing elements has a smaller dimension in the
circumferential direction and/or in the radial direction compared
to the dimensions of said at least one first indexing element.
12. The dental component as claimed in claim 1, wherein said at
least one first indexing element and said at least two second
indexing elements have elongate extensions in the coronal-apical
direction.
13. The dental component as claimed in claim 1, wherein said at
least two first indexing element and said at least two second
indexing elements project radially from the first cylindrical
surface portion of the fixture engagement portion.
14. The dental component as claimed in claim 1, wherein the apical
end of at least one of said at least two second indexing elements
is provided with a chamfer.
15. The dental component as claimed in claim 1, being a component
selected from the group consisting of an abutment, an abutment
replica, an abutment blank, a customized abutment, a scan abutment,
a digital transfer coping, an impression pick-up element, a healing
cap and a driver.
16. A dental implant, comprising a dental component comprising a
fixture engagement portion provided with at least two radially
projecting first indexing elements, each having an apical end,
wherein the at least two radially projecting first indexing
elements include a primary first indexing element and a secondary
first indexing element being spaced from one another by a first
cylindrical enveloping surface portion therebetween, and at least
two radially projecting second indexing elements being
circumferentially spaced from one another and interposed
circumferentially in the first groove cylindrical enveloping
surface portion and between the primary first indexing element and
the secondary first indexing element, each one of the second
indexing elements having an apical end located further apically
relative to the apical ends of the primary first indexing element
and the secondary first indexing element, wherein the first
cylindrical enveloping surface portion is free of additional
radially projecting first indexing elements, a dental fixture
adapted to be inserted into a jawbone and comprising a component
engagement portion adapted to mate with said fixture engagement
portion, the component engagement portion being provided with at
least two third indexing elements, each one having a coronal end,
and at least two fourth indexing elements, each one having a
coronal end, wherein the apical ends of said at least two second
indexing element are located apically of the apical end of the at
least two first indexing element and/or the coronal ends of said at
least two fourth indexing elements are located coronally of the
coronal end of the at least two third indexing elements, wherein
the first, second, third and fourth indexing elements are
distributed along the circumference of the fixture engagement
portion and the component engagement portion, respectively, in such
way that the dental component can only mate in one rotational
orientation with respect to the dental fixture, and wherein the at
least two first indexing elements are only enabled to mate with the
at least two third indexing elements after said at least two second
indexing elements have mated with said at least two fourth indexing
elements.
17. The dental implant as claimed in claim 16, wherein a play
between the at least two first indexing elements and the mating at
least two third indexing elements is smaller than a play between
said at least two second indexing elements and said at least two
mating fourth indexing elements, whereby a tighter fit is provided
between the at least two first and at least two third indexing
elements compared to the fit between the second and fourth indexing
elements.
18. The dental implant as claimed in claim 16, wherein said first
and second indexing elements are provided as radial projections
which project from a surface of the fixture engagement portion of
the dental component, and wherein said third and fourth indexing
elements are provided as radial depressions in a surface of the
component engagement portion of the dental fixture.
19. The dental implant as claimed in claim 16, wherein said at
least two second indexing elements are symmetrically distributed
along the circumference of the fixture engagement portion, and
wherein said at least two fourth indexing elements are
symmetrically distributed along the circumference of the component
engagement portion.
20. The dental implant as claimed in claim 16, wherein said at
least two second indexing elements are asymmetrically distributed
along the circumference of the fixture engagement portion, and
wherein said at least two fourth indexing elements are
asymmetrically distributed along the circumference of the component
engagement portion.
21. The dental implant as claimed in claim 16, wherein a radius
from a central axis of the fixture engagement portion to the centre
of one of said at least two second indexing elements and a radius
from said central axis to the centre of one of said at least two
first indexing elements form a first angle .theta., wherein a
radius from said central axis to another one of said at least two
second indexing elements and said radius from said central axis to
the centre of one of said at least two first indexing element form
a second angle .phi., and wherein said second angle .phi. is
different from said first angle .theta. and from any angle being a
multiple of said first angle .theta., so that .phi..noteq.n.theta.,
where n is a positive integer.
22. The dental implant as claimed in claim 16, wherein the fixture
engagement portion and the first and second indexing elements of
the dental component are rotatable inside the component engagement
portion of the fixture before the second indexing elements have
mated the fourth indexing elements.
23. A dental fixture comprising a component engagement portion
being provided with at least two first radially projecting or
indenting indexing element having a coronal end, wherein the at
least two radially projecting or indenting first indexing elements
include a primary first indexing element and a secondary first
indexing element being spaced from one another by a first
cylindrical enveloping surface portion therebetween, and at least
two second radially projecting or indenting indexing elements being
interposed between the primary first indexing element and the
secondary first indexing element, each one having a coronal end
which is located coronally of the coronal end of the primary first
indexing element and the secondary first indexing element, wherein
the first cylindrical enveloping surface portion is free of
additional radially projecting first indexing elements.
24. The dental fixture of claim 23, wherein the dental fixture is
adapted to be inserted into a jawbone.
25. The dental component as claimed in claim 23, wherein said at
least two second indexing elements are asymmetrically distributed
along the circumference of the component engagement portion.
26. The dental component as claimed in claim 23, wherein said at
least two first indexing elements and said at least two second
indexing elements are asymmetrically distributed along the
circumference of the component engagement portion.
27. The dental component as claimed in claim 23, wherein said at
least two second indexing elements are symmetrically distributed
along the circumference of the component engagement portion.
28. The dental component as claimed in claim 23, wherein said at
least two first indexing elements and said at least two second
indexing elements are symmetrically distributed along the
circumference of the component engagement portion.
Description
RELATED APPLICATIONS
[0001] This is a continuation application U.S. application Ser. No.
13/613,118, filed on Sep. 13, 2012, which claims the benefit of and
priority to EP Application Ser No. 11181242.6, filed on Sep. 14,
2011 and U.S. Provisional Patent Application Ser. No. 61/534,521,
filed on Sep. 14, 2011, which are herein incorporated by reference
for all purposes.
TECHNICAL FIELD
[0002] The present invention relates to a dental component
comprising a fixture engagement portion for engaging the dental
component with a dental fixture adapted to be inserted into a
jawbone or for engaging the dental component with a fixture
replica. The invention also relates to a dental implant comprising
a dental fixture adapted to be inserted into a jawbone and a dental
component connectible to the dental fixture. The invention also
relates to such a dental fixture.
BACKGROUND OF THE INVENTION
[0003] Dental implant systems are widely used for replacing damaged
or lost natural teeth. In such systems, a dental fixture is placed
in the jawbone of a patient in order to replace the natural tooth
root. An abutment structure comprising one or several parts may
then be attached to the fixture in order to build up a core for the
part of the prosthetic tooth protruding from the bone tissue,
through the soft gingival tissue and into the mouth of the patient.
On said abutment, the prosthesis or crown may finally be
seated.
[0004] The final prosthesis should be sized and configured so as to
naturally fit with the remaining teeth of the patient, both for
functionality and aesthetics. To this end a dental technician may
try out a proper prosthesis for the individual patient, using a
model of the jaw of the patient, said model including the fixture.
The dental technician may also digitally work out a proper
prosthesis based on a digital model of the jaw of the patient
either with a fixture already installed or prior to such
installation. The dental technician may also modify a
pre-fabricated abutment to match the contour of the soft gingival
tissue.
[0005] There are various fixture configurations. For instance, a
fixture may have a flat topped coronal head portion, which may be
installed in any rotational position relative to the jawbone.
Another type of fixture configuration is a fixture having a sloped
coronal end portion, such as disclosed in U.S. Pat. No. 6,655,961,
in which the length of the fixture is greater on the lingual side
than on the buccal side in order to match the contour of the
jawbone.
[0006] Similarly, to the above described fixture/jawbone-interface,
for a superstructure, such as an abutment, there may be an
abutment/fixture-interface in which the abutment should only be
positioned in one way relative to the fixture, e.g. an abutment
having a sloped portion matching the sloped head portion of a
fixture. This is one type of asymmetrical superstructure, in which
the asymmetrical feature should be positioned in a desired
rotational relationship to either or both of the fixture and the
jawbone with surrounding teeth. Thus, with regard to these
interfaces, it would be desirable to ensure that the dentist
connects the superstructure with a correct rotational orientation
relative to certain fixtures or jawbone features. Also for
patient-specific or customized superstructures, such as a
customized abutment, such superstructure may often be made with a
certain intended rotational orientation relative to the fixture and
surrounding contours. Thus, also in these cases it would be
desirable to ensure that the dentist connects the superstructure
with a correct rotational orientation relative to the fixture and
other features in the oral cavity.
