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| United States Patent | 5006068 |
| Link to this page | http://www.wikipatents.com/5006068.html |
| Inventor(s) | Lee; Chong Jin (291-1, Namgajwa-Dong, Seodaemun-gu, KR);
Kim; Dong Seok (5-5, 852-744, Mia 7-Dong, Dobong-gu, both of Seoul, KR) |
| Abstract | A dental implant comprising a foundation shaft having a head spaced apart
from a supporting ring with a carrier body slidably positioned
therebetween is disclosed. The movement of the carrier body is limited to
the distance between the head and the supporting ring less the length of
the foundation shaft occupied by the carrier body. The second end of the
foundation shaft includes a securing means for fixing the dental implant
to the jaw bone. An aperture is formed in an elongated body for receiving
a resilient force dampening means which maintains contact of the carrier
body with the head in the absence of masticatory movement of the jaw and
also resists axial movement of the tooth assembly generated by masticatory
movement of the jaw thereby cushioning the masticatory forces received by
the foundation shaft during use. A connecting means secures the elongated
body to the carrier body such that upon the attachement of the artificial
tooth to the elongated body-carrier body, a tooth assembly is defined.
Means are disclosed for attaching an artificial tooth to the elongated
body. |
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Title Information  |
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Drawing from US Patent 5006068 |
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Dental implant |
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| Publication Date |
April 9, 1991 |
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| Filing Date |
August 28, 1990 |
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| Priority Data |
Jul 14, 1990[KR]90-10696 |
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Title Information |
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Description |
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BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to a dental implant system utilizing a force
dampening means, and more particularly, to a resilient force dampening
means having a bi-frustum shaped silicon rubber body for positioning into
a frustum shaped aperture in order to absorb the forces generated during
chewing.
There is a need to provide an improved dental implant which better
simulates the reaction of a natural tooth upon receiving the forces
associated with chewing. Recent implant systems have been designed to
mimic the natural tooth's ability to deal with the forces encountered in
chewing in both tooth movement and tooth shock absorbing characteristics.
One such system, U.S. Pat. No. 4,552,532, utilizes a root secured to the
jaw bone, a post supported to the root with a crown connected thereto. A
member is provided for cushioning the forces applied to the crown. A stop
is also included to limit the movement between the crown and the root. A
cushioning member surrounds the portion of the post positioned in the root
and extends horizontally across the interface between the crown-upper post
and the root-lower post. The cushioning members may be composed of silicon
rubber or TEFLON.
Another system, U.S. Pat. No. 4,626,214, utilizes a first body, having an
axial hole, secured in the jaw bone, into which an O-ring and the lower
portion of a second body are positioned. The upper portion of the second
body holds the crown. At the interface between the bottom of the crown and
the top of the first body, a second O-ring is positioned. The O-rings
enable a slight axial dampening movement to mimic a natural tooth.
However, such implant systems are relatively complex and utilize more than
one force dampening means to simulate the action of a natural tooth. Other
implant systems fail to sufficiently absorb the axial forces, impacts and
the like generated during chewing. Thus, such systems may feel unnatural
to the person using such prior art dental implant systems.
An object of the present invention is to provide a dental implant which
utilizes a single force dampening means to attenuate the forces received
by the implant during chewing.
A further object of the present invention is to provide a dental implant
which utilizes a bi-frustum shaped silicon rubber body with an opening
formed therethrough which is positioned into a frustum shaped aperture.
A further object of the present invention is to provide a dental implant
which simulates the force dampening effect of a natural tooth.
A further object of the present invention is to provide a dental implant
having a single force dampening means which can be easily replaced.
A further object of the present invention is to provide a dental implant
which is relatively inexpensive to manufacture.
The preceding objects should be construed as merely presenting a few of the
more pertinent features and applications of the invention. Many other
beneficial results can be obtained by applying the disclosed invention in
a different manner or modifying the invention within the scope of the
disclosure.
Accordingly, other objects and a fuller understanding of the invention may
be had by referring to both the summary of the invention and the detailed
description, below, which describe the preferred embodiment in addition to
the scope of the invention defined by the claims considered in conjunction
with the accompanying drawings.
