(12) United States Patent
`US 8,684,734 B1
`(10) Patent No.:
`(45) Date of Patent:
`*Apr. 1, 2014
`Igyrerl
`
`US008684734B1
`
`DENTAL IMPLANT WITH POROUS BODY
`
`(54)
`
`(56)
`
`(76)
`
`Inventor: Philip Scott Lyren, Bangkok (TH)
`
`(*)
`
`Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 18 days.
`
`This patent is subject to a terminal dis-
`claimer.
`
`(21)
`
`Appl. No.: 13/571,375
`
`(22)
`
`Filed:
`
`Aug. 10, 2012
`
`(63)
`
`(51)
`
`(52)
`
`(58)
`
`Related US. Application Data
`
`Continuation-in-part of application No. 13/195,872,
`filed onAug. 2, 201 1, now Pat. No. 8,297,974, whichis
`a continuation of application No. 11/358,375, filed on
`Feb. 21, 2006, now Pat. No. 8,043,090, which is a
`continuation of application No. 10/375,343, filed on
`Feb. 27, 2003, now Pat. No. 7,291,012.
`
`Int. Cl.
`
`(2006.01)
`
`A61C 8/00
`US. Cl.
`USPC .......................................................... 433/173
`Field of Classification Search
`USPC .................................. 433/173, 174, 175, 176
`See application file for complete search history.
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`9/1975 Rostoker et a1.
`3,906,550 A
`1/1976 Lash et a1.
`.................... 433/173
`3,934,347 A *
`
`
`2/1980 Nyce ...................
`433/201.1
`4,187,608 A *
`3/1981 Hirabayashiet a1.
`...... 433/173
`4,259,072 A *
`3/1984 Small
`..................
`433/173
`4,439,152 A *
`
`4,547,327 A * 10/1985 Bruins et a1.
`..... 264/16
`4,842,517 A *
`6/1989 Kawahara et a1.
`433/173
`..
`4,957,819 A *
`9/1990 Kawahara et a1.
`428/547
`..
`
`5,049,074 A *
`9/1991 Otaniet a1.
`.....
`433/173
`5,989,027 A * 11/1999 Wagner et a1.
`..
`433/173
`
`7,291,012 B2* 11/2007 Lyren ..........
`433/173
`
`8,043,090 B1* 10/2011 Lyren
`433/173
`8,297,974 B1* 10/2012 Lyren ............................ 433/173
`2008/0050699 A1
`2/2008 Zhang et a1.
`
`FOREIGN PATENT DOCUMENTS
`
`W0
`
`WO 02/34155 A1 *
`
`5/2002
`
`* cited by examiner
`
`Primary Examiner 7 Ralph Lewis
`
`ABSTRACT
`(57)
`A dental implant has a coronal body that connects to a bone
`fixation body. The bone fixation body has a porous structure
`that includes a location at which the porous structure extends
`throughout the bone fixation body and through a center ofthe
`bone fixation body in a cross-sectional View of the bone
`fixation body. The bone fixation body also includes an inter-
`nal cavity with a substance to stimulate bone growth.
`
`27 Claims, 5 Drawing Sheets
`
`
`
`Page 1 of 15
`
`ZIMMER EXHIBIT 1001
`
`Page 1 of 15
`
`ZIMMER EXHIBIT 1001
`
`

`

`US. Patent
`
`Apr. 1, 2014
`
`Sheet 1 of5
`
`US 8,684,734 B1
`
`
`
`24
`
`r 7.14
`
`324
`
`‘f
`
`
`
`Page 2 of 15
`
`Page 2 of 15
`
`

`

`US. Patent
`
`Apr. 1, 2014
`
`Sheet 2 of5
`
`US 8,684,734 B1
`
`
`
`Fig. 5
`Fig. 9
`
`110
`
`Page 3 0f 15
`
`Page 3 of 15
`
`

`

`U.S. Patent
`
`Apr. 1, 2014
`
`Sheet 3 of 5
`
`US 8,684,734 B1
`
`210
`
`240
`
`FIG. 10A
`
`FIG. 103
`
`312
`
`FIG. 11A
`
`FIG. 113
`
`Page 4 of 15
`
`Page 4 of 15
`
`
`
`

