U.S. patent number 3,919,772 [Application Number 05/366,853] was granted by the patent office on 1975-11-18 for dental implant assembly and method for attaching the same to the jaw bone.
Invention is credited to Joseph J. Lenczycki.
United States Patent |
3,919,772 |
Lenczycki |
November 18, 1975 |
Dental implant assembly and method for attaching the same to the
jaw bone
Abstract
A dental implant assembly consists of one or more planar members
adapted to be introduced into complementary cavities or slots
formed in the jaw bone. Threaded fasteners are disposed through
holes in the jaw bone and oriented in directions generally normal
to the planar members. Threaded apertures are provided in the
planar members which are engageable with the threaded fasteners for
immobilizing the planar members within the cavities relative to the
jaw bone. At least one of the fasteners includes a support portion
which projects exteriorly of the jaw bone when the planar members
and the fasteners are in engagement. The support portion is adapted
to support a dental prosthetic device in fixed relation to the jaw
bone during engagement. A dental jig for accurately drilling the
holes in a jaw bone which receive the fasteners is described. The
method of inserting a planar dental implant assembly member into a
jaw bone includes cutting in the jaw bone a slot complementary to
the planar member and drilling holes in the jaw bone between the
alveolar crest and the slot under the guidance of the apertures in
the jig. The planar member is inserted into the complementary slot
and screws are introduced through the holes drilled in the jaw bone
and engage threaded apertures provided in the planar member. At
least one exposed portion associated with the threaded screws is
retained exposed which is adapted to support a prosthetic device. A
jig is also described for forming two slots essentially aligned in
a common plane and disposed in opposite lingual sides of the jaw
bone.
Inventors: |
Lenczycki; Joseph J.
(Riverside, CT) |
Family
ID: |
23444843 |
Appl.
No.: |
05/366,853 |
Filed: |
June 4, 1973 |
Current U.S.
Class: |
433/173;
606/96 |
Current CPC
Class: |
A61C
8/001 (20130101); A61C 1/084 (20130101) |
Current International
Class: |
A61C
8/00 (20060101); A61C 1/08 (20060101); A61C
013/00 () |
Field of
Search: |
;32/1A,14A ;128/92C,92D
;3/1 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Implant Research Corp. Publication, Oct. 1968, "Significant New
Concept in Endosseous Implantology"..
|
Primary Examiner: Peshock; Robert
Assistant Examiner: Lever; J. Q.
Attorney, Agent or Firm: Friedman & Goodman
Claims
What is claimed is:
1. Dental implant assembly for maintaining a dental prosthetic
device in fixed relation with respect to a jaw bone, the implant
assembly comprising a planar member adapted to be introduced into a
blind generally transverse complementary cavity formed in the jaw
bone without extending exteriorly therefrom; and securing means
engageable through a bore substantially normal to the cavity with
said planar member for immobilizing the latter within the cavity
relative to the jaw bone, a portion of said securing means
including support means projecting exteriorly of the jaw bone when
said planar member and said securing means are in engagement, said
support means being adapted to support a dental prosthetic device
in fixed relation to the jaw bone during such engagement, said
planar member comprising a flat plate having at least one threaded
aperture therethrough, said securing means comprising a threaded
fastener configurated to pass through a hole drilled in the jaw
bone and engageable with said threaded aperture, three threaded
apertures being provided in said flat plate, and three threaded
screws being provided each of which being engageable with a
respective one of said threaded apertures subsequent to passage
through holes drilled in the jaw bone.
2. Dental implant assembly for maintaining a dental prosthetic
device in fixed relation with respect to a jaw bone, the implant
assembly comprising a planar member adapted to be introduced into a
blind generally transverse complementary cavity formed in the jaw
bone without extending exteriorly therefrom; and securing means
engageable through a bore substantially normal to the cavity with
said planar member for immobilizing the latter within the cavity
relative to the jaw bone, a portion of said securing means
including support means projecting exteriorly of the jaw bone when
said planar member and said securing means are in engagement, said
support means being adapted to support a dental prosthetic device
in fixed relation to the jaw bone during such engagement, a
gripping portion detachably connected to said planar member, said
gripping portion being integrally constructed with said planar
member and meeting the latter at a weakened line portion.
