Note: Descriptions are shown in the official language in which they were submitted.
CA 02718783 2010-09-16
WO 2009/141801 PCT/IB2009/052141
1
Title: One-Piece Inclined Dental Implant
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to dental implants and, in particular, it
concerns a one-piece, inclined dental-implant configured for the optimal
exploitation of areas having relatively abundant bone structure as anchoring
regions
Common treatment methods of edentulous, atrophic bone patients
require either complicated bone augmentation procedures to construct an
anchoring structure for dental implants or insertion of dental implants at
angles
non-perpendicular to the crestal surface of alveolar process to exploit those
areas having relatively more ample supply of bone tissue. These angles of
inclination cause the abutment surface to be orientated in positions
unsuitable
for use with prosthetics or bridges. Generally, additional hardware is
attached
to the implant to provide a properly orientated abutment surface useful for
the
attachment of dental prosthetics and bridges.
However, such arrangements suffer from inevitable microbial
colonization along the line of connection between the abutment head and the
implant shaft thereby resulting in loss of biological width and consequent
bone
resorption.
CA 02718783 2010-09-16
WO 2009/141801 PCT/IB2009/052141
2
A second draw back of the above-described, two-piece implants relates
to inclined implantation limitations for which the abutment heads are able to
correct. The connection arrangement used to attach the abutment correction
hardware to the shaft limits abutment surface angles of inclination (relative
to
the longitudinal axis of the implant) to less than thirty degrees, thereby
limiting
the deployment of the implants specifically to areas requiring a corresponding
implant inclination.
US patent 5,362,236 discloses an angular, dental implant configured to
be anchored in the maxilla the zygomatic process. The shortcoming with this
implant is that its exceedingly long shaft makes it limited to use in the
maxilla
and zygomatic process.
There is, therefore, a need for a dental-implant configured to exploit
those areas of the mandible or the maxillae having sufficient anchoring
structure while preserving the biological width.
SUMMARY OF THE INVENTION
The present invention is a one-piece, inclined dental-implant and
corresponding method for exploiting areas of relatively abundant bone
structure as anchoring regions while preserving biological width and enhancing
implant recovery.
According to the teachings of the present invention there is provided, a
method for inclined implantation of one-piece dental implants into a crestal
surface of an alveolar process of a patient comprising: (a) drilling a bore
CA 02718783 2010-09-16
WO 2009/141801 PCT/IB2009/052141
3
into the crestal surface of the alveolar process at a angle non-perpendicular
to
the crestal surface, (b) inserting the dental implant into said bore, the
dental implant having: i. a threaded shaft not exceeding twenty-two
millimeters in length, and ii. an abutment surface on top of an abutment
head integrally formed with said shaft, said abutment surface being disposed
so
as to form an angle with said shaft so that when said shaft is implanted in an
inclined position within the alveolar process, said abutment surface is
disposed
in a substantially parallel position relative to the crestal surface, suitable
for
attachment of a dental prosthetic or an arch bridge, and (c) rotating said
implant until said implant advances into a final, implant position in which
said
abutment head is disposed in a position substantially parallel to the crestal
surface of the alveolar process, suitable for the attachment of a dental
prosthetic or an arch bridge.
According to a further feature of the present invention the shaft is
implemented as a first shaft-section integrally formed with a second-shaft
section, said second shaft-section having a diameter and said first shaft-
section
having a diameter changing as a function of increasing distance from said
abutment head such that the diameter of said first shaft-section progressively
decreases and then progressively increases to the diameter of said second
shaft-
section.
According to a further feature of the present invention the second shaft-
section is implanted as a tapered shaft decreasing in diameter as a function
of
increasing distance from said first shaft section.
CA 02718783 2010-09-16
WO 2009/141801 PCT/IB2009/052141
4
According to a further feature of the present invention the
abutment head is implemented with a lateral surface geometry having at least
one engagement surface for being engaged by an insertion tool having
corresponding inner socket geometry.
There is also provided according to the teaching of the present
invention a one-piece dental-implant for implantation non-perpendicular to a
crestal surface of an alveolar process of a patient comprising: a threaded
shaft
not exceeding twenty-two millimeters in length, and (b) an. abutment
surface on top of an abutment head integrally formed with said shaft, said
abutment surface being disposed so as to form an angle with said shaft so that
when said shaft is implanted in an inclined position within the alveolar
process,
said abutment surface is disposed in a substantially parallel position
relative to
the crestal surface of the alveolar process, suitable for attachment of a
dental
prosthetic or an arch bridge.
