WO2012093044A1

WO2012093044A1 - Device for destroying a connection between an implant and biological tissue

Info

Publication number: WO2012093044A1
Application number: PCT/EP2011/073860
Authority: WO
Inventors: Thomas Schwenk; Marcus Striegel
Original assignee: Thomas Schwenk; Marcus Striegel
Priority date: 2011-01-05
Filing date: 2011-12-22
Publication date: 2012-07-12
Also published as: DE102011000046A1

Abstract

The invention relates in particular to a method for destroying a connection formed between an implant (1) and a biological tissue (2). According to the invention, energy is applied to the implant (1) in such a way that the implant (1) is heated at least to a specified destruction temperature at least at an interface with the tissue (2).

Description

DEVICE FOR DESTRUCING A CONNECTION BETWEEN AN IMPLANT AND

BIOLOGICAL TISSUE

description

5

The invention relates to a method and a device for the destruction of a connection formed between an implant and a biological tissue.

In the case of dental implants, the bone tissue of the jaw grows into or onto the surface of the implant (so-called osseointegration). The implant should normally remain in the jaw. However, with infections or jawbone shrinkage, it may sometimes be necessary to surgically remove the dental implant. A

However, such subsequent surgical removal of the dental implant is usually very complicated and associated with high bone substance losses.

The object of the invention is to avoid these disadvantages or at least to reduce them. In particular, a method preceding the removal of the implant and a corresponding device are to be specified, with which a downstream mechanical removal of the implant can be simplified.

This object is solved by the features of the independent claims. Refinements and developments of the invention will become apparent in particular from the dependent claims.

A first aspect of the invention relates to a method for at least partially destroying a connection formed or existing between an implant and a biological tissue.

The implant may in particular be a dental implant, and in the tissue around bone tissue, for. B. of the lower jaw. In particular with dental implants, in general also with other types of implants, it may sometimes be desirable for reasons of improved mechanical retention that adjacent or surrounding tissue, in particular bone tissue, grows into the dental implant or infiltrates it at least in the surface area. The resulting improved grip is indeed for the intended mechanical loads of advantage. However, the removal of the implant, which is usually surgical, is made considerably more difficult by the stronger connection between implant and tissue.

In particular, to simplify the removal of the implant according to the invention, the actual, z. As surgical, distance upstream, to apply the implant with energy. The application of energy should be such that the tissue is necrosed at the interface to the implant and / or that the tissue is heated at the interface to the implant to at least a predetermined destruction temperature and / or that the tissue at the interface to the implant by vibration is replaced. The term "compound" is to be understood essentially as meaning any association, adhesion, infiltration, adhesion and the like of tissue and implant, in particular so-called osseointegration, in particular by biological processes and activity, growth or regeneration. By way of example and without limitation of the generality should be mentioned that a compound according to the invention may arise, for example, by the fact that bone tissue grows into porous or open-pored surfaces of the implant.

The terms destructive, destructive, etc. are intended to mean that the compound is at least partially, eg. B. part of the area, weakened, dissolved and / or destroyed. Thus, the required at least partial destruction in the range between local weakening of the connection can be up to the breaking up of essential parts of the compound. The respectively achieved or achievable degree and extent of the destruction may be dependent z. Example of the type of tissue, the shape and the surface condition of the implant, the material of the implant, the nature and density of the impinging energy and other factors.

A second aspect of the invention relates to a device for at least partially destroying at least one connection formed or existing between an implant, in particular a dental implant, and a biological tissue, in particular bone cells, which device is preferably provided for carrying out the method according to the invention. The device comprises an energy source designed to energize the implant, wherein the energy is adjustable or adjusted so that when the implant is exposed to energy, the tissue at the interface to the implant is necrosed and / or heated to at least a predetermined destruction temperature is and / or is replaced by vibrations.

