U.S. patent application number 10/732542 was filed with the patent office on 2004-06-24 for method and apparatus for replicating the position of intra-osseous implants and abutments relative to analogs thereof.
Invention is credited to Morgan, Vincent J..
Application Number | 20040121288 10/732542 |
Document ID | / |
Family ID | 27804237 |
Filed Date | 2004-06-24 |
United States Patent
Application |
20040121288 |
Kind Code |
A1 |
Morgan, Vincent J. |
June 24, 2004 |
Method and apparatus for replicating the position of intra-osseous
implants and abutments relative to analogs thereof
Abstract
The position of intra-osseous implants and abutments to analogs
is enabled and enhanced by using the longitudinal axial locked
position of a post (12a) of an implant (12) having a locking taper
in a bore (10a) of an implant (10) having a generally matching
locking taper as a reference to determine the position of a stop
surface (14c) on impression posts, abutment analog posts and the
like received in the bore of an implant and implant analog. In
another embodiment the bore (16) of an implant analog (16) is
provided with a shelf (16c) located at a position determined by the
axial distance of the locked position of the abutment post to
prevent over-seating. Controlled retentive resistance and stability
of a post is provided by using flats formed in the bore of an
implant analog and by forming rings on a post receivable in the
bore of an implant or implant analog. One such ring (18c) is formed
with an outer periphery sized and configured to allow bending of
the outer peripheral portion in a direction opposite to the
direction of insertion in a bore to provide greater retentive
resistance than insertion resistance.
Inventors: |
Morgan, Vincent J.; (Boston,
MA) |
Correspondence
Address: |
John A. Haug
P.O. Box 386
West Harwich
MA
02671
US
|
Family ID: |
27804237 |
Appl. No.: |
10/732542 |
Filed: |
December 11, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10732542 |
Dec 11, 2003 |
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10093991 |
Mar 7, 2002 |
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6688887 |
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60274498 |
Mar 9, 2001 |
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Current U.S.
Class: |
433/173 |
Current CPC
Class: |
A61C 8/0001
20130101 |
Class at
Publication: |
433/173 |
International
Class: |
A61C 008/00 |
Claims
What is claimed:
1. In an implant system having an implant for placement in an
osteotomy of a patient, the implant having an inner end for
placement in the inner part of the osteotomy and an outer end
having a surface, an abutment receiving bore extending through the
surface of the outer end of the implant, the bore formed with a
locking taper for receipt of the post of an abutment having a
generally matching locking taper, the abutment post and the bore
having a longitudinal axis and the abutment being seated at a first
axial position in the bore upon use of first relatively low
insertion pressure and a second further locked axial position in
the bore upon use of a second relatively higher clinical insertion
force, the bore extending beyond the post of the abutment post in
the second locked position, the method of replicating the relative
position of an intra-osseous implant and abutment in a laboratory
analog comprising the steps of taking an analog implant member and
forming a bore through the surface thereof, the bore having
generally the same diameter as the bore of the implant, and forming
a shelf at a depth selected to be essentially equal to the distance
of the second axial position of the bore of the implant from the
surface of the outer end of the implant so that a post inserted in
the bore of the implant analog member will be limited to a position
corresponding to the second locked position of the abutment in the
implant.
2. The method of claim 1 further comprising the step of mitigating
the build up of hydraulic pressure in the bore as a post is
inserted in the bore of the implant analog member.
3. The method of claim 2 in which mitigation of the build up of
hydraulic pressure is effected by extending the bore beyond the
shelf.
4. The method of claim 1 in which the implant analog member is
formed of suitable non-metal material.
5. The method of claim 1 in which the implant analog member is
formed of suitable metallic material.
6. The method of claim 4 in which the material for the implant
analog member is selected from the group consisting of
polycarbonate and ultra high molecular weight polyethylene.
7. The method of claim 1 further comprising the step of increasing
retentive resistance and stability of a post received in the bore
of the implant analog member.
8. The method of claim 7 in which retentive resistance and
stability of a post received in the bore is increased by forming
the bore as a cylinder where at least one flat surface is formed in
the bore.