`

`US. Patent
`
`Apr. 1, 2014
`
`Sheet 4 of5
`
`US 8,684,734 B1
`
`
`
`FIG- 12A
`
`FIG. 123
`
`420
`450B
`
`432
`
`470
`
`FIG. 120
`
`FIG. 120
`
`Page 5 0f 15
`
`Page 5 of 15
`
`

`

`U.S. Patent
`
`Apr. 1, 2014
`
`Sheet 5 0f 5
`
`US 8,684,734 B1
`
`
`
`610
`
`640
`
`630
`650
`
`620
`
`\growing to
`
`Wral\bone
`
`\Natural\[bone
`
`\growing into
`\ surface of
`\ imp/ant to core
`
`
`
`Bone from core
`growing to \
`
`nar\uralbone\\\\
`Natural bone\
`k growing into\
`surface of \\
`imp/ant to core \
`L
`
`FIG. 14
`
`
`
`FIG. 15
`
`Page 6 0f 15
`
`Page 6 of 15
`
`

`

`US 8,684,734 B1
`
`1
`DENTAL IMPLANT WITH POROUS BODY
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This application is a continuation-in-part of U.S. Pat. No.
`8,297,974 having Ser. No. 13/195,872 filed 2 Aug. 2011,
`which is a continuation ofU.S. Pat. No. 8,043,090 having Ser.
`No. 11/358,375 filed 21 Feb. 2006, which is a continuation of
`U.S. Pat. No. 7,291,012 having Ser. No. 10/375,343 filed 27
`Feb. 2003, which are incorporated herein by reference.
`
`BACKGROUND OF THE INVENTION
`
`Much effort has been directed to integrating dental
`implants into surrounding bone. Ideally, a dental implant
`would be placed into alveolar bone, and thereafter bone
`wouldreadily grow into the surface ofthe implant. To achieve
`this objective, many different surface technologies have been
`applied to dental implants. In some instances, the surface of
`the implant is roughened, grit-blasted, plasma-sprayed, or
`microtextured. In other instances, the surface is coated with a
`biological agent, such as hydroxylapatite (HA). In all ofthese
`instances, the goal is the same: Produce a surface on the dental
`implant into which surrounding bone will grow or bond.
`Porous coatings have also been applied to surfaces of den-
`implants. U.S. Pat. No. 5,989,027 entitled: “Dental
`tal
`Implant Having Multiple Textured Surfaces” to Wagner et al.
`(and expressly incorporated herein by reference) teaches a
`dental implant having multiple textured surfaces on the same
`implant. One surface includes a porous coated substrate, and
`another surface includes a nonporous surface adapted to
`encourage bone growth or bonding.
`Porous coatings are advantageous since bone will indeed
`grow into the surface of the implant. Osseointegration, to a
`limited extent then, has been achieved with porous coated
`surfaces. These surfaces though are far from ideal in terms of
`accepting and encouraging bone growth into the body of the
`implant.
`Porous surfaces are often thin coatings applied to the
`metallic substrate of the implant. Bone surrounding the
`implant can only grow into the coating itself. Bone cannot
`grow through the coating and into the metallic substrate. The
`depth of bone growth into the implant is limited to the depth
`of the porous coating. Bone simply cannot grow completely
`through the implant.
`
`SUMMARY OF THE INVENTION
`
`One example embodiment is a dental implant with a coro-
`nal body that connects to a bone fixation body. The bone
`fixation body has a porous structure and also includes an
`internal cavity with a substance that stimulates bone growth.
`The porous structure extends through a center of the bone
`fixation body in a cross-sectional view of the bone fixation
`body.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a side view of one embodiment of a dental
`
`implant.
`FIG. 2 is a cross-sectional view of the implant of FIG. 1
`embedded in a jawbone of a patient.