[0007] When making an abutment and a prosthetic tooth, the dental
technician has thus taken the contours and locations of surrounding
tissue and adjacent teeth into account. A system used at present
time to manoeuvre the rotational position of asymmetrical
superstructures is to provide a two-part abutment having a
centrally positioned threaded screw, which mates with an internally
threaded bore of the fixture, and a sleeve which is given the
asymmetrical patient specific features at its coronal end which are
needed to be a suitable basis for the prosthetic tooth. The sleeve
may be rotated into the correct position in a seating of the
internal bore of the fixture and be fixed therein by the screw. The
seating in the fixture and the apical end of the sleeve of the
abutment are, axially symmetrical to ensure that a correct final
position may be achieved. The correct positioning is this way
depending on the dentist's ability to visually verify the
result.
[0008] The dentist receives the abutment and prosthetic tooth
either as one integral unit or as separate parts to be assembled in
the oral cavity of the patient. Often, the dentist who receives the
abutment and the prosthetic tooth should understand how the
abutment should be rotationally oriented relative to the fixture in
order to obtain the alignment as intended by the dental technician.
Nevertheless, it may sometimes be difficult for the dentist to see
which is the correct orientation and, of course, there may be a
risk of the dentist simply overlooking or ignoring the correct
rotational orientation of the abutment relative to the fixture.
[0009] There have been proposed different solutions which only
allow the abutment to be placed in a single rotational orientation
relative to the fixture. Nevertheless, dentists may still
experience difficulties in finding the correct orientation, and may
have to rotate the abutment for a while before it falls into
place.
[0010] An object of the invention is to enable the dentists to find
a desired rotational orientation of a dental component, such as an
abutment, relative to a fixture more easily than what is offered by
the currently available solutions.
[0011] These and other objectives, which will become apparent in
the following, are achieved by the dental component and the dental
implant as defined in the accompanied claims.
SUMMARY OF THE INVENTION
[0012] The present invention is based on the insight that when
connecting a dental component to a dental fixture, two or more
leading indexing elements may be used for guiding the dental
component into a desired rotational position relative to the
fixture before one or more subsequent trailing indexing elements
are engaged to form the final rotational lock.
[0013] According to a first aspect of the invention, a dental
component is provided. The dental component comprises a fixture
engagement portion for engaging the dental component with a dental
fixture adapted to be inserted into a jawbone or for engaging the
dental component with a fixture replica, the fixture engagement
portion having a geometrical central axis and being provided with
at least one radially projecting first indexing element having an
apical end, and at least two radially projecting second indexing
elements, each one having an apical end located apically of the
apical end of said first indexing element.
[0014] This has the effect that when the dental component is to be
connected with the fixture and thus moved towards the fixture, the
at least two second indexing elements will be the first to mate
with the fixture. In this way, the location finding function of the
indexing elements will be concentrated to only part of the
circumference of the fixture engagement portion. The dentist will
experience a more distinct perception when said at least two second
indexing elements fall into place with a corresponding receiving
portion of the fixture, compared to if all indexing elements around
the circumference of the fixture engagement portion were to connect
simultaneously as in the prior art.
[0015] According to at least one example embodiment, said at least
two second indexing elements are asymmetrically distributed along
the circumference of the fixture engagement portion. Since the
second indexing elements are asymmetrically distributed along the
circumference of the fixture engagement portion, a
component/fixture interface may, if desired, be provided in which
the second indexing elements only have one correct rotational
position, thereby avoiding that the dentist connects the dental
component to the fixture in an incorrect rotational
orientation.
[0016] According to at least one example embodiment, said at least
one first indexing element is circumferentially separated from any
one of said at least two second indexing elements This means that
said first indexing element is located at a different position
along the circumference of the fixture engagement portion than any
one of the second indexing elements. In other words, a radius drawn
from the geometrical central axis to the first indexing element
extends in a different direction from said axis than any radii
drawn from said axis to the second indexing elements.
[0017] Suitably, the apical ends of said at least two second
indexing elements are arranged at substantially the same level in
the apical-coronal direction.
[0018] Having at least two second indexing elements with a leading
function achieves a stabilizing or balancing effect. If the dental
component is intended to be connected to a dental fixture allowing
the dental component to be arranged in any one of a plurality of
rotational orientations, it can be connected in any one of those
rotational orientations. However, when the dentist wishes to
connect the dental component to a dental fixture only allowing the
dental component to be connected in a single specified rotational
orientation, the advantage of having two leading second indexing
elements will become apparent. If there would have been only one
leading second indexing element it could have incorrectly be
received by anyone of the mating (suitably indented) indexing
elements of the fixture, before the dentist annoyed realizes the
incorrect rotational orientation because of the trailing first
indexing element does not find a mating indexing element. By having
two leading second indexing elements, only when both have been
aligned with the correct indexing elements of the fixture will the
mating be possible. As long as one of the second indexing elements
rests on a surrounding wall portion (e.g. a shelf) in the fixture,
it prevents the dental component from moving further apically, and
thus also prevents the other second indexing element from dropping
into an incorrect indentation in the fixture.
[0019] According to at least one example embodiment, the axial
extension of the indexing elements is such that the first indexing
element and the second indexing elements are intersected by a
common geometrical plane which is perpendicular to the central axis
of the fixture engagement portion. Thus, apart from having the
apical ends located at different apical positions, the first and
second indexing elements may have substantially the same
configuration which may be advantageous from a manufacturing
perspective. Furthermore, although the dental component may only
have one specific rotational orientation in one type of fixture, it
could be allowed to have other rotational orientations in other
types of fixtures, in which case the mating indexing elements in
the fixture could receive any one of the first and second indexing
elements of the dental component. Such freedom of choice would be
more complicated if the first and second indexing elements are
completely separated in the axial direction of the fixture
engagement portion.
[0020] According to at least one example embodiment, said at least
one radially projecting first indexing elements comprises at least
two radially projecting first indexing elements. Thus, in such
case, there will be at least two leading (second) indexing elements
which will facilitate finding the correct location and at least two
trailing (first) indexing elements which will provide and/or
complement a rotational locking of the dental component to the
fixture.
[0021] According to at least one example embodiment, said at least
two radially projecting second indexing elements are arranged as at
least three radially projecting second indexing elements,
interposed between two of said first indexing elements, wherein
each one of said at least three second indexing elements has an
apical end which is located apically of the apical ends of said
first indexing elements. This provides increased stability when the
dentist intends to find of the correct rotational orientation of
the dental component in the fixture.
[0022] Thus, it should be understood that said at least two second
indexing element may, for instance, be three, four or more indexing
elements.
[0023] According to at least one example embodiment, a radius from
said central axis to the centre of one of said at least two second
indexing elements and a radius from said central axis to the centre
of said first indexing element form a first angle, wherein a radius
from said central axis to another one of said at least two second
indexing elements and said radius from said central axis to the
centre of said first indexing element form a second angle, wherein
said second angle is different from said first angle and from any
angle being a multiple of said first angle. A multiple is the
product of a quantity by an integer. In other words,
.phi..noteq.n.theta., where .theta. is the first angle, .phi. is
the second angle and n is a positive integer.
[0024] Since said second angle is different from said first angle
(and any multiple thereof) an asymmetry is achieved. Only by
rotating the dental component a full 360.degree. can the first and
second indexing elements obtain the same positional distribution
relative to the surrounding environment. This is in contrast to a
symmetrical distribution of indexing elements; for instance, a
component having four symmetrically distributed indexing elements
can be rotated 90.degree. to obtain the same positional
distribution as before relative to the surrounding environment. The
asymmetry provided by this example embodiment reduces the risk of
the second indexing elements getting caught in incorrect indexing
elements in the fixture.
[0025] The asymmetrical distribution of the indexing elements
comprising at least two first and at least two second indexing
elements is reflected in at least one example embodiment, according
to which the spacing between said two second indexing elements is
different from the spacing between any two of said first indexing
elements. The two second indexing elements do not have to lie next
to each other. There may be one or more first indexing elements
which are placed between said two second indexing element. Also, if
there are more than two second indexing elements, some of them may
be spaced at the same distance as the spacing between first
indexing elements, as long as there can be identified one pair of
second indexing elements having a different spacing. The advantage
of this asymmetry will now be explained. Assuming the dental
component is to be connected to a dental fixture having
corresponding mating third and fourth indexing elements, wherein
the third indexing elements are designated to mate with the first
indexing elements of the dental component while the fourth indexing
elements are designated to mate with the second indexing elements
of the dental component, then there will be only one correct
rotational orientation. Since the apical ends of the second
indexing elements will be leading and be the first to form contact
with the dental fixture, because of the distinct spacing between
said pair of second indexing elements these cannot inadvertently be
mated with the differently spaced third indexing elements.
[0026] According to at least one example embodiment said at least
one first indexing element and said at least two second indexing
elements together form a series of indexing elements which
comprises the following two classifications:
[0027] Classification A: Indexing elements which are separated from
their neighboring indexing elements by no more than a first
distance.
[0028] Classification B: Indexing elements that are separated from
their neighboring indexing elements by more than said first
distance, wherein at least one of the second indexing elements is
present in Classification A.