According to a further feature of the present invention the shaft is
implemented as a first shaft-section integrally formed with a second shaft-
section, said second shaft-section having a diameter and said first shaft-
section
having a diameter changing as a function of increasing distance from said
abutment head such that the diameter of said first shaft-section progressively
decreases and then progressively increases to the diameter of said second
shaft-
section.
CA 02718783 2010-09-16
WO 2009/141801 PCT/IB2009/052141
According to a further feature of the present invention the second shaft-
section is implanted as a tapered shaft decreasing in diameter as a function
of
increasing distance from said first shaft section.
According to a further feature of the present invention the abutment
5 head is implemented with. a lateral surface geometry having at least one
engagement surface for being engaged by an insertion tool having
corresponding inner socket geometry.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is herein described, by way of example only, with
reference to the accompanying drawings, wherein:
FIG. I is an isometric view of the dental-implant depicting the inclined
abutment surface and reduced diameter portion of the shaft.
FIG. 2 is schematic side view of the dental-implant of Figure 1.
FIG. 3 is a schematic, partial cross-sectional side view of the dental-
implant of Figure 1.
FIGS. 4 and 5 are isometric views of the dental-implant depicting the
inclined abutment surface and an engagement arrangement.
FIGS. 6 and 7 are schematic cross-sectional views of the dental implants
implanted in alveolar processes of lower and upper jawbones, respectively.
CA 02718783 2010-09-16
WO 2009/141801 PCT/IB2009/052141
6
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is a one-piece, inclined dental-implant and a
corresponding method for exploiting areas of relatively abundant bone
structure as anchoring regions while preserving biological width and enhancing
implant recovery. The principles, methods and operation according to the
present invention may be better understood with reference to the drawings and
the accompanying description. It should be noted that the term "alveolar
process" appearing throughout this document refers to the process found on the
mandible and the maxillae.
Figures 1 and 2 depict a one-piece dental-implant designated generally
1, which includes abutment head 2, and threaded shaft 3. Threaded shaft 3
includes a first shaft-section 4, a second shaft-section 5 and self tapping
recess
6. Abutment head 1 includes abutment surfaces 7, and threaded connection
arrangement 10. Abutment surface 7 is a surface or a collection of surfaces
disposed on the uppermost portion of abutment head 2 and provides the
supporting structure for attached dental prosthetics or bridges structures as
will
be discussed later in this document. For the purposes of convenience, the
present document refers to the totality of annular abutment surfaces disposed
at
different heights in the non-limiting, preferred embodiment disclosed herewith
as an "abutment surface". It should be noted however that any abutment
surface 7 disposed on abutment head 2 in a manner so as to form a non-
perpendicular angle with longitudinal shaft axis 9, as is most clearly visible
in
Figure 3, is included within the scope of the current invention. As mentioned
CA 02718783 2010-09-16
WO 2009/141801 PCT/IB2009/052141
7
above, implant 1 is configured to be anchored in an area of the alveolar
process
having a sufficient anchoring structure adjacent to a region of inadequate
anchoring structure in vertical alignment with the point of implant insertion.
The prosthetic or bridge structure requires abutment surface 7 to be disposed
substantially parallel with the crestal surface of alveolar process. The
abutment
surface angle-of-inclination, as shown in Figure 3 designation 8, serves as a
built-in, corrective feature for devices implanted at angles non-perpendicular
to
the crestal surface of the alveolar process. Implant I is constructed in
accordance to the needs of the patient, so that angle-of-inclination of
abutment
surface 7 matches the prescribed implant inclination; consequently
implantation abutment surface 7 is disposed substantially parallel with the
crestal surface of alveolar process. A dental prosthetic attached to such an
abutment will then be in alignment with the natural dentition without the use
of
additional correction hardware. Furthermore, the absence of correction
hardware enables the implants to be constructed with relatively large abutment
surface angles thereby enabling corresponding large implantation inclinations;
i.e. exceeding 45 degrees. Consequently, the implants may be employed in a
large range of locations according to the patient's needs. It should be noted
that
in certain non-limiting, exemplary embodiments, abutment surface 7 is
disposed on the abutment head 2 so as to form an angle of inclination 8 with
longitudinal axis 9 of 17 degrees, 30 degrees, and in certain cases, 45
degrees.
It should be noted; however, that angles of inclination 8 ranging from one to
ninety degrees relative to longitudinal axis 9 are within the scope of the
current
CA 02718783 2010-09-16
WO 2009/141801 PCT/IB2009/052141
8
invention. Furthermore, angle of inclinations 8 advantageously enables the
usage of bridge structures to be attached to a plurality of implants 1 having
a
total implant inclination between two adjacent implants ranging from 0-180
degrees; figure 7 depicts implants I whose collective implant inclination is
80
degrees.
