JP2006521465A - Apparatus for electrodeposition of molded dental parts and parts thereof - Google Patents

Abstract

The present invention relates to an electrodeposition apparatus, and more particularly to an electrodeposition apparatus for dental parts to be molded. In addition to standard components, the device includes at least one magnetic connection means for creating electrical contact for electrodeposition between at least one electrode and the current / voltage source of the device. The present invention further describes an electrode having a magnet that acts as a holding / contacting element and a component having a second magnet for interacting with this electrode to provide a magnet contact connection. The component is then provided in the current / voltage supply source or head part or cover part of the electrodeposition tool.

Description

  The present invention relates to a device for electroplating according to the preamble of claim 1, in particular to electroplating of dental parts to be molded, such as skeletons for crowns, inlays, bridges, etc.

  The electrodeposition of metal layers, i.e. deposition under current, has already been known for a long time. If this method is used on molded parts, i.e. inherently stable bodies, it can be called electroforming.

  The use of electroforming in dental technology dates back to the early 1960s when Rogers and Armstrong made inlays and onlays by electrodeposition. Gold baths that were still cyanide based at that stage have now moved to various gold baths such as the sulfite-based gold baths of the applicant (EP 0360848).

  Gold layers produced by electrodeposition have a significantly higher hardness than cast gold layers between 60-80 HV or between 100-130 HV, depending on the electrolyte composition. These electrodeposited gold layers are generally free of unavoidable cavities, inhomogeneities and impurities when cast. Nevertheless, there is a possibility of destruction to the resulting deposits due to unclean working conditions and resulting contaminants, or as a result of instrument specific process variations related to the manufacturer. These breaks on adhesion are manifest themselves by, for example, the incorporation of impurities in the electrodeposition material, the formation of buds in the layers or the formation of individual layers or pores. Under the worst conditions, this failure of properties can lead to a lack of stability during firing, and thus can create a layer / molded body that is not suitable for further dental processing. A problem in producing dental restoration parts / molded dental parts by electrodeposition is in some cases the complex geometry required and the special adhesion properties. For stability and processability, a uniform and homogeneous layer structure and a layer thickness distribution that is as uniform as possible are desirable. Current-controlled electrodeposition, when formed, has a much higher reliability and good reproducible properties, for example, in Applicant's AGC instrument.

  Over the years, a variety of instruments have been marketed in the dental market and have been utilized in dental technology laboratories for making dental restorations or skeletons by electrodeposition. In this context, the term skeleton should be understood to mean a metal substructure such as a crown cap or a bridge cap, which is then coated with ceramic by, for example, a dental technician and then the final tooth. Calcination to form a substitution. For various reasons, especially for biocompatibility for patients, these scaffolds are made from pure gold. The tool referred to is what is known as a small electrodeposition tool, which, unlike industrial scale electrodeposition equipment, does not operate continuously but rather operates discontinuously. Depending on the type and size of the instrument, the process time is generally several hours, for example 1 to 16 hours. These appliances are typically installed on a small workbench, together with a usable volume of electrolyte of approximately 1 liter or less and a few dental restorations that can be manufactured in-process, such as the capacity of a crown cap. Can be manipulated.

  Users of this type of electrodeposition apparatus are generally people working in the dental laboratory, for example, dental technicians, ie, skilled staff who perform electrodeposition without special training. Thus, in particular, it is possible to use this type of electrodeposition apparatus without risk and with ease with regard to the quality of the dental restoration material produced there and with regard to potential harm to the health of the operator. is important. Therefore, manufacturers of this type of electrodeposition apparatus are trying to provide an instrument that is as user friendly as possible and reliable in process. Examples that can be mentioned in this background include the AGC range of instruments made by the applicant, which, for example, gives a total power of 1-16 objects that can be electrodeposited simultaneously and a process time of 1-16 hours. Cover.