9. In an implant system having an implant for placement in an
osteotomy of a patient, the implant having an inner end for
placement in the inner part of the osteotomy and an outer end
having a surface, an abutment receiving bore extending through the
surface of the outer end of the implant, the bore formed with a
locking taper for receipt of the post of an abutment having a
generally matching locking taper, the abutment post and the bore
having a longitudinal axis and the abutment being seated at a first
axial position in the bore upon use of a first relatively low
insertion pressure and a second further locked axial position in
the bore upon use of a second relatively higher clinical insertion
force, the bore extending beyond the post of the abutment post in
the second locked position, the method of replicating the relative
position of an intra-osseous implant and abutment in a laboratory
analog comprising the steps of taking a member formed with a
generally cylindrical post having a longitudinal axis and being
closely receivable in non-locking relationship in the bore of one
of an implant and an implant analog, each having a generally
cylindrical post receiving bore of a selected diameter, forming a
stop surface on the post extending radially outwardly therefrom
beyond the selected diameter to limit insertion of the post into
the bore of one of the implant and the implant analog, forming an
index configuration on the member at a distance along the
longitudinal axis from the stop surface essentially equal to the
distance between an index configuration on an implant abutment and
the surface of the outer end of the implant when the implant
abutment is in the second locked position in the implant.
10. The method of claim 9 further comprising the step of increasing
the retentive resistance and stability of the post received in the
bore of an implant and an implant analog.
11. The method of claim 9 in which retentive resistance of the post
received in the bore of an implant analog is increased by forming
at least one ring around the circumference of the post having an
outer diameter slightly greater than the bore of the implant and
the analog implant.
12. The method of claim 11 in which the said at least one ring has
an outer periphery which is configured so that it will bend in a
direction opposite to the direction of insertion thereby requiring
greater force in removing the post from the bore than is required
for inserting the post into the bore.
13. The method of claim 9 in which the member is formed of
non-metal.
14. In an implant system having an implant for placement in an
osteotomy of a patient, the implant having an inner end for
placement in the inner part of the osteotomy and an outer end
having a surface, an abutment receiving bore extending through the
surface of the outer end of the implant, the bore formed with a
locking taper for receipt of the post of an abutment having a
generally matching locking taper, the abutment post and the bore
having a longitudinal axis and the abutment being seated at a first
axial position in the bore upon use of first relatively low
insertion pressure and a second further locked axial position in
the bore upon use of a second relatively higher clinical insertion
force, the bore extending beyond the post of the abutment post in
the second locked position, the method comprising the step of
taking an elongated member having a distal free end and a periphery
selected to be freely insertable into the bore of an implant and
forming spaced apart indicator configurations on the elongated
member at a distance from the distal free end essentially equal to
the distance from the bottom of a bore of an implant and a given
reference point of an abutment when it is seated in the implant in
the second locked position.
15. A post for placement in the bore of one of an implant and an
implant analog comprising a generally cylindrical end portion
having a selected diameter and having at least one
circumferentially extending ring having a diameter greater than the
selected diameter.
16. A post according to claim 15 comprising first and second spaced
apart rings, each having a diameter greater than the selected
diameter.
17. A post according to claim 15 in which the post has a free end
and the first ring is closest to the free end of the post and the
second ring has a greater diameter than the first ring.
18. A post according to claim 15 in which the material of the post
is selected from the group consisting of polycarbonate and ultra
high molecular weight polyethylene.
19. A post according to claim 15 in which the post is composed of
non-metal.
20. A post according to claim 15 in which the at least one ring has
an outer periphery configured so that upon insertion in the bore
the outer periphery will bend in a direction opposite to the
direction of insertion.
Description
RELATED APPLICATIONS
[0001] Benefit is claimed of provisional application 60/274,498
filed Mar. 9, 2001.
FIELD OF THE INVENTION
[0002] This invention relates generally to medical and dental
implant devices and more particularly to a method for transferring
the relative position of an intra-osseous implant relative to a
laboratory replicated position, as in a dental abutment, and for
determining the appropriate height of a dental abutment received in
an implant for an aesthetic submucosal prosthetic margin
placement.