3. Dental implant assembly as defined in claim 2, wherein a stub
remains on said planar member when said gripping portion is removed
from said planar member at said weakened line portion, both said
planar member and said stub being configurated to be fully
receivable in the cavity without protruding exteriorly of the
latter.
4. Dental implant assembly for maintaining a dental prosthetic
device in fixed relation with respect to a jaw bone, the implant
assembly comprising two spaced and substantially parallel planar
members connected to each other and adapted to be introduced into
spaced blind complementary cavities formed in a jaw bone without
extending exteriorly therefrom; and securing means engageable with
at least one of said planar members for immobilizing said members
within the cavities relative to the jaw bone, a portion of said
securing means including support means projecting exteriorly of the
jaw bone when said at least one planar member and said securing
means are in engagement, said support means being adapted to
support a dental prosthetic device in fixed relation to the jaw
bone during such engagement.
5. Dental implant assembly as defined in claim 4, wherein each of
said planar members has at least one aperture in alignment with the
corresponding aperture in the other of said planar members, at
least one of said apertures being threaded, said securing means
comprising a threaded fastener adapted to pass through one of said
apertures and engage the threaded aperture.
6. Dental implant assembly as defined in claim 4, further
comprising a gripping portion detachably connected to both of said
planar members.
7. Dental implant assembly as defined in claim 6, wherein said
gripping portion is integrally constructed with said planar members
and is connected to the latter at a weakened line portion.
8. Dental implant assembly for maintaining a dental prosthetic
device in fixed relation with respect to a jaw bone, the implant
assembly comprising at least one planar member adapted to be
introduced into a respective generally transverse blind
complementary cavity formed in the jaw bone without extending
exteriorly therefrom, said planar member being provided with at
least one threaded aperture therethrough engageable by a threaded
fastener disposed through a hole in the jaw bone oriented generally
normally to said planar member, whereby said planar member
distributes stresses applied to the fastener by a dental prosthetic
device mounted on an exterior portion of the fastener, and a
gripping portion detachably connected to said planar member.
9. Dental implant assembly as defined in claim 8, wherein said
gripping portion is integrally constructed with said planar member
and meets the latter at a weakened line portion.
10. A method of inserting a planar dental implant assembly member
into a jaw bone comprising the steps of cutting a slot in the jaw
bone complementary to the planar member; inserting one alignment
member of a jig into the slot while positioning an associated
alignment member of the jig above the alveolar crest of the jaw
bone; drilling holes in the jaw bone between the alveolar crest and
the slot under the guidance of the apertures in the alignment
members; inserting the planar member into the complimentary slot;
introducing fastener means through the holes drilled in the jaw
bone; and engaging the fastener means with the planar member while
retaining an exposed portion of the fastener means adapted to
support a prosthetic device.
11. A method as defined in claim 10, wherein the planar member is
provided with threaded apertures, said fastener means are threaded
screws, and wherein the step of engaging comprises the step of
threadedly engaging the screw threads of the apertures and the
threaded screws.
Description
BACKGROUND OF THE INVENTION
This invention generally relates to dental implants, and more
specifically to dental implant assemblies having generally planar
members receivable in complementary slots formed in a jaw bone and
threaded fasteners engageable with the planar members while being
oriented in directions generally normal to the planes defined by
the planar members. The present invention also relates to the
method of establishing such implants in the jaw bone as well as the
various jigs instrumental in the method.
Frequently, when the natural tooth structure has deteriorated,
bridges or partial dentures may be formed and connected to the
remaining natural teeth if the latter are sufficiently strong to
support a denture or bridge. Frequently, however, the remaining
natural teeth do not have sufficient strength upon which to base an
artificial bridge. In these cases, it has become common to utilize
bridge stabilizing systems which are connected in one way or
another to the jaw bone. The devices utilized are generally termed
dental implants and are generally securely fixed to the underlying
bone structure of the jaw in order to realize the requisite
strength necessary to support a bridge.
Most of the known dental implants have not been entirely
satisfactory for the purposes intended. For example, some implants
are in the form of pins, nails or screws which are directly urged
into the jaw bone. The disadvantage of these types of implants is
that they do not provide sufficient anchorage in the jaw bone under
great stresses and do not evenly distribute the forces applied
thereto the the jaw bone. Consequently, the danger exists that the
implant will exert excessive stresses on the jaw bone which may
cause the implant to separate from as well as damage the
latter.