  It is also necessary to consider contact connections in connection with achieving maximum user friendliness and process reliability. In an “electrodeposition tool” (at least) 1 in the state of teeth or mouth, provided with a layer of connecting silver, connected as electrolyte (eg AGC gold bath made by the applicant), anode and cathode. There are two replication models. The replica model is connected to a current / voltage source in the instrument via a holding rod / wire that generally serves as an electrical contact at the same time. The retaining rod may be a stainless steel rod or, for example, a copper / titanium rod, and may be designed for single use or reuse. With this kind of contact rod, a particular part should always be immersed in the electrolyte during the process and this part should be electrically insulated from the electrolyte so that it is not plated by gold. This is generally done by what is known as a shrink fit tube made of plastic or a suitable dressing.

  The contact / holding rod is then connected to a current / voltage source in the instrument via a plug connection contact (eg, a socket) with a metal clamp or pinch connection. Contact to the instrument also needs to have a long service life and should not be susceptible to corrosion if located within the electroplating cell. Corrosion products can contaminate the electrodes and put the overall function of the process at risk. The generation of the contact, i.e. the coupling between the instrument and the replica model and the electrical contact connection, is in this case achieved by the operator.

  In this context, special requirements rest on the contact connection method, arranged in one to ensure process reliability and the other to keep it as simple as possible. With regard to process reliability, for example, it is important that electrical contact remain reproducible for a long time, ie, the entire process time.

  One drawback of the types of contacts described above is that contact resistance may always occur and may not be determined, and under certain circumstances prevents sufficient current from flowing through the replica model to be electroplated. . Under such conditions, defects occur during electrodeposition, which may be due to an electrodeposited gold skeleton having a layer structure that is too thin and / or destroyed, or at extremes due to an electrodeposition process that is totally disturbed. It becomes clear in itself. Furthermore, the aforementioned contacts are sometimes difficult to handle by an operator and the components connected to it are difficult to adjust with respect to each other.

  As a result, the present invention is based on the object of avoiding or substantially eliminating the contact connection problems that occur in the prior art. Connecting to a current / voltage source should be simple for the part or model to be electroplated and this connection should be reliably maintained throughout the processing time. Furthermore, it should be possible for the electrical connection to be interrupted again in a simple manner in order to be able to introduce new parts / models into the electroplating apparatus.

  This object is achieved by the features of claim 1 and its important components: an electrode having the features of claim 12, a current / voltage source having the features of claim 19, and a head component having the features of claim 22. This is achieved by a device having a cover part. Preferred embodiments of the device or corresponding parts are presented in the dependent claims 2-11, 13-18 and 20, 21, 23 and 24. The language of all claims is incorporated by reference into the contents of this specification.

  The device according to the invention comprises at least one current / voltage source and an electrode that can be placed in a container that can be filled with electrolyte. To create an electrical contact for electrodeposition, at least one magnetic connection means is provided between the at least one electrode and the current / voltage source. In this background, the core concept of the present invention is based on providing a magnetic contact connection to create an electrical contact between the electrode and the current / voltage source. The magnetic coupling force of two magnetic metal parts under voltage results in an electrical circuit to be closed by corresponding contact between these parts.

  It will be apparent from the foregoing that the magnetic connection means provided in accordance with the present invention is preferably a two-part design. In this case, such a two-part design may include a magnet as the first part and a second part made of magnetizable metal. In a particularly preferred embodiment, the two-part magnetic connection means comprises two magnets that produce the required contact due to their mutual attractive forces. A particularly good holding force and minimal contact resistance are achieved if two magnets are used.

  The magnet described above is preferably what is known as a permanent magnet, as is known from the prior art. They provide the required holding force against each other, without the need for magnetizable metals or further auxiliary means to be used. Furthermore, the magnet used is preferably circular in cross section. This type of magnet can be described as a round magnet.

  In an improvement, in the device according to the invention, the magnet is provided in a current / voltage supply. If the present invention is implemented with the electroplating tool mentioned in the introduction, this type of tool is known as a head part or cover part which is placed on a container containing an electrolyte when performing electrodeposition. Often has what is. In such an embodiment, the magnet provided in the current / voltage supply is preferably arranged on the head part or cover part. In this way, it is then particularly easy to make contact with the electrode. In said embodiment, a sleeve is then provided in which the magnet is housed, in particular at the current / voltage supply, in particular at the head part or cover part. Such particularly preferred embodiments are described in more detail below in conjunction with the drawings.