[0029] For instance, indexing elements under Classification B may
be distributed around the fixture engagement portion at intervals
of an angle .theta., and an indexing element under Classification A
would be interposed between the other indexing elements. As an
example, there may be six indexing elements which are spaced at
60.degree. intervals from one indexing element to the next, and a
seventh indexing element which is located in-between two of the
other six elements (i.e. spaced at 30.degree. from those two
indexing elements). Said six regularly distributed indexing
elements could go under classification B, however, out of those six
indexing elements, the two indexing elements neighboring the
seventh indexing element could also go under Classification A (as
would the seventh indexing element). Thus, at least the extra
seventh indexing element is in the form of one of said at least one
second indexing elements having an apical end located apically of
the apical ends of the first indexing element. However, if the
mating fixture has seven receiving recesses of substantially equal
dimensions, the seventh indexing element could incorrectly enter
anyone of those recesses. Therefore, in order to make sure that
there is only one rotational orientation in which the dental
component can mate with the fixture, at least one of the other six
indexing elements should also be a "second" indexing element having
an apical end located apically of the apical ends of the first
indexing elements. Advantageously, although not necessarily, the
two indexing elements which neighbor the seventh indexing element
may be "second" indexing elements having an apical end located
apically of the apical ends of the first indexing elements.
[0030] The above example of the six equidistantly spaced indexing
elements, and a seventh extra indexing element is encompassed by at
least the following example embodiments. According to at least one
example embodiment, said at least one first indexing element and
said at least two second indexing elements add up to N number of
indexing elements, wherein N-1 of the indexing elements are
equidistantly distributed around the fixture engagement portion,
and wherein the remaining indexing element (the N:th indexing
element) is interposed between two of said equidistantly
distributed N-1 indexing elements, wherein the remaining indexing
element is one of said at least two second indexing elements. At
least one of said equidistantly distributed N-1 indexing elements
is also a second indexing element having its apical end located
apically of the other equidistantly distributed (first) indexing
elements. According to at least one example embodiment, one or both
of the indexing elements neighboring said remaining indexing
element is/are also a second indexing element.
[0031] According to at least one example embodiment, following the
circumferential direction of the fixture engagement portion, said
at least two second indexing elements are interposed between two of
said first indexing elements. Thus, there is at least one
geometrical plane which is perpendicular to the central axis of the
fixture engagement portion and which extends through the first
indexing elements as well as through the second indexing elements.
The coronal extension of the second indexing elements may suitably
be to the same axial level as the coronal extension of the first
indexing elements. Alternatively, the coronal extension of the
second indexing elements may be longer or shorter than the coronal
extension of the first indexing elements.
[0032] In order for the second indexing elements to perform a
guiding or leading function and the trailing first indexing element
to follow with a final rotational locking function, it is not
necessary for the second indexing element to be interposed between
two first indexing elements. The entire second indexing element may
be located apically of the apical end of the at least one first
indexing element. For instance, the second indexing elements may be
in the form of short protrusions at an apical sub-portion of the
fixture engagement portion, while the apical end of the at least
one first indexing element is located coronally thereof, at a
coronal sub-portion of the fixture engagement portion. Once the
second indexing elements have engaged with matching indexing
elements in the fixture, the dental component will continue its
relative movement towards the fixture and eventually the at least
one first indexing element will also engage a matching indexing
element (it is assumed that the indexing elements in the fixture
receiving the leading second indexing elements are long enough to
allow said continued motion of the dental component). Thus, in view
of the above discussion, according to at least one example
embodiment, there is at least one geometrical plane which is
perpendicular to the central axis of the fixture engagement portion
and which is located apically of the at least one first indexing
element and coronally of the second indexing elements.
[0033] According to at least one example embodiment, the fixture
engagement portion of the dental component comprises a cylindrical
surface from which said at least one first indexing element and
said at least two second indexing elements project radially. This
is advantageous from a manufacturing point of view. However, it is
conceivable to have the indexing elements project radially from
other surfaces as well, e.g. from a tapered surface.
[0034] According to at least one example embodiment, the number of
first indexing elements is greater than the number of second
indexing elements. While the number of second indexing elements may
suitably be two or three, the trailing first indexing elements
which complete the rotational locking may suitably be more for
increased strength. This may be particularly advantageous if the
dental component is a driver, wherein the indexing elements are
adapted to transfer a torque to the dental fixture when driving it
into the jawbone.
[0035] According to at least one example embodiment, the apical end
of at least one of said at least two second indexing elements is
provided with a chamfer. When the fixture engagement portion of the
dental component is inserted into the fixture, the dentist will
rotate the dental component in order to align the indexing elements
of the dental component with mating indexing elements of the
fixture. The provision of the two second indexing elements, at
least partly reduces the risk of one of those indexing elements
engaging with the wrong indexing element in the fixture.
Nevertheless, if for instance the dentist tilts the dental
component when trying to connect it to the dental fixture, a second
indexing element might accidently drops into the wrong indexing
element (such as a groove) in the dental fixture upon rotation of
the dental component, despite the supporting function of the other
second indexing element. In such case, when the dentist continues
to apply a rotating force onto the dental component the provision
of a chamfer on that second indexing element will facilitate
lifting that second indexing element out of the temporary incorrect
engagement.
[0036] According to at least one example embodiment, each one of
said second indexing elements has a smaller dimension in the
circumferential (transverse) direction and/or in the radial
(projecting) direction compared to the dimensions of said at least
one first indexing element. This is advantageous if, for instance
the dental fixture has equally dimensioned recesses for receiving
the indexing elements (projections) of the dental component,
because in such case the second indexing elements, which have a
smaller dimension (e.g. transverse to the coronal-apical direction)
than the at least one first indexing element, will be received in
their receiving recesses with a relatively large play (in this
example, a large play in the transverse direction). The second
indexing elements, having their apical ends located apically of the
apical end of the at least one first indexing element, will be
received by their corresponding recess before the trailing first
indexing element is received by its corresponding recess in the
fixture. The relatively large play facilitates for the dentist to
get the second indexing elements into engagement with the
corresponding recesses in the fixture. Thus, at this stage, when
only the second indexing elements have been engaged, a small
rotational movement of the dental component relative to the fixture
may be possible. However, when the at least one first indexing
element follows to engage with its corresponding recess, since it
is suitably more accurately dimensioned to fit closely in its
recess, the dental component will become rotationally locked when
the one or more first indexing elements have entered in engagement
with their respective recesses.
[0037] According to at least one example embodiment said at least
one first indexing element and said at least one second indexing
elements have an elongate extension in the coronal-apical
direction. This provides additional strength to the rotational lock
compared to if the radially projecting indexing elements would have
a shorter extension.
[0038] According to at least one example embodiment, the dental
component is a component selected from the group consisting of an
abutment, an abutment replica, an abutment blank, a customized
abutment, a scan abutment, a digital transfer coping, an impression
pick-up element, a healing cap and a driver.
[0039] For instance, a customized abutment may have a shape which
is adapted to the contours of the surrounding tissue and teeth of
the patient, in which case it is advantageous if the dentist can
easily fit the customized abutment in the intended rotational
orientation.
[0040] A digital transfer coping having some distinguishing feature
indicating its rotational orientation and being connected to a
dental fixture may be scanned, and a digital file is then sent to
an abutment manufacturer. The digital file will contain information
about the position and orientation of the distinguishing feature
and thus also the position and orientation of the dental
fixture.
[0041] A driver having a distinctive marking may be used as an
indication to determine if the fixture has been inserted at a
desired orientation relative to the jawbone and other surrounding
features in the oral cavity. For instance, the fixture may have a
sloping coronal end. The driver may be intended to be inserted such
that the distinctive marking is aligned with the very top of the
sloping end of the fixture. Thus, during rotation of the fixture
into the jawbone, the dentist will know the rotational orientation
of the fixture and its sloping end by looking at the distinctive
marking. It is therefore advantageous if the dentist can easily fit
the driver into the intended position relative to the fixture.
[0042] According to a second aspect of the invention, a dental
implant is provided. The dental implant comprises a dental
component comprising a fixture engagement portion provided with at
least one first indexing element having an apical end, and at least
two second indexing elements, each one having an apical end, a
dental fixture adapted to be inserted into a jawbone and comprising
a component engagement portion adapted to mate with said fixture
engagement portion, the component engagement portion being provided
with at least one third indexing element having a coronal end, and
at two fourth indexing elements, each one having a coronal end,
wherein the apical ends of said at least two second indexing
element are located apically of the apical end of the first
indexing element and/or the coronal ends of said at least two
fourth indexing elements are located coronally of the coronal end
of the third indexing element, wherein the first, second, third and
fourth indexing elements are distributed along the circumference of
the fixture engagement portion and the component engagement
portion, respectively, in such way that the dental component can
only mate in one rotational orientation with respect to the dental
fixture, wherein the first indexing element is only enabled to mate
with the third indexing element after said at least two second
indexing elements have mated with said at least two fourth indexing
elements.
