WO2011086529A1

WO2011086529A1 - Three dimensional lattice implant body

Info

Publication number: WO2011086529A1
Application number: PCT/IB2011/050184
Authority: WO
Inventors: Eliezer Bar Shalom
Original assignee: A.B. Dental Devices Ltd.
Priority date: 2010-01-18
Filing date: 2011-01-16
Publication date: 2011-07-21
Also published as: GB201017709D0; GB2477010A; GB201000674D0; GB2476969A

Abstract

A dental implant with a body made of a porous core, e.g. having a three dimensional lattice, arranged to enhance bone growth into the body, that is produced layer by layer by laser sintering. Bone growth into the body enhances implant stability and allows for close implantation of neighbouring implants. The porous core may comprise a three dimensional lattice that has a spatially varying density and may continuously change to form the inner and outer threads of the implant. The density, affected by opening sizes, form and spacing, may change according to structural considerations, and may be tailor made and produced in mass.

Description

THREE DIMENSIONAL LATTICE IMPLANT BODY

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.K. Patent Application GB 1000674.0 filed on

January 18, 2010, and of U.K. Patent Application GB1017709.5 filed on October 20, 2010, which are incorporated herein by reference.

BACKGROUND TECHNICAL FIELD

The present invention relates to the field of dentistry, and more particularly, to dental implants.

DISCUSSION OF RELATED ART

Dental implants are implanted in the patients jaw in order to allow attachment of prostheses. Anchoring the dental implant in the jaw poses difficulties of bone abrasion and implant de-stabilization as the implant stays an alien part in the jaw. The following patents and patent applications disclose various dental implants and implantation appliances with pores or tunnels. European Patent Document No. 1133957 discloses implants with channels that promote bone ingrowth, European

Patent Document No. EP1764061 discloses producing dental implants with surface cavities by laser sintering, U.S. Patent Publication No. 20030224328 discloses a biofunctional dental implant system for affixing a crown to an implant socket, that enables the crown to have a selectively controllable mobility relative to the root portion that is anchored within the implant socket, Spanish Patent Document No. 2288437 discloses an implant having conduits for introducing substances into the surroundings of the implant, European Patent Document No. 1430843 discloses an apparatus for embedding an implant in bone tissue in a way that encourages bone tissue growth , WIPO Publication No. 2006096720 discloses an implantable dental screw, WIPO Publication No. 03073912 discloses implants constructed of a biodegradable polymer formed into a structure having micro-architectural features for in-situ application of a liquid biodegradable polymer, European Patent Document No. 1093766 discloses implants with numerous microscopic dents which increase the surface area, and European Patent Document No. 1991169 discloses laser treating the surface of implantable devices.

BRIEF SUMMARY

Embodiments of the present invention provide a dental implant having a body comprising an inner thread for connecting an abutment thereto and an outer thread for connecting the dental implant to a jaw bone, characterized in that the body is at least partially porous. The porosity structure is arranged to enhance bone growth into the body, and the dental implant is produced layer by layer by laser sintering, wherein the bone growth into the body enhances implant stability and allows for close implantation of neighbouring implants. These, additional, and/or other aspects and/or advantages of the present invention are: set forth in the detailed description which follows; possibly inferable from the detailed description; and/or learnable by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more readily understood from the detailed description of embodiments thereof made in conjunction with the accompanying drawings of which:

Figures 1A-1D are high level schematic illustrations of a dental implant, according to some embodiments of the invention;

Figures 2A and 2B are high level schematic illustrations of a dental implant, according to some embodiments of the invention;

Figure 3 is a high level flowchart illustrating a method of dental implants' production, according to some embodiments of the invention;

Figure 4 shows a dental implant having "through channels", according to some embodiments of the invention;

Figure 5 shows the dental implant shown in Figure 4 in partial cross section, according to some embodiments of the invention; and

Figure 6 shows a cross-sectional portion of the dental implant shown in Figure 4, according to some embodiments of the invention; and

Figure 7 shows a schematic drawing of a manufacturing device configured for producing a dental implant according to some embodiments of the invention. DETAILED DESCRIPTION

Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is applicable to other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

For a better understanding of the invention, the usage of the following term in the present disclosure is defined in a non-limiting manner:

The term "three dimensional lattice" as used herein in this application, is defined as a three dimensional network of material comprising spaces of various dimensions (e.g. tunnels) that penetrate the whole volume. The density of the three dimensional lattice may be uniform or variable. The spaces may be of constant or variable cross sectional form and area. The three dimensional lattice may comprise multiple adjacent two dimensional meshes such that the spaces are interconnected and characterized by the mesh opening parameters.