`FIG. 3 is a side view of another embodiment of a dental
`
`implant.
`FIG. 4 is a cross-sectional view of FIG. 3.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`2
`
`FIG. 5 is a side view ofyet another embodiment of a dental
`implant.
`FIG. 6 is a cross-sectional view of FIG. 5.
`FIG. 7 is side view of another embodiment of a dental
`
`implant.
`FIG. 8 is a top view of the FIG. 7.
`FIG. 9 is an alternate top view of FIG. 7.
`FIG. 10A is a side view of another example embodiment of
`a dental implant.
`FIG. 10B is a cross-sectional view of FIG. 10A taken along
`lines 10B-10B.
`
`FIG. 11A is a side view of another example embodiment of
`a dental implant.
`FIG. 11B is a cross-sectional view of FIG. 11A taken along
`lines 11B-11B.
`
`FIG. 12A is a side view of another example embodiment of
`a dental implant.
`FIG. 12B is a cross-sectional view of FIG. 12A taken along
`lines 12B-12B.
`
`FIG. 12C is a cross-sectional view of FIG. 12B taken along
`lines 12C-12C.
`
`FIG. 12D is a cross-sectional view of FIG. 12B taken along
`lines 12D-12D.
`
`FIG. 13 is a side view of another example embodiment of
`a dental implant.
`FIG. 14 is a partial cross-sectional view of a dental implant
`embedded in a jawbone of a patient.
`FIG. 15 is a partial cross-sectional view of a coronal end of
`another example embodiment of a dental implant.
`
`DETAILED DESCRIPTION
`
`Referring to FIGS. 1 and 2, an implant 10 is shown accord-
`ing to an example embodiment. Implant 10 is preferably
`constructed of a biocompatible material such as titanium and
`includes two primary components or bodies, a coronal body
`14 and a bone fixation body 16.
`The coronal body 14 has a short cylindrical configuration
`that extends from a proximal end surface 20 to a distal end
`surface 22. A transgingival section 24 is formed with a
`smooth outer surface. A dental interface 26 extends upwardly
`and adjacent the transgingival section. This interface (also
`referred to as an abutment-engaging end) is formed as a male
`hexagonal connector. The interface can have other embodi-
`ments, such as splines, internal and external octagons, stars,
`and other polygons. A threaded bore 28 extends into the
`coronal body and is adapted to receive a fixation screw for
`connecting the dental implant to a dental component, such as
`an abutment, prosthesis, healing collar, or the like. Preferably,
`the coronal body 14 is formed of a biocompatible metal, such
`as a solid metal piece of titanium or titanium alloy. The body
`can be machined to have a size and shape shown in the figures.
`The bone fixation body 16 has an elongated cylindrical
`shape that extends from a proximal end 30 to a rounded distal
`end 32. Body 16 is formed from as a porous metal, such as
`titanium. Preferably, the body has a completely porous struc-
`ture that extends throughout the entire body from the proxi-
`mal to distal ends. Specifically, as shown in FIG. 2, body 16
`does not include a metal substrate. The distal end surface 22
`
`of coronal body 14 connects or fuses to the proximal end 30
`of the bone fixation body 16 at a junction 40.
`FIG. 2 shows the implant 10 embedded in a jawbone 34 of
`a patient. Preferably, the length of the body 16 extends along
`the region where the implant contacts surrounding bone 36
`once the implant is implanted into the jawbone. The transgin-
`gival section 24 extends along the gum tissue or gingival
`tissue 38.
`
`Page 7 0f 15
`
`Page 7 of 15
`
`

