WO2006084425A1

WO2006084425A1 - Method and device for producing by electrophoresis fully ceramic tooth elements having a predefined spatial shape

Info

Publication number: WO2006084425A1
Application number: PCT/DE2006/000002
Authority: WO
Inventors: Stefan Wolz
Original assignee: Stefan Wolz
Priority date: 2005-02-12
Filing date: 2006-01-03
Publication date: 2006-08-17
Also published as: DE102005006624A1; EP1850787A1; JP2008529612A; DE112006000893A5; US20090038945A1

Abstract

The invention relates to a method and device for producing by electrophoresis fully ceramic tooth elements having a predefined spatial shape, wherein an electric conductive plate (1) having different conductive areas is applied to a working model or a structural element directly or at a certain distance. According to a known method, a power is supplied to the plate by means of a cable, which is removable after coating by means of a slip and prior to sintering. According to the inventive method, said laborious operation is nor required anymore. The inventive method consists in fixing the plates (1) to a conductive tooth stump (2) by means of an adhesive conductive material (5) or to an implant abutment (3). The power can be supplied by the tooth stump, the abutment or a leg (7) integrateable with the plate. Said plate is preferably made of zinc or an adhesive conductive material, preferably a mixture of wax and zinc powder which disappears without residues by sintering. A plate which is particularly suitable for carrying out said method and whose conductivity variations are obtainable by means of recesses embodied therein is also disclosed.

Description

description

Method and device for producing all-ceramic tooth parts with a predetermined spatial form by means of electrophoresis

WO 2004/041113 A1 already discloses a process for the production of all-ceramic tooth parts. Electrophoresis in which an electrically conductive plate on a working model or on a

Scaffold part, such as an implant abutment, is arranged directly or at a distance, wherein the plate has different conductivity. With the method directly any desired spatial form can be achieved with appropriate selection of the plate without much rework. In this known method, the power is supplied via a cable to the or the platelets.

After coating with the slurry, it is necessary to separate the cables from the plate. That this is not without effort, should be obvious to the skilled person, since a violation of the applied slip layer is inevitable. In order to produce a satisfactory green body, therefore, it requires a certain rework.

It is therefore the object of the invention specified in claim 1 to further develop the electrophoresis method known from WO 2004/041113 A1 in such a way that no reworking is required. This object is achieved with the method features of claim 1. Advantageous developments are described in the dependent claims. The invention further relates to the structural design of the platelets, which are particularly suitable for the claimed method.

It should also be noted that the term "slurry" as used in dental practice refers to a slurry of ceramic powder in a primarily aqueous suspension liquid. So it's not a model duplicated by the working model. This finding is significant in that other, not invented by the inventor electrophoresis method only work with duplicated models, since the skilled worker knows that apart from the additional workload each duplication generates additional errors that can be repaired in tedious rework. It goes without saying, however, that the claimed method can also be carried out on a duplicated model. The invention will be explained in more detail with reference to Figures 1 to 8.

Show it:

Figure 1: a sawn out of a working model section with two tooth stumps

FIG. 2 shows a section with two implant abutments. ..

Figure 3: a section with a tooth stump and an implant abutment

Figure 4: a section also with a tooth stump and an implant abutment in a different arrangement

FIG. 5: a plate for producing an anterior tooth

FIG. 6 shows a plate for producing molar teeth

FIG. 7 shows a plate for producing premolar teeth

FIG. 8 shows a small plate for producing a canine tooth

From the dentition of a patient, a working model is first created in the usual way. From this working model, the section is sawn out in which the restoration of the teeth is to take place. Figures 1 to 4 schematically show four such different sections of working models, on. by electrophoresis a ceramic framework, e.g. made of alumina, to be built. These sections are fixed in a holder of the electrophoretic coating machine and coated by immersion in the aqueous slurry, whereby they are turned down by 180 °, in contrast to the position shown in the drawings.