According to still other types of known implants, these are in the
form of wedge members which are tapped into the jaw bone. The
disadvantage with this last type of implant, which is also common
with the above described known implants, is that all these implants
rely for their retention in the jaw bone upon the pressure
relationship which exists when the implants are urged or forced
into the jaw bone. However, the jaw bone frequently deteriorates
with time and the wedging relationship between the jaw bone and the
implant may be lost -- this sometimes resulting in the implant
becoming loose.
Implants generally are provided with portions which extend
exteriorly of the jaw bone when the implant is fully mounted
therein -- the exposed portions being suitable for connection with
dental prosthetic devices. According to one known dental implant, a
transverse member passes through the jaw bone and extends to each
side thereof in its permanent position. A jig, which is engageable
with the exposed portions of the transverse member is utilized for
drilling a hole from the alveolar crest of the jaw bone to the
transverse member. However, when the jig is removed and a suitable
threaded fastener passes through the hole so drilled into
engagement with the transverse member, the protruding portions of
the latter remain exposed. This has the disadvantage that the
extended portions of the transverse member interfere with the
tissues surrounding the jaw bone and hinder these tissues from
growing over the opening drilled in the sides of the jaw bone
through which the extended portions project.
Another disadvantage of the known implants has been the difficulty
an inconvenience of establishing the latter in the jaw bone. The
procedures for installing the implants are generally time consuming
and uncomfortable to the patient. Implants which provide the
possibility of becoming loose only necessitate further dental work
at a later time.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a
dental implant assembly which is not possessed of the above
described disadvantages associated with prior art dental
implants.
It is another object of the present invention to provide a dental
implant which is simple in construction and economical to
manufacture.
It is still another object of the present invention to provide a
dental implant which provides the sufficient strength or support to
the dental prosthetic device which is mounted thereon.
It is yet another object of the present invention to provide a
dental implant which more evenly distributes the stresses supplied
thereon to the surrounding jaw bone instead of concentrating those
stresses over relatively small areas.
It is a further object of the present invention to provide jigs for
accurately drilling holes in the jaw bone which facilitate both the
drilling operation as well as the assembly of the dental
implant.
It is still a further object of the present invention to provide
dental implants which are provided with handles severable at
weakened portions which makes the dental implants easier to
manipulate inside the mouth prior to insertion of the implant
inside associated complementary cavities previously formed in the
jaw bone.
It is yet a further object of the present invention to provide
dental implants which include one or more substantially flat plates
or blades each associated with a complementary slot or cavity in
the jaw bone and each arranged in cooperative relationship with
threaded fastening screws oriented normal to the flat implants
which are engaged in threaded apertures provided in at least one of
the implants.
It is an additional object of the present invention to provide a
dental jig for forming two slots aligned essentially in a common
plane and disposed on opposite lingual sides of a jaw bone.
It is still an additional object of the present invention to
provide planar implants associated with complementary slots or
cavities in the jaw bone -- the implants being fully receivable
interiorly of the cavities without protruding exteriorly of the
latter when the dental implant is fully assembled.
It is yet an additional object of the present invention to provide
a method for establishing planar implants in complementary slots
formed in a jaw bone.
In order to achieve the above object, as well as others which will
become apparent hereafter, the dental implant assembly for
maintaining a dental prosthetic device in fixed relation with
respect to a jaw bone comprises a planar member adapted to be
introduced into a complementary cavity or slot formed in a jaw
bone. Securing means are provided which are engageable with said
planar member for immobilizing the latter within the cavity
relative to the jaw bone. A portion of said securing means includes
support means projecting exteriorly of the jaw bone when said
planar member and said securing means are in engagement. Said
support means is adapted to support a dental prosthetic device in
fixed relation to the jaw bone during such engagement.
In accordance with a presently preferred embodiment, either one or
two planar members may simultaneously be introduced into
complementary cavities spaced from each other in the jaw bone. The
planar members are in the form of flat plates having at least one
threaded aperture therethrough. Said securing means comprise a
threaded fastener configurated to pass through a hole drilled in
the jaw bone and engageable with said threaded aperture.
Advantageously, the dental implant further comprises a gripping
portion detachably connected to the planar member. In the preferred
embodiments, said gripping portion is integrally formed with said
planar member and meets the latter at a weakened line portion. The
gripping portion facilitates manipulation of the planar member
during assembly of the dental implant. Once the planar member has
been received in its complementary cavity or slot, the gripping
portion may be removed from said planar member at said weakened
line portion to thereby leave a stub at the point of severance.