BACKGROUND OF THE INVENTION
[0003] Implant systems comprising an implant having a tapered bore
adapted to receive therein an abutment post or the like formed with
a matching taper for retention of the post in the implant are
known. See for example U.S. Pat. No. 4,738,623, assigned to the
assignee of the present invention, the disclosure of which is
incorporated herein by this reference. It is also known to provide
such posts, which are intended to be used as impression posts or
temporary abutment posts, with a longitudinally extending slot in
the end thereof in order to more easily remove the posts.
Generally, such posts are made of titanium or titanium alloy due to
their biocompatibility characteristics. However, titanium has a
major limitation relating to the phenomenon of memory. It is
possible for the diameter of the slotted post to either widen or
narrow over time making the nature of the fit of the post in an
abutment unpredictable. The property of memory can cause an
abutment to become loose in clinical function and result in an
unpredictable degree of retention.
[0004] There is a need to be able to replicate the position that an
abutment would have in an implant in a system using abutment
analogs, impression posts and the like made of the same or
different materials which accurately and reliably correspond to the
locked position of a permanent abutment in an intra-osseous
implant. Among the factors which need to be dealt with in doing
this is the existence of hydraulic pressure resisting the seating
of a post as well as the need for having the post retain its seated
position whether gravity is adding a force against seating or
toward seating, as in the use in upper teeth versus lower teeth.
There is also a need to be able to determine the appropriate height
of an abutment which will provide an aesthetic submucosal
prosthetic margin placement.
SUMMARY OF THE INVENTION
[0005] It is an object of the invention to overcome the prior art
limitations noted above. Another object of the invention is the
provision of an impression post and any other post, such as a
temporary abutment post, wherein a clinician will want to remove
the post with minimal, predictable effort.
[0006] Briefly, in accordance with one embodiment of the invention,
the post of a member, such as an abutment analog, impression post,
implant transport handler, healing plug and the like, is formed
with a radially outwardly extending stop surface such as a shelf
having a diameter larger than the diameter of the bore in a
permanent implant and an implant analog and located at a distance
from the longitudinal axial position of a reference location of a
head formed on the post essentially equal to the distance from the
top end surface of a permanent implant to a corresponding reference
location of a head of an abutment with the abutment in a clinically
locked position as a result of being tapped into the implant.
[0007] According to another embodiment, an implant analog is formed
with a shelf in the bore of the implant analog located at a
distance from the mouth of the bore, i.e., the top surface of the
implant analog, essentially equal to the distance between the
bottom end face of the tapered post of a permanent abutment and the
longitudinal axial position on the tapered post at the top face
surface of the permanent implant with the permanent abutment in the
locked position upon receiving clinical tapping insertion force.
The shelf prevents a tapered permanent abutment post from
over-seating in an implant analog, which is particularly important
when the implant analog is composed of plastic material. According
to a feature of the invention, the cylindrical bore of the implant
analog can be provided with one or more flats to increase the
retention resistance of a cylindrical post, with or without a
taper, received therein as well as to provide an axially extending
air passage to relieve or prevent the build up of hydraulic
pressure in the closed end of the bore.
[0008] According to a feature of the invention, retentive
resistance of the post of the abutment analog, impression post,
implant transport handler, healing plug and the like can be
increased by forming one or more circumferential rings about the
posts, at least one of the rings having an outer diameter larger
than the diameter of an implant to form an interference fit and
preferably, the at least one ring being flexible and having a
feathered, or otherwise shaped configuration so that upon being
inserted into the bore of the implant the outer peripheral portion
of that ring will bend in a direction opposite to the direction of
insertion so that upon removal of the post the outer peripheral
portion of the ring will have to bend back on itself thereby
requiring a greater removal force than insertion force.