SUMMARY OF THE INVENTION
The dental implant of the present invention is defined by the claims with a
specific embodiment shown in the attached drawings. For the purpose of
summarizing the invention, the invention relates to a dental implant for
placement into the jaw bone of the patient. The dental implant comprises a
carrier body having a first end and a second end with a first aperture
centrally positioned on the carrier body and extending from the first end
and partially into the carrier body and a second aperture coaxially formed
with the first aperture and extending through the carrier body. A
foundation shaft having a first end and a second end is employed, with the
first end of the foundation shaft terminating in a head having a diameter
less than the diameter of the first aperture of the carrier body and
greater than the diameter of the second aperture of the carrier body. The
second end of the foundation shaft terminates in a jaw bone securing means
for fixing the dental implant to the jaw bone of the patient. A supporting
ring is secured proximate the first end of the foundation shaft and spaced
apart relative to the second end of the carrier body. This head prevents,
in use, axial movement of the carrier body along the foundation shaft in a
first direction beyond the head and the supporting ring prevents axial
movement of the carrier body along the foundation shaft in a second
direction beyond the supporting ring thereby enabling axial movement of
the carrier body along the foundation shaft between the second end of the
carrier body and the supporting ring. The "first direction" is the
direction toward the crown of the tooth and the "second direction" is the
direction toward the jaw bone. An elongated body is employed having a
first end and a second end, with the second end having an aperture formed
therein. Preferably, the aperture is frustum shaped. That is, the volume
of the aperture includes a frustum shape. A means is used for attaching in
use an artificial tooth, or the like, at the first end of the elongated
body. A connecting means secures the second end of the elongated body to
the carrier body such that in use the attachment of the artificial tooth
to the elongated body attached to the carrier body defines a tooth
assembly. A resilient force dampening means is positioned into the
aperture of the elongated body. The resilient force dampening means
maintains contact of the carrier body with the head in the absence of
masticatory movement of the jaw thereby maintaining the tooth assembly in
a natural no-load appearance and resists axial movement of the tooth
assembly in the second direction along the foundation shaft generated
masticatory movement of the jaw thereby cushioning the masticatory forces
received during use.
Preferably, the resilient force dampening means defines a resilient
bi-frustum shaped body. However, other shapes which accomplish the purpose
of the present invention are also envisioned, such as a circular shaped
dampening means. The resilient force dampening means is preferably
composed of silicon rubber. The preferred silicon rubber compositions are
SILASTIC (HS 100U, HS 230U, HS 330U, most preferred; and LCS 140U, LCS
380U manufactured by Dow Corning Corp., U.S.A.), and TECH-SIL (HR-1130U,
HR-1140U, HR-1150U, HR-1170U manufactured by HAE RYONG Silicone Co., Ltd.,
Korea). Other resilient compositions may be used. However, the composition
of the resilient force dampening means should be oil resistant,
physiologically inert, stable at high (hot foods) and low temperatures and
flexible at low temperature (cold foods). Most preferably, the resilient
force dampening means is composed of silicon rubber having a bi-frustum
shape.
The bi-frustum shaped silicon rubber body, preferably, substantially fills
the aperture formed in the elongated body and the silicon rubber body
further includes an opening formed therethrough to permit a portion of the
silicon rubber body to be received into the opening when the silicon
rubber body is compressed, i.e. deformed, by the masticatory forces
received during use.
The preferred means for attaching the artificial tooth at the first end of
the elongated body includes a bore formed in the first end of the
elongated body with internal threads to threadingly receive a bolt having
external threads such that in use the bolt secures the artificial tooth to
the elongated body.
The preferred connecting means for securing the second end of the elongated
body to the carrier body is internal threads formed in the first aperture
of the carrier body and external threads formed on the second end of the
elongated body such that in use the external threads of the elongated body
are threadingly received by the internal threads of the carrier body
thereby securing the elongated body to the carrier body.
The axial movement of the carrier body along the foundation shaft between
the second end of the carrier body and the supporting ring is preferably
about 0.3 mm and most preferably 0.2 mm to accurately mimic the movement
of a natural tooth.
