Endosseous plastic implant

Claim 2

A dental implant adapted for tooth replacement in a living being, said implant including at least a support member for a tooth crown, said support member comprising a lower portion adapted to fit into a mating alveolar socket such that the top of the lower portion is substantially at the level of the alveolar ridge and a neck portion having a cross section adapted to match the cross section of a tooth crown contiguous thereto, said neck portion being connected to the top of the lower portion such that the top of the neck portion is substantially at the level of the gingival sulcus, wherein the entire exposed surfaces of said lower portion and said neck portion consist essentially of a porous plastic surface portion said plastic consisting of essentially pure polymethylmethacrylate containing no polymerizing catalyst, said surface portion having exposed interconnected pores adapted to promote only connective tissue ingrowth from surrounding subcutaneous and alveolar environments, said porous surface portion having preselected pore sizes restricted to the range of from about 50 to about 150 microns, and said interconnected pores in said surface portion extending to a depth of at least two millimeters.

Claim 3

The plastic dental implant of claim 1 wherein the porosity of said porous portion is in the range of about 50 percent to about 75 percent by volume.

Claim 4

An implant according to claim 1 wherein said lower portion comprises part of a replica tooth root portion.

Claim 5

A dental implant according to claim 3 comprising an elongated inner solid core portion in part of the root portion and a crown portion joined to said root portion.

Claim 6

The dental implant of claim 4 wherein said solid core portion has one end extending beyond said root portion and providing anchoring means for said crown portion.

Claim 7

The dental implant of claim 5 wherein said solid core portion and said crown portion comprise polymethylmethacrylate.

Claim 8

A dental implant according to claim 4 comprising at least one outwardly disposed shoulder portion along part of the length of the root portion between said lower portion and said neck portion, said shoulder being adapted to contact the jawbone so as to implement the alveolar height in use, said shoulder portion having interconnected pores restricted to the range from about 200 microns to about 400 microns, the shoulder portion thereby being adapted to promote hard bony ingrowth from contiguous alveolar bone.

Claim 9

A dental implant according to claim 3 wherein said porous portion extends throughout the entire root portion.

Claim 10

A dental implant according to claim 8 comprising a solid plastic tooth crown integrally formed on one end of said root portion.

Claim 11

An implant according to claim 1 comprising a support for a tooth crown, said support having a conically shaped portion comprising the porous surface portion of the implant and a crown mounting post extending axially from the larger diameter end of the conical portion.

Claim 12

A dental implant comprising a support member for a tooth crown, said support member having a plastic lower portion adapted to fit into a mating alveolar socket such that the top of the lower portion is substantially at the level of the alveolar ridge and a plastic neck portion extending from the top of the lower portion, said lower portion and said neck portion consisting of essentially pure polymethylmethacrylate containing no polymerizing catalyst, said neck portion having a porous outer surface extending to the level of the gingival sulcus when the support member is fitted into an alveolar socket, said porous surface having interconnected pores extending for at least part of said surface to a depth of at least two millimeters, said pores being formed by the leaching from the lower and neck portions of soluble crystals distributed contiguously therein, said crystals having preselected sizes restricted essentially to the range of from about 50 to about 150 microns whereby the resulting pore sizes are adapted to promote only non-osseous periodontal connective tissue ingrowth into the lower portion from a surrounding alveolar environment and epithelial tissue ingrowth into the upper portion from a surrounding gingival environment.

Claim 13

A dental implant comprising a support member for a tooth crown, said support member having a plastic lower portion adapted to fit into a mating alveolar socket such that the top of the lower portion is substantially at the level of the alveolar ridge and a plastic neck portion extending from the top of the lower portion, said lower portion and said neck portion consisting of essentially pure polymethylmethacrylate containing no polymerizing catalyst, said neck portion having a porous outer surface extending to the level of the gingival sulcus when the support member is fitted into an alveolar socket, said porous surface having interconnected pores extending for at least part of said surface to a depth of at least two millimeters, said pores being formed by the leaching from the lower and neck portions of soluble crystals distributed contiguously therein, said crystals having preselected sizes restricted essentially to the range of from about 50 to about 150 microns whereby the resulting pore sizes are adapted to promote only non-osseous periodontal connective tissue ingrowth into the lower portion from a surrounding alveolar environment and epithelial tissue ingrowth into the upper portion from a surrounding gingival environment.

Claim 14

A dental implant according to claim 11 wherein the entire porous outer surface of said lower portion and said neck portion extends inwardly to a depth of at least two millimeters.

Claim 15

A dental implant according to claim 11 wherein the support member comprises a replica tooth root portion.