[0043] Thus, the second and fourth indexing elements will act to
guide the dental component into a desired rotational orientation
relative to the fixture. Once this rotational orientation has been
found, and the dental component is continued to be displaced
apically, the first and third indexing element will then engage
each other to provide a final rotational stop. While the first and
third indexing elements, suitably, form a relatively tight fit in
order to reduce the risk of small rotational movements between the
dental component and the dental fixture, the fit between the second
and fourth indexing elements may advantageously be provided with a
play. This is reflected in at least one example embodiment,
according to which a play (e.g. a lateral play or a radial play)
between the first indexing element and the mating third indexing
element is smaller than a play between said at least two second
indexing element and said at least two mating fourth indexing
element, whereby a tighter fit is provided between the first and
third indexing elements compared to the fit between the second and
fourth indexing elements.
[0044] The play between the second and fourth indexing elements
makes it easy for the dentist to find the desired rotational
orientation as the second indexing element will more easily be
received by the fourth indexing element than what would be the case
without such a play. The tight fit between the first and third
indexing elements makes sure that the same rotational position is
obtained throughout a multi-step procedure, e.g. making an
impression with a dental component (such as a transfer coping)
connected to the fixture, making a model based on the impression,
making another dental component (such as an abutment) based on the
model and connecting the latter dental component to the dental
fixture. A potential rotational error, although small, in each
step, may in the end result in a large rotational error. The tight
fit between the first and third indexing elements reduces the risk
of rotational errors in each step.
[0045] According to at least one example embodiment, said first and
second indexing elements are provided as radial projections which
project from a surface of the fixture engagement portion of the
dental component, and wherein said third and fourth indexing
elements are provided as radial depressions in a surface of the
component engagement portion of the dental fixture. However, it
would be conceivable to have it the other way around, i.e. the
projections on the fixture and the depressions in the dental
component. Other mixed alternatives are also conceivable as long as
the second and fourth indexing elements mate before the mating of
the first and third indexing elements.
[0046] According to at least one example embodiment, said at least
one first indexing element is circumferentially separated from any
one of said at least two second indexing elements, and wherein said
at least one third indexing element is circumferentially separated
from any one of said at least two fourth indexing elements.
[0047] According to at least one example embodiment, said at least
two second indexing elements are asymmetrically distributed along
the circumference of the fixture engagement portion, and wherein
said at least two fourth indexing elements are asymmetrically
distributed along the circumference of the component engagement
portion.
[0048] According to at least one example embodiment, a radius from
a central axis of the fixture engagement portion to the centre of
one of said at least two second indexing elements and a radius from
said central axis to the centre of said first indexing element form
a first angle, wherein a radius from said central axis to another
one of said at least two second indexing elements and said radius
from said central axis to the centre of said first indexing element
form a second angle, wherein said second angle is different from
said first angle and from any angle being a multiple of said first
angle.
[0049] According to at least one example embodiment, in the dental
fixture, a radius from a central axis of the component engagement
portion to the centre of one of said at least two fourth indexing
elements and a radius from said central axis to the centre of said
third indexing element form a first angle, wherein a radius from
said central axis to another one of said at least two fourth
indexing elements and said radius from said central axis to the
centre of said third indexing element form a second angle, wherein
said second angle is different from said first angle and from any
angle being a multiple of said first angle.
[0050] According to at least one example embodiment, the dental
component has at least two first indexing elements and the dental
fixture has at least two mating third indexing elements. According
to at least one example embodiment, the spacing between the two
second indexing elements is different from the spacing between any
two of said first indexing elements; and the spacing between said
two fourth indexing elements is different from the spacing between
any two of said third indexing elements. The two second indexing
elements do not have to lie next to each other; nor do the two
fourth indexing elements have to lie next to each other. There may
be one or more first indexing elements which are placed between
said two second indexing elements. Likewise, there may be one or
more third indexing elements which are placed between said two
fourth indexing elements. Also, if there are more than two second
indexing elements, some of them may be spaced at the same distance
as the spacing between first indexing elements, as long as there
can be identified one pair of second indexing elements having a
different spacing. Likewise, if there are more than two fourth
indexing elements, some of them may be spaced at the same distance
as the spacing between third indexing elements, as long as there
can be identified one pair of fourth indexing elements having a
different spacing. The advantage of this asymmetry has already been
explained above in connection with the discussion of the first
aspect of the invention.
[0051] According to at least one example embodiment, the fixture
engagement portion and the first and second indexing elements of
the dental component are rotatable inside the component engagement
portion of the fixture before the second indexing elements have
mated the fourth indexing elements. This facilitates the location
finding function and reduces the risk of skewing of the dental
component relative to the fixture. For instance, the fixture may at
its coronal end have an internal socket defined by a wall portion
in which third and fourth indexing elements in the form of radially
extending recesses are provided. The dental component and its first
and second indexing elements may be inserted into the socket and
rotated. Suitably, the second indexing element, may during rotation
bear upon a shelf which contains said recesses. As the dental
component is rotated and the second indexing elements moves along
the shelf, the second indexing elements will eventually drop into
the recesses.
[0052] According to at least one example embodiment, the dental
component of the dental implant according to the second aspect of
the invention, is a dental component having the features discussed
in connection with the first aspect of the invention.
[0053] According to a third aspect of the invention, a dental
fixture adapted to be inserted into a jawbone is provided. The
dental fixture comprises a component engagement portion adapted to
mate with a dental component, the component engagement portion
being provided with at least a first radially projecting or
indenting indexing element having a coronal end, and at least two
second radially projecting or indenting indexing elements, each
having a coronal end which is located coronally of the coronal end
of the first indexing element.
[0054] According to at least one example embodiment, the coronal
end of the first indexing element is circumferentially separated
from the coronal end of any one of said second indexing
elements.
[0055] According to at least one example embodiment, said second
indexing elements are asymmetrically distributed along the
circumference of the component engagement portion.
[0056] The dental fixture according to the third aspect of the
invention, may have any one of the features of dental fixtures
mentioned in connection with the first and second aspects of the
invention and/or any one of the features of dental fixtures
mentioned in the following.
[0057] As mentioned above, a dental implant comprises a dental
fixture and a dental component.
[0058] A dental fixture is for use as the anchoring member of a
dental prosthesis. To this end, the dental fixture is insertable
into a pre-prepared bore hole in the bone tissue of a jawbone
(maxilla or mandible) at a site where the dental prosthesis is
required. The dental fixture is normally rotated into the bore
hole.
[0059] For screw-type dental fixtures the bore hole may be provided
with internal threads in advance or may be left un-tapped with the
dental fixture provided with a self-tapping capacity, e.g. by the
provision of one or more axially-extending cutting recesses, edges
or notches, etc in the fixture thread. For instance, an apical end
portion of the fixture may be provided with 2-4 cutting recesses,
such as 3 cutting recesses. Other number of cutting recesses are
readily conceivable.
[0060] A dental component may, as discussed previously be any one
of a number of different components. One example is a driver for
inserting the dental fixture into the jawbone. Another example is a
superstructure for connecting a prosthetic part to the fixture. The
superstructure may comprise an abutment, spacer or other
transmucosal component which engages to the dental fixture to
bridge the gingiva overlying the maxilla or mandible. The
prosthetic part, e.g. a crown, bridge or denture may be secured to
the abutment. There are various other forms that the superstructure
can take. For instance, the prosthetic part may be secured directly
to the dental fixture.
[0061] The term "coronal" is here and throughout this application
used to indicate a direction towards a head end or trailing end of
the dental implant. For instance, in a situation where a dental
abutment is connected to a dental fixture, the coronal direction of
the abutment would be a direction towards the part of the abutment
being directed away from the fixture. Conversely, the term "apical"
indicates a direction towards an insertion or leading end of the
component. Thus, apical and coronal are opposite directions.
Furthermore, the terms "axial", "axial direction" or "axially" are
used throughout this application to indicate a direction taken from
the coronal end to the apical end, or vice versa. The terms
"radial", "radial direction" or "radially" indicate a direction
perpendicular to the axial direction.
[0062] A blind bore or socket may extend apically into the fixture
body from the coronal end to an end surface in-between the apical
and coronal ends of the fixture body for a superstructure to be
secured to the fixture. The socket may comprise an
internally-threaded section for screw connection of the dental
component to the fixture. A rotational lock for the dental
component may be provided in the socket, such as an internal
polygonal side wall, e.g. hexagonal, or alternatively one or more
protrusions from or indentation in the wall of the socket. A
section of the socket, such as the coronal section, may be tapered
towards the apical end. The tapered section is suitably arranged
coronally of the internally-threaded section.
[0063] The fixture may be used in a one stage procedure or a two
stage procedure. In a one stage procedure a healing or temporary
abutment is connected to the fixture to form the gingival tissue,
and after a healing period the healing or temporary abutment is
replaced by a permanent abutment. For a two stage procedure the
fixture is provided with a cover screw and the gingival tissue is
sutured over the fixture and cover screw, and after a healing
period the tissue is opened up and an abutment is connected to the
fixture after removal of the cover screw.