The jaw bone securing means which secures the device of the present
invention to the jaw of the patient. The jaw bone securing means includes
blade form implants and sockets. Blade form implants are manufactured by
Calcitek, Inc. (BIO BLADE) among others. The preferred jaw bone securing
means is a dental socket, i.e. a cylinder shaped implant. Such sockets are
well known in the art. For example, such sockets are manufactured by
Core-vent Corporation (MICRO-VENT and BIO-VENT), Interpore International
(INTERPORE IMZ) and Driskell Bioengineering among others.
Preferably, the dental implant for placement into a jaw comprises the
combination of a carrier body with a first end and a second end and with a
first aperture extending from the first end and partially into the carrier
body and a second aperture coaxially formed with the first aperture and
extending through the carrier body. A foundation shaft with a first end
and a second end is used. The first end of the foundation shaft terminates
in a head having a diameter less than the diameter of the first aperture
of the carrier body and greater than the diameter of the second aperture
of the carrier body. The second end of the foundation shaft terminates in
the jaw bone securing means for fixing the dental implant to the jaw bone.
A supporting ring is secured proximate the first end of the foundation
shaft and is spaced apart relative to the second end of the carrier body.
This structural assembly prevents axial movement of the carrier body along
the foundation shaft in a first direction beyond the head and prevents
axial movement of the carrier body along the foundation shaft in a second
direction beyond the supporting ring thereby only allowing axial movement
of the carrier body along the foundation shaft between the second end of
the carrier body and the supporting ring. An elongated body with a first
end and a second end is employed. The second end of the elongated body
includes an aperture having a frustum shape formed therein. A means for
attaching in use an artificial tooth at the first end of the elongated
body is utilized. A connecting means secures the second end of the
elongated body to the carrier body such that when the artificial tooth is
attached to the elongated body, which in turn is attached to the carrier
body, a tooth assembly is defined. A resilient force dampening means is
positioned into the frustum shaped aperture of the elongated body. The
resilient force dampening means maintains contact of the carrier body and
the head in the absence of masticatory movement of the jaw thereby
maintaining the tooth assembly in a natural no-load appearance. The
resilient force dampening means also resists axial movement of the tooth
assembly in the second direction along the foundation shaft generated
masticatory movement of the jaw thereby cushioning the masticatory forces
received during use.
The more pertinent and important features of the present invention have
been outlined above in order that the detailed description of the
invention which follows will be better understood and that the present
contribution to the art can be fully appreciated. Additional features of
the invention described hereinafter form the subject of the claims of the
invention. Those skilled in the art can appreciate that the conception and
the specific embodiment disclosed herein may be readily utilized as a
basis for modifying or designing other structures for carrying out the
same purposes of the present invention. Further, those skilled in the art
can realize that such equivalent constructions do not depart from the
spirit and scope of the invention as set forth in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the invention,
reference should be had to the following detailed description taken in
connection with the accompanying drawings in which:
FIG. 1 is a sectional view of the dental implant of the present invention;
FIG. 2 is a plan view of the bi-frustum shaped body; and
FIG. 3 is a disassembled view of the dental implant of the present
invention.
Similar reference characters refer to similar parts throughout the several
views of the drawings.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the dental implant 10 according to the present invention
fixed into the jaw bone 12.
The elongated body 50 has a first end 52 and a second end 54, with the
second end having an aperture 56 formed therein. The aperture 56 of the
elongated body, preferably, includes a frustum shape 58, as illustrated at
FIG. 1.
The means 66 for attaching in use an artificial tooth 74 at the first end
52 of the elongated body 50 is utilized. The means 66 for attaching the
artificial tooth 74 at the first end of the elongated body is preferably a
bore 68, having internal threads 70, formed in the first end of the
elongated body. A bolt 72 with external threads 73 engages the internal
threads 70 of the bore 68 to threadably secure the artificial tooth, or
the like, to the elongated body upon tightening the bolt 72 into the bore
68. Other dental prosthesis may be secured to the elongated body, such as
a bridge, or the like, where natural tooth like action is desired.