Claim 16

A dental implant according to claim 13 comprising a solid plastic smooth-surfaced tooth crown integrally formed on the support member and extending from the neck portion at the upper level of the porous surface.

Claim 17

A dental implant according to claim 13 comprising a non-porous crown mounting post extending from the neck portion of the support member above the upper level of the porous surface.

Claim 18

A dental implant according to claim 15 comprising a smooth-surfaced preformed tooth crown attached to said neck portion and crown mounting post, the implant having a smooth transition from the porous surface of the neck portion to the smooth surface of the tooth crown.

Claim 19

A dental implant according to claim 11 further comprising a central reinforcing member extending upwardly from a lower point spaced a substantial distance above the bottom of the implant, the remainder of the lower and neck portions of the implant being completely porous.

Claim 20

A dental implant according to claim 17 further comprising at least one transverse hole large enough to promote hard bony ingrowth therethrough, the hole extending through the completely porous lower portion below the reinforcing member, whereby the implant is additionally secured by bone growing through the hole while at the same time additional porous surface area is obtained for promoting soft connective tissue ingrowth.

Claim 21

A plastic dental implant comprising an alveolar support for a tooth crown, said support having a threaded lower portion adapted to screw into a tapped alveolar socket and an upper portion adapted to extend to the gingival sulcus when the implant is fitted into an alveolar socket, both said threaded lower portion and said upper portion of the support having a porous surface adapted to promote only soft periodontal connective tissue ingrowth into the lower portion from a surrounding alveolar environment and epithelial tissue ingrowth into the upper portion from a surrounding gingival environment, said surface having interconnected pores extending to a depth of at least two millimeters and formed by the leaching from the plastic material of said upper and lower portions of soluble crystals distributed contiguously therein and having preselected sizes restricted essentially to the range of from about 50 to about 150 microns; a crown mounting post at the upper end of said upper portion; and a flared lip at the upper end of said threaded lower portion between the threaded portion and the upper portion.

Claim 22

A plastic dental implant comprising an alveolar support for a tooth crown, said support having a threaded lower portion adapted to screw into a tapped alveolar socket and an upper portion adapted to extend to the gingival sulcus when the implant is fitted into an alveolar socket, both said threaded lower portion and said upper portion of the support having a porous surface adapted to promote only soft periodontal connective tissue ingrowth into the lower portion from a surrounding alveolar environment and epithelial tissue ingrowth into the upper portion from a surrounding gingival environment, said surface having interconnected pores extending to a depth of at least two millimeters and formed by the leaching from the plastic material of said upper and lower portions of soluble crystals distributed contiguously therein and having preselected sizes restricted essentially to the range of from about 50 to about 150 microns; a crown mounting post at the upper end of said upper portion; and a flared lip at the upper end of said threaded lower portion between the threaded portion and the upper portion.

Claim 23

An implant according to claim 19 wherein said threaded portion is tapered from adjacent the flared lip to a reduced diameter at the lower end of the implant.

Claim 24

An implant according to claim 19 wherein said porosity extends completely through the threaded portion of the alveolar support.

Claim 25

An implant according to claim 19 wherein said threaded lower portion of the alveolar support has a constant mean diameter.

Claim 26

An implant according to claim 19 wherein said upper portion of the support comprises a cylindrical porous portion between said flared lip and said crown mounting post.

Claim 27

An implant according to claim 19 comprising an axial center hole extending inward from the lower end of the threaded portion to provide space for the ingrowth of hard bony cells.

Claim 28

A plastic dental implant comprising a foundation member for an artificial tooth crown support, the foundation member being adapted to be installed in a mating alveolar socket such that the top of the implant is below the level of the gingival sulcus and having a recess extending axially inward from said top, said recess being adapted to receive a mating crown support; and the entire exposed surface of said foundation member being a porous surface adapted to promote only soft periodontal connective tissue ingrowth from a surrounding alveolar environment, said surface having interconnected pores extending to a depth of at least two millimeters and having preselected sizes restricted essentially to the range of from about 50 microns to about 150 microns and said plastic foundation member consisting of essentially pure polymethylmethocrylate containing no polymerizing catalyst.

Claim 29

A plastic dental implant comprising a foundation member for an artificial tooth crown support, the foundation member being adapted to be installed in a mating alveolar socket such that the top of the implant is below the level of the gingival sulcus and having a recess extending axially inward from said top, said recess being adapted to receive a mating crown support; and the entire exposed surface of said foundation member being a porous surface adapted to promote only soft periodontal connective tissue ingrowth from a surrounding alveolar environment, said surface having interconnected pores extending to a depth of at least two millimeters and having preselected sizes restricted essentially to the range of from about 50 microns to about 150 microns and said plastic foundation member consisting of essentially pure polymethylmethocrylate containing no polymerizing catalyst.