This energy source can be coupled with the implant to heat it either mechanically or by other interaction. In particular, the energy source may be a sound source, in particular a high or high frequency sound source, in particular an ultrasound source, a heat source, in particular an electric heat source, in particular resistance heating, and / or a heat radiation source, an induction source or a radiation source for electromagnetic radiation, in particular light or Infrared, in particular a laser act. Any combination of these enumerated energy sources can also be used. Advantages and advantageous effects of the device according to the second aspect are particularly evident from the comments on the first aspect of the invention (method). Preferably, at least the implant is heated at least at its boundary surface or boundary layer to the tissue to at least a predetermined destruction temperature. As a result of the application of energy, at least the implant is heated. Under certain circumstances, and depending on the type of energy source and type of implant material, there may also be an immediate warming of the tissue. However, a heating caused by the implant is preferred. As a result, the respective connections to the respective implant can be more selectively destroyed.

A heating of the implant leads, in particular via heat conduction processes, which take place readily between the implant and biological tissue, to a heating of at least the interface or

Boundary layer between implant and tissue. In that regard, a warming of the implant is associated with a heating of the tissue. Such heating to or above the destruction temperature leads to at least partial destruction of the compound or compounds if several different types of compounds are considered. The destruction of the compound (s) can be achieved, for example, by at least partially necrotizing the tissue of the interface with the implant or the tissue of the boundary layer, preferably by supplying thermal energy or heating. The heating of the tissue by heat conduction processes via the implant is especially in hard to reach places, eg. As the jawbone tissue in dental implants, an advantage.

A destruction of the connection between tissue and implant, particularly in bone tissue on dental implants, particularly advantageously at a temperature (destruction temperature) in the range of 40 ° C to 60 ° C, in particular at about 50 ° C, can be achieved Destruction temperatures but also be chosen differently depending on the application and especially during the application vary can. At the stated values for the destruction temperatures, the tissue can be at least partially destroyed or necrosed, so that the connection (s) formed between the tissue and the implant are also destroyed. In this case, constant or even variable temperature profiles can be used, in particular depending on the implant.

The energy supplied to the implant may be higher or high-frequency sound energy, in particular ultrasonic energy, heat energy, thermal energy, in particular electrically generated Joule heat energy and / or heat radiation energy, magnetic energy, eg. As induction energy, and / or electromagnetic energy, in particular light or infrared, preferably of lasers act. Preferably, an energy form or a combination of several forms of energy is used for which the implant has good propagation properties or interaction properties and / or which efficiently converts into heat energy in the implant. The abovementioned forms of energy are particularly suitable for the common implant materials such as metals, alloys, ceramics, etc.

Higher or higher frequency sound such as ultrasound can be coupled in via the implant, for example. The coupled-in energy can spread in the implant material and lead to a heating of at least the tissue located at the interface or boundary layer to the implant. By heating, the tissue can be necrotized, resulting in at least partial destruction of the connection between tissue and implant. However, the wave energy of the ultrasound, ie its vibrations itself, as such, can also lead to the tissue being at least partially mechanically detached from the implant, ie even without necrotizing heating. As such, the implant may be formed such that the ultrasound propagates anisotropically with a preferred direction toward the compound to be dissolved. Heat energy may be applied by direct coupling of a heat source, such as a resistance heater or resistance heating wire, which is electrically heated by generating Joule heat, or a heat radiation source, to or into the implant, and heat conduction in the implant to necrotize the tissue. This is particularly advantageous for those implants which have good heat conduction properties. Depending on requirements, but also already the implant a corresponding location, mass or density distribution, z. As in layers, slices or branches, a good heat-conducting mate- rials, whereby an anisotropic heat conduction can be achieved for the connection to be solved. The targeted incorporation of suitable materials into the implant, which is also particularly suitable in the case of ultrasound energy and for other forms of energy, makes it possible to achieve respectively targeted and, in particular, locally specific, necrosis. Advantageously, the energy is coupled into the implant and distributed in such a way that at least the sites relevant for the detachment of the implant are necrosed, or the corresponding connections are released. As far as possible, the above statements also apply to the use of induction energy. In this case, the implant is heated by Joule heat, which results from eddy currents and / or magnetic reversals produced by alternating electrical and magnetic fields.