[0064] The dental fixture may have a conically tapering end portion
which tapers towards the coronal end. The axial extent of this
coronal end portion is small compared to the total length of the
fixture, as an example no more than 4% of the total length, such as
in the range of 1.5%-3.7%. The coronal end portion may suitably be
provided without a threaded surface, e.g. having a smooth or a
roughened (such as blasted) surface.
[0065] The fixture may have a substantially flat coronal end
surface which is perpendicular to the longitudinal axis of the
fixture. Alternatively, the coronal end surface may have a sloped
contour relative to the longitudinal axis of the fixture, e.g. such
that when positioned within the jawbone the length of the fixture
is larger on a lingual side and shorter on a buccal side of the
fixture. Another alternative is a saddle-shaped or wave-like
coronal end surface.
[0066] The length of the dental fixture may be in the range of 5-19
mm, depending on the clinical situation. The outer diameter of the
dental fixture may suitably be in the range of 2-6 mm, such as 3-5
mm.
[0067] The fixture may be substantially cylindrical or slightly
tapering from the coronal end towards the apical end. If the
fixture has a slight tapering, the core of the fixture and the
outer periphery defined by e.g. thread tops may have the same or
different angle of taper. Furthermore, the core of the fixture may
be cylindrical while the thread tops describe a conicity or,
conversely, the core of the fixture may be tapered while the thread
tops describe a generally cylindrical geometry. Alternatively, the
fixture may comprise a combination of one or more cylindrical
and/or one or more tapering portions. Thus, one or more portions of
the fixture may have e.g. thread tops lying in a common imaginary
cylindrical surface, which cylindrical surface is parallel with the
longitudinal axis of the fixture. Alternatively or additionally,
one or more portions of the fixture may have thread tops lying in
an imaginary conical surface which in the apical direction is
tapering towards the longitudinal axis.
[0068] The externally threaded fixture may comprise one or more
thread spirals.
[0069] The term "pitch" is used to indicate the axial distance
between adjacent tops of a threading. The term "lead" is used to
indicate the distance advanced parallel to the longitudinal axis
when the fixture is turned one revolution, i.e. it corresponds to
the pitch multiplied with the number of thread spirals. For a
single thread spiral having a constant pitch, the lead is equal to
the pitch; for a double thread spiral, the lead is twice the
pitch.
[0070] The term "microthread" is used to indicate a thread having a
height which is no greater than 0.2 mm. According to at least one
example embodiment, the fixture is provided with microthreads
having a height in the range of 0.02-0.2 mm, such as 0.05-0.015 mm,
for instance 0.1 mm. The term "macrothread" is used to indicate a
thread having a height which is greater than 0.2 mm. According to
at least one example embodiment, the fixture is provided with
macrothreads having a height in the range of 0.25-0.35 mm, such as
0.3 mm.
[0071] Suitably, microthreads may be located coronally of
macrothreads. For instance, microthreads may be arranged to engage
dense cortical bone and macrothreads may be arranged to engage
porous spongious/cancellous bone. The lead of a microthread
suitably corresponds to the lead of a macrothread. The macrothread
pitch may, as an example, be 2-4 times, such as 3 times, the pitch
of the microthreads. The pitch (top-to-top spacing) at a fixture
portion provided with microthreads may be around 0.10-0.30 mm, for
instance 0.20-0.24 mm. The pitch (top-to-top spacing) at a fixture
portion provided with macrothreads may be around 0.30-0.90 mm, for
instance 0.60-0.72 mm.
[0072] Microthreads can be regarded as defined, oriented roughness.
A non-oriented roughness having smaller dimensions, for instance
obtained by blasting, etching, etc., may be superimposed on
microthreads as well as on macrothreads.
[0073] A thread profile may comprise two flanks, a top
interconnecting said two flanks, a bottom formed between two
adjacent threads, said flanks forming an acute angle v with a plane
which is perpendicular to the fixture axis and which angle v lies
in a plane containing the extension of the fixture axis, said
profile further having a height D. The top may be curved and may
have a top radius. Suitably, for
10.degree..ltoreq.v.ltoreq.35.degree., the top radius is greater
than 0.4.times.D and, for 35.degree..ltoreq.v.ltoreq.55.degree.,
the top radius is greater than 0.2.times.D.
BRIEF DESCRIPTION OF THE DRAWINGS
[0074] FIGS. 1A-1C illustrate a dental component according to at
least one example embodiment of the invention.
[0075] FIG. 2 illustrates a dental component according to at least
one other example embodiment of the invention, which is to be
connected to a dental fixture in a specific rotational orientation
with respect to the dental fixture, wherein the dental component
and the dental fixture together represent a dental implant
according to at least one example embodiment of the invention. FIG.
2 also illustrates another dental component which may be arranged
in a number of different rotational orientations with respect to
the same dental fixture.
[0076] FIG. 2A is a top view of the dental fixture in FIG. 2.
[0077] FIGS. 2B-2C are bottom views of the dental components in
FIG. 2.
[0078] FIG. 3 illustrates a fixture engagement portion of a dental
component according to at least one example embodiment.
[0079] FIGS. 4A-4E illustrate schematically circumferential
distributions of first and second indexing elements on dental
components according to different example embodiments.
[0080] FIG. 5 illustrates, in accordance with at least one example
embodiment, a dental component in the form of a driver to be
connected to a dental fixture.
DETAILED DESCRIPTION OF THE DRAWINGS
[0081] Each drawing illustrates a dental component having first and
second indexing elements, and some of the drawings also illustrate
a dental fixture having third and fourth indexing elements.
[0082] FIGS. 1A-1C illustrate a dental component 100 according to
at least one example embodiment of the invention, wherein FIG. 1A
is a perspective view, FIG. 1B is a bottom view and FIG. 1C is a
partial side view. The dental component 100 may, for instance, be
an abutment, an abutment replica or an abutment blank. The dental
component 100 comprises a body part 110 which is provided with a
central through-hole 112, through which a screw part 150 is
insertable and connectible to internal threads of a dental fixture,
in order to secure the body part 110 to the fixture. The body part
110 comprises a fixture engagement portion 114, which is herein
illustrated as having a generally cylindrical enveloping surface,
although other enveloping surfaces, such as tapering, would be a
conceivable alternatives. The body part 110 further comprises a
dental crown-receiving or prosthesis-receiving portion 116 which
extends coronally of the fixture above the gingiva. An extension
portion 118, herein illustrated as coronally flaring up to a
shoulder 120, is intended to extend through the gingiva and is
provided between the fixture engagement portion 114 and the
prosthesis-receiving portion 116. In case the dental component 100
is provided as an abutment blank, at least one of the extension
portion 118 and the prosthesis-receiving portion 116 may be further
processed to a desired shape, which may suitably be customized for
the patient receiving the resulting processed abutment.
[0083] The fixture engagement portion 114 is provided with a
radially projecting first indexing element 130 having an apical end
132, and two radially projecting second indexing elements 140a,
140b having apical ends 142a, 142b. The apical ends 142a, 142b of
the second indexing elements 140a, 140b are located apically of the
apical end 132 of the first indexing element 130. The overall axial
extension of the first indexing element 130 and the second indexing
elements 140a, 140b is such that the first indexing element 130 and
the second indexing elements 140a, 140b are intersected by a common
geometrical plane which is perpendicular to the central axis of the
fixture engagement portion 114. Thus, the axial extension of the
first indexing element 130 is at least partly overlapped by the
axial extension of the second indexing elements 140a, 140b.
[0084] Following the circumference of the fixture engagement
portion 114, the first indexing element 130 is located at a
position which is spaced from the positions of the second indexing
elements 140a, 140b, i.e. the first indexing element 130 is
circumferentially separated from any one of the second indexing
elements 140a, 140b. Expressed differently, in a cylindrical
coordinate system (r, .phi., z) wherein the z axis coincides with
the central geometrical axis of the engagement portion 114, the
angle .phi. will be different for each one of the first indexing
element 130 and the two second indexing elements 140a, 140b.
[0085] The close positioning of the two second indexing elements
140a, 140b results in that they are asymmetrically distributed
along the circumference of the fixture engagement portion 114.
Asymmetrical distribution means that the two second indexing
elements are not evenly distributed around the fixture engagement
portion. An even, symmetrical distribution would have the two
second indexing elements distributed 180.degree. from each other
around the fixture engagement portion 114.
[0086] This dental component 100 may be connected to a dental
fixture having indexing elements in the form of indexing
indentations/recesses/depressions which sizewise match the indexing
elements 130, 140a, 140b of the dental component 100. Thus, as the
dental component 100 is brought into contact with the fixture, the
second indexing elements 140a, 140b will be leading and will be the
first to enter associated indexing recesses in the fixture. Once
the second indexing elements 140a, 140b have mated with their
associated indexing recesses in the fixture, the trailing first
indexing element 130 of the dental component 100 will be
substantially aligned with its associated indexing recess.