  In a further preferred embodiment, the magnet is provided on the electrode or part of the electrode. As mentioned in the introduction, the electrode is a rod-like component for convenience and can be referred to as a contact / holding rod. Thus, in these embodiments, magnets are preferably provided on these rod-like components. Such electrodes, in particular rods, preferably have a sleeve-like container in which a magnet is introduced. This will likewise be explained in more detail in conjunction with the drawing.

  As will be apparent from the description given so far, the present invention also includes novel electrodes for electrodeposition, in particular for electrodeposition of molded dental parts. According to the invention, the electrode is constructed in such a way that it has at least one magnetic connection means, in particular at least one part of a two-part magnetic connection means. The electrode is preferably in the form of a rod which essentially corresponds to the contact / holding rod shape disclosed so far.

  In accordance with the present invention, in a novel electrode, a magnetic connection means or one part thereof is provided at one end of the electrode. This is usually the end provided on the current / voltage supply during electrodeposition after the generation of the electrical contact.

  In this case, the magnetic connection means may be a magnetizable metal, which then interacts with a magnet set to a current / voltage source. However, the magnetic connection means in the electrode is preferably a magnet, as already explained in detail above. This type of magnet is preferably a permanent magnet. A magnet having a round cross section (round magnet) is preferred.

  In another preferred embodiment of the electrode according to the invention, the magnet is located in a sleeve-like container at one end of the electrode (preferably a rod-like design). In order to protect the magnets in the container from corrosion, the container is preferably partitioned by a cover part. The cover part is preferably a flat plate design. In this case, the cover table forms a contact surface that interacts with other parts of the magnetic connection means set in the current / voltage supply.

  The electrode itself is composed of any conductive material in principle. However, it is preferred that the cover part present to close the container containing the electrodes and magnets is made from stainless steel. This material provides good protection against corrosion. If appropriate, the entire outer surface of the electrode or preferably at least the surface of the cover part, which forms the contact surface, may be coated with another metal. With this type of metal coating, corrosion resistance or electrical conductivity can be further increased. In this context, particular mention should be made of a coating made of gold or a gold alloy which can preferably be deposited by electroplating only on the electrode or on the cover part.

  At the “lower” end carrying the part / model to be coated during electrodeposition, the electrodes according to the invention are preferably from the “upper” end, ie the end facing the current / voltage source or the head or cover part. Also have a small cross-section. It is preferred that the electrode narrow or taper towards its tip at its “lower” end. In this way, the part / model to be coated is easily fixed to the electrode, which simultaneously acts as a holding rod.

  Finally, it should also be mentioned that the electrode may be provided on its outer surface with an electrically non-conductive coating, in particular a plastic coating. This prevents the metal electrodeposition and / or corrosion action and damage to the electrodes there. To ensure a simple contact connection to the part / model to be coated, it is preferred that the “lower” end of the electrode lack this type of coating.

  As a further novel component, the present invention includes a current / voltage source for electrodeposition, in particular for electrodeposition of molded dental parts, and a head part or cover part (as described above). These components are likewise characterized by having at least one magnetic connection means, in particular at least one part of a two-part magnetic connection means. This may be a magnetizable metal or preferably a magnet. Even in this case, special mention should be made of permanent magnets. The magnet is preferably round in cross section (round magnet).

  In these two new components, the magnet is preferably located in a sleeve-like container. To protect against corrosion, the container may preferably be provided with a cover part. In this regard, reference may be made to further earnest explanations given with the electrodes according to the invention. In this case as well, the contact surface is then formed by the front of the cover part.

  Finally, the core concept of the present invention is formulated as the use of at least one magnetic connection means to make electrical contact between at least one electrode and a current / voltage source during electrodeposition. Is done.

  The electrodeposition is preferably an electrodeposition used for the production of shaped dental parts such as skeletons for crowns, inlays, bridges and the like.

  The device according to the invention or the component according to the invention of the device has a number of advantages over those having previously disclosed contact connections.