Both said planar member and said stub are configurated to be fully
receivable in the cavity without protruding exteriorly of the
latter.
A dental jig in accordance with the present invention for drilling
holes in a jaw bone which are to be aligned with apertures in a
planar dental implant assembly member to be positioned in a
complementary cavity of the jaw bone, comprises a first alighment
member insertable into the jaw bone cavity. A second alignment
member is positionable above the alveolar crest of the jaw bone.
Both said alignment members are provided with at least one pair of
aligned apertures one in each alignment member in which a drill bit
is receivable, said pair of aligned apertures being similarly
aligned with respect to the cavity as are the apertures in the
planar dental implant assembly member. In this manner, holes
drilled in the jaw bone by a drill bit passing through said pair of
aligned apertures are simultaneously in alignment with each the
apertures in the planar dental implant assembly member when the
latter is positioned in the cavity. The dental jig may include a
third alignment member when two spaced planar dental implant
assembly members are to be positioned in respective complementary
spaced cavities of the jaw bone. In such a case, first and second
alignment members are insertable in to the respective jaw bone
cavities while the third alignment member is positionable above the
alveolar crest of the jaw bone.
A dental jig in accordance with the present invention for forming
two slots aligned essentially in a common plane and disposed on
opposite lingual sides of the jaw bone comprises rigid first
extension member provided at one end thereof with a planar portion
receivable in one slot cut on one lingual side of the jaw bone. A
rigid second extension member is provided at one end thereof with a
guide portion adapted to guide suitable slot cutting means.
Connecting means is provided for connecting said first and second
extension members to each other, said extension members being so
configurated to position said guide portion adjacently to the other
lingual side of the jaw bone offset from the desired opposite
lingual position of the other slot when said extension members are
connected to each other. Said offset is approximately equal to the
height of the second slot. In this manner, said slot cutting means
can be guided by said guide portion to cut the other slot in
alignment and at the desired opposite lingual side of the jaw
bone.
The method of inserting a planar dental implant assembly member
into a jaw bone in accordance with the present invention comprises
the steps of cutting a slot in the jaw bone which is complementary
to the planar member. One alignment member of the jig above the
alveolar crest of the jaw bone. Holes are drilled in the jaw bone
between the alveolar crest and the slot under the guidance of the
apertures in the alignment members. The planar member is inserted
into the complementary slot. Fastener means is introduced through
the holes drilled in the jaw bone and the fastener means are
engaged to the planar member while a portion of the fastener means
is retained exposed to make the latter adapted to support a
prosthetic device.
BRIEF DESCRIPTION OF THE DRAWINGS
With the above and additional objects and advantages in view, as
will hereinafter appear, this invention comprises the device,
combinations and arrangements of parts hereinafter described and
illustrated in the accompanying drawings of a preferred embodiment
in which:
FIG. 1 is a schematic perspective representation of a jaw bone
section, showing the dental implant assembly structure in
accordance with the present invention embedded in the jaw bone and
having a post and a head or coping at one end one end thereof
extending above the jaw bone adapted to support a dental prosthetic
device;
FIG. 2 is a horizontal section of the jaw bone with the implant
positioned therein, taken along line 2--2 in FIG. 1;
FIG. 3 is a cross section through the jaw bone and the dental
implant in accordance with the present invention taken through a
vertical section taken along line 3--3 in FIG. 2;
FIG. 4 is a schematic representation of the jaw bone of FIG. 1
prior to insertion of the dental implant, showing the initial step
of the implanting procedure wherein a slot is cut on the side of
the jaw bone;
FIG. 5 is a perspective view of a jig for accurately drilling
aligned holes in the jaw bone after the slot shown in FIG. 4 has
been cut;
FIG. 6 is a perspective view wherein the jig for drilling holes of
FIG. 5 both cooperates with the slot drilled in the jaw bone and
covers the alveolar crest of the jaw bone with an alignment member
through which a drill bit can pass to thereby drill holes in the
jaw bone which are to be aligned with corresponding apertures in
the dental implant when the latter is subsequently inserted into
the slots;
FIG. 7 schematically shows the jaw bone of FIG. 6 after the jig has
been removed and the holes have been drilled, and also showing flat
or planar implant and threaded posts or pins in positions to be