Threaded attachment arrangement 10 is implemented in a non-limiting,
preferred arrangement as a bore disposed in the center of abutment head 2 as
shown in Figures 1, 3 and 4. It should be appreciated that a bored frustum
structure or any other single screw connection arrangement for dental
prosthetics or bridges are within the scope of the current invention.
Abutment head 2 is integrally formed with shaft 3, and more specifically
with first shaft-section 4. This integral connection between the abutment head
and first shaft-section 4 advantageously eliminates surface irregularities
characteristic of joints that inevitably serve as a haven for microbial.
colonization leading to biological width reduction and eventual bone
resorption
as mentioned above. The single piece construction advantageously adds
strength to dental implant I and simplifies procedures involved in
implantation
by eliminating the need to connect additional hardware used to provide a
useful
abutment surface for the connection of dental prosthetics and bridges. First
shaft-section 4 is implemented in a non-limiting, preferred embodiment as a
progressively changing diameter as a function of increasing distance from
abutment head 2 such that the diameter of the first shaft-section is at a
maximum at the juncture point with abutment head 2, progressively decreases
CA 02718783 2010-09-16
WO 2009/141801 PCT/IB2009/052141
9
and then progressively increases until it reaches its maximum diameter at the
juncture point with the second shaft-section 5 as shown in Figures 1 and 2.
This
shaft configuration advantageously facilities blood flow and regeneration of
connective tissue thereby enhancing recovery after implant surgery. It should
be appreciate that any shaft configuration a progressively increasing a
progressively decreasing diameter is within the scope of the current
invention.
providing the In a non-limiting, preferred embodiment, second shaft-section 5
is implemented as a tapered shaft narrowing in diameter as a function of
increasing distance from first shaft-section 4 and includes self tapping
recess 6
disposed in the distal end of second shaft-section 5 to facilitate self
tapping as
implant 1 advances through a bore drilled into the patient's alveolar process.
In
a non-limiting, exemplary embodiment, the degree of taper ranges from one to
three degrees. It should be noted that a second shaft-section having a
constant
diameter throughout its length is also included within the scope of the
current
invention. In a non-limiting, preferred embodiment first shaft-section 4
ranges
in diameter from 2.0-5.0 millimeters (including threading heights) at the
widest
diameter whereas the widest diameter of the shaft 3 ranges between 2.5-6.0
millimeters
Figures 4 and 5 depict an additional feature relating to the insertion and
removal of implant 1 from the upper and lower jawbones by way of an
insertion tool (not-shown). Abutment head 2 has a lateral surface geometry
including curved surface 12 and a planar surface 11 that collectively form a
an
engagement structure suited for receiving a torque applied by an insertion
tool
CA 02718783 2010-09-16
WO 2009/141801 PCT/IB2009/052141
having a socket with a corresponding, inner-surface geometry. Lateral
insertion configurations advantageously eliminate the danger of deforming
abutment surface 7 or connection arrangements 10 disposed within the
boundaries of abutment head 2 when applying a torque during insertion or
5 removal of implant 1. It should be noted that any combination of lateral
surface geometries configured to be engaged by a torque directing device is
within the scope of the current invention.
In a preferred, unlimited embodiment, the implants are constructed from
titanium or any other material having the b io -compatibility and strength
10 associated with titanium. Furthermore, it should be noted that single,
double,
or multiple threading are included in the scope of the current invention.
Thread
and taper dimensions are those employed by practitioners skilled in the art.
In
a non-limiting, preferred embodiment, the length of entire implant 1, from the
uppermost portion of abutment head 2 to the distal portion of shaft 3 does not
exceed twenty millimeters, of which shaft 3 is about 15 millimeters.
Dental implant 1 is implanted by drilling a bore of a diameter
appropriate for the implant of choice into the alveolar process at an angle of
inclination leading into a region of relatively abundant bone structure as
shown
in Figures 6 and 7. The self tapping shaft 3 advances through the bore as
implant 1 is rotated by way of the insertion tool (not shown) until implant 1
is
disposed in the desired anchoring regions where it is held firmly in place. As
mentioned above, when implant 1 is positioned in its final implant position,
abutment surface 7 is disposed in a position substantially parallel to the
crestal
CA 02718783 2010-09-16
WO 2009/141801 PCT/IB2009/052141
11
surface of the alveolar process in preparation of connection of a dental
prosthetic or bridge structure.
It will be appreciated that the above descriptions are intended only to
serve as examples, and that many other embodiments are possible within the
scope of the present invention as defined in the appended claims.