In particular, for materials with pronounced ferromagnetic properties, induction heating can be used. However, inductive heating is also considered for materials with less pronounced or even missing ferromagnetic properties. As is known, eddy currents, which are converted into Joule heat in the material, are induced by time-varying magnetic fields as they occur during induction. With suitably selected magnetic fields, it is thus possible, the implant material purely on To heat eddy current losses to the desired destruction temperature. This is all the more so as in biological tissue comparatively low destruction temperatures, eg. B. in the range of 50 ° C, can already lead to success.

A commonly used for implants material is titanium or alloys thereof, such as. Eg TiAl5Fe2.5. Titanium as such and, where appropriate, the alloys are not or only extremely weakly ferromagnetic. However, from the point of view of heating via eddy currents, such implants can also be heated to destruction temperature within a reasonable time frame.

As has been indicated above in connection with heat conduction and sound propagation, in the case of induction it is possible in an analogous manner to use ferromagnetic materials deliberately introduced into the implant. The ferromagnetic material may be provided in particular in at least one ferromagnetic induction region. This may be in the form of one or more layers, rings, lines, etc., or otherwise run in the material. The induction region may preferably be provided in spatial proximity to the regions in which destruction is to take place, for example in a near-surface layer of the implant.

The induction principle can generally be used to heat a ferromagnetic material coupled to the exterior or the interior of the implant in order to heat it in a heat-conducting manner or thermally conductively coupled. Depending on the type of coupling, it may happen that the induction energy leads only indirectly to the heating, and the actual heating takes place at least partially by heat conduction.

To avoid unwanted, especially damaging, effects and effects of the applied energy on surrounding tissue and / or on surrounding other implants and the like. It can be provided that a shield is used. The shield can be designed and arranged in such a way during the heating of the implant that the energy is essentially focused on a respectively desired or predefined effective range. Outside the desired or desired effective range, the shielding effect should at least be such that significant, in particular health, impairment or even damage can be avoided. Such a shield may include, for example, a radiation shield.

The shield can be at least partially enclosed by the implant and / or integrated into it. In addition to the thus achievable protective effect can thus be achieved a better focusing of the energy to the particular desired range of action.

Overall, it is found that the mechanical removal of the implant from the tissue can be significantly simplified and facilitated by the method according to the invention. The energy supplied by the energy source (s) and / or the achieved destruction temperature can be measured or recorded in an advantageous development by means of at least one sensor. Thus, the destruction process can be monitored by means connected to the or each sensor control device, for example, gives a corresponding control signal to the dentist.

The invention will be further explained with reference to embodiments. Reference is also made to the drawings, in which FIG. 1 shows an embodiment with an external energy source, in particular an induction source, for the destruction of a connection of a

Dental implant with the jawbone and 2 shows an embodiment of a device for breaking a connection between a dental implant and a jawbone with an energy source that can be inserted into the dental implant, in each case shown schematically. Corresponding parts and sizes are provided in the Figures 1 and 2 with the same reference numerals.

FIGS. 1 and 2 show two exemplary embodiments of a device for a dental implant 1 according to the second aspect of the invention. From the description of the device results in particular the inventive method according to the first aspect of the invention.

The dental implant 1 located in a jawbone 2 is at least partially fused therewith. The latter is just desirable for the strength of the implant, but complicates the removal of the dental implant. 1

In order to facilitate the removal of the dental implant 1, the device has an induction source 3, with which the connection between the jawbone 2 and the dental implant 1 can be at least partially de- structed.

Instead of the induction source 3, or combined with it but also another source of energy, for. B. an ultrasonic or heat source or laser light source can be used. The following general embodiments can be largely transferred to any energy sources without further notice. To destroy the connection between the jawbone 2 and the dental implant 1, the induction source 3 is initially positioned in a suitable manner to the dental implant 1, in the case of FIG. 1 laterally and externally. The induction source, for example, in the mouth, or else be positioned outside of the oral cavity. After positioning, the induction source 3 is activated so that it generates an acting on the dental implant 1 alternating magnetic field (induction field).

