DENTAL IMPLANT MADE OF ZIRCONIA OR ALUMINA WITH HEALING ELECTRICAL PROPERTIES AND ITS PRODUCTION METHOD

Abstract

The present disclosure relates to a dental implant which comprises in its interior vertical and radial channels terminating in the form of holes in the lateral and lower surfaces of the implant and wherein each channel is filled by electrically conductive material in order to promote multiple electric fields along the surface of the implant. Electric fields range from 5 to 100 mv. A dental implant is described defining an axis along its length, obtained from a sintered block, which comprises in its interior longitudinal and radial channels which terminate in the form of holes in the surface of the implant and wherein each channel comprises an electrically conductive material for promoting multiple electric fields along the surface of the implant.

Claims

1. A dental implant defining an axis along its length, and being defined from a sintered block, which comprises: in its interior longitudinal and radial channels terminating at holes in the surface of the implant, and an electrically conductive material positioned to create multiple electric fields along the surface of the implant.

2. The dental implant according to claim 1, wherein the radial channels terminate at the holes in a lateral surface of the implant and the longitudinal channels terminate at the holes in a top surface of said implant.

3. The dental implant according to claim 1, wherein the radial channels terminate at the holes in a lateral surface, the respective electrically conductive material being connected in such a way as to alternate electrical poles along the lateral surface of the implant.

4. The dental implant according to claim 1, wherein the longitudinal and radial channels terminate at the holes in lateral and lower surfaces of the implant.

5. The dental implant according to claim 1, comprising an electronic component located on the abutment or crown, which comprises a battery having an integrated circuit, a chip, or a piezoelectric component.

6. The dental implant according to claim 5, wherein the electronic component is configured so that said electric fields range between 5 and 100 mV.

7. The dental implant according to claim 1, wherein the electrically conductive material is a metal or a polymer charged with particles or fibers that render the polymer electrically conductive.

8. The dental implant according to claim 7, wherein the metal is selected from the group consisting of: silver, gold, platinum, and a metal alloy which is biocompatible and electrically conductive.

9. The dental implant according to claim 7, wherein the polymer is selected from PEEK or PMMA or other biocompatible polymer.

10. The dental implant according to the claim 9, wherein the polymer further comprises silver particles or carbon nanotubes, or other biocompatible material that renders the polymer electrically conductive.

11. The dental implant according to claim 1, wherein the sintered implant block is of ceramic or a ceramic based composite material.

12. The dental implant according to claim 11, wherein said sintered implant block is of zirconia or alumina or a mixture thereof.

13. The dental implant according to claim 12, wherein said implant comprises from 1 to 20% of yttrium, cerium, magnesium, or a combination thereof.

14. The dental implant according to claim 1, comprising hydroxyapatite, TCP, bioglass, or a combination thereof.

15. A process for obtaining a dental implant, comprising the following steps: mixing constituent ceramic materials of the dental implant and pressing the constituent ceramic materials at a pressure between 10 and 200 MPa until a compact block is obtained; pre-sintering the obtained block; machining the block by milling or by laser ablation to obtain the implant with the longitudinal and radial channels and the respective holes; and sintering the block at a temperature between 1200 and 1600 C. for a period of 1 to 5 hours.

16. The process according to claim 15, wherein the process is a lost wax casting process comprises the following steps: placing the implant in a feeding system, in the form of a tree-shaped structure, composed by wax; adding wax to the implant holes; immersing the implant-containing feeding system in plaster until a plaster mold is obtained; heating the mold to a temperature of 400 C. for extraction of the wax; placing the mold in a furnace at 800 C. for a period of 2 hours; and removing the mold and pouring a metal into the plaster mold and into the holes of the implant.

17. The process according to claim 15, further comprising filling of the interior channels by an electrically conductive polymer which comprises the following steps: the implant with the holes is placed inside a mold of graphite material in which the mold includes a main body, a lower part, and an upper part, together with the implant; and the polymer is placed inside the mold and the combination of polymer and mold is heated until the polymeric combination reaches a liquid, pasty or semi-solid state, and impregnates the holes.

18. The process according to claim 17, wherein the impregnation of the holes is performed by applying pressure under vacuum, which causes the flow of the polymeric combination into the holes of the implant to fill the holes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] For an easier understanding, the figures are attached, which represent preferred embodiments which are not intended to limit the object of the present description.

[0046] FIG. 1exemplary schematic representation of a ceramic implant constituted by the main body (1) (a), before machining the inner channels, which will give rise to the internal electric circuit, and after machining the internal channels (b), which will give rise to the internal electric circuit, and local for housing the battery and electronic components or piezoelectric element on the top of the implant. Also shown are cuts with top views (c) of the electric wire system showing the circuit with a polarity, for example the negative (2) and with the other polarity, for example the positive (3).

[0047] FIG. 2exemplary schematic representation of a mould in plaster (4), containing the implants (1), and on which metal will be poured in the liquid state (6), which will flow through the feeding channel (5), and which will fill the electric circuit (2) and (3) in FIG. 1) of the implants (1).