  For example, in the present invention, the required electrical contact is caused by the targeted magnetic force. This is strong enough that this contact is maintained throughout the electrodeposition. This advantage is evident per se when using the above-described preferred embodiment of the two interacting parts of the magnetic connection means, in particular the two magnets described above. Because of the targeted magnetic force, the two interacting parts necessarily attract each other in the correct position with respect to each other so that the two parts, in particular the two magnets, lie on top of each other. This ensures that there is always a defined contact surface and virtually eliminates the result of poor electrodeposition caused by undefined contact resistance.

  A further advantage of the present invention that should be mentioned is that the operator can make electrical contact connections quickly and easily. For example, the electrode / contact rod can be easily replaced, which significantly increases the working efficiency for the operator. Furthermore, for example, contact surface contamination is substantially excluded, so there is no need for maintenance management whatever is to be performed on the component. If it turns out that cleaning is necessary from time to time, this cleaning can easily be accomplished by simply wiping the components.

  Moreover, another advantage of embodiments according to the present invention becomes apparent per se when standard electrodeposition process temperatures are applied, especially in the dental field. Such process temperatures are generally between 50 ° C. and 70 ° C., and usually about 65 ° C. The result is that the condensation product of the electrolyte collects at the top of the container or in the electroplating cell. Because of their chemical composition, this type of condensation product can lead to corrosion in parts that make electrical contact. The product produced by the corrosion can then enter the electrolyte and contaminate the latter. Such impurities are then included in the electrodeposition, for example deposited together with gold, and thus have a detrimental effect on the quality of the electrodeposited molded part, especially the tooth replacement skeleton. Yes. Contact connections achieved in accordance with the present invention can be ruled out with practical certainty. This applies in particular to embodiments in which the magnet is located in a sleeve-like component that is firmly partitioned by a cover part.

  The advantages of the present invention manifest themselves more clearly, especially in the latter embodiment, with the type of coated structure for the magnet used to make the electrical contact. In this type of embodiment, the magnet is completely protected by this coated structure. Therefore, the material used for this type of structure is preferably corrosion resistant stainless steel. This eliminates corrosion on electrical contact connections. If a gold layer is additionally applied to the stainless steel electrode / stainless steel rod, at least on the contact surface, for example in the cover part, on the one hand this corrosion resistance is further increased and on the other hand Then, excellent electrical conductivity is achieved. Thus, these embodiments in combination with other design features provide excellent, permanent and reproducible contact positions between the electrode / holding rod and the current / voltage source or head or cover component. An electrical contact is created.

  Finally, the electrode according to the invention or the holding / contact rod according to the invention can be permanently reused. This is applied if it is coated on its surface with a protective layer, in particular a non-conductive protective layer such as plastic.

  These and other features of the invention will become apparent from the examples and figures set forth below in combination with the claims. In this context, individual features can be implemented by themselves or in combination with each other.

  In accordance with the present invention, the type, AGC speed electroplating tool made by the applicant is modified. This starting point is a single cell version of this instrument which is not described in more detail in the figure. The instrument substantially includes a housing that houses a current / voltage source and a control unit. Furthermore, the instrument has an electrolyte container with a head part or a cover part, to which an anode and a cathode provided with a part / model to be coated by electrodeposition are fixed. In the case of an AGC speed instrument made by the applicant, the entire electrolyte container with the head part or cover part can be removed from the instrument. This simplifies the introduction of the part / model to be coated into the electrolyte container and protects the remaining components of the instrument from contamination, for example by electrolyte.

  Previous designs of AGC speed devices made by applicants use plug connection contacts to fix / contact connect anodes that are generally designed as annular anodes, and especially holding / contact rods that are connected as cathodes. It was. In this background, the upper end, which is a rod-like design of these electrodes, was introduced into the corresponding container in the head part or cover part, for example, latched in place. However, this inherently reliable contact connection often cannot be quickly replaced. Furthermore, the contact surface had to be protected against corrosion from vapor rising from the electrolyte in a relatively complex manner.

  The two components illustrated in FIGS. 1 and 2 are used by the applicant to make and modify the described instrument in accordance with the present invention.

