Method, computer, machine-readable medium, computer program and system, concerning the manufacture of dental prostheses

This is a divisional of co-pending U.S. patent application Ser. No. 11/486,979, which was filed on Jul. 13, 2006, and which in turn claims priority under 35 U.S.C. § 119(b) of German Patent Application Serial No. 102005035475.0, which was filed on Jul. 28, 2005.

The invention relates to a method, a computer, a machine-readable medium, and a computer program with program code means by which a data record representing a dental prosthesis can be examined.

Further, the invention relates to a method and a system for the manufacture of a dental prosthesis, wherein a data record for a dental prosthesis is created and transmitted to a production system on the basis of a data record representing a remaining tooth area.

Furthermore, the invention relates to two methods and two systems for the manufacture of a dental prosthesis as well as a method for examining a dental prosthesis data record, a computer, a machine-readable medium, and a computer program concerning the examination of a dental prosthesis data record. These objects relate to the treatment of manufacturing data (e.g. milling data) as they are employed for the manufacture of dental prostheses.

Furthermore, the invention relates to two methods and two systems for creating dental prosthesis data records.

From WO 02/39056 A1, it is known to digitally detect the shapes of remaining tooth areas by means of patterns and to generate the shapes of dental prostheses on the basis thereof with the aid of software. In the process, data records representing a dental prosthesis are created which can subsequently be used when the dental prostheses are manufactured, for example by milling.

It is an object of the present invention to improve the dental prostheses which can be manufactured by this procedure. This object is achieved by a method according to claim 1, a computer according to claim 12, a machine-readable medium according to claim 13, and a computer program according to claim 14.

It is another object of the present invention to facilitate or accelerate the manufacture of dental prostheses. This object is achieved by a method according to claim 15 and a system according to claim 20.

It is another object of the present invention to integrate as optimally as possible existing appliances into the manufacture of dental prostheses. This object is achieved by a method according to claim 21, a system according to claim 25, a method according to claim 26 or 30, a system according to claim 29, a computer according to claim 31, a machine-readable medium according to claim 32, and a computer program with program code means according to claim 33.

It is another object of the present invention to permit the user the modeling of dental prostheses with means as simple as possible. This object is achieved by a method according to claim 37 and a system according to claim 39.

This object is also achieved by a method according to claim 40 and a system according to claim 42.

Advantageous embodiments are disclosed in the respective subclaims.

For improving the dental prostheses, it is suggested to examine the data records of the dental prostheses with finite element methods. With these methods, very diverse properties of the dental prostheses can be examined or else simulated. For example, the breaking strength of the dental prosthesis or the stability of a dental prosthesis during production etc. can be examined.

In application, dental prostheses underlie strong forces, for example, during chewing. In the process, the dental prosthesis is subjected to the pressure between upper and lower jaws. Therefore, in the examination of the data record, the data record of the remaining tooth area onto which the dental prosthesis is to be fitted and/or the data of the opposite tooth area (i.e. the upper jaw if the dental prosthesis is intended for the lower jaw, or vice versa, respectively) are advantageously considered. However, an examination without these data is also possible if, for example, any kind of force onto the dental prosthesis is simulated with predetermined limits. In the process, one can examine whether the dental prosthesis can deal with these forces.

A dental prosthesis is subjected to certain forces even during production, while it is, for example, manufactured by milling it out of a blank with a cutter head. The stability of the dental prosthesis for the production process can also be examined with finite element methods. Here, it has to be considered that the forces during production might be smaller than those in application, that, however, the milling material sometimes is raw ceramic material which is essentially more brittle compared to fired ceramic material.

In an advantageous operation, the result of the examination is filed for documentation purposes. Depending on the result of the examination, the data record of the dental prosthesis can be modified to achieve a sufficiently high and desired breaking strength.

The examination of the data record can be performed before as well as after the manufacture of the dental prosthesis. The performance beforehand has the advantage that the dental prosthesis can be possibly manufactured in a modified manner. On the other hand, an examination is possibly only necessary when the dental prosthesis is already broken and one has to determine why it is broken.

If the dental prosthesis is broken or if the examination of the dental prosthesis shows that it can be easily broken, a dental prosthesis data record is created which was preferably automatically changed such that the breaking strength was increased at the point of break. This can be performed, for example, by correspondingly increasing the wall thickness, by additional or thicker webs or the like. Moreover, the dental prosthesis of the new dental prosthesis data record is preferably manufactured directly. The new dental prosthesis data record can again be examined for its breaking strength. Here, with a repeating iteration method (breaking strength test, change of the dental prosthesis data record), a dental prosthesis data record can be obtained which corresponds to an optimized dental prosthesis.

Moreover, if only after the manufacture of the dental prosthesis the breaking strength is possibly doubted, the examinations with respect to the breaking strength can be performed in order to prove that the dental prosthesis can meet possible requirements.

Here, it is advantageous to graphically represent the tensions and/or forces and/or pressures that can lead to breaking, for example with colors, shades of gray, etc. These tensions, forces and/or pressures are established with the finite element method. This graphical representation as a rule permits a good possibility of judging the breaking strength by skilled observers and then also provides a good indication for possible or necessary changes of the dental prosthesis data record.