Claim 30

An implant according to claim 25 wherein the foundation member is adapted to fit into a mating alveolar socket so that the top surface of the foundation member is slightly below the alveolar ridge, thereby encouraging the natural bone to grow over the foundation member to lock the member firmly in place, wherein the recess comprises a threaded hole, and wherein the implant further comprises an externally threaded plug screwed into the hole, the plug having a slotted top surface adapted to be no higher than surrounding gingival sulcus when the foundation member is fitted into an alveolar socket, whereby the plug serves as a temporary cap for the hole during the period that connective tissue attachment is developing between the alveolar socket and the foundation member.

Claim 31

A plastic dental implant comprising a support for a tooth crown, said support having an alveolar support portion substantially wider in one dimension than in a cross dimension and adapted to be inserted in a mating slotted socket in the jawbone of a living being so that the top of the portion does not extend above the surface of the jawbone, with said one dimension aligned with the mesial-distal direction and said cross dimension aligned with the buccal-lingual direction, an integral collar portion extending from the top of the alveolar support portion, said alveolar support portion being tapered in the cross-dimension from a maximum thickness at the top of the portion to a minimum thickness at the bottom of the portion and having a porous surface adapted to promote only non-osseous periodontal connective tissue ingrowth from a surrounding alveolar environment, and said collar portion having a porous surface extending upward to the level of the gingival sulcus when the insert is inserted in a jawbone and adapted to promote epithelial tissue ingrowth from a surrounding gingival environment, said porous surfaces having interconnected pores extending to a depth of at least two millimeters and formed by the leaching from the plastic material of said support portion and collar portion of soluble crystals distributed contiguously therein, said crystals having preselected sizes restricted essentially to the range of from about 50 to about 150 microns, and a crown mounting post extending from the top of the collar portion.

Claim 32

A plastic dental implant comprising a support for a tooth crown, said support having an alveolar support portion substantially wider in one dimension than in a cross dimension and adapted to be inserted in a mating slotted socket in the jawbone of a living being so that the top of the portion does not extend above the surface of the jawbone, with said one dimension aligned with the mesial-distal direction and said cross dimension aligned with the buccal-lingual direction, an integral collar portion extending from the top of the alveolar support portion, said alveolar support portion being tapered in the cross-dimension from a maximum thickness at the top of the portion to a minimum thickness at the bottom of the portion and having a porous surface adapted to promote only non-osseous periodontal connective tissue ingrowth from a surrounding alveolar environment, and said collar portion having a porous surface extending upward to the level of the gingival sulcus when the insert is inserted in a jawbone and adapted to promote epithelial tissue ingrowth from a surrounding gingival environment, said porous surfaces having interconnected pores extending to a depth of at least two millimeters and formed by the leaching from the plastic material of said support portion and collar portion of soluble crystals distributed contiguously therein, said crystals having preselected sizes restricted essentially to the range of from about 50 to about 150 microns, and a crown mounting post extending from the top of the collar portion.

Claim 33

An implant according to claim 27 wherein the crown mounting post comprises solid nonporous plastic.

Claim 34

A implant according to claim 28 wherein said collar portion comprises a tapered plastic collar at the junction of the alveolar support portion and the crown mounting post.

Claim 35

An implant according to claim 27 wherein the alveolar support portion has a plurality of holes extending through the cross-dimension and large enough to permit bone ingrowth therethrough when the implant is inserted in an alveolar socket.

Claim 36

An implant according to claim 27 wherein the side of the alveolar support portion opposite said one side is curved convexly, the curvature being adapted to conform to the curvature of the maxillary sinus when the blade portion is implanted in the upper jaw of a living being.

Claim 37

An implant according to claim 27 wherein said alveolar support portion has an arrowhead shaped comprising an upper portion that tapers inwardly from a region of maximum width in said one dimension upwardly to said collar portion and a lower portion that tapers inwardly from said region of maximum width downwardly to the bottom of the blade portion.

Claim 38

An implant according to claim 27 wherein said alveolar support portion has a fishtail shaped comprising an upper portion that tapers inwardly from a region of maximum width in said one dimension upwardly to said collar portion and a lower portion that curves arcuately downward from said region of maximum width.