Figures 1A-1D are high level schematic illustrations of a dental implant 100, according to some embodiments of the invention. Figure 1A is a perspective view, Figure IB is a side view, Figure 1C is a cross sectional view, and Figure ID presents a detail marked 97 in Figure 1C which illustrates in magnification the structure of the three dimensional lattice, according to some embodiments of the invention. The three dimensional lattice is represented in Figures 1A-1C in a schematic manner. Dental implant 100 has a body 110 comprising an inner thread 90 for connecting an abutment (not shown) thereto and an outer thread 95 for connecting dental implant 100 to a jaw bone (not shown). Inner thread 90 may extend to varying depths within body 110, according to the size of implant 100 and its type of connection with the abutment. Inner thread 90 may be supported by a layer 120 of solid material, to ensure the stability of the connection to the abutment. Outer thread 95 may also be supported by a solid layer (not shown). Supporting layers (e.g. layer 120) may be either solid or have a higher density than other parts of body 110.

Dental implant 100 is characterized in that body 110 is at least partially porous, e.g. comprising a three dimensional lattice (hatched in Figures 1A-1C) arranged to enhance bone growth into body 110. The porosity of body 110 is arranged to create many free trajectories through implant 110 for the bone to grow into and to occupy, resulting in a good integration of implant 110 in the jaw.

Figure ID illustrates a possible structure of the porous core as a three dimensional lattice - interwoven or parallel layers of a two dimensional mesh, optionally with openings of different forms and sizes 115A, 115B. Openings 115A may be larger than openings 115B according to their position in implant 100 and to implantation considerations in case of tailored implants 100.

Figure 2A is high level schematic illustration of dental implant 100, according to some embodiments of the invention. Body 110 may comprise a solid part 110A and a porous part HOB. Figure 2B illustrates a pattern 111 of one type of porosity that may be implemented - square openings 115C arranged in rows that are shifted from each other. Pattern 111 may be applied to both a side view and a view from the bottom of dental implant 100, or may be applied on other two surfaces to build the three dimensional lattice with specified characteristics.

Dental implant 100 is produced layer by layer by laser sintering. The bone growth into body 110 enhances the stability of dental implant 100 and allows for close implantation of neighbouring implants.

Layer wise laser sintering allow generating continuous changes in the density of the three dimensional lattice through body 110 and in the transition to outer thread 95 and to inner thread 90. The border illustrated in Figure ID between body 110 and outer thread 95 is for illustrative purposes, and may be replaced by continuous changes without any clear-cut border.

The three dimensional lattice may have an opening diameter between 0.1 and 1 millimeter, that may be selected according to implant size, intended use and surrounding tissue. Opening size may vary among different regions of body 100, in relation to expected surrounding tissue (bone type, gum) and its characteristic growth, in relation to the expected location of implant 100 in the jaw, and in respect to structural considerations or implant planning and the need to assure sufficient mechanical support to the inner and outer threads 90, 95.

Opening size may vary continuously within body 110, according to the afore mentioned criteria. Implant density may vary together with opening size to yield implants 100 with a continuously variable density.

The form of the lattice openings may be chosen according to functional or structural criteria. Lattice openings may be round, square, hexagonal, or variable within body 110. The distances between adjacent openings may be between 0.2 and 1.5 millimeter and may also vary within implant 100 according to implant size and intended use. Changing distances between adjacent openings may be associated with the density variation of implant 100.

Dental implant 100 may be produced layer-wise by laser sintering. This production methods allows to tailor implants 100 according to implantation requirements (size, form and density distribution), as well as to mass produced specifically planned implant. The layer- wise production allows exact planning of lattice opening sizes and separation according to optimized models, adapted to bone growth parameters.

Layer- wise by laser sintering allows generating a very fine and a three dimensionally complex implant structure, which is difficult to achieve in other methods.