`

`US 8,684,734 B1
`
`3
`As noted, the bone fixation body 16 has a porous structure
`that extends from the outer surface and throughout the body.
`By “porous,” it is meant that the material at and under the
`surface is permeated with interconnected interstitial pores
`that communicate with the surface. The porous structure can
`be formed by sintering titanium or titanium alloy powder,
`metal beads, metal wire mesh, or other suitable materials.
`The porous structure ofbody 16 is adapted for the ingrowth
`of cancellous and cortical bone spicules. More particularly
`the size and shape of the porous structure emulates the size
`and shape of the porous structure of natural bone. Preferably,
`the average pore diameter of body 16 is about 40 pm to about
`800 um with a porosity from about 45% to 65%. Further, the
`interconnections between pores can have a diameter larger
`than 50-60 microns. In short, the geometric configuration of
`the porous structure should encourage natural bone to migrate
`and grow into and throughout the entire body 16.
`Preferably, body 16 is created with a sintering process. One
`skilled in the art will appreciate that many variations exist for
`sintering, and some of these variations may be used to fabri-
`cate example embodiments. In a preferred embodiment, the
`coronal body is prepared using machining techniques. Next,
`a ceramic mold is provided. The mold has a first cavity that is
`sized and shaped to match the size and shape of the bone
`fixation body. In this first cavity, the sintering material can be
`placed. The mold also has a second cavity that is adjacent and
`connected to the first cavity. This second cavity is sized and
`shaped to receive the coronal body. The coronal body is
`positioned in the second cavity such that the distal end surface
`is adjacent and continuous with the first cavity.
`The sintering material is then placed into the first cavity.
`This material may be a titanium alloy powder, such as Ti-6Al-
`4V. Some of this powder will contact the distal end surface of
`the coronal body. The mold is then heated to perform the
`sintering process. During this process, as the material in the
`first cavity heats and sinters, the bone fixation body forms and
`simultaneously bonds or fuses to the distal end surface of the
`coronal body.
`The size and shape of the pores and porous structure pro-
`duced in the first cavity depend on many factors. These factors
`include, for example, the temperature obtained in the fumace,
`the sintering time, the size and shape of sintering material, the
`composition of the sintering material, and the type of ceramic
`mold used. These factors (and others) can be varied to pro-
`duce a bone fixation body in accordance with an example
`embodiment. Further, these factors (and others) can be varied
`to produce a strong bond between the bone fixation body and
`coronal body.
`Once the sintering process is finished, the distal surface of
`the coronal body is directly fused to the bone fixation body.
`These two bodies are now permanently connected together to
`form the dental implant.
`In the aforementioned sintering process, the bone fixation
`body simultaneously forms and attaches to the coronal body.
`One skilled in the art though will appreciate that each ofthese
`bodies can be fabricated independently and subsequently
`connected together. If the bodies are made separately, then
`they may be attached or fused together using welding or
`brazing techniques, for example.
`FIGS. 3 and 4 show another implant 50 according to
`another example embodiment. With some differences,
`implant 50 is similarly configured to the implant 10. As one
`difference, the bone fixation body 52 has a gradual and con-
`tinuous taper that extends from the proximal end 54 to the
`distal end 56. Further, the coronal body 60 has two different
`and distinct regions on the outer surface. A first region 62 has
`a smooth outer surface. A second region 64 has a bone-
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`4
`
`engaging surface that is contiguous and adjacent to the first
`region 62 on one side and contiguous and adjacent the porous
`bone fixation body 52 on the other side. The second region is
`non-porous and can be formed with various techniques.
`These techniques include, for example, coating with HA,
`grit-blasting, etching, micro-texturing, other non-porous sur-
`face treatments, or combinations of these techniques. This
`surface is provided as an intermediate zone between the
`porous body and the smooth first region 62.
`FIGS. 5 and 6 show another implant 70 according to
`another example embodiment. With some differences,
`implant 70 is similarly configured to the implant 10. As one
`difference, implant 70 has a bone fixation body 72 with an
`outer surface that has a plurality ofundulation 74, such as hills
`and valleys. These undulations are adapted to firmly secure
`the implant into the jawbone after the implant is placed
`therein. Further, the coronal body 80 has a dental interface 82
`formed as an internal connection, such as an internal hexagon
`or other internal polygon. Further yet, the distal end surface
`84 ofthe coronal body has an elongated protrusion 86 extend-
`ing outwardly. This protrusion extends into the bone fixation
`body 72 and is adapted to increase the interface between the
`coronal body and bone fixation body. This protrusion may
`have various configurations, such as non-tapering, tapering,
`cylindrical,
`square,
`rectangular, hexagonal, octagonal,
`polygonal, or other shapes. Preferably,
`the protrusion is
`formed as a cylinder or square.
`FIGS. 7 and 8 show another implant 100 according to
`another example embodiment. With some differences,
`implant 100 is similarly configured to the implant 10. As one
`difference, implant 100 has a bone fixation body 102 with an
`uneven outer surface 104. This surface is adapted to aid in
`bone integration and anti-rotation between the bone fixation
`body and surrounding bone. Further, the coronal body 110
`has two different and distinct regions on the outer surface. A
`first region 112 has a smooth outer surface; and a second
`region 114 has a bone-engaging surface. These regions are
`similar to the regions 62 and 64 described in connection with
`FIGS. 3 and 4.
`
`As yet another difference, the coronal body 110 has a shape
`and size adapted to conform to the size and shape of natural
`teeth. The shape of this body is used, for example, in single-
`stage dental implants. The shape and size of the coronal body
`can thus contour the gingival or gum tissue to a natural shape
`that surrounds teeth. The size and shape, for example, can be
`similar to a molar, premolar, or incisor. FIG. 8 shows a top
`view of the coronal body 110 to have a shape of an oval or
`ellipse. As shown in FIG. 7, coronal body can taper upwardly
`from the distal end 120 to proximal end 122.
`FIG. 9 shows a top view of the coronal body 110 in an
`alternate embodiment to have a triangular shape.
`The bone fixation body can be adapted to induce bone
`growth into and entirely through the body. The body, for
`example, can be doped with biologically active substances.
`These substances may contain pharmaceutical agents to
`stimulate bone growth all at once or in a timed-release man-
`ner.
`
`implant 200 that
`FIGS. 10A and 10B show a dental
`includes a coronal body 202 and a bone fixation body 204.
`The coronal body 202 connects the bone fixation body 204
`along an interface or juncture 206.
`The coronal body 202 has a short cylindrical configuration
`that extends from a proximal end surface 210 to a distal end
`surface 212. External threads or grooves 214 extend along an
`exterior surface from the proximal end surface 210 to the
`distal end surface 212. A dental
`interface 216 extends
`
`inwardly into the coronal body 202. This interface includes a
`
`Page 8 0f 15
`
`Page 8 of 15
`
`