Claim 39

A plastic implant adapted for bone replacement in a living being, said implant comprising a first surface portion having exposed interconnected pores adapted to promote only connective tissue ingrowth from surrounding subcutaneous and osseous environments, said first surface portion having preselected pore sizes restricted to the range from about 50 microns to about 150 microns, and the interconnected pores of said first surface portion extending to a depth of at least two millimeters, the implant further comprising another exposed porous surface portion adapted to promote only hard bony ingrowth from a contiguous osseous environment, said other porous surface portion having preselected pore sizes restricted to the range of from about 200 to about 400 microns.

Claim 40

A plastic implant adapted for bone replacement in a living being, said implant comprising a first surface portion having exposed interconnected pores adapted to promote only connective tissue ingrowth from surrounding subcutaneous and osseous environments, said first surface portion having preselected pore sizes restricted to the range from about 50 microns to about 150 microns, and the interconnected pores of said first surface portion extending to a depth of at least two millimeters, the implant further comprising another exposed porous surface portion adapted to promote only hard bony ingrowth from a contiguous osseous environment, said other porous surface portion having preselected pore sizes restricted to the range of from about 200 to about 400 microns.

Claim 41

The implant of claim 34 wherein said other surface portion extends inwardly to a depth of at least two millimeters.

Claim 42

An implant comprising a joint prosthesis having a condylar head composed of solid, smooth-surfaced plastic, a midbody joint to the head and having a first porous surface, interconnected pores, and a fixation pin extending from the midbody and having a second porous surface of interconnected pores, the pore sizes of the first porous surface of said midbody being restricted essentially to the range of from about 50 to about 150 microns and being adapted to permit only soft tissue ingrowth for ligament attachment, and the pore sizes of the second porous surface of said fixation pin being restricted essentially to the range of from about 200 to about 400 microns and being adapted to permit only hard bony cell ingrowth for endosseous fixation when the prosthesis is implanted in a bone of a living being.

Claim 43

An implant comprising a joint prosthesis having a condylar head composed of solid, smooth-surfaced plastic, a midbody joint to the head and having a first porous surface, interconnected pores, and a fixation pin extending from the midbody and having a second porous surface of interconnected pores, the pore sizes of the first porous surface of said midbody being restricted essentially to the range of from about 50 to about 150 microns and being adapted to permit only soft tissue ingrowth for ligament attachment, and the pore sizes of the second porous surface of said fixation pin being restricted essentially to the range of from about 200 to about 400 microns and being adapted to permit only hard bony cell ingrowth for endosseous fixation when the prosthesis is implanted in a bone of a living being.

Claim 44

An implant according to claim 36 wherein the fixation pin includes transverse bone ingrowth holes.

Claim 45

An implant according to claim 36 comprising a hip joint prosthesis.

Claim 46

An implant according to claim 36 comprising a mandibular hinge prosthesis.

Claim 47

An endosseous non-toxic polymer plastic implant consisting essentially of pure polymethylmethacrylate, the implant comprising a porous surface portion of interconnected pores adapted to mate with a corresponding bone implant site in a living being, said surface portion having preselected pore sizes restricted essentially to the range from about 200 microns to about 400 microns, a porosity in the range from about 50 percent to about 75 percent, and a depth of porosity of at least 2 millimeters, wherein said porous surface portion is formed with a dovetail for making a dovetail joint with the bone implant site.

Claim 48

An endosseous non-toxic polymer plastic implant consisting essentially of pure polymethylmethacrylate, the implant comprising a porous surface portion of interconnected pores adapted to mate with a corresponding bone implant site in a living being, said surface portion having preselected pore sizes restricted essentially to the range from about 200 microns to about 400 microns, a porosity in the range from about 50 percent to about 75 percent, and a depth of porosity of at least 2 millimeters, wherein said porous surface portion is formed with a dovetail for making a dovetail joint with the bone implant site.

Claim 49

An endosseous non-toxic polymer plastic implant consisting essentially of pure polymethylmethacrylate, the implant comprising a porous surface portion of interconnected pores adapted to mate with a corresponding bone implant site in a living being, said surface portion having preselected pore sizes restricted essentially to the range from about 200 microns to about 400 microns, a porosity in the range from about 50 percent to about 75 percent, and a depth of porosity of at least 2 millimeters, wherein said porous surface portion is formed with a tenon for making a mortise and tenon joint with the bone implant site.

Claim 50

An endosseous non-toxic polymer plastic implant consisting essentially of pure polymethylmethacrylate, the implant comprising a porous surface portion of interconnected pores adapted to mate with a corresponding bone implant site in a living being, said surface portion having preselected pore sizes restricted essentially to the range from about 200 microns to about 400 microns, a porosity in the range from about 50 percent to about 75 percent, and a depth of porosity of at least 2 millimeters, wherein said porous surface portion is formed with a tenon for making a mortise and tenon joint with the bone implant site.