[0048] FIG. 3exemplary schematic representation of a mould, for example in graphite, constituted by a main body (8), and for example a lower part (10) and an upper part (9), where the implant (1) is placed with the channels which will constitute the electrical circuit and the location for the electronic component and battery, or piezoelectric component, already made, and where the powder or granules of the polymeric material, which is electrically conductive (7) are also placed. Pressure (11) and temperature (12), preferably in vacuum, is applied to fill the channels which will constitute the electric circuit by the polymeric composite.

[0049] FIG. 4exemplary schematic representation of a ceramic implant constituted by the main body, after machining and filling (14) of the internal channels that constitute the internal electric circuit, and example of electric fields (15) created, and battery and electronic components or piezoelectric element (13), and on which the crown (16) will be mounted.

DETAILED DESCRIPTION

[0050] The present disclosure consists in a dental implant, which is made up of a ceramic or ceramic composite (1) (FIG. 1), biocompatible, with an aesthetic function, and possibly bioactive, containing in its interior an electric circuit (2) (3) intended for providing electric fields to multiple points of the implant surface (15). This circuit is powered by a small battery that is housed on the top of the implant, in a possible abutment, or in the crown, together with a chip that coordinates the electrical stimuli (13), and/or alternatively by a piezoelectric component (13), which is actuated by the mastication force.

[0051] The present disclosure consists in a dental implant, which is made up of a ceramic or ceramic composite (1) (FIG. 1), biocompatible, with an aesthetic function, and possibly bioactive, containing in its interior an electric circuit (2) (3) which is intended for providing electric fields to multiple points of the implant surface (15). This circuit is powered by a small battery that is housed on the top of the implant, in a possible abutment, or in the crown, together with a chip that coordinates the electrical stimuli (13), and/or alternatively by a piezoelectric component (13), which is actuated by the mastication force.

[0052] In a preferred mode, the implant material consists ofa ceramic based on zirconia, possibly containing alumina percentages or on alumina possibly containing zirconia. In addition to those, it may contain small percentages, for example from 1% (v/v) to 20% (v/v) of yttria, ceria, Magnesia, among other zirconia stabilizing materials, or even hydroxyapatite, TCP, bioglass, among other bioactive and/or anti-bacterial materials.

[0053] These materials, after being mixed, are pressed with pressures from 10 to 200 MPa, preferably between 50 and 100 MPa. The blocks may then be pre-sintered at temperatures between 800 C. and 1200 C., for periods between 0.5 and 5 hours. Alternatively, commercially available pre-sintered blocks, may be used.

[0054] The pressed and/or pre-sintered blocks are then subjected to machining by mechanical route, with cutting tools, in numerically controlled equipments, for the creation of an housing area of the electronic and piezoelectronic components, and internal channels (2) (3), which will consist in the electric circuit. These channels will have a vertical distribution, along the main direction of the implant, and a radial one, at various implant heights. Alternatively, the laser ablation method for machining the holes that will consist in the internal channels may be used. The positive and negative electrical poles are in pairs (+ ) along the implant surface, in order to create multiple micro electric fields (15).

[0055] The machined blocks will be followed by final sintering of the component, which will occur at temperatures between 1200 C. and 1600 C., for periods between 1 h and 5 h, between periods of heating and cooling, which can last between 2 to 4 hours each with heating ramps of about 5 C./minute.

[0056] After final sintering the implants will be subjected to filling of their internal channels with an electrically conductive material. In case the conductive material is metallic, for example silver or gold or platinum, among others that are biocompatible, these will be impregnated in the ceramic implant using the lost wax casting process. Briefly, the implants will be mounted on a feeding system (5), for example in the shape of a tree, in wax, the holes being filled with wax. Then the wax tree, which contains the implants, is immersed in plaster, inside a container giving rise to a plaster mould (4). Thereafter, this mould is subjected to a temperature of up to about 400 C. for around 30 minutes, for extraction of the wax. Then the plaster mould is subjected to a baking cycle of the plaster in which it reaches about 800 C. for a period of about 2 hours. Finally, the plaster mould is removed from the furnace and the liquid metal (6) which will consist in the electric circuit is poured into the interior of the mould (5), which contains the implants, filling the mould cavities and the internal holes of the implants (2) and (3).

[0057] In the case where the conductive material is of polymer matrix, for example Polyether ether ketone (PEEK), or Poly (methyl methacrylate (PMMA), or other biocompatible polymer charged with a material that renders it electrically conductive, for example silver particles, carbon nanotubes, among others, this polymer matrix composite (7) is placed inside a mould, for example in graphite, for example constituted by a main body (8), a lower part (10), and an upper part (9), together with the implant (1) already containing the holes (2) and (3), and these are heated (12) until the polymeric composite reaches the liquid, pasty or semi-solid state and impregnates the holes. This impregnation is done due to the applied pressure (11), under vacuum, which causes the polymeric composite to flow into the implant holes, filling them completely.