inserted into the drilled holes for engagement with the implant
after the latter has been fully inserted into the slots;
FIG. 8 is a perspective view of a further embodiment of a dental
implant in accordance with the present invention, the second
embodiment including two spaced flat or planar implants, each being
similar to the implant according to the first embodiment;
FIG. 9 is similar to FIG. 4, but showing the first step of the
procedure of lodging an implant as shown in FIG. 8 into the jaw
bone -- this initially comprising the formation of two spaced slots
or cavities;
FIG. 10 is similar to FIG. 5, but showing a modified jig having an
additional alignment member which is receivable in the additional
slot formed in the jaw bone, as shown in FIG. 9;
FIG. 11 is similar to FIG. 6, but showing the jig of FIG. 10
cooperating with the jaw bone for drilling holes in the latter
which extend or communicate with both of the slots;
FIG. 12 is comparable to FIG. 7, wherein the dental implant shown
in FIG. 8 is positioned within the spaced slots shown in FIG. 9,
and also showing the threaded posts or pins in positions just prior
to passage through the holes drilled in the jaw bone and engagement
with the dental implant; and
FIG. 13 is a front elevational view of jig, wherein opposite jaw
sections are shown in cross section, for forming two slots aligned
essentially in a common plane and disposed on opposite lingual
sides of the jaw sections.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, in which similar or identical parts
have been designated by the same reference numerals, and first
referring to FIG. 1, a representation of the jaw bone 10 is shown
having the alveolar crest 12 disposed in the region where teeth
normally arise. The reference numeral 14 represents the lingual
surface of the jaw bone. The tissues which surround the jaw bone
have not been shown for purposes of clarity.
Referring to FIGS. 1-3, the jaw bone 10 is provided with a slot 16,
to be more fully described hereafter, in which the implant 20 in
accordance with the present invention is insertable. The dental
implant assembly is shown in its fully assembled condition wherein
the implant 20 is fully positioned interiorly of the slot 16. The
implant 20 is in the form of a planar member or flat element which
is provided with two end threaded apertures 24 and a central
threaded aperture 26.
In the assembled condition of the implant, a central post 30,
having a threaded portion 32 and a shoulder 34 at one free end
thereof and a head or coping portion 36 at the other end thereof,
extends through a hole in the jaw bone 10, as to be described
hereafter, and threadedly engages with the central threaded
aperture 26. Similarly, two lateral or side pins 40 are provided
with threaded end portions 42 at one end thereof and shoulders 44
at the same end -- the threaded portions 42 being engageable with
the threaded apertures 24 when the pins 40 pass through holes in
the jaw bone 10, as to be described hereafter.
The post 30 is selected to have a length sufficiently large so as
to extend above the alveolar crest 12 to thereby expose a head
portion 36 which is adapted to support a dental prosthetic device.
The manner in which the prosthetic device is connected to the post
30 and head or coping portion 36 is well known in the art.
Although the first embodiment of the invention has been illustrated
and described in connection with one central post 30 and two side
pins 40, it should be clear that the actual number of threaded
members which engage the implant 20 is not critical for the
purposes of the present invention. Thus, it is possible to include
as few as one and as many threaded fasteners as desired in order to
secure the implant 20 and immobilize the same interiorly of the
slot 16. The shoulder 34 of the post 30 and the shoulders 44 of the
pins 40 are adapted to engage the top surface of the implant 20
when full threaded engagement has been achieved and prevent the
threaded fasteners from excessively moving downwardly beyond the
confines of the slot 16. The shoulders also serve the function of
locking the post 30 and pins 40 when the latter are turned
sufficiently so as to tighten the same and cause the shoulders to
frictionally engage the top surface of the implant 20 to thereby
prevent rotation and separation between the fasteners and the
implant.
The method of inserting the implant 20 is generally illustrated in
FIGS. 4-7. Although not shown, the first step of the method
requires that the jaw bone be exposed as illustrated in the
FIGURES. This involves refracting or folding back of the gum tissue
and periosteum layers. A slot 16 is then formed in the jawbone
through the lingual surface of the latter in any conventional
manner. In accordance with the preferred method, a grinding tool 80
having a shaft 82 and a grinding portion 84 is utilized. The slot
16 is formed so as to have dimensions which are complementary to
those of the implant 20. In this manner, the implant 20 is
insertable into the slot 16 with little clearance. Engagement with
little or no clearance provides for best support.