  In this context, FIG. 1 shows an electrode 1 according to the invention in the form of a holding or contact rod. The electrode 1 is made of stainless steel and has a smaller cross-sectional area at one end 2 than the other end 3. In this case, the end 2 is designed in the form of a tip that serves to secure the electrode to the part or model (not shown in FIG. 1) to be coated by electrodeposition. This will be described in more detail below.

  At the other end 3 is a sleeve-like container / housing 4 into which a magnet 5 is introduced. The magnet 5 is a permanent magnet having a round cross-sectional area, that is, known as a round magnet. In order to protect the magnet 5 from corrosion, a cover part 6, which is likewise made from stainless steel and partitions the container 4 in a sealed manner, is present on the electrode 1. As a result, the design 3 of the electrode 1 means that the magnet 5 is completely encapsulated.

  According to the invention, the surface 7 present outside the cover part 6 forms a contact surface, via which the magnet 5 as one part of the two-part magnetic connection means interacts with the second part. In order to optimize the electrical contact caused by the magnetic force, the surface 7 of the electrode 1 or, if appropriate, the entire outer surface thereof may be gold-plated. This is not shown in detail in FIG. Similarly, it is possible to provide a plastic coating on the outer surface of the electrode 1 except for the surface 7 which acts as a contact surface. This then prevents unwanted electrodeposition from occurring on the electrode itself. In the absence of a plastic coating, this adhesion can be prevented by the operator by other measures, for example by surrounding the electrode 1 with a shrink-fit tube.

  FIG. 2 shows a sleeve-like component 11 which is round in cross section and is also made from stainless steel. This component 11 forms a part that is integral with the electrode 1 of FIG. 1 acting as a holding / contacting rod. For example, the component 11 may be introduced into the head part or cover part of an AGC speed device made by the applicant, or in the case of differently designed electrodeposition devices, set in different ways to the current / voltage source May be.

  At one end 12, the component 11 has a container / housing 13 in which a magnet 14 is introduced. Also in this case, the magnet 14 is a permanent magnet having a round cross section, that is, a round magnet. The container 13 with the round magnet 14 is partitioned in a sealing manner by a cover part 15 made of stainless steel. This again prevents the magnet 14 from being corroded by the vapor rising from the electrolyte.

  In the case of the component 11, the outer surface 16 present on the cover part 15 represents a contact surface with the magnet 14 and interacts with the other part of the two-part magnetic connection means. Again, the surface 16 and, if appropriate, the entire outer surface of the component 11 may be gold plated. A corresponding plastic coating (apart from surface 16) is also possible.

  If the surface 7 of the electrode 1 is now moved towards the surface 16 of the component 11 (the magnets 5 and 14 have been introduced in the correct orientation), the two surfaces are attracted by the magnetic force and are correctly positioned with respect to each other. At the same time, the electrical contact required for electrodeposition occurs. The current then flows, for example, across the component 11 with the surface 16 to the surface 7 of the electrode 1 and thus also to the model of the dental restoration fixed at its end 2. Of course, electrical contact can occur to the electrode connected as the anode as well. This type of anode is usually simply a metal rod.

  The tooth restoration material is made by electroforming using an AGC speed appliance made by the applicant, modified using the components shown in FIGS. In this case, the component 11 (eg, FIG. 2) is introduced into the head or cover part of the appliance, and the electrode 1 (eg, FIG. 1) is used as a holding / contacting rod in a dental restoration or model.

  In the two experiments presented below, the starting material is a plaster stamp in one case, making it conductive in the usual way using conductive silver. In other cases, the starting point is a metallic primary crown, which is then coated with conductive silver, taking into account the cement that joins the primary crown to the secondary crown (double teeth) Crown technique). The electrolyte used is a sulfite-based gold bath produced by the applicant. However, the composition of the gold bath is not critical to the benefits of the present invention that produce an effect.

  Preparations for performing electrodeposition are summarized in the following table. Both examples produce complete molded parts made of high purity gold with a layer thickness of 300 μm. This reveals that the “magnet contact connection” according to the present invention results in high quality molded parts required for dental technology. As already mentioned in the introduction and description, the modification to the device according to the invention represents a real advance, taking into account the advantages achieved over the previous contact connection.