[0058] The implants will now have a geometry close to the final one, with the electric channels completely filled (14). They may possibly be subjected to machining for a final definition of geometry or thread. They may also be subjected to a polishing, or surface treatment by particle blasting, acid etching, laser, among others intended to create a surface texture suitable for a good bond to the bone tissues.

[0059] At the top of the implant, or at the abutment, if the implant has it, it can then be mounted the signal processing station and the battery (13), or alternatively the piezoelectric component (13), which will give rise to the electric fields, distributed along the surface of the implant (15). The electric fields on the surface of the implant may be in the range of 5 to 100 my. The crown (16) will be cemented or screwed over the implant body. In the event that the electronic system is made up of a controller and a battery, these (13) must operate while there are no mastication forces, and can then be removed and the electric fields become promoted by a piezoelectric component, which will actuate with the forces of mastication, throughout the entire life of the implant. The piezoelectric component consists of a biocompatible material, for example Barium Titanate BaTiO3, or niobate perovskite compounds, ((K, Na)NbO3), called KNN, and which generate an electric field when subjected to a deformation, due to a load such as that of mastication.

BIBLIOGRAPHIC REFS

[0060] [1] U.S. Pat. No. 8,374,697 B2Electrical dental screw implant [0061] [2] CN 103006343 BDental implant micro-electrical stimulation healing device [0062] [3] WO 2006043748 A1Apparatus for accelerating osseointergration [0063] [4] US 2003/0153965 A1Electrically conducting nanocomposite materials for biomedical applications. [0064] [5] U.S. Pat. No. 5,738,521 AMethod for accelerating osseointegration of metal bone implants using electrical stimulation.

[0065] In one embodiment of the present disclosure the dental implant can comprise in its interior vertical channels (i.e., longitudinal channels along the dental implant defining an axis along its length) and radial ones that terminate in the form of holes in the lateral and lower surface of the implant and in which each channel comprises an electrically conductive material so as to promote multiple electric fields along the surface of the implant.

[0066] In one embodiment, the implant may comprise an electronic component located on the abutment or crown consisting in a battery with a chip or in a piezoelectric component.

[0067] In one embodiment, the electric fields range from 5 to 100 my.

[0068] In one embodiment, the electrically conductive material may be metal or polymer charged with particles or fibers that render the polymer electrically conductive.

[0069] In one embodiment, the metal is selected from silver or gold or platinum or another biocompatible and electrically conductive metal.

[0070] In one embodiment, the polymer may be selected from PEEK or PMMA or another biocompatible polymer.

[0071] In one embodiment, the polymer may further comprise particles of silver or carbon nanotubes, or other biocompatible material that renders the polymer electrically conductive.

[0072] In one embodiment, the implant may be of ceramic or ceramic composite material.

[0073] In one embodiment, the implant may be of zirconia or alumina or a mixture thereof.

[0074] In one embodiment, the implant may further comprise from 1 to 20% of yttria and/or ceria and/or Magnesia.

[0075] In one embodiment, the implant may further comprise hydroxyapatite and/or TCP and/or bioglass.

[0076] In one embodiment, the process for obtaining the implant may comprise the following steps: [0077] a. mixing the constituent ceramic materials of the implants and press them at a pressure between 10 and 200 MPa until a compact block is obtained; [0078] b. pre-sintering the obtained block; [0079] c. machining the blocks by milling in order to obtain the implants with the vertical and radial channels and the respective holes; [0080] d. sintering the blocks at a temperature between 1200 and 1600 C. for a period of 1 to 5 hours.

[0081] In one embodiment, the process may comprise channels which may be produced alternatively by laser ablation.

[0082] In one embodiment, the lost wax casting process may comprise the following steps: [0083] a. placing the implants in the feeding system, tree-shaped, composed of wax; [0084] b. adding wax to the implant holes; [0085] c. immersing the implant-containing feeding system in plaster until a plaster mould is obtained; [0086] d. heating the mould to a temperature of 400 C. for extraction of the wax; [0087] e. placing the mould in a furnace at 800 C. for a period of 2 hours; [0088] f. removing the mould and pouring the metal into the plaster mould and into the holes of the implant.

[0089] In one embodiment, the process of filling the inner channels with an electrically conductive polymer may comprise the following steps: [0090] a. The implant with the holes is placed inside a mould of graphite material or similar, wherein the mould is constituted by a main body, a lower part, and an upper part, together with the implant; [0091] b. The polymer is placed inside the mould and these are heated until the polymeric composite reaches the liquid, pasty or semi-solid state, and impregnates the holes.

[0092] In one embodiment, the impregnation process of the holes may be made by pressure applied under vacuum, which causes the polymeric composite to flow into the orifices of the implants, filling them completely.

[0093] The present disclosure is not, of course, in any way restricted to the embodiments described in this document and a person with average knowledge in the art may provide many possibilities of modifying it and replacing of technical characteristics by equivalent ones, depending on the requirements of each situation, as defined in the appended claims.

[0094] The following claims further define preferred embodiments.