`

`US 8,684,734 B1
`
`5
`female hexagonal connector 220 and a threaded bore 222. The
`interface can have other embodiments, such as friction-fit
`connections, splines, internal polygons, and/or external poly-
`gons.
`The dental interface 216 connects to another dental com-
`
`ponent, such as an abutment or a tooth-shaped prosthesis. For
`example, a tooth-shaped prosthesis has a distal end with a
`male hexagonal connector that fits into and engages with the
`female hexagonal connector 220. A screw extends from the
`tooth-shaped prosthesis and into the threaded bore 222 to
`connect the tooth-shaped prosthesis to the dental implant 200.
`In one example embodiment, the coronal body 202 is
`formed of a biocompatible metal, such as a solid metal piece
`of titanium, titanium alloy, or other biocompatible metals
`and/or biocompatible materials. The external
`threads or
`grooves 214 are machined into the exterior surface of the
`coronal body 202 and include a micro-textured surface, such
`as a micro-textured surface created by grit-blasting with HA.
`The bone fixation body 204 has an elongated cylindrical
`shape that extends from a proximal end 230 at the interface
`206 to a distal end 232. An external surface 234 of the bone
`
`fixation body 204 includes threads, channels, and/or grooves
`240 that extend from the proximal end 230 to the distal end
`232. An internal cavity 250 is located inside the bone fixation
`body 204 and extends from a location adjacent the interface
`206 to the distal end 232.
`
`The internal cavity 250 forms a circular opening 252 at the
`distal end 232 of the bone fixation body 204. The internal
`cavity 250 has a cylindrical shape and is centrally located
`inside ofthe bone fixation body 204 such that the sides or wall
`254 of the cavity are equally spaced from the external surface
`234. The wall 254 includes grooves 256 that are formed in and
`spiral around the wall. These grooves 256 circumferentially
`extend around the wall 254 and form a continuous channel
`
`that extends from the circular opening 252 to an end surface
`260 of the internal cavity 250.
`While the dental implant 200 is being positioned into the
`jawbone ofthe patient, bone enters and fills the internal cavity
`250. As the implant rotates and threads into thejawbone, bone
`is forced into the cavity and travels upwardly along the
`grooves 256 toward the end surface 260. The grooves guide
`and facilitate the passage of bone into the internal cavity. For
`example, bone travels in the grooves 256 from the opening
`252 to the end surface 260 in order to fill the internal cavity
`250.
`
`Example embodiments are not limited to the grooves 256
`spiraling around the wall 254. For example, the grooves can
`be straight and extend parallel to each other from the opening
`252 to the end surface 260. Such grooves facilitate the transfer
`of bone into the cavity 250 while the dental implant 200 is
`being screwed, forced, or pressed into the jawbone. Altema-
`tively, the cavity 250 can be formed without grooves.
`The distal end 232 of the bone fixation body 204 includes
`a self-tapping end 270. This self-tapping end 270 includes
`one or more of recesses, channels, threads, and/or flutes that
`create cutting edges 272. These edges cut into bone and tissue
`as the implant is being placed into the jawbone. The recesses
`between the cutting edges also create pathways for holding
`and transporting bone and/or tissue displaced during insertion
`of the dental implant. Furthermore, these recesses align and/
`or communicate with the grooves 240 so bone can smoothly
`travel and flow from the self-tapping end 270, into grooves
`240, and toward the coronal body 202.
`Since the bone fixation body 204 is formed from a porous
`structure, the external grooves 240, the internal grooves 256,
`and the self-tapping end 270 are formed into the porous
`structure ofthe bone fixation body. Thus, the porous structure
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`6