FIG. 2 is a diagrammatic cross-sectional view of an electrode according to the invention or a holding / contact rod according to the invention with a magnet inserted. FIG. 2 is a cross-sectional view of a component according to the present invention in which a magnet is inserted and can be provided in a current / voltage source or a head component or cover component of the device according to the present invention.

Claims (25)

  Electrodeposition, in particular electroplating of molded dental parts such as skeletons for crowns, inlays, bridges etc., placed in a container that can be filled with at least one current / voltage source and electrolyte A device having electrodes that can be characterized in that there is at least one magnetic connection means for creating an electrical contact for electrodeposition between at least one electrode and a current / voltage source Device to do.   2. A device according to claim 1, characterized in that the magnetic connecting means comprises two parts which interact with each other via a magnetic force.   3. A device according to claim 2, wherein the magnetic connection means comprises two magnets.   3. A device according to claim 2, wherein the magnetic connection means comprises a magnet and a magnetizable metal part.   Device according to claim 3 or 4, characterized in that the magnet has a round cross-sectional area.   Device according to one of claims 2 to 5, characterized in that one of the components of the magnetic connection means, in particular a magnet, is provided in the current / voltage supply.   7. A component according to claim 6, characterized in that the component, in particular the magnet, is located on a container that can be filled with an electrolyte during electrodeposition and is preferably provided on a head component or cover component on which an electrode is arranged. apparatus.   8. A device according to claim 6 or 7, characterized in that the magnet is arranged on the sleeve-like component.   9. A device according to claim 2, wherein a part of the magnetic connection means is provided on the electrode or part of the electrode.   Device according to claim 9, characterized in that the electrode or part of the electrode has a rod-like design.   Device according to claim 9 or 10, characterized in that the magnet is placed in a sleeve-like container at the electrode or part of the electrode.   Electrodes for electrodeposition, in particular for electrodeposition of molded dental parts such as skeletons for crowns, inlays, bridges, etc., comprising at least one magnetic connection means, in particular one of two-part magnetic connection means An electrode having a portion.   13. Electrode according to claim 12, characterized in that it is a rod-like design.   14. Electrode according to claim 12 or 13, characterized in that a magnetic connection means is arranged at one end of the electrode, this end being preferably provided at the current / voltage supply during electrodeposition.   15. The electrode according to claim 12, wherein the magnetic connecting means is a magnet.   16. Electrode according to claim 15, characterized in that the magnet is arranged in a sleeve-like container in the electrode, preferably the container can be partitioned by a cover part.   The end of the electrode without magnetic connecting means has a smaller cross-sectional area than the end of the electrode with magnetic connecting means, and the end of the electrode without magnetic connecting means preferably narrows conically or tapers towards the tip The electrode according to claim 12, wherein the electrode is one of the following.   18. An electrically nonconductive coating, in particular a plastic coating, is provided, and the end of the electrode without magnetic connection means preferably lacks such a coating. electrode.   A current / voltage source for electrodeposition, in particular for electrodeposition of molded dental parts such as skeletons for crowns, inlays, bridges, etc., comprising at least one magnetic connection means, in particular two-part magnetic A current / voltage supply comprising at least one part of the connection means.   20. The current / voltage source according to claim 19, wherein the magnetic connecting means is a magnet.   21. A current / voltage source according to claim 20, characterized in that the magnet is arranged in a sleeve-like container, preferably the container can be partitioned by a cover part.   Electro-deposition, especially electro-deposition of molded dental parts such as skeletons for crowns, inlays, bridges, etc. of the container in which this head part or cover part can be filled with electrolyte during electrodeposition A head part or cover part arranged thereon, comprising at least one magnetic connecting means, in particular at least one part of a two-part magnetic connecting means.   The head component or cover component according to claim 22, wherein the magnetic connecting means is a magnet.   24. A head part or cover part according to claim 23, characterized in that the magnet is arranged in a sleeve-like container, preferably the container can be partitioned by a cover part.   To make electrical contact between at least one electrode and at least one current / voltage source during electrodeposition, particularly during electrodeposition of molded dental parts such as crowns, inlays, bridges, etc. Use of at least one magnetic connection means.

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