Therefore, when the dental component 100 is continued to be
inserted into the fixture, the first indexing element will easily
mate with its associated indexing recess in the fixture. Thus, the
leading second indexing elements 140a, 140b have an initial
guiding/aligning function while the trailing first indexing element
130 completes the rotational locking.
[0087] In FIGS. 1A-1C the indexing elements 130, 140a, 140b have
been confined to a small area of the fixture engagement portion
114. This small area spans over approximately 60.degree. of the
total (360.degree.) circumference of the fixture engagement portion
114, the central (second) indexing element 140a being spaced from
its neighbours at approximately 30.degree.. The dental component
100 may thus mate with a fixture having similar distribution of
indexing elements, one exemplary fixture 4 being illustrated in
FIG. 2. The three indexing elements or indexing recesses of the
fixture 4 in FIG. 2 which would mate the indexing elements 130,
140a, 140b of the dental component 100 in FIG. 1 are denoted 30e,
30f, 30g. The fixture 4 has four other indexing elements 30a-30d,
however, these are separated at a larger distance. Thus, the dental
component 100 can only mate with this fixture 4 in one rotational
orientation. If one of the second indexing elements (e.g. 140a),
would be aligned over an incorrect indexing element in the fixture
4, the other second indexing element (e.g. 140b) will rest against
a shelf 32 in the fixture 4, thus rendering further apical movement
difficult. If there would have been only one second indexing
element, it could have dropped into any one of the seven indexing
recesses 30a-30g in the fixture 4, before the dentist realizes that
the dental component is incorrectly orientated. Although, having
two second indexing elements stabilizes and reduces the risk of one
of the second indexing elements 140a, 140b dropping into an
undesired indexing recess of the fixture, it may accidently happen
if e.g. the dentist tilts the dental component too much. Therefore,
turning back to FIG. 10, as an optional feature the second indexing
elements may be provided with a respective chamfer 144a, 144b, on
the side facing away from the other second indexing element. Such a
chamfer 144a, 144b facilitates continued rotating movement by the
dentist in case one of the second indexing elements 140a, 140b
would slightly drop into an incorrect indexing recess. As a further
optional feature, the second indexing elements 140a, 140b may have
a somewhat smaller radial or circumferential extension compared to
the first indexing element 130, in order to provide a certain play
when mating with the indexing recesses of the fixture 4. In such
case, even though the second indexing elements 140a, 140b may not
provide a sufficient rotational lock, their underdimensioning will
facilitate the location finding function, and the first indexing
element 130 can still be relied upon for the rotational locking
function.
[0088] It should be noted that the dental component 100 is not
limited to be used with fixtures permitting only one rotational
orientation. The dental component 100 could for instance be
connected to a fixture having twelve indexing recesses, each recess
being equidistantly spaced at 30.degree. from the neighbouring
recesses. With such a fixture, the dentist may select any one of
twelve rotational positions for the dental component 100. Thus, the
exemplified dental component 100 maintains the possibility of
multiple rotational positioning with some types of fixtures, while
providing the above-presented benefits in connection with fixtures
permitting only a single rotational positioning.
[0089] FIG. 2 illustrates a dental component 2 according to at
least one other example embodiment of the invention, which is to be
connected to a dental fixture 4 in a specific rotational
orientation with respect to the dental fixture 4, wherein the
dental component 2 and the dental fixture 4 together represent a
dental implant according to at least one example embodiment of the
invention. FIG. 2 also illustrates another dental component 6 which
may be arranged in a number of different rotational orientations
with respect to the same dental fixture 4.
[0090] The herein illustrated dental fixture 4 has a coronal
portion 8 extending apically from a coronal end 12 of the fixture
4, and an apical portion 10 extending coronally from an apical end
14 of the fixture 4.
[0091] The apical portion 10 may have a conicity tapering towards
the apical end 14 of the fixture 4 to ease insertion of the fixture
4 into a bore-hole in the jawbone.
[0092] The fixture 4 has a core from which a surface structure
projects, in the illustrated example being in the form of
threads.
[0093] The coronal portion 8 is herein illustrated as being at
least partly provided with microthreads 16, e.g. having three
thread spirals, although another number is conceivable, such as 1,
2, 4 or more spirals. Although microthreads 16 have been
illustrated, according to at least an alternative example
embodiment the coronal portion 8 is at least partly provided with
macrothreads 18, similarly to the apical portion 10, either as a
separate thread spiral or as a continuation of the thread spiral at
the apical portion 10. According to at least another alternative
example embodiment, instead of microthreads 16, the coronal portion
may be provided with a plurality of annular ridges, which to the
naked eye could give the same visual appearance as microthreads.
Other conceivable alternatives are circumferential lines of beads
or non-oriented/randomly provided projections such as bulges.
[0094] In the illustrated example embodiment, the macrothreads 18
at the apical portion 10 has the same lead as the microthreads 16
at the coronal portion 8. However, the pitch of the macrothreads 18
is three times the pitch of the microthreads 16, since the
microthreads 16 comprise three thread spirals.
[0095] The apical portion 10 comprising macrothreads 18 is herein
illustrated as having one thread spiral, however, the apical
portion 10 may alternatively have two or more thread spirals.
[0096] The length of the herein illustrated coronal portion 8 may
be about 1-2 mm, such as 1.5 mm. However, shorter or longer lengths
are readily conceivable. The relative length of the coronal portion
8 may also be selected from a wide range, such as 5-50% of the
total length of the fixture 4, e.g. 10-20%.
[0097] The coronal portion 8 comprises a tapering end portion 20,
which tapers towards the coronal end 12 of the fixture 4. The
tapering end portion 20 is no more than 4% of the total length of
the fixture 4. The surface of the tapering end portion 20 may be
non-threaded, either smooth or blasted (or otherwise
roughened).
[0098] Cutting recesses 22 or grooves extend coronally from the
apical end 14. The number of cutting recesses 22 may be one or
more, such as two, three or four cutting recesses, suitably
symmetrically positioned about the circumference of the apical end
14 of the fixture 4 for self-tapping of the fixture 4 when being
screwed/rotated into the bore-hole provided in the maxilla or
mandible.
[0099] A socket 24 having an open end is provided in the coronal
end 12 of the fixture 4. The socket 24 extends apically into the
fixture 4. The socket 24 is for receiving a dental component 2 such
as the illustrated abutment which will bridge the gingiva overlying
the bore-hole and support/present a prosthetic part. However, it
may also receive other dental components such as an abutment
replica, a driver, a healing cap, an impression pick-up element, a
digital transfer coping, etc.
[0100] Although various alternative configurations are conceivable,
the socket 24 is herein illustrated as having a conical coronal
section 26 and a substantially cylindrical intermediate wall
section 28. Seven indexing elements 30a-30g, herein illustrated as
radially extending recesses 30a-30g are provided in the
intermediate wall section 28 (see also FIG. 2A). The intermediate
wall section 28 and the radially extending recesses 30a-30g act as
a component engagement portion of the fixture 4. The coronal end of
the intermediate wall section 28 forms a shelf 32 with gaps formed
by said seven recesses 30a-30g. Six of the recesses 30a-30e, 30g
are equidistantly distributed along the circumference of the
intermediate wall section 28. The seventh recess 30f is interposed
between two (30e, 30g) of said six equidistantly distributed
recesses. This is clearly illustrated in the top view of FIG.
2A.
[0101] The socket 24 is further provided with an internally
threaded apical section 34.
[0102] A dental component 2 according to at least one example
embodiment of the invention is herein illustrated as a two-piece
abutment 2 consisting of a body part 40 and a screw part 42. The
body part 40 of the abutment 2 is provided with a through-hole 44,
wherein the screw part 42 is adapted to be inserted into the
through-hole 44 and engage the internal thread 34 of the fixture 4
in order to secure the body part 40 to the fixture 4. The body part
40 comprises a fixture engagement portion 46, which is herein
illustrated as having a generally cylindrical enveloping surface,
although other enveloping surfaces, such as tapering, would be a
conceivable alternatives. The body part 40 further comprises a
dental crown-receiving or prosthesis-receiving portion 48 which
extends coronally of the fixture 4 above the gingiva. An extension
portion 50, herein illustrated as coronally flaring up to a
shoulder 52, is intended to extend through the gingiva and is
provided between the fixture engagement portion 46 and the
prosthesis-receiving portion 48.
[0103] Seven indexing elements 60a-60g, herein illustrated as
radial projections 60a-60g, are provided sequentially in the
circumferential direction of the cylindrical enveloping surface of
the fixture engagement portion 46 (see also 2B). Similarly to the
distribution of the radial recesses 30a-30g in the fixture 4, there
are six equidistantly distributed radial projections 60a-60e, 60g
on the dental component 2, while the seventh radial projection 60f
is interposed between two (60e, 60g) of said six equidistantly
distributed radial projections. With this configuration, the
seventh radial projection 60f and its two neighbouring radial
projections 60e, 60g can only mate in one correct way with the
seventh radial recess 30f and its two neighbouring recesses 30e,
30g. Thus, there is only one rotational orientation possible for
the dental component 2 to be connected with respect to the dental
fixture 4.
