DE102008022575A1 - Method for producing dental workpieces e.g. abutment of a dental implant by a copy milling unit, comprises determining the dimensions of the workpiece by scanning a model and then transferring to molded blank by a rotary machine tool - Google Patents

Abstract

The method comprises determining the dimensions of workpiece to be formed by scanning a model (1) and then transferring to a molded blank by a rotary machine tool. The model which can be scanned is fixed on a carrier plate at the occlusion side and a probe element (2) is led up to 360[deg] around the model, so that lumen surfaces (4) of the model is scanned in the same machining procedure. The machine tool comprises a milling head with a conical shape of 1-10[deg] . The milling procedure is controlled in a computer-assisted manner.

Description

The The invention relates to a method for the production of dental technology Workpieces, according to the preamble of the claim 1.

depth Caries or accidental damage lead often to significant losses of the tooth crown. Often it is no longer possible to fill the tooth with a filling to repair. In such cases, at a dental Treatment used artificial dental crowns.

crowns include parts or the whole in the oral cavity protruding portion of a tooth and give it its form and sufficient Stability and natural appearance again.

Provided the tooth root of a tooth can not be preserved or is missing, can these also be replaced by an "artificial root" become. In this case, we talk about an implant.

One Implant usually consists of three parts: the implant body, an abutment and the superstructure applied thereto. Of the Implant body is a example of titanium or ceramic manufactured grub screw, which is anchored in the jawbone. Attached or screwed on there is the so-called abutment, which the connecting element between the implant body and Represents superstructure. Are used u. a. abutments made of titanium, aluminum oxide ceramics or zirconium oxide ceramics.

A Special feature are so-called telescopic crowns, which in principle made of two parts, the inner and outer telescope (also primary and secondary crown). The inner telescope, which u. a. can be made of metal or ceramic, is about the artificial or naturally preserved tooth stump used solid and insoluble, about which the removable Secondary crown attacks.

It can distinguish between cylinder telescope crowns and cone telescope crowns become. For cylinder telescope crowns are the surfaces the primary crown and the lumen of the primary crown milled exactly cylindrical, which is why ideal adhesion values regarding the interlocking crown parts.

The On the other hand, the cone of the cone head is tapered upwards (conical) too. The so-called cone angle is decisive for the stiction between primary and secondary crown the cone of the telescope. Here are angles between 4 ° and 6 ° conventional cone angle.

A common method to make telescopic crowns is the so-called Kopierfräsmethode. The lesson after DE 10 2006 027 A1 In this case, a copy milling device for the production of dental workpieces is disclosed, wherein a milling unit and a model to be scanned are assigned a key unit to a workpiece to be machined from ceramic materials. The stylus and milling unit are in operative connection with each other in the manner of a pantograph. As a result, the workpiece to be machined can be manufactured in an enlarged or reduced scale with respect to the model.

To an increasing extent so-called. Zirconia is used for the production of dental workpieces, as well as the teaching DE 199 38 143 A1 describes.

typically, the model to be scanned is on a denture impression of the patient manufactured. To do this, first of all, of course obtained or artificially replaced tooth stump a mass from Pattern Resin or similar self-curing Given acrylic modeling clay. To over this first plating from, for example, light-curing plastic the missing To model tooth crown or row of teeth.

The Resulting scaffolding is subsequently away from the tooth stump around this in a plastic disc Fasten. For this purpose, webs between the lateral outer surfaces the model and the plastic disc attached. Preferably two to three bars per tooth attached to the framework. The disk is subsequently placed in a fixing device of the button unit clamped a copy milling machine.

The Model is therefore, together with the connecting webs in a to be processed Transfer ceramic block. At the fixation points of the webs on the tooth can not be precise cylindrical or Milled conical outer surfaces. This has an obviously bad milling surface in Zirkonweissling result. Especially in the production of Internal telescopes or implant abutments are high accuracy of fit for the life of the manufactured crown extremely important, but can by the common copy-milling technique can not be guaranteed.

In addition, the webs must be removed after the sintering process with a cutting disc or a turbine with water jet. Due to this, further inaccuracies are incorporated into the workpiece. In addition, any reworking of the surface in the finished sintered state, considerable damage to the zircons, since especially after the sintering process, any impact on the workpiece zirconia with material disadvantages such as micro cracks and cracks ver is bound. This significantly shortens the life of a dental crown.

Out The above, it is therefore an object of the invention, an evolved Process for the production of dental workpieces indicate which of the problems mentioned in the conventional Production of dental workpieces by means of a Copy milling machine overcomes.

The Solution of the object of the invention is achieved by a method according to the combination of features according to claim 1, wherein the dependent claims at least expedient Represent refinements and developments.

The Process for the production of dental workpieces assumes that the dimensions of a workpiece to be formed determined by sampling a model and by means of a rotating Transfer machining tool to a mold blank become.

According to the invention while the scanned model only on the occlusal side fixed on a support plate so that the button unit 360 ° around the model can be performed. It is omitted consequently, the web connections known from the prior art which do not allow a 360 ° guidance around the model.

moreover it is possible with this arrangement of fixation, the Lumen of a dental workpiece to be processed to work during the same work step, without To span the workpiece or otherwise fix it.

Around a precisely cylindrical or conical milling surface are obtained in the present process for the preparation of Dental workpieces according to the invention conical used shaped milling heads. With a substantially tapered milling head tapering towards the shank On the one hand, it is possible to make the lumen of a crown exactly cylindrical to milled and on the other hand on the outer surface the workpiece mounted protrusions and edges to work out of the zirconia block at a 360 ° angle.

Of the Cone angle of the used milling head can be 1 ° to 10 °.

moreover the milling head is preferably made of sintered zirconia shaped. Milling heads made of this material are much more cheaper to produce than conventional Milling instruments with diamond-coated surfaces.