[0009] According to yet another embodiment of the invention, an
elongated probe member having a size to be freely insertable in the
bore of an implant is formed with a plurality of axially positioned
index configurations, such as circumferential grooves, located in
the probe member at selected distances from the free distal end of
the probe member corresponding to the position of given reference
locations of a clinically seated abutment in the implant. The index
configurations indicate the axial position of a given geometry of
the implant bore as a reference point so that the appropriate
height of an abutment shoulder can be determined to achieve an
aesthetic submucosal prosthetic margin placement.
[0010] Additional objects and features of the invention will be set
forth in part in the description which follows and in part will be
obvious from the description and drawings. The objects and
advantages of the invention may be realized and attained by means
of the instrumentalities, combinations and methods particularly
pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate preferred
embodiments of the invention and, together with the description,
serve to explain the objects, advantages and principles of the
invention. In the drawings:
[0012] FIGS. 1a, 1b are cross sectional views which show a prior
art arrangement of an abutment received in the bore of an implant
using a first level of pressure, such as finger pressure and a
second level of pressure, such as by clinically applied tapping, to
a locked position in the bore, respectively; FIGS. 1c, 1d are
similar cross sectional views which show an impression post made in
accordance with a first embodiment of the invention, partially
received in the bore of an implant and fully seated therein,
respectively; FIGS. 1e, 1f are similar cross sectional views which
show an impression post partially received in the bore of an
implant analog made in accordance with another embodiment of the
invention and fully seated therein; and FIGS. 1g, 1h are similar
cross sectional views which show an abutment partially received in
the bore of the implant analog of FIGS. 1e, 1f and fully seated
therein, respectively;
[0013] FIG. 2 is an elevational view of an impression post made in
accordance with another embodiment of the invention and FIG. 2a is
an enlarged, broken away portion of FIG. 2; and
[0014] FIG. 3a is a cross section view taken through an
intra-osseous mounted implant with an indicator probe made in
accordance with the invention received in the bore of the implant,
and FIG. 3b is a view similar to FIG. 3a but showing an abutment
received in the bore of the implant at an apical position related
to index configurations of the indicator probe.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] With reference to FIGS. 1a, 1b, a conventional implant 10 is
shown having a well or bore 10a formed with a female locking taper
as disclosed in detail in U.S. Pat. No. 4,738,623 referenced above.
Dashed line 2 extends through the top end surface 10b of the
implant shown in FIGS. 1a-1d and the top end surface 16b of the
implant analogs shown in FIGS. 1e-1h to be discussed. Dashed lines
4 and 6 show the same reference distances from dashed line 2 in the
respective figures. The post 12a of an abutment 12, also provided
with a male locking taper, is received in bore 10a at a first
apical position relative to the top end surface 10b of the implant
when a first lower pressure level is used to place the implant, as
by finger pressure. Dashed line 2 aligned with the top end surface
10b denotes the axial position of post 12a in the first, partially
seated position at a distance d1 measured along the longitudinal
axis of post 12a and bore 10a from a reference point of the
abutment, e.g., the lower end of basal portion 12c of head 12b.
Abutment 12 is shown with a head 12b including curved basal portion
12c and shoulder 12d for receiving thereon a suitable crown or the
like, not shown. FIG. 1b includes the same implant and abutment but
is shown with the abutment post after being seated in a second
locked position as by tapping the abutment with a clinically
applied tapping force. In the fully seated second position the
axially measured distance between dashed line 2 and the same
reference point is d2. The change in the apical positions of FIGS.
1a and 1b has been shown to be 0.006 inch for 0.0785 inch diameter
post and 0.010 inch for 0.1185 inch diameter post systems having a
locking taper of 1.5 degrees and received in respective bores of
0.0785 inch and 0.1185 inch having a matching locking taper. The
distance d2 is the average distance which was determined by taking
a group of abutments for each diameter post and measuring the
individual d2 distance for each abutment upon clinical seating
thereof. The distance is essentially equal from one abutment to
another of a group within manufacturing tolerances and with little
or no difference noted for any variations of clinical insertion
force used.