An additional advantage of producing implant 100 with three dimensional lattice body 110 by laser sintering is sparing implant material, as hollows in implant 100 are not cut out.

Bone growth factors may be associated with the produced implants 100 (e.g. implants may be soaked with bone growth factor prior to implantation) to enhance bone growth. The sizes and connectivity of lattice inner spaces may be selected to admit predefined amounts of specified solutions (e.g. bone growth factors, disinfectors, antibiotics, etc.).

The three dimensional lattice may have interconnected inner spaces, isolated inner spaces or a mix of the two, according to functional requirements from implant 100. Implant size may vary between 0.6 to 2 millimeter in length. Different overall implant lengths and widths may determine the extent of body 110 and of the three dimensional lattice throughout body 110.

Figure 3 is a high level flowchart illustrating a method 150 of dental implants' production, according to some embodiments of the invention.

Method 150 comprises defining at least one three dimensional structure (e.g. a lattice) of a dental implant, to yield enhanced bone growth into the dental implant upon implantation (stage 155); and producing, simultaneously, by layer-wise laser sintering, a plurality of dental implants according to the at least one three dimensional structure (stage 160), wherein the enhanced bone growth into the body enhances implant stability and allows for close implantation of neighbouring implants.

The at least one three dimensional lattice structure may comprise a plurality of three dimensional lattice structures, each defined according to specified implantation requirements. Method 150 allow producing any number of any specially designed dental implant.

Thus producing the implants (stage 160) may comprise producing many implants of a single defined three dimensional lattice structures (stage 162), producing simultaneously different dental implants with individually tailored three dimensional lattice structures (stage 164) or a combination thereof.

Method 150 may further comprise deriving body structural parameters of dental implants according to implantation conditions (stage 152) and defining and producing the implants (stages 155, 160) accordingly. Advantageously, the described implant 100 and method 200, allow generating a "bone implant" within the jaw, which both stabilizes implant 100, by reducing rejection and improper healing around implant 100, and allows placing multiple implants in closer proximity to each other, to better support the prostheses.

Figures 4-6 illustrate dental implant 100 having "through channels", according to some embodiments of the invention. Figure 4 is a perspective view, Figure 5 is a partial cross section, and Figure 6 is a cross-sectional view.

Dental implant 100 has a body 110 comprising an inner thread 90 for connecting an abutment (not shown) thereto and an outer thread 95 for connecting dental implant 100 to a jaw bone (not shown). Inner thread 90 may be supported by a layer 120 of solid material, to ensure the stability of the connection to the abutment. Outer thread 95 may also be supported by a solid layer (not shown). Supporting layers (e.g. layer 120) may be either solid or have a higher density than other parts of body 110.

Figures 4 and 5 show a dental implant 100 having channels 122 therethrough. Dental implant 100 additionally includes threads 95 and a prosthetic head 116.

Prosthetic head 116, as seen partial cross section in Figure 5, includes an abutment receptacle 114 configured for supporting an abutment (not shown). Abutment receptacle 114 optionally comprises an octagonal cross-sectional shape which receives an abutment having an octagonal shape.

Alternatively, the cross-sectional shape of abutment receptacle 114 is triangular, square configured for receiving projections of similar shapes from the corresponding abutments. In still other options, the cross-sectional shape of abutment receptacle 114 is a five or six point star design. Additionally, receptacle 114 comprises a cylinder having a round cross sectional cross section, and the walls of the cylinder are optionally threaded to receive a threaded screw.

In still further embodiments, receptacle 114 comprises a peg that extends above dental implant 100 and is configured to pass into an appropriately shaped receptacle in an abutment and/or prosthetic. The many options for connecting dental implant 100 to abutments and/or prosthetics are well known to those familiar with the industry.

As seen in Figures 5 and 6, channels 122 pass through the thickness of implant 100 into a core 118 which is hollow. Channels 122 are optionally cylindrical and have a round cross- section to those familiar with the industry n shape. Optionally abutment receptacle 114 includes channels 122.

Alternatively, channels 122 have a polygon cross-sectional shape. The many options for creating cylindrical channels 122 are well known to those familiar with the industry.