Conveniently, is the blank to be machined a ceramic white, preferably a Zirkonoxidweißling. This material is particularly suitable for dental technician processing, should but already fully formed before the sintering process be to later micro jumps and tears avoid. Since the workpiece to be cut only fixed on the occlusal side, this can after the Kopierfräsvorgang be manually milled out of the zirconia block to then the occlusal surface by handcutter to edit. At this surface side processing steps Manually is much easier than difficult to be formed outer or lumen surface. The workpiece therefore, can already be completely worked and shaped in the sintering furnace so that no reworking on the sintered Zirkonoxidobjekt must be made. That is, all invasive Processing steps are harmless before sintering instead of and the already mentioned microcrape and cracks do not occur in this processing order. This As a result, this gentle production of dental technology Workpieces counteract the aging of the tooth crown and a much longer life guaranteed.

The inventive method is preferably at the production of inner telescopes of a telescope or Konsteleskopkrone apply, especially in these dental workpieces the Maintaining exact fit dimensions of utmost importance is and the common web connections prevent this.

moreover It is possible to have several side-by-side inner telescopes with the aid of the method according to the invention during milling out of a zirconia block.

Furthermore The method set out for the production and adaptation of Abutments are applied, as well as this connecting element between Implant body and superstructure similar how an inner telescope is constructed and the same constructive Has to meet conditions.

Furthermore, it is possible to produce a fixed or removable dentures with the indicated method. In the latter model of dental prosthesis is mainly the regular precise introduction of dental prosthesis in the patient's jaw in the foreground, since for daily cleaning the dentures removed from the patient and after cleaning again pushed or clicked. For this purpose, the crowns must be milled extremely precisely in order to create a common insertion direction of possibly several dental crowns. With the help of erfindungsge In accordance with the method, such a dental prosthesis can also be manufactured, since both the lumen and the outer surfaces of the dental prosthesis can be precisely milled due to the occlusal attachment of the workpiece.

Especially advantageous is the use of computerized systems for controlling the milling process. So, first Designs of the dental technology to be produced using CAD programs Workpiece to be prepared with this information Help of a CAM program for computer-aided control the milling and manufacturing of the workpiece use.

The Invention will be described below with reference to an embodiment and explained in more detail with the aid of figures become.

in this connection demonstrate:

1 a representation of the scan during a copy milling operation;

2 a representation of the milling during a copy milling and

3 a sectional view of an occlusally fixed dental workpiece.

In the 1 illustrated scanning of a crown model ( 1 ), which typically consists of light-curing plastic, shows that the feeler element ( 2 ) of the sampling unit ( 3 ) can be guided completely unobstructed 360 ° around the outer surface of the model, since the model is fixed only on its occlusal side. In addition, the inventive fixation of the model allows the scanning of the luminal surface ( 4 ) within a scanning process without having to change the fixation of the model.

At the same time, by the in 1 shown sampling data obtained by means of a milling unit ( 5 ) into a zirconium oxide white ( 6 ) and make an exact copy of the model ( 1 ) milled out of the ceramic material. The in 2 shown milling head ( 7 ) has a clear conical shape, which in particular for milling edges ( 8th ) and protrusions on a parallel or conical surface.

3 illustrates the occlusal fixation ( 9 ) of the model ( 1 ) or the milled crown ( 10 ) due to their arrangement, for example, the smooth milling of the lumen surfaces, the outer crown surface and the 360 ° milling of the edge ( 8th ). In this embodiment, it is the limit for the secondary crown.

After completion of the milling process, the occlusal fixation ( 9 ) manually removed by hand milling cutter and the occlusal surface adapted to the desired dimensions. The crown is completely milled after this process and has all the desired contours and dimensions, so that they no longer have to be processed after the subsequent sintering process.

by virtue of this is a crown with extremely smooth surfaces ago, which are no quality-reducing microcracks and cracks.

1

Krone model

2

scanning element

3

scanning unit

4

lumen area

5

milling unit

6

Zirkonoxidweißling

7

milling head

8th

edge

9

occlusal fixation

10

milled Crown

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 102006027 A1 [0009]
• - DE 19938143 A1 [0010]

Claims (10)

Method for producing dental workpieces by means of a Kopierfräßeinheit, wherein the dimensions of a dental workpiece to be formed determined by scanning a model and transmitted by a rotating machining tool on a mold blank, characterized in that the scanned model fixed only on the occlusal side on a support plate is and a probe element is performed up to 360 ° around the model, so that in the same step, the lumen surfaces of the model can be scanned. Process for the production of dental workpieces according to claim 1, characterized in that the machining tool having a conically shaped milling head. Process for the production of dental workpieces according to claim 2, characterized in that the conical shaping of the milling head can be 1 ° to 10 °. Process for the production of dental workpieces according to claim 2 or 3, characterized in that the milling head is made of sintered zirconia. Process for the production of dental workpieces according to one of the preceding claims, characterized that the blank is a ceramic white. Process for the production of dental workpieces according to claim 5, characterized in that it is the ceramic white to a Zirkonweißling acts. Process for the production of dental workpieces according to one of the preceding claims, characterized that it is at the dental workpiece to be formed one or more inner telescope (s) of a telescope or telescope telescope crown is. Process for the production of dental workpieces according to one of claims 1 to 6, characterized that it is in the dental workpiece to be formed is an abutment of a dental implant. Process for the production of dental workpieces according to one of claims 1 to 6, characterized that it is in the dental workpiece to be formed is a removable or fixed dentures. Process for the production of dental workpieces according to one of the preceding claims, characterized that the milling process controlled by computer becomes.