In FIG. 5, a jig 50 for drilling holes in the jaw bone 10 is shown
which is suitable for accurately centering or aligning the holes in
the jaw bone to thereby facilitate and decrease the time of
establishment of the implant assembly.
The drilling jig 50 includes a bottom or lower alignment member 52
and an upper or top alignment member 54. Apertures 60 are provided
in the alignment member 54 while apertures 62 are provided in the
alignment member 52. The apertures in each of the alignment members
are arranged so as to be aligned along lines generally normal to
the lower or bottom alignment member 52. As described above, the
present invention discloses an implant which utilizes three
fastening members, although this is not a critical feature of the
present invention. Accordingly, the drilling jig 50 is provided
with three apertures in each of the alignment members which are
disposed relative to each other similarly as are disposed the
threaded apertures 24, 26 in the implant 20.
In FIG. 6, the jig 50 is engaged with the jaw bone 10. More
specifically, the lower or bottom alignment member is positioned
interiorly of the slot 16 while the top or upper alignment member
54 is disposed above the alveolar crest 12. The drilling jig 50 is
provided with a gripping portion or handle 58 which facilitates the
manipulation of the jig 50 inside the patient's mouth.
It should be clear from the above description, that the lower
alignment member 52 simulates the implant 20 for purposes of
drilling holes in the jaw bone 10. Thus, advantageously, the
dimensions of the bottom alignment member 52 are similar to the
dimensions of the implant 20 -- the dimensions of each being
complementary to the internal dimensions of the slot 16. In this
manner, the slot 16 engages the implant 20 as well as that portion
of the bottom alignment member 52 which is receivable therein with
little clearance.
Since the holes or alignment apertures 60 in the upper or top
alignment member 54 are in vertical alignment with the holes 62 in
the lower alignment member 52, the holes 60 in FIG. 6, when the
upper alignment member 54 is disposed above the alveolar crest 12,
provides an indication of the positions of the apertures 62 in the
lower alignment member when the latter is fully inserted in the
slot or cavity 16. Due to the closely corresponding dimensions of
the implant 20 and that portion of the lower or bottom alignment
member 52 which is receivable in the slot 16, the holes 60 also
provide an indication of the locations of the threaded apertures
24, 26 when the implant is received in the slot 16.
With the jig 50 in position as shown in FIG. 6, holes can now
accurately be drilled in the jaw bone 10 which extend between the
alveolar crest 12 and the slot 16. A drill bit 64 represents any
suitable drilling machine which may be utilized and guided into the
holes 60 successively to thereby form a central elongate hole 70
and two lateral elongate holes 72 one on each side of the hole 70,
as shown in FIG. 7. In drilling the holes, the drill bit 64 is
advantageously lowered sufficiently so that the drill bit fully
passes through the holes 62 in the lower alignment member 52 to
thereby form holes of uniform diameter along the entire extent
thereof. This requires that the drill bit 64 be capable of passing
through both holes 60 as well as the holes 72.
Once the jaw bone has been prepared, as shown in FIG. 7, the dental
implant may be fully assembled in a relatively simple and quick
manner. Firstly, the implant 20 is placed on the lingual side of
the jaw bone 10 so as to permit insertion of the implant 20 into
the slot or cavity 16.
In accordance with the presently preferred implant configuration,
the latter is provided with a handle 29 similar to handle 58 of the
jig 50, which facilitates manipulation of the implant 20 inside the
patient's mouth. Advantageously, the handle 29 is integrally formed
with the implant 20 and meets the latter at a weakened line portion
or neck 28. Once the implant 20 is fully inserted in the desired
position in the slot 16, the handle 28 may be severed from the
implant by merely angularly moving the handle 29 relative to the
implant 20 and severing the two portions at the weakened line
portion 28 to thereby form a stub 22, best seen in FIGS. 1 and 2.
Advantageously, the implant 20 and the weakened line portion 28 are
so configurated that subsequent to severance between the handle 29
and the implant 20, the stub 22 remains fully contained within the
slot 16 and does not protrude exteriorly from the latter. This
represents an advantageous feature of the present invention since
this minimizes engagement between the implant 20 or the stub 22 and
the sensitive tissues in the vicinity of the jaw bone 10 which
ultimately revert into abutment against the lingual surface 14 of
the jaw bone. Such full containment of the implant 20 within the
confines of the slot 16 decreases the dangers of irritation, or
infection, and promotes the growth of tissues which have been
damaged during oral or dental implant procedures.