`of the bone fixation body not only provides a structure for
`integrating with bone but also provides a surface to tap bone
`and move bone fragments.
`As noted, the self-tapping end 270 is formed in the porous
`structure of the bone fixation body 204. For example, the
`self-tapping end is formed from the material of the porous
`structure and is integrally formed with the rest of the bone
`fixation body. FIG. 10B shows the porous structure of the
`self-tapping end 270 as being continuous with the remainder
`of the bone fixation body. Alternatively, the self-tapping end
`can include additional or different material (i.e., material not
`found in the remainder ofthe bone fixation body) to assist the
`distal end 232 in functioning to tap into the bone. For
`example, a coating is applied to the self-tapping end to pro-
`vide additional strength to the porous structure at the end of
`the dental implant.
`The grooves 240 spiral around the external surface 234 of
`the dental implant 200. These grooves 240 circumferentially
`extend around the external surface 234 and form a continuous
`
`channel that extends from the distal end 232 to the proximal
`end 230 at the interface 206. These grooves also align and/or
`communicate with the grooves 214 at the coronal body 202 so
`bone can smoothly travel and flow from the self-tapping end
`270, into grooves 240, and into grooves 214. The grooves
`along the exterior surface of the dental implant thus facilitate
`the movement ofbone from the distal end ofthe implant to the
`proximal end of the dental
`implant. Bone travels in the
`grooves and around the exterior surface to facilitate place of
`the dental implant and to assist in forming a secure mechani-
`cal attachment between the dental implant and surrounding
`bone and tissue.
`
`Example embodiments are not limited to the grooves 240
`spiraling around the exterior surface 234. For example, the
`grooves can be straight and extend parallel to each other from
`the opening 252 to the interface 206. Such grooves facilitate
`the transfer of bone along the exterior surface 234 while the
`dental implant 200 is being forced or pressed into the jaw-
`bone. Alternatively, the exterior surface 234 can be formed
`without grooves (for example, formed of the porous material
`but with a smooth exterior surface).
`FIGS. 11A and 11B show another dental implant 300
`according to an example embodiment. With some differ-
`ences, the implant 300 is similarly configured to the implant
`200 in FIGS. 10A and 10B.As one difference, the implant 300
`includes an internal cavity 310 that is enclosed within the
`bone fixation body 312. This cavity 310 has a cylindrical
`shape, extends from near or adjacent the juncture 318 at the
`proximal end 314 of the bone fixation body to near the distal
`end 316 ofthe bone fixation body, and is completely enclosed
`within the bone fixation body. In one example embodiment,
`the bone fixation body 312 completely surrounds the sides,
`the top, and the bottom of the cylindrically-shaped internal
`cavity 310 (i.e., the internal cavity is surrounded on all sides
`by the porous structure). As such, the internal cavity 3 1 0 lacks
`an ingress (such as a hole or a passageway) for entering the
`cavity or an egress for exiting the cavity (such as a hole or a
`passageway). Nonetheless, the open-celled configuration of
`the porous structure ofthe bone fixation body does allow bone
`to grow into and through the bone fixation body. Thus, the
`internal cavity can still communicate with the bone fixation
`body and with bone external to the bone fixation body through
`the interconnected interstitial pores to enable bone growth
`since the internal cavity is surrounded by and formed within
`an open-celled porous structure.
`As shown in FIG. 11B, the internal cavity includes a sub-
`stance 320 to cause or stimulate bone growth. This substance
`320 fills the internal cavity 310 from a proximal end surface
`
`Page 9 0f 15
`
`Page 9 of 15
`
`