[0016] In accordance with a preferred embodiment of the invention,
a radial, outwardly extending shoulder 14c is formed on post 14a of
impression post 14 at an axial distance d2 from a reference point
14f corresponding to the reference point 12f of the abutment shown
in FIGS. 1a, 1b. The outer portion of post 14a is preferably formed
with no taper and with a diameter to permit full insertion into the
tapered bore of implant 10. The provision of shoulder 14c, chosen
to have an outer diameter greater than the opening of bore 10a,
results in placement of head portion 14b in essentially the same
position in implant 10 as head 12b of abutment 12 in implant 10. A
reference configuration, e.g., circumferential groove 14g of post
14 can be used to reflect the position of top end face 12e of an
abutment as noted by dashed line 6. Although an impression post
member is shown in the drawings, it will be understood that
shoulder 14c can be provided on the post of other members such as
abutment analogs, healing plugs and the like for receipt in the
bore of an implant to obtain the same benefits. Further, it should
be realized that shoulder 14c can be discontinuous or formed as
spaced apart stop surfaces, if desired.
[0017] Referring to FIGS. 1e-1h, an implant analog 16 made in
accordance with another embodiment of the invention comprises a
body made of polycarbonate or other suitable plastic such as ultra
high molecular weight polyethylene (UHMW-PE), or a composite,
ceramic or metal and is shown having a bore 16a of generally the
same diameter as bore 10a of implant 10 however the bore may have a
straight bore if desired. Bore 16a is formed with a shelf 16c
formed at a depth or axial distance from the end face surface 16b
of the implant analog which is essentially the same as the distance
between dashed lines 2 and 4, that is, the axial distance from the
top end surface 10b of implant 10 and the bottom end face surface
12g of abutment 12 when in the second, fully seated locked position
of FIG. 1b. Placement of shelf 16c in this position limits travel
of an abutment post when inserted into bore 16a as shown in FIG. 1h
and prevents over-seating of an abutment having no shoulder on the
post thereof for that purpose. Bore 16a preferably extends beyond
shelf 16 as indicated at 16d to minimize the effects of hydraulic
pressure build up as a post is inserted in the bore. Preferably the
axial distance of post 14a of impression post 14 from shoulder 14c
to end face surface 14h of the post is selected to be slightly less
than the distance of post 12a of abutment 12 from an axial location
at dashed line 2 in FIG. 1b indicating a clinically seated abutment
and end face surface 12g of the abutment to ensure that shoulder
14c limits travel as it engages top end surface 16b of implant
analog 16.
[0018] Typically, implants 10 and abutments 12 are composed of
titanium or titanium alloys for biocompatibility while the implant
analogs and impression posts and the like are composed of plastic
such as polycarbonate and ultra high molecular weight polyethylene
(UHMW-PE), composites or other suitable materials. This results in
a problem in simulating the locking taper of the titanium implants
and abutments when using a different material for the abutment
analog or impression post and when using them without a locking
taper. That is, the problem of achieving the same axial
displacement without the same retention and in achieving the same
lateral stability of the posts from one female bore to another.
According to a modified embodiment of the invention, one or more
flat surfaces 16e (FIG. 1e) is formed in bore 16a of implant analog
16 to form a limited interference with a generally cylindrical post
to increase retentive force and stability of a post received
therein. Usually, a plurality of flats, preferably symmetrically
spaced about the periphery of the bore, are formed to provide
consistent placement of a post in the bore of an implant analog
relative to the bore of an implant. Such flats also provide an
axially extending air passage to allow air to escape as a post is
being inserted in the bore and thereby minimize hydraulic pressure
build up.