The alternating magnetic field interacts with the dental implant 1 and generates eddy currents in the dental implant 1 made from the titanium alloy TiAl5Fe2.5. The eddy currents are converted into Joule heat in the dental implant material, so that the dental implant 1 heats up.

In order for the dental implant 1 to be heated more quickly, in the present case it has ferromagnetic material 4 in the form of layers, rings or strips, etc. By means of such ferromagnetic materials 4 embedded in the dental implant 1, heat can additionally be generated by inductively induced remagnetization processes, which contributes to the faster heating of the dental implant 1.

As a rule, the region or areas at which connections between the implant and tissue are to be formed or to be formed are specific to the respective implant. In that regard, the ferromagnetic materials 4 may preferably be embedded in those areas at which the commonly formed connections between tissue and implant can be most effectively destroyed by heating. To think here is, for example, a near-surface embedding. Furthermore, z. B. the volume or type of ferromagnetic material 4 are selected and formed according to the compound or compounds to be destroyed. By a selective, targeted and in particular minimal embedding of ferromagnetic materials 4, undesired effects of such materials can at least be reduced. As an example, be here Magnetic resonance examinations called, which are only conditionally feasible with implants with high ferromagnetic portions.

If the induction fields are sufficiently high, the desired heating can be achieved within a reasonable time frame, even when limited to eddy currents. This is especially true at destruction temperatures in the range of 40 ° C to 60 ° C, especially around 50 ° C, which may already be sufficient for dental implants 1. At or above the destruction temperature, the bone tissue is necrosed at least in the boundary layer between the dental implant 1 and the jawbone 2. As a result, the existing between dental implant 1 and jaw bone 2 connection is weakened or even destroyed. This in turn means that the dental implant 1 can be removed more easily.

The heating to the destruction temperature can be carried out continuously or in individual successive steps and / or with an approximately constant temperature profile, ie at a constant temperature or a specifically varying temperature profile in a temperature interval.

It is advantageous if the necrotizing effect can be limited or focused on the particular area of interest. Because it should be avoided that by the induction source 3, generally the energy source, located outside of the region of interest or the desired effective range tissue, etc. is affected. In order to achieve this, the device has a shield 5 which can be designed and placed relative to the induction source 3 and the dental implant 1 so that the tissue of interest and / or further implants are not damaged and / or subsequently influenced. After destruction of the connection between dental implant 1 and jaw tissue, the dental implant 1 can be removed in a surgical procedure. By the upstream destruction of the compound, the dental implant can be mechanically removed much easier. It turns out that the problem underlying the invention is solved.

In the further embodiment of FIG 2, a dental implant 1 is provided with a cavity 10 having an internal thread 11. In this internal thread 11 was previously the tooth crown, which is not shown in FIG 2, screwed. In this exemplary embodiment, an energy source 30 with an external thread 31 is screwed into the internal thread 11 in the cavity 10 of the dental implant 1 so that the energy source 30 can be inserted very far into the dental implant 1 and thus very close to the surface areas to be necrosed or heated within the jawbone 2. The energy source 30 can also be, for example, an ultrasound source or a laser light source or an infrared source or simply a resistance heating element.

If the dental implant 1 does not have such a cavity 10, the energy source can also be attached to the free surface of the dental implant or brought into contact, for example. Likewise, the energy source can be introduced in the absence of an internal thread 11 in the dental implant 1 only in the cavity 10 without screwing.

The energy source 30 is via a connecting line 32 which transmits a light beam or the required other energy, such as electrical energy, from a control device 15 or other supply unit to the power source 30. The control device 15 is further connected via a sensor line 72 to a sensor 7, which may for example be arranged between the jawbone 2 and the gum or a lip 8 in the vicinity of the dental implant 1 to be treated. The sensor 7 can monitor the destruction process and For example, the depth of the introduced power source 30, d. H. how far the energy source 30 is within the dental implant 1 or from its lowest point in the jawbone 2 removed, is, can measure. Depending on the measured or detected position or position of the energy source 30 relative to the dental implant 1, the control device 15 can then give a signal to the attending physician or interrupt the power supply for the energy source 30, in particular via the connection line 32.