FIG. 1 shows a section of a working model with two tooth stumps 2. Between these tooth stubs, a plate 1 is fastened by means of a conductive, adhesive material 5. This material may consist of dental wax, as used in a dental laboratory for fixing parts. In cjjesem wax 5g zinc powder are incorporated on 1g wax. In the development of the invention was surprisingly found that different waxes at the same mixing ratio of zinc powder to wax different conductivities, although wax alone is not conductive.

Since a working model usually consists of plaster or other non-conductive material, the surface of the tooth stumps must be made conductive. This is done by applying a conductive varnish whose conductivity is also achieved by zinc powder. The usual in dental practice silver conductive coatings are less suitable because they do not evaporate without residue during sintering. In order for the green body to be easily lifted from the model after electrophoresis, the covering of the model with a release agent is indicated, as taught in DE 198 12 664 A1. The power is supplied in Figure 1 via a tongue. 8

The platelet itself is preferably made of zinc. This is done with a

Laser from a zinc foil cut out the desired shape. Since zinc is easily deformable, a prefabricated platelet becomes the local one

Need adapted by bending or by cutting material.

Thus, in electrophoresis already the desired spatial form that makes little or no rework required.

After drying and removal from the model, the green body is sintered by known methods. Here is another advantage of zinc as a material for the platelets 1 and the adhesive wax 5, since it is at the high

Sintering temperature volatilizes without residue.

In Figure 2, the model has two implant abutments 3, which are usually made of titanium and thus are conductive. The power supply can be effected in this case via a terminal 6 which is conductively connected to an abutment 3.

FIG. 3 shows an abutment 3 and a tooth stump 2. After the tooth stump 2 has been rendered conductive as described above, the

Power supply via a foot 7 of a small plate. As shown in Figures 5 to 8, the platelets in their original shape always have this foot 7, which also serves to facilitate handling of the platelet and is cut off when not needed.

In Figure 4 it is shown that with the adhesive wax 5 and a platelet can be attached to another plate. The power is supplied via the connection 6 to the abutment 3. The tooth stump 2 is, as already described above, made conductive.

From the foregoing, it will be seen that with the invention, because of its versatility, any scaffolding structure is possible. FIGS. 5 to 8 show different platelets of twice the size in their original form. FIG. 5 shows a small plate for producing an anterior tooth. The plate according to FIG. 6 serves to produce a molar tooth, which according to FIG. 7 is a premolar tooth. With the platelet of Figure 8, a canine can be produced.

As all figures show, the regions of different conductivity are produced by recesses 4 in the platelets. The platelets also each have a foot 7, which serves better handling, but can also be used as a conductor for the electric current.

Claims

claims

1. A method for producing all-ceramic tooth parts with a predetermined spatial shape by means of electrophoresis, wherein an electrically conductive plate (1) on a working model (2) or on a framework part (3) is arranged directly or at a distance and the plate regions (4) of different conductivity , characterized in that the power supply to at least one plate. (.1) about a senior ,. Adhesive material (5) takes place.

2. The method according to claim 1, characterized in that in implant abutments, the plate is adhesively secured to at least one abutment (3) and the power is supplied via the abutment.

3. The method according to claim 1, characterized in that in a non-conductive working model (2) at least one tooth stump is coated with a residue-free dissolving during sintering, metalliferous film.

4. The method according to claim 3, characterized in that zinc is used as the metal for the coating.

5. The method according to at least one of claims 1 to 4, characterized in that the power supply via a foot (7) of the plate takes place.

6. The method according to at least one of claims 1 to 6, characterized in that the conductive, adhesive material consists of wax and a metal powder, in particular zinc.

7. platelets, in particular for carrying out the method according to one of claims 1 to 6, characterized in that regions of different conductivity are produced by recesses in the platelet.

8. platelets according to claim 7, characterized in that it consists of zinc.

9. platelet according to claim 7 or 8, characterized by a thickness of 0.03 to 0.15 mm.

10. platelet according to one of claims 7 to 9, characterized in that it is cut out by means of a laser from a metal foil.