`

`US 8,684,734 B1
`
`7
`330 of the internal cavity to an oppositely disposed distal end
`surface 332 of the internal cavity.
`In one example embodiment, the substance 320 is trapped
`within the enclosed internal cavity. For example, the sub-
`stance is placed in the internal cavity during manufacturing or
`formation of the dental implant. Alternatively, the substance
`is placed in the internal cavity after the dental implant is
`constructed. For instance, a small opening is formed through
`the implant, the substance is placed through the opening and
`into the internal cavity, and then the opening is sealed and/or
`closed. By way of example, an opening or hole is placed at the
`end of the screw cavity 336. This opening or hole provides
`temporary access to the internal cavity 310. After the sub-
`stance is placed in the internal cavity, the opening or hole is
`closed. As yet another example, the substance is liquefied and
`forced through the interconnected interstitial pores of the
`bone fixation body and into the internal cavity.
`In this
`example, the substance travels from an exterior surface 338,
`through the bone fixation body 312, and into the internal
`cavity 310.
`FIGS. 12A, 12B, 12C, and 12D show another dental
`implant 400 according to an example embodiment. With
`some differences, the implant 400 is similarly configured to
`the implant 300 in FIGS. 11A and 11B. As one difference, the
`implant 400 includes an internal cavity 410 that has a shape of
`a wheel enclosed within the bone fixation body 404. This
`internal cavity has a cylindrically shaped main body portion
`420 with a plurality of spokes or channels 430 that extend
`outwardly from the main body portion 420. The main body
`portion and the spokes are surrounded and enclosed within
`the bone fixation body (for example, in a similar manner as
`the internal cavity is enclosed within the bone fixation body
`discussed in connection with FIGS. 11A and 11B).
`As shown in FIGS. 12B and 12C, the internal cavity 410
`includes a substance 432 to cause or stimulate bone growth.
`This substance 432 fills the internal cavity 410 from a proxi-
`mal end surface 434 of the internal cavity to an oppositely
`disposed distal end surface 436 of the internal cavity. In one
`example embodiment, the substance 432 is trapped within the
`internal cavity.
`FIG. 12B shows a series of sets of spokes 438 that are
`stacked on top ofeach other inside the bone fixation body 404.
`Six sets of spokes are vertically arranged in the bone fixation
`body. These sets of spokes are evenly spaced apart from each
`other and extend outwardly from the main body portion 420.
`A first set of spokes 444 is located near the proximal end 434
`of the internal cavity, and a sixth set of spokes 446 is located
`near the distal end 436 of the internal cavity.
`FIG. 12C shows that each set of spokes includes four
`spokes 450A, 450B, 450C, and 450D that are evenly spaced
`from each other and radiate outwardly from the main body
`portion 420. These spokes are in fluid communication with
`each other, with the other spokes in the other sets, and with the
`main body portion such that the substance 432 located inside
`the cavity can flow or migrate among the sets of spokes and
`the main body portion. As discussed herein, the substance,
`however, is not limited to being a fluid, but can be a solid
`structure, such as a scaffold, a membrane, a powder, a metal,
`and/or a polymer.
`FIG. 12C also shows that the internal cavity 410 is centrally
`located in the bone fixation body 404. An exterior wall 462 of
`this internal cavity is equally spaced from an exterior wall 466
`of the bone fixation body 404.
`The sets of spokes facilitate the dispersement and growth
`of bone throughout the bone fixation body 404. Specifically,
`the sets of spokes are filled with the substance 432, and this
`substance causes and/or encourages bone to grow from and