A second embodiment of the implant 20 is described in connection
with FIGS. 8-12. The second embodiment, shown in FIG. 8, differs
from the implant 20 described above by including an upper planar
member 20a and a lower planar member 20b -- each of the planar
members being essentially constructed in a similar manner to the
construction of the above described implant 20. The upper and lower
planar members, in the form of flat plates, are spaced from each
other and are fixed in the spaced relationship by a detachable
handle 29'. As with the handle 29 in FIG. 7, the handle 29' is
advantageously integral with the planar members 20a, 20b and meet
the latter at a neck or weakened line portion 28'. Each of the
planar members includes a central aperture 26' and two lateral
apertures 24'. Accordingly to one possible arrangement, only the
apertures in one of the planar members are threaded. However, it is
equally possible to provide internal threads in all of the
apertures on both of the members.
The method of inserting a dental implant as shown in FIG. 8 into a
lingual side of the jaw bone will now be described. Referring to
FIG. 9, a grinding tool 80' includes two grinding discs 84a and 84b
mounted on a shaft 82. The spacing between the two grinding discs
84a and 84b is selected to be equal to the spacing between the
planar members 20a and 20b of the dental implant. Two blind slots
16a and 16b, each similar to the slot 16 described in connection
with FIG. 4, are formed in the jaw bone 10. After the two slots or
cavities 16a, 16b have been formed, a recess or depression 16c is
provided which extends between the two slots 16a, 16b, for reasons
to become apparent hereafter. The recess 16c may be formed in any
conventional manner.
A drilling jig 50', not unlike the drilling bit 50 of FIG. 5, is
provided for facilitating accurate alignment of holes to be drilled
through the jaw bone 10. The drilling jig 50' differs from the
drilling jig 50 only in that an additional alignment member 59 is
disposed between the lower or bottom alignment member 52' and the
top or upper alignment member 54'. Now, the lower alignment member
52' and the middle alignment member 59 are each receivable in
respective slots 16b and 16a. As with the first embodiment, the
dimensions of the alignment members as well as of the planar
members 20a, 20b are configurated and dimensioned so as to be
complementary to the slots 16b, 16a. The slots are so dimensioned
as to closely receive either the planar members or the alignment
members with little clearance. The apertures in the planar members
share common alignment patterns with the apertures in the alignment
members. Thus, once holes have been drilled in the jaw bone 10
which are in alignment with the apertures in the alignment members,
the same holes automatically become aligned with the holes in the
planar members when the latter are appropriately positioned in the
slots.
In FIG. 11, the drill jig is shown in the drill bit guiding
position wherein the bottom and middle alignment members are
disposed in their respective complementary slots 16a, 16b while the
top alignment member is disposed above the alveolar crest 12 of the
jaw bone 10. The drill bit 64 represents drilling means suitable
for passage through the apertures 60 -- the latter apertures
guiding the drill bit 64 while holes are drilled in the jaw bone in
accordance with the alignment pattern of the apertures 60.
After the slots have been cut, as illustrated in FIG. 9, and the
holes have been drilled, as illustrated in FIG. 11, the dental
implant may be inserted into the respective slots 16a, 16b. To
facilitate manipulation of the planar members, the handle 29' may
be gripped during the insertion step. After the planar members 20a,
20b are fully received in their respective slots, it is possible to
sever the handle 29' by breaking off the latter at the weakened
line portion 28'. However, a stub remains which bridges the two
planar members 20a, 20b. In order to prevent the stub from
extending beyond the lingual surface of the jaw bone, the stub is
urged into the recess or depression 16c which has been provided
therefor.
Once the double-plate dental implant is fully inserted interiorly
of the jaw bone 10, as shown in FIG. 12, suitable fastening means
such as shouldered and threaded post 30, as well as threaded and
shouldered pins 40 are inserted through the drilled holes 70, 72
and the post and pins are threadedly engaged with the apertures in
the planar members. As suggested above, both planar members 20a,
20b may be provided with threaded apertures. Alternately, only the
bottom planar member 20b is provided with threaded apertures while
the apertures in the top planar member are sufficiently oversized
to permit free passage therethrough of the post 30 and pins 40.