The resilient force dampening means 90 is positioned in the aperture 56
formed in the elongated body 50. The resilient force dampening means acts
as a spring. The resilient force dampening means 90 serves two functions.
First, it maintains contact of the carrier body and the head in the
absence of masticatory movement of the jaw, as shown at FIG. 1. That is,
the tooth assembly is maintained in a natural no-load appearance. Second,
it resists axial movement of the tooth assembly in the second direction
along the foundation shaft thereby cushioning or attenuating the
masticatory forces received by the foundation shaft during use. Such axial
movement is generated during the masticatory movement of the jaw.
In the preferred embodiment the resilient force dampening means 90 is a
resilient bi-frustum shaped body 92 composed of resilient silicon rubber
93 which is used in combination with a frustum shaped aperture 58 formed
in the elongated body 50 and where the bi-frustum shaped body 92 composed
of silicon rubber 93 substantially fills the frustum shaped aperture 58
formed in the elongated body. An opening 96 is formed through the silicon
rubber body 93 which permits a portion of the silicon rubber body to be
received into the opening in use when the silicon rubber body is
compressed by the masticatory forces received during use. Preferably the
opening 96 extends through the entire bi-frustum shaped body 92.
The carrier body 16 has a first end 18 and a second end 20 with a first
aperture 22 extending from the first end, part way into the carrier body.
The second aperture 24 is formed along the same axis as the first aperture
22 and coaxially extends from the bottom 25 of the first aperture
completely through the carrier body. The diameter of the first aperture is
greater than the diameter of the second aperture formed in the carrier
body.
The foundation shaft 30 has a first end 32 and a second end 34 with the
first end of the foundation shaft terminating in a head 36. The diameter
38 of the head is less than the diameter 26 of the first aperture 22 of
the carrier body 16 and greater than the diameter 28 of the second
aperture 24 of the carrier body. This prevents the carrier body 16 from
moving along the foundation shaft and past the head 36. The diameter 39 of
the foundation shaft 30 is slightly less than the diameter 28 of the
second aperture 24 formed in the carrier body 16 to permit the passage of
the foundation shaft 30 into the apertures 22, 24 of the carrier body 16.
The second end 34 of the foundation shaft 30 terminates in a jaw bone
securing means 40 which fixes the dental implant to the jaw bone. That is,
the head and supporting ring limit the movement of the carrier body
positioned between the head and the supporting ring to the distance
between the head and the supporting ring less the length of the foundation
shaft occupied by the carrier body.
The supporting ring 44 is secured, utilizing a press fit for example,
proximate the first end 32 of the foundation shaft and spaced apart
relative to the second end 20 of the carrier body 16. The head-supporting
ring structural arrangement prevents axial movement of the carrier body
along the foundation shaft 30 in a first direction 46 beyond the
engagement of the bottom 25 of the first aperture 22 of the carrier body
16 by the head 36; and, also prevents axial movement of the carrier body
along the foundation shaft in a second direction 48 beyond the supporting
ring. The "first direction" 46 is the direction toward the crown of the
tooth. Thus, the head 36 prevents the carrier body 16 from coming off the
first end 32 of the foundation shaft 30. The "second direction" 48 is the
direction toward the jaw bone. Thus, the supporting ring 44 prevents the
carrier body 16 from bumping into the means which fixes the implant to the
jaw, such as socket 42. In view of the spacing of the supporting ring and
the head, the axial movement of the carrier body along the foundation
shaft is limited to that length 49 of the foundation shaft which extends
between the second end of the carrier body, i.e. the terminal end 17 of
the carrier body, and the supporting ring 44. The axial movement of the
carrier body along the foundation shaft between the second end of the
carrier body and the supporting ring is, preferably, about 0.3 mm and most
preferably 0.2 mm to mimic the movement and "feel" of a natural tooth.