Channels 122 optionally form a lattice structure as seen in Figure 5. The configuration of the lattice structure may be as a ladder configuration however the lattice structure of channels 122 may include angled channels 122 for example that 45° to the vertical channels shown. The many forms that channels 122 can form to create optimal infusion of bone 130 can be easily understood to those familiar with the industry.

Core 118 optionally includes an octagonal cross-sectional shape which is optionally contiguous with abutment receptacle 114. In some embodiments, the cross- sectional shape of core 118 is triangular, square, or hexagonal. In still other embodiments, the cross-sectional shape of core 118 is a five or six point star design. Following implantation, channels 122 are optimally filled with bone. Bone ingrowth into channels 122 of dental implant 100 contributes to positional stability of dental implant 100 in bone 130 in which the implant is implanted. The stability results in even distribution of mastication forces between implant 100 and bone 130.

The inventors have discovered that as a result of the bone ingrowth into channels 122, a greater long-term stability is possibly created for implant 100 within bone 130, than when implant 100 includes only pores taught in the above-noted prior art of EP 1764061 Al (Mangano, Carlo).

Further the inventors have discovered that distance between multiple dental implants 100 may possibly be reduced from a standard amount of approximately 2 millimeters to about 1 millimeter.

In embodiments, channels 122 have a cross-sectional square area of between 70 and 800 microns and a depth of between about 10 and 100 microns.

In embodiments, channels 122 have a square area of between about 70 and 800 microns.

Figure 7 shows a schematic drawing of a manufacturing device configured for producing a dental implant according to some embodiments of the invention. As shown in a schematic drawing in Figure 7, implant 100 is produced in a production unit 11 including an atmosphere-controlled chamber 12 in which implant 100 is formed. Layers of a powder 18 are optionally deposited with a thickness of between about 1 and 100 microns on a vertical platform 14 along a cylinder 19 utilizing a dispenser 111 that optimally moves across vertical platform 14.

Each time a layer of powder 18 is deposited, a striker arm 13 of a laser generates a laser beam 140 that is directed by a reflector 142 towards the layer of powder 18 which was just deposited.

Powder 18 struck by laser beam 140 melts and solidifies to form an implant portion

16 having a thicknesses of between about 1 and 100 microns as noted above.

In embodiments platform 14 is moved downward as implant 100, consisting of one or more implant portions 16, is formed.

Laser beam 140 is controlled by a controller 15 to form channels 122. Controller 15 typically includes a computer processing unit (CPU) 146 that includes a software module 144 that provides digital three dimensional instructions that control movement of, inter alia, laser beam 140, reflector 142 and downward motion 148. In alternative embodiments, for example where production unit 11 does not include downward movement in direction 148, software module 144 provides digital three dimensional instructions that control movement of, inter alia, laser beam 140 and reflector 142.

As implant 100 is formed, reserve powder 17 around implant 100 can be recovered for a subsequent manufacturing process.

Layers of powder 18 optionally have a thickness of between about 1 and 100 microns. Powder 18 optionally comprises medical grade 2 or 4 titanium powder or ceramic titanium powder. The grains within each layer of powder 18 optionally are between about 10 and 200 nanometers in dimension. However, the thickness of the layers of powder 18 as well as the grains within the layer may vary according to a variety of factors including improvements in existing art.

In embodiments, layers of powder 18 are sintered by laser beam 140 so that implant 100 acquires a generally cylindrical form.

During manufacture of implant 100, chamber 12 is filled with an inert gas 149, for example argon, at a controlled atmospheric pressure so as to reduce potential impurities in implant 100.

To clean implant 100 of any remaining powder 18, implant 100 is optionally introduced into a bath of distilled water or organic acids, and subjected to ultrasound treatment.

The device illustrated in Figure 7 may be similarly used to produce dental implant 100 illustrated in Figures 1A-1D and particularly its porous part of implant body 110.

Referring to Figures 4, 5 and 6, the inventors have discovered that dental implant 100 becomes affixed in place by the ingrowth of bone 130 into channels 122.

Additionally, the inventors have discovered that implant 100 provides greater long- term stability than the implant taught in EP 1764061 Al (Mangano, Carlo) which only includes pores on the surface of the implant.