[0104] Four of the radial projections can be regarded as first
indexing elements 60a-60d, each having an apical end (in FIG. 2 the
apical end of the indexing element 60d is designated with reference
numeral 62d). The other three radial projections 60e-60g, namely
said seventh radial projection 60f and its two neighbouring
projections 60e, 60g, can be regarded as second indexing elements
60e-60g having apical ends 62e-62g located apically of the apical
ends of the first indexing elements 60a-60d. This facilitates for
the dentist to connect the dental component 2 to the dental fixture
4 in the correct rotational orientation. Contrary to the example
embodiment shown in FIG. 1, in this example embodiment the number
of first indexing elements 60a-60d is greater than the number of
second indexing elements 60e-60g. In the circumferential direction
of the fixture engagement portion 46, each one of the first
indexing elements 60a-60d is located at a position which is
different from the positions of the second indexing elements
60e-60g. Thus, each one of the first indexing elements 60a-60d is
circumferentially separated from any one of the second indexing
elements 60e-60g.
[0105] When the body part 40 of the abutment 2 is to be connected
to the fixture 4, the projections forming said second indexing
elements 60e-60g may come in contact with the shelf 32 in the
fixture 4. The projections forming said first indexing elements
60a-60d will still be spaced from the shelf 32. The body part 40 is
then rotated so that the second indexing elements 60e-60g fall into
the designated recesses 30e-30g of the fixture 4, i.e. into the
seventh recess 30f and its two neighbouring recesses 30e, 30g.
[0106] Thus, the second indexing elements 60e-60g will first engage
with the seventh recess 30f and its two neighbouring recesses 30e,
30g which represent fourth indexing elements 30e-30g, and
thereafter having already found the correct rotational position,
the first indexing elements 60a-60d of the dental component 2 can
engage with the third indexing elements 30a-30d (the other four
recesses 30a-30d) of the dental fixture 4.
[0107] If only a single one (for example 60f) of the seven indexing
elements 60a-60g of the dental component 2 would have an apical end
located apically of the other six indexing elements, that single
one (for example 60f) of the indexing elements 60a-60g could have
mated with any one of the seven indexing elements 30a-30g of the
fixture 4. However, only one (in this example 30f) of those seven
indexing elements 30a-30g of the fixture is the correct one which
allows the trailing indexing elements of the dental component to
also mate with the corresponding indexing elements in the fixture.
If the dentist would place said single one (e.g. 60f) of the seven
radially projecting indexing elements 60a-60g into one of the six
incorrect radially indented indexing elements (e.g. 30a-30e, 30g),
the trailing indexing elements (e.g. 60a-60e, 60g) of the dental
component 2 would not find a mating indexing element in the fixture
4 but would abut the shelf 32. The dentist would have to lift the
dental component 2 and try again to find the correct rotational
orientation of the dental component 2 relative to the fixture 4. By
additionally letting another one (for example 60g) of the seven
indexing elements (60a-60g) have an apical end extending apically
of the apical ends of the other indexing elements, said indexing
element (in this example 60g) will be in contact with the shelf 32
of the fixture reducing the risk of the other indexing element (in
this example 60f) falling into the incorrect recess in the fixture
4. Thus, having a dental component with at least one first indexing
element and at least two second indexing elements having apical
ends apically of the apical end of the first indexing element
reduces the risk of the second indexing elements falling into the
incorrect recesses in the fixture. Nevertheless, if the dentist
brings the dental component 2 towards the fixture 4 in a slightly
inclined direction, one of said second indexing elements may still
be able to reach into an incorrect recess in the fixture, albeit
not very deeply because of the other second indexing element
contacting the shelf 32 preventing further advancement. Because the
second indexing element cannot fall deeply into an incorrect
recess, a rotating motion will easily lift the second indexing
element and after continued rotation the correct position will be
found.
[0108] Having three radially projecting second indexing elements
with longer apical extensions than the trailing first indexing
element further facilitates correct alignment of the indexing
elements of the dental component with those of the fixture. FIG. 2
illustrates an advantageous distribution of three second indexing
elements 60e-60g interposed between two (60a, 60d) of the first
indexing elements 60a-60d. The middle one (60f) of the second
indexing elements 60e-60g cannot fall into an incorrect recess
(30a-30e, 30g) in the fixture 4, because of the other two (60e,
60g) second indexing elements provided on either side thereof. When
the dental component 4 is to be connected to the fixture 2, the
second indexing elements 60e-60g will with high likelihood land on
the shelf 32, thus requiring the dentist to rotate the dental
component 4 into the correct orientation. During such rotation,
unless the dentist holds the dental component 4 absolutely
straight, one of the two outer second indexing elements (60e, 60g)
might just slightly drop into an incorrect recess in the fixture.
Since the drop is so small, the dentist can easily continue the
rotation until the correct alignment is found. Nevertheless, in
FIG. 3, showing a fixture engagement portion 46' of a dental
component, an example embodiment is illustrated in which each one
of the two outer second indexing elements 60'e, 60'g are provided
with a respective chamfer 61'e, 61'g on the side facing away from
the middle one (60'f) of the second indexing element. Such a
chamfer 61'e, 61'g further facilitates the continued rotating
movement by the dentist in case one of the outer second indexing
elements 60'e, 60'g would slightly drop into an incorrect recess.
In FIG. 3, two shorter first indexing elements 60'a, 60'd are also
visible. Also, it may be noted that the apical ends of the second
indexing elements 60'e-60'g are not flush with the apical end of
the dental component as in FIG. 2, but instead located somewhat
coronally thereof.
[0109] As illustrated in the bottom view of FIG. 2B, the first
indexing elements 60a-60d are somewhat wider than the second
indexing elements 60e-60g. In the dental fixture 4, however, the
third and fourth indexing elements 30a-30g have substantially the
same width. This has the effect that due to a larger width
difference between the second indexing elements 60e-60g and the
fourth indexing elements 30e-30g, there will be a lateral play
between these indexing elements facilitating the finding of the
correct rotational orientation. In other words, because the
radially projecting second indexing elements 60e-60g are
laterally/transversely underdimensioned with respect to the
radially indenting fourth indexing elements 30e-30g, they will more
easily fall into place than if they were of substantially the same
dimensions. The radially projecting first indexing elements 60a-60d
are dimensionally closer matched to the radially indenting third
indexing elements 30a-30d, reducing potential lateral play, and
instead ensuring a substantially well-defined rotational position
of the dental component 2 with respect to the dental fixture 4. It
should be understood that rather than making the second indexing
elements 60e-60g narrower than the first indexing elements 60a-60d,
an option would be to make them of equal width and instead make the
fourth indexing elements 30e-30g wider than the third indexing
elements 30a-30d. Thus, the relatively large lateral play between
the second and fourth indexing elements can be accomplished with
various designs of the dental component and/or dental fixture.
[0110] In FIG. 2, the second indexing elements 60e-60g have been
illustrated as extending all the way to the apical end of the body
part 40, however, other alternatives are conceivable. For instance,
the second indexing elements 60e-60g may extend somewhat shorter,
as long as the apical ends 62e-62g thereof are located apically of
the apical ends of the first indexing elements 60a-60d, or they may
extend longer, i.e. beyond the apical end of the body part (see
e.g. FIG. 3).
[0111] Furthermore, it should be noted that the coronal extension
of the second indexing elements 60e-60g may also be shorter. In
fact, it should be understood that, for the radially projecting
second indexing elements 60e-60g to fall into connection with the
radially indenting fourth indexing elements 30e-30g, the second
indexing elements 60e-60g could be designed as substantially flat
plates projecting from the surface of the fixture engagement
portion 46 of the body part 40. Once the flat plates are received
by the associated recesses 30e-30g, the whole body part 40,
including the following indexing elements 60a-60d (i.e. the other
radial projections which have the purpose to provide a rotational
lock) will be guided in the desired direction for completing the
insertion of the body part 40 into the dental fixture 4.
[0112] It should also be noted that, although second indexing
elements 60e-60g have been presented in FIG. 2 as the seventh
radial projection 60f and its two neighbouring radial projections
60e, 60g, other alternatives are possible. For instance, the
seventh radial projection 60f and a non-neighbouring projection
(such as projection 60a, 60b or 60c) could have their apical ends
located apically of the apical ends of the other radial
projections. These two radial projection would be leading and be
the first ones to abut the shelf 32 provided between the recesses
in the dental fixture 4. They can only fall down from the shelf
when the seventh radial projection 60f is aligned with the seventh
radial recess 30f. Thus, in general terms, according to at least
one example embodiment, the distribution of the second indexing
elements around the fixture engagement portion is asymmetrical
relative to the distribution of the first indexing elements. In
other words there is at least one pair of second indexing elements
(for instance corresponding to the illustrated positions of
60f/60g, or 60f/60a, or 60f/60b) spaced differently than the
spacing between any pair of first indexing elements.