The exact sizing of the supporting ring 44 and foundation shaft 30 will be
determined by the relative size of the teeth of the patient being fitted
with the dental implant according to the present invention in order to
match the existing natural teeth. The connecting means 76 secures the
elongated body to the carrier body. Upon attaching the artificial tooth 74
to the elongated body 50 which is itself attached to the carrier body 16 a
tooth assembly 86 is defined. In practice the bolt securing the artificial
tooth 74 to the elongated body 50 is covered by a white cement 75 to aid
in simulating a natural looking tooth, to secure the bolt 72 in bore 68
and to protect the bolt 72 during chewing. Connecting means 76 secures the
second end 54 of the elongated body 50 to the first end 18 of the carrier
body 16. Preferably, the first aperture 22 formed in the carrier body
includes internal threads 78 and the second end 54 of the elongated body
50 includes external threads 80. This enables the external threads 80 of
the elongated body 50 to be threadingly received by the internal threads
78 of the carrier body 16 to secure the elongated body 50, including its
attached artificial tooth, to the carrier body 16.
The vertical chewing forces are dampened by the resilient force dampening
means. The lateral forces associated with chewing are dampened by the fit
of the foundation shaft into the second aperture of the carrier body. That
is, the tooth assembly 86 yields very slightly from the vertical plane to
thereby dampen lateral force received by the tooth assembly.
FIG. 2 illustrates the bi-frustum shaped body 92 which has a first 92A and
a second 92B frustum with a common base 95. The opening 96 preferably
extends through the entire bi-frustum shaped body 92, i.e. from the first
end 97 of the bi-frustum shaped body 92 thorough the second end 98 of the
bi-frustum shaped body 92. In use, the opening 96 together with the
peripheral void 99 between the frustum shaped aperture 58 and the
bi-frustum shaped body 92 provides space for the bi-frustum shaped body 92
to be received during compression. That is, the bi-frustum shaped silicon
rubber body substantially fills the frustum shaped aperture 58 formed in
the elongated body 50. During use, the volume of the frustum shaped
aperture of the elongated body is decreased by the intrusion of the head
into the aperture caused by the chewing force exerted on the tooth
assembly during chewing. The presence of the void 99 and the opening 96
permit a portion of the silicon rubber body to be received therein when
the silicon rubber body is compressed during chewing. Because the volume
of the void 99 is not enough for the silicon rubber body to deform into in
the required quantity, the presence of the opening 96 in the bi-frustum
body 92 is important. Thus, the volume of the void 99 and the opening 96
must be suitably designed in consideration of each other in order to
provide space for the silicon rubber body to be deformed into in order to
accomplish the required tooth assembly movement, i.e. the same as natural
tooth movement.
Thus, the resilient silicon rubber body 93 having a bi-frustum shape 92 is
received into an aperture 56 which includes a frustum shape 58. That is,
the volume of the aperture includes a frustum shape. The frustum shaped 58
aperture 56 receives frustum 92A of the bi-frustum shaped body 92, while
the remaining frustum 92B of the bi-frustum shaped body 92 is received
into the volume below the frustum shaped 58 aperture 56, as illustrated at
FIG. 1. Preferably, the resilient silicon rubber body 93 is bonded to the
head 36 of the foundation shaft 30. The device 10 is symmetrical and
displacement of the tooth assembly due to the load of the piston with
respect to the resilient silicon rubber body 93 is along its axis of
symmetry thereby mirroring natural tooth movement.
FIG. 3 illustrates the component parts of the dental implant of the present
invention positioned for assembly of the device 10. A bolt 72 secures the
artificial tooth, not shown, or other dental prosthesis to the elongated
body 50. The connecting means 76 secures the elongated body 50 to the
carrier body 16. The elongated body is then secured to the carrier body
which enables the tooth assembly 86 to transfer the force received during
chewing. When the device 10 is secured into the socket 42 and operatively
positioned into the jaw of a patient, action simulating the movement of a
natural tooth is made possible.
Although this invention has been described in its preferred form with a
certain degree of particularity, it is appreciated by those skilled in the
art that the present disclosure of the preferred form has been made only
by way of example and that numerous changes in the details of the
construction, combination and arrangement of parts may be resorted to
without departing from the spirit and scope of the invention.
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Description |
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