It should be noted from the above description of both embodiments
of the dental implant, that the planar members or flat plates
comprising the dental implants positioned interiorly of the slots
are disposed in generally horizontal planes while the posts and
pins which threadingly engage therewith are vertically disposed.
Such arrangement is merely illustrative and both the planar members
as well as the fastening members may be disposed in any other
advantageous orientations. The orientations of the planar members
and of the fastening members may be influenced by the degree to
which the jaw bone has deteriorated along one portion thereof or
another.
The dental implants in accordance with the present invention
eliminate many of the disadvantages described in the Background Of
The Invention associated with prior art implants. Firstly, the
implants are simple in construction and economical to manufacture.
The procedure for establishing a dental implant in accordance with
the present invention is particularly simple and requires
substantially less time than that associated with prior art
implantation procedures.
A further advantage of the present implant is the provision of the
handles or gripping portions 29, 29' which facilitate manipulation
of the implants inside a patient's mouth -- the handles being
severable from the implants after appropriate positioning thereof
has been effected. The dimensions of the implants are
advantageously selected so that, even with a remaining stub from a
broken off handle or gripping portion, the entire implant is fully
contained within an associated complementary slot or cavity without
extending exteriorly therefrom. By eliminating projections which
protrude beyond the original jaw bone surfaces, or by fully
implanting the present implant interiorly of the jaw bone, minimum
interaction is obtained between the implant and the sensitive
tissues around the jaw bone. Such construction minimizes or
eliminates tissue damage during and after the implantation
procedures.
Of substantial important in regard to the present invention is the
improved distribution of stresses provided by the subject implants
as compared to prior art implants. It should be clear that by
providing a planar or flat implant mounted in a complementary slot,
stresses applied by a dental prosthetic device on a post 30 on
which it is mounted, produces markedly reduced local stresses in
the regions of the post 30 due to the increased surface areas of
the implant over which the stresses may be distributed. Instead,
the stresses applied to the post 30 are simultaneously transmitted
to the planar members 20 or 20a and 20b. In this manner, instead of
the stresses being localized about the periphery of the post 30,
the stresses are distributed over the surface areas of the planar
member 20. By providing a double planar member implant as shown in
FIG. 8, the stresses are still further distributed by virtue of the
increased area which comes into contact with the jaw bone. Stated
otherwise, the greater the surface area which the implant makes
with the jaw bone, the less concentrated are the local stresses on
the jaw bone and the less likely that damage will be caused to the
latter.
When it is desired to form two slots aligned essentially in a
common plane and disposed on opposite lingual sides of the jaw
bone, a jig 92 shown in FIG. 13 may be utilized. The jig 92
includes a rigid first extension member 94 provided at one end
thereof with a planar portion 98 receivable in a slot 90 cut on one
lingual side of the jaw bone, as described above in connection with
FIGS. 4 and 9. A rigid second extension 100 is provided at one end
thereof with a guide portion 104 adapted to guide suitable cutting
means 106, 108. In order to compensate for different jaw bones in
which oppositely disposed jaw portions are spaced different
distances, each of the extension member is provided with straight
end portion 96, 102. Each of these straight end portions 96, 102 is
provided with a slot or guideway (not shown). A screw 120 having a
head 122 disposed on one side of the straight end portions extends
through the guideways and is threadingly engaged with a nut 124. In
this manner, the extension members 94, 100 may be moved relative to
one another to thereby vary the distance between the planar and
guide portions 98, 104. The screw 120, when the nut 124 is loose,
permits relative sliding of the end portions 96, 102 to change the
spacing between the portions 98, 104. The extension members are so
configurated so as to position the guide portion 104 adjacently to
the desired lingual position of the jaw bone where the second slot
110 is to be cut but offset therefrom a distance approximating the
height of the slot 110, when the extension members are connected to
each other as shown. In this manner, the grinding disc 106 can be
guided by the guide portion 104 to cut the other slot 110, showed
in dashed outline in FIG. 13, in alignment and at the desired
opposite lingual side of the jaw bone.
Numerous alterations of the structure herein disclosed will suggest
themselves to those skilled in the art. However, it is to be
understood that the present disclosure relates to a preferred
embodiment of the invention which is for purposes of illustration
only and is not to be construed as a limitation of the
invention.
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