Alternatively or additionally, the sensor 7 or a further sensor can also monitor the temperature and / or intensity of the energy supplied to the dental implant 1. For example, a radiation sensor could detect the heat radiation emitted by the implant 1, or an induction sensor that detects the induction intensity emitted by the energy source 30 or the energy source 3 in FIG. Such an embodiment with a control device 15 and a sensor 7 gives the attending physician the possibility of feedback as to how far the process and the heating of the dental implant 1 are already advanced and whether the process can already be stopped, ie the tissue is already sufficiently necrosed.

In general, the dentist will then wait a certain amount of time, for example one or more days, until the necrotized tissue has broken down or dissolved and then remove the dissolved dental implant 1 from the jawbone 2. Reference number list

1 dental implant

2 jaw bones

3 induction source

4 ferromagnetic material

5 shielding

6 tooth crown

7 sensor

8 gums / lip

10 cavity

11 internal thread

15 control device

30 energy source

31 external thread

32 connecting cable

72 sensor cable

Claims

Method for at least partially destroying at least one connection formed or existing between an implant (1), in particular a dental implant (1), and a biological tissue (2), in particular bone cells, wherein at least the implant (1) is energized, in such a way in that the tissue (2) is necrosed at the interface to the implant (1) and / or is heated to at least a predetermined destruction temperature and / or is detached by vibration.

A process according to claim 1, wherein the destruction temperature (s) is in a range from 40 ° C to 60 ° C, especially at about 50 ° C.

A method according to claim 1 or claim 2, wherein at least one of the following forms of energy is used as energy: higher or high frequency sound energy, in particular ultrasonic energy, heat energy, in particular electrically generated Joule heat energy and / or heat radiation energy, magnetic energy, e.g. As induction energy, and electromagnetic energy, in particular light or infrared, preferably a laser.

4. The method according to any one of claims 1 to 3, wherein the implant (1) comprises titanium or a titanium alloy and / or a ferromagnetic material (4), in particular a ferromagnetic induction region, in particular one or more induction layers comprises.

Method according to one of claims 1 to 4, wherein a shield (5) is used, by which, at least partially, tissue (2) and / or one or more further implants outside a desired effective range is shielded from the application of energy, in particular, the shield (5) at least partially from the implant (1) and / or is integrated into this.

Method according to one of the preceding claims, in which the supplied energy and / or the reached destruction temperature is detected or measured by means of at least one sensor and preferably also the destruction process is monitored.

Device for at least partially destroying at least one connection formed or existing between an implant (1), in particular a dental implant (1), and a biological tissue (2), in particular bone cells, in particular for carrying out the method according to one of the preceding claims,

the device comprising an energy source (3) designed to apply energy to the implant (1),

wherein the energy is adjustable or adjusted so that upon exposure of the implant with the energy, the tissue (2) at the interface to the implant (1) is necrosed and / or at least heated to a predetermined destruction temperature and / or detached by vibration.

Apparatus according to claim 7, in which the energy source comprises or is at least one of the following energy sources: sound source, in particular higher or high frequency sound source, in particular ultrasound source, heat source, in particular electric heat source, in particular resistance heating, and / or heat radiation source, induction source, radiation source for electromagnetic radiation , in particular light or infrared, in particular laser.

Device according to claim 7 or claim 8, in which the implant (1) comprises titanium or a titanium alloy and / or a ferromagnetic material (4), in particular a ferromagnetic material Induction region, in particular one or more induction layers comprises and / or in which a shield (5) which is designed and positioned such that, at least partially, tissue (2) and / or one or more further implants outside a desired effective range before loading with

Energy is shielded / be provided is provided which shield in particular at least partially from the implant (1) and / or is integrated into this. 10. Device according to one of claims 7 to 9, and with at least one sensor for detecting or measuring the energy supplied by the energy source (s) and / or the achieved destruction temperature and preferably with a connected to the or each sensor control device (15). that monitors the destruction process.