[0019] FIGS. 2 and 2a show an impression post 18 made in accordance
with another preferred embodiment of the invention which is formed
of suitable material which in thin configurations has a degree of
flexibility, such as some plastic materials, e.g., polycarbonate or
ultra high molecular weight polyethylene (UHMW-PE), and formed with
circumferentially extending rings or rib like formations 18b, 18c
on the portion of post 18a receivable in the bore of an implant or
implant analog. Post 18a is cylindrical and can be formed with or
without a taper. At least one of the rings is formed to provide an
interference fit. Ring 18b is used in cooperation with ring 18c to
provide enhanced lateral stability in a bore. Ring 18c has a
slightly larger diameter than ring 18b to form an interference fit
and is somewhat feathered at its outer periphery or otherwise
configured to allow it to be bent in a direction toward or away
from the distal free end of the post. When used in a properly sized
bore with or without a locking taper, the material of ring 18c is
bent upon insertion of the post into such a bore in a direction
opposite to the direction of insertion with the outer portion of
the ring material being closer to the entrance to the bore than the
remainder of the ring. When the post is then removed the outer
portion bends back in the opposite direction, that is, in effect,
it is folded back on itself into an ogee type of configuration, due
to the limited space available, with the base of the ring or rib
like formation gradually advancing to the position of the outer
portions and finally assuming a position with the base portion
being closer to the entrance of the bore than the outer portion.
This reverse bending increases the retentive force for removal, in
a manner predictably controlled by the material and dimensions of
the rings relative to the bore. As a result of this, the force
required to remove the post from such a bore is greater than the
force required to insert the post into the bore. It will be
understood that ring 18c can be used by itself, if desired, to
provide a retention resistance greater than an insertion resistance
for a post. Likewise, ring 18b can be used by itself to provide
lateral stability as well as retention resistance with the ring
having a tight fit or an interference fit, as desired. It will also
be understood that rings as described above can be provided on the
posts of other members receivable in the well of an implant
abutment, e.g., an abutment analog.
[0020] Impression posts were made in accordance with the invention
having a nominal post diameter of 0.113/0.112 inch for a 0.1185
inch diameter bore and provided with first and second spaced apart,
circumferentially extending, rings or rib like formations. The
first ring, closest to the free end of the post has an outer
diameter of 0.116/0.115 inch and the second ring has an outer
diameter of 0.119/0.118 inch. Members having another post size were
made having a nominal post diameter of 0.073/0.072 inch for a
0.0785 inch diameter bore, the first ring has a diameter of
0.076/0.077 inch and the second ring has a diameter of
0.079/0.080.
[0021] With reference to FIGS. 3a and 3b, a generally elongated
indicator probe 20 comprises a head portion 20a formed with an
outer periphery of a size selected to be freely received in the
bore of an implant 10 with the distal free end engaging the bottom
wall of the bore. Implant 10 is shown in the drawings implanted in
the bone of a patient. Horizontally extending, spaced apart index
points or configurations 20c are formed on the probe body at
locations corresponding to the axial positions of reference points
or configurations of an abutment 12 (FIG. 3b) to be clinically
seated in the implant. For example, a longitudinal axial distance
d3 from the bottom surface of the bore of implant 10, represented
by dashed line 8, to shoulder 12d of abutment 12, represented by
dashed line 9, clinically seated in the second locked position in
the implant as shown and described in FIG. 1b, is essentially the
same as the axial longitudinal distance d3 from the distal end
surface 20b to index configuration 20c of probe 20 when bottomed
out in the bore of implant 10 of FIG. 3a. Thus probe 20, when
seated in the bore of an intra-osseous implant will indicate the
axial position of various geometries on posts inserted into the
implant relative to the height of soft tissues overlying the
implant by index configurations 20c-20g.
[0022] Axial adjustment is essential for the fabrication of
integrated abutment crowns, i.e., prefabricated or custom crowns
mounted, bonded or fabricated on abutments extra-orally, where the
proper anatomical relationships and adjustments needed to obtain
them are greatly enhanced and facilitated by means of the above
described features of the invention.
[0023] Although the invention has been described with regard to a
certain specific embodiment thereof, variations and modifications
will become apparent to those skilled in the art. For example,
although the post is described as generally cylindrical, it is
within the skill of the art to use any selected outer
configuration, such as elliptical, if desired, in conjunction with
rib like formations extending around the circumference as taught by
the invention. It is, therefore, the intention that the appended
claims be interpreted as broadly as possible in view of the prior
art to include all such variations and modifications.
* * * * *