`
`5
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`8
`into the sets of spokes and surrounding areas of the bone
`fixation body. The sets of spokes assist in dispersing the
`sub stance 432 into a larger volume or area ofthe bone fixation
`body since these spokes radiate throughout the bone fixation
`body.
`FIG. 12D shows a cross-section ofthe dental implant taken
`adjacent the interface 460. As shown, the porous structure
`continuously extends through an entire cross-sectional view
`of the bone fixation body at this location such that the porous
`structure includes a center 470 ofthe bone fixation body in the
`cross-sectional view. Thus, in this view, the porous structure
`completely fills the cross-section of the dental implant.
`FIG. 13 shows another dental implant 500 according to an
`example embodiment. With some differences, the exterior
`configuration of this implant is similar to the exterior con-
`figuration of the dental implant 200 shown in FIG. 10A. As
`one difference, the dental implant 500 has three separate
`sections that include a coronal body 510, a bone fixation body
`520, and a self-tapping body 530. The bone fixation body 520
`has a structure and/or is formed of a material that is different
`
`than the coronal body 510 and the self-tapping body 530. For
`example, the bone fixation body 520 has a porous structure,
`while the coronal body 510 and the self-tapping body 530
`have a non-porous structure (e. g., formed of solid titanium or
`titanium alloy with a roughened or porous surface).
`In the example embodiment of FIG. 13, the bone fixation
`body 520 is positioned between the coronal body 510 and the
`self-tapping body 530. A proximal end 550 of the bone fixa-
`tion body connects to the coronal body 510 along an interface
`552, and a distal end 560 connects to the self-tapping body
`530 along an interface 562. At the interfaces 552 and 562, the
`bone fixation body has a circular cross-section with the
`porous structure completely filling this cross-section (for
`example, as shown in the circular cross-section in FIG. 12D).
`These circular cross-sections of the bone fixation body con-
`nect to solid metal circular cross-sections ofthe coronal body
`510 and the self-tapping body 530.
`The coronal body 510 and the self-tapping body 530 are
`structurally stronger than the bone fixation body 520 since
`they are formed to have a non-porous structure whereas the
`bone fixation body is formed to have a porous structure. As
`such, the bone fixation body is configured so that bone can
`grow completely through the porous structure. By contrast,
`the coronal body and the self-tapping body are configured so
`that bone can grow into an outer surface but not into and
`through center of the bodies since these locations are filled
`with solid metal. For example, the outer surfaces of coronal
`body and the self-tapping body are micro-textured or covered
`with a porous structure. These surfaces can integrate with
`surrounding bone after the dental implant is implanted in the
`jawbone.
`The dental implant 500 can have different interior configu-
`rations. In one example embodiment, the dental implant 500
`is configured with an internal cavity as shown in FIG. 10B
`(see internal cavity 250 shown in FIG. 10B). As another
`example embodiment, the dental implant 500 is configured
`with an internal cavity as shown in FIG. 11B (see internal
`cavity 310 in FIG. 11B). As another example embodiment,
`the dental implant 500 is configured with an internal cavity as
`shown in FIG. 12B (see internal cavity 410 in FIG. 12B).
`FIG. 14 is a partial cross-sectional view of a dental implant
`embedded in a jawbone of a patient. For example, this cross-
`section can represent the proximal end of the bone fixation
`body 204 of implant 200 shown in FIG. 10B. As another
`example, this cross-section can represent the proximal end of
`the bone fixation body 312 o