[0113] FIG. 2 and FIG. 2C also illustrate another dental component
6 in the form of an abutment 6. It has six equally-dimensioned and
equidistantly distributed indexing elements in the form of radial
projections 70. Unlike the first abutment 2, this other abutment 6
lacks a seventh projection. Thus, this other abutment 6 may be
connected to the dental fixture 4 in six different rotational
orientations.
[0114] FIGS. 4A-4E illustrate schematically circumferential
distributions of first and second indexing elements on dental
components according to different example embodiments. Although not
viewable from the drawings, in each of these example embodiments
each one of the second indexing elements has an apical end located
apically of the apical ends of the first indexing elements.
[0115] In FIG. 4A, the dental component is provided with one first
indexing element 80 and two second indexing elements 81a, 81b. A
radius r.sub.1 from the central axis to the centre of said first
indexing element 80 and a radius r.sub.2 from the central axis to
the centre of one 81a of the second indexing elements form a first
angle .theta.. A radius r.sub.3 from the central axis to the centre
of the other one 81b of said second indexing elements and said
radius r.sub.1 from the central axis to the first indexing element
80 form a second angle .phi.. The second angle .phi. is different
from said first angle .theta. and any angle being a multiple of
said first angle .theta.. In other words, .phi..noteq.n.theta.,
where n is a positive integer. The dashed line illustrate the
contour of receiving indexing elements in the fixture. As can be
seen not all of the indexing elements in the fixture are occupied
by indexing elements of the dental component. Because of the
asymmetry, the dental component can only mate in one correct
rotational orientation with the fixture.
[0116] In connection with FIG. 4A, the following should be noted.
The angle .theta. defining the positions of the first indexing
element 80 and one 81a of the second indexing elements is
illustrated as being 180.degree.. Assuming a dental component would
be manufactured differently, with the position of the first
indexing element 80 and the position of the other one 81b of the
second indexing elements being switched, then the two second
indexing elements would have been located at 180.degree. with
respect to each other. If a dentist misplaces the dental component
by 90.degree., the two oppositely located second indexing elements
could enter receiving indexing elements in the fixture. However,
the first indexing element would land on a shelf. When the dentist
wishes to rotate the dental component to the correct position,
he/she will experience a non-smooth, intermittent motion. However,
the illustrated configuration in FIG. 4A, with the second indexing
elements 81a, 81b being asymmetrically arranged will make the
location finding process much smoother. Even if one of the second
indexing elements would catch into an incorrect indexing element in
the fixture, the other second indexing element will prevent it from
falling too deeply, since both of the second indexing elements 81a,
81b have an apical end located apically of the apical end of the
first indexing element 80.
[0117] In the embodiment of FIG. 4B, an additional second indexing
element 81c is provided, compared to the embodiment in FIG. 4A. The
three indexing elements 81a-81c makes the location finding even
smoother.
[0118] In the embodiment of FIG. 4C, the dental component is
provided with five first indexing elements 80a-80e and two second
indexing elements 81a, 81b. The five first indexing elements
80a-80e and one 81a of the second indexing elements are
equidistantly arranged at 60.degree. intervals. The other one 81b
of the second indexing elements is interposed and spaced at
30.degree. from its neighbouring indexing elements 80e, 81a. The
previously described first angle .theta. will, depending on which
one of the first indexing elements 80a-80e is selected as a
reference point, have a value of n*60.degree. in relation to one
81a of second indexing elements, where n=1, 2, 3, 4, 5. In FIG. 4C
the first indexing element 80b has been chosen (n=2), wherein the
first angle .theta.=120.degree. and the second angle
.phi.=150.degree..
[0119] In the embodiment of FIG. 4D, the dental component is
provided with two first indexing elements 80a, 80b and two second
indexing elements 81a, 81b. Unlike in the previous illustrations,
the two second indexing elements 81a, 81b are not neighboring to
each other in FIG. 4D. The first angle .theta.=90.degree. and the
second angle .phi.=225.degree.. Thus, the relationship
.phi..noteq.n.theta. is valid also for this example embodiment.
[0120] In FIG. 4E the distribution corresponds to that in FIG. 2,
thus four first indexing elements 80a-80d and three second indexing
elements 81a-81c. It is also similar to the distribution in FIG.
4C, with the exception that one of the first indexing elements has
now been replaced by a second indexing element. The second indexing
elements 81a-81c have a smaller dimension in the radial direction
than the first indexing elements 80a-80d. Thus, when placed in a
fixture having substantially uniformly recessed indexing elements,
there will be a larger play in the radial direction between the
second indexing elements 81a-81c and the walls of the mating
indexing element in the fixture than any play in the radial
direction between the first indexing elements 80a-80d and the walls
of their mating indexing elements. Once the correct rotational
position is found, the larger play facilitates insertion of the
second indexing elements 81a-81c into the mating recessed indexing
elements of the fixture.
[0121] FIG. 5 illustrates, in accordance with at least one example
embodiment, a dental component in the form of a driver 302 to be
connected to a dental fixture 304. In this example, the interface
between the dental fixture 304 and the driver 302 corresponds to
the interface between the dental fixture 4 and dental component 2
illustrated in FIG. 2. Thus, the driver 304 has three radial
projections (second indexing elements 360e-360g) having an apical
end 362e-362g located apically of the apical ends (only 362c, 362d
shown) of the other four radial projections (first indexing
elements 360c, 360d; only two out of four can be seen in the
perspective view shown in FIG. 5). The fixture has mating third and
fourth indexing elements, respectively (only one third indexing
element 330b and two fourth indexing elements 330f and 330g can be
seen in this view). Thus, similarly to the connection in FIG. 2,
the driver 302 can only be connected in one rotational orientation
relative to the fixture 304.
[0122] The driver 302 is used for rotatingly driving the fixture
304 into a bore hole in the jawbone. The driver may be designed as
a piece which can be used on its own, or alternatively, at its
coronal end, the driver may be designed to be connectible to a
handle, a wrench (such as a ratchet wrench), a power driver
machine, etc.
[0123] The driver 302 is provided with a visually distinctive
marking 380, herein illustrated as an axial line, aligned with the
middle second indexing element 360f at the fixture engagement
portion 346 of the driver 302. The distinctive marking 380 may have
a color which is different from the rest of the driver 302, it may
have different texture, or be slightly bulging, or any other
appropriate viewable distinction compared to the rest of the
driver.
[0124] The driver 302 can only be positioned in a single rotational
indexing position relative to the fixture 304, meaning that each
time the driver 302 engages such a fixture 304, the rotational
position of the distinctive marking 380 relative to the fixture 304
will always be the same. Thus, by viewing the axial line provided
by the marking 380, a user will be able to deduce the rotational
position of the fixture 304 in the jawbone. This allows
pre-planning and designing of the surgical and laboratory procedure
before a dental fixture 304 is even inserted into the bone. For
instance, a scan of the tooth-less site can be made, and a complete
patient-specific implant may be designed in which the abutment
should have a certain orientation relative to the fixture 304 and
relative to the surrounding tissue, and therefore the fixture 304
should have a certain orientation in the jawbone.
[0125] A driver, such as the driver 302 illustrated in FIG. 5, may
suitably be used with other dental fixtures. According to at least
one example embodiment, the driver adapted to be connected to a
dental fixture having a coronal end portion which is not flat. For
instance, the fixture may have a sloped coronal end portion, in
which the length of the fixture is greater on the lingual side than
on the buccal side in order to match the contour of the jawbone.
During installation of the fixture in the jawbone, the distinctive
marking of the driver will indicate to the dentist in which
direction the coronal end portion of the fixture is sloping, thus
allowing the dentist to make appropriate adjustments to correctly
align the slope of the fixture with the slope of the jawbone.
[0126] Although the drawings have illustrated dental components
provided with indexing elements in the form of radial projections
and dental fixtures with indexing elements in the form of radial
recesses, it should be understood that in other embodiments, the
indexing elements of the dental components may instead be radial
recesses and the indexing elements of the fixtures may be radial
projections.
[0127] Furthermore, although the drawings have illustrated that the
dental component as a male component having a fixture engagement
portion to be inserted into a socket of the fixture (acting as a
female component), other embodiments are also conceivable. For
instance, the fixture may have a summit portion, which may suitably
be adapted to extend beyond the bone crest, and apical end of the
dental component may be provided with an socket extending coronally
into the dental component, whereby the socket is intended to be
placed onto the summit portion. Radially projecting or indenting
indexing elements may be provided also for such a component/fixture
interface.
[0128] Although the indexing elements have been illustrated as
elongate radial projections and recesses, in other embodiments they
would not be elongate. Furthermore, the cross-section of the
indexing elements may be of any suitable shape, such as curved,
triangular, rectangular, trapezoid, or any other regular or
irregular shape.
[0129] It should also be noted that the number of indexing elements
in the dental component does not necessarily have to be equal to
the number of indexing elements in the dental fixture. For
instance, in FIG. 2, one of the radial projections forming a first
indexing element could be removed, although the effect of the
rotational lock will be somewhat weakened.
* * * * *