In embodiments, the porous core structure and the three dimensional lattice core are arranged to accommodate bone ingrowth, and may be further individually designed and mass produced utilizing the layer-wise laser sintering method. The porous core may be designed to have a complex structure without increasing the production complexity, in sharp contrast to most prior art.

In the above description, an embodiment is an example or implementation of the invention. The various appearances of "one embodiment", "an embodiment" or "some embodiments" do not necessarily all refer to the same embodiments.

Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment.

Furthermore, it is to be understood that the invention can be carried out or practiced in various ways and that the invention can be implemented in embodiments other than the ones outlined in the description above.

The invention is not limited to those diagrams or to the corresponding descriptions. For example, flow need not move through each illustrated box or state, or in exactly the same order as illustrated and described.

Meanings of technical and scientific terms used herein are to be commonly understood as by one of ordinary skill in the art to which the invention belongs, unless otherwise defined.

While the invention has been described with respect to a limited number of embodiments, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of some of the preferred embodiments. Other possible variations, modifications, and applications are also within the scope of the invention. Accordingly, the scope of the invention should not be limited by what has thus far been described, but by the appended claims and their legal equivalents.

Claims

CLAIMS What is claimed is:

1. A dental implant having a body comprising an inner thread for connecting an abutment thereto and an outer thread for connecting the dental implant to a jaw bone, characterized in that at least a part of the body is porous and is arranged to enhance bone growth into the body, and the dental implant is produced layer by layer by laser sintering, wherein the bone growth into the porous part of the body enhances implant stability and allows for close implantation of neighbouring implants.

2. The dental implant according to claim 1, wherein the porous part of the body comprises a three dimensional lattice.

3. The dental implant according to claim 2, wherein the three dimensional lattice has an opening diameter between 0.1 and 1 millimeter.

4. The dental implant according to claim 1, wherein the porous part of the body comprises a three dimensional lattice of interconnected channels extending therethrough.

5. The dental implant according to claim 4, wherein the channels have a diameter between 0.1 and 1 millimeter.

6. The dental implant according to any of claims 1 to 5, wherein the dental implant is produced layer- wise by laser sintering.

7. The dental implant according to any of claims 1 to 6, wherein the dental implant comprises titanium or titanium alloys.

8. The dental implant according to any of claims 1 to 7, wherein the body has a variable density according to required strength specifications, and wherein the variable density is achieved by accommodating the opening sizes and the distances between openings in the porous part of the body.

9. A method comprising:

defining at least one three dimensional structure of a dental implant having a porous core, to yield enhanced bone growth into the dental implant upon implantation; and

producing, simultaneously, by layer-wise laser sintering, a plurality of dental implants according to the at least one three dimensional structure, wherein the enhanced bone growth into the porous core enhances implant stability and allows for close implantation of neighbouring implants.

10. The method of claim 9, wherein the at least one three dimensional structure comprises at least one three dimensional lattice structure.

11. The method of claim 10, wherein the at least one three dimensional lattice structure comprises a plurality of three dimensional lattice structures, each defined according to specified implantation requirements.

12. The method of claim 9, wherein the at least one three dimensional structure comprises a three dimensional lattice of interconnected channels extending therethrough.

13. The method according to claim 9, further comprising defining the spatial structure of the porous core such as to comprise at least one of: a three dimensional lattice, a three dimensional lattice of interconnected channels.

14. The method according to any of claims 9 to 11, wherein the implants' production comprises at least one of: producing many implants of a single defined three dimensional structure; and producing simultaneously different dental implants with individually tailored three dimensional structures.

15. The method according to any of claims 9 to 12, further comprising deriving body structural parameters of dental implants according to implantation conditions, wherein implant definition and production are carried out according to the derived body structural parameters.

16. The method of claim 9, wherein the producing comprises:

supplying a layer of powder;

applying a laser beam that melts a portion of the powder;

repeating the supplying and the applying to form the dental implant with channels passing through at least a portion of the implant,

such that the channels are configured to promote ingrowth of bone and to contribute to positional stability of the implant in a bone in which the implant is to be implanted.

17. The method according to claim 16, wherein the layers of powder are deposited in thicknesses of between about 1 and 100 microns.