WO2008040380A1

WO2008040380A1 - Method for producing a complete dental prosthesis

Info

Publication number: WO2008040380A1
Application number: PCT/EP2006/009711
Authority: WO
Inventors: Ralf Bannuscher
Original assignee: 3D Lab Service Gmbh
Priority date: 2006-10-07
Filing date: 2006-10-07
Publication date: 2008-04-10
Also published as: WO2008040400A1

Abstract

The invention relates in particular to an arrangement aid for positioning teeth during the production of a complete prosthesis, comprising partial denture impressions of the teeth forming at least one full denture arch, the partial denture impressions being configured in such a manner that teeth can be inserted in their desired position and desired alignment. The invention also relates to a method for producing such an arrangement aid. The invention finally relates to an at least computer-assisted method for producing a complete prosthesis.

Description

Process for producing a complete dental prosthesis

The invention relates to a method for producing a complete dental prosthesis, also an erection aid for positioning of teeth in the manufacture of a complete dental prosthesis and a method for producing the same.

Full dentures are currently manufactured by a series of purely manual steps. First, the dentist takes impressions of the edentulous mandible and maxilla, which is usually done using a face bow to achieve an exact spatial model assignment for later processing in the articulator. The impressions are then sent to the dental technician and filled with a model mass, such as plaster, to produce appropriate models of the maxilla and mandible. The dental technician uses the jaw models spatially assigned to an articulator in accordance with the cranial relation of the patient's upper and lower jaws detected by the dentist's facebow, thereby positioning the lower jaw model and upper jaw model relative to one another. The dental technician then selects a set of artificial teeth that fits the patient type, the jaw models, and their spatial arrangement. Subsequently, the individual teeth are manually sequentially inserted and aligned on the jaw models with the aid of an adhesive such as wax, whereupon the bite of the later co-operating teeth is established. The final result, which is achieved by the interaction of the selection of the set of teeth, the positioning and alignment of the teeth and fine adjustment of the bite, depends exclusively on the Expertise and dexterity of the dental technician. After fitting this set of teeth to the patient in the dentist's office, the work returns to the dental technician. The teethed models are removed from the articulator, embedded in a cuvette in plaster, and a negative model of each toothed jaw model is created. After curing the model, the adhesive (wax) used to fix the teeth in positioning and aligning them in the jaw model is removed, leaving the teeth in the negative model. The resulting by removing the adhesive cavity is finally filled with a polymer (plastic). After curing of the plastic, the full denture can be removed from the negative model, to which the negative model is usually destroyed.

A major disadvantage of the tooth set-up described in wax, that is, the procedure described above, is that it is very time-consuming and demands in particular the dental technician a high Mali of expertise and dexterity.

In order to remedy these disadvantages, DE 198 38 238 A1 has proposed a method for the computer-controlled production of dental prostheses for the restoration of at least one tooth or jaw region, in which the conventionally produced upper and lower jaw models or parts thereof, taking into account the virtual axis of rotation of the articulator and specific reference points are digitized, so that the construction of the dental prosthesis by means of CAD and the manufacture of the dental prosthesis by means of CAM can subsequently be carried out computer-controlled. Disadvantageously, this method is extremely complex and inaccurate, so that in particular the transmission of the digitally present spatial geometries of the denture on the virtual design and the implementation of the digital signals using CAM to the finished real dentures only inadequately possible. Above all, however, even a complete denture can not be produced by this method.

From DE 103 04 757 A1 discloses a similar computer-assisted method for the production of dental prostheses is also known, in which the data collected by a surveying device for generating a medical Part, for example, a dental crown to be evaluated. In this method, the placement of the teeth is virtually performed on the computer, the records of ready-made teeth are fitted into a virtual model of the oral situation. From the data available afterwards, the denture base can be produced directly by means of CAM methods; or the prefabricated teeth are inserted into the physical model. In this case, special structures are provided at the locations of the prosthesis base, where the artificial teeth are to be set up, which ensure a defined spatial allocation of the artificial tooth to be polymerized, pasted in or otherwise permanently affixed to the artificial tooth. As a special structure, it has been proposed to construct a plateau on the base of the prosthesis which has three hemispherical triangular elevations which can be uniquely positioned in congruent depressions of the dental base. Another possibility provides to produce a ring-like shape, which is adapted exactly and defined the geometry of the respective artificial tooth. In this attachment, the artificial tooth can be inserted, so that the spatial orientation of the tooth relative to the attachment is always defined constant. In the preparation of the prosthesis base corresponding conforming depressions are worked out or released at the respective tooth position, which in turn ensure an exact and defined positioning of the attachment. Also, this method is extremely aufwäπdig and ultimately not precise enough to produce dentures in an economical way. Above all, however, this method is not suitable to generate a full denture as a denture for edentulous patients with low production times.

The invention is based on the invention, while avoiding the disadvantages mentioned, to develop a computer-controlled method and associated devices for dental prosthetic work which, while shortening the production times and optimizing the quality, are suitable for generating a complete dental prosthesis.

The object is achieved according to the invention by the method features and device features cited in the patent claims. This is achieved above all by virtue of the fact that, in a virtual image of the articulator, taking into account all the relevant parameters which serve as data records Computers are present, a virtual list of computer-selected teeth selected for virtual total prosthesis is made and on this basis a virtual erection is created in which the maxilla and / or mandibular teeth are formed as recesses / dental impressions. On the basis of the virtual erection aid, a real erection aid is then generated, in particular in the rapid prototyping method, and then arranged on a holder in the articulator so that a simple and precise placement of the artificial teeth can be made, the hitherto unachieved generation speeds and freedom from errors justified in the production of individual full dental prostheses.

Further details, features and advantages of the invention will be described below with reference to an exemplary embodiment with reference to the accompanying drawings. In the drawing shows:

1 is a perspective view of a virtual articulator in which a maxillary model and a mandibular model are inserted;

FIG. 2 shows a perspective view of a virtual model with computer-controlled total installation; FIG.

3 shows a perspective view of a virtual articulator with a positioning aid held therein;

4 is a perspective view of a Artikulatorausschnitts with positioning aid positioned therein, are inserted into the teeth.

5 shows a perspective view of the articulator section shown in FIG. 4 with an upper jaw model additionally arranged in the latter;

6 shows a perspective view of an articulator cutout with an erection aid arranged therein, into which teeth are inserted, and with a lower jaw model inserted therein; Fig. 7 shows a special, cooperating with an articulator holder for the above erection aid and

Fig. 8 the erection aid in an overall view with holder and in a partial view from below with Zahnteilimpressioπen for a lower jaw.

Like reference numerals refer to similar components below.

According to a preferred embodiment of the method according to the invention for producing a complete prosthesis, the steps described in more detail below are carried out:

First, impressions of the maxilla and mandible of the edentulous patient are produced at the dentist (impression taking). The impression is preferably taken using a face bow, via which the exact spatial allocation of the jaw halves relative to each other can be detected (Relations determination / Bissnahme). Based on these impressions, an upper jaw model and a lower jaw model are produced, for example by casting over the impressions with a gypsum mass. The jaw models are sent to a dental laboratory along with the spatial assignment data. There, the upper jaw model and the lower jaw model are used based on the spatial assignment data in a conventional articulator such that the spatial assignment of the models corresponds to the actual spatial allocation of the patient's maxilla and mandible. Articulators per se are known in the art, which is why the exact structure is not described in detail below.

Then, the jaw models in a corresponding measuring device, such as a laser scanner, a strip light projector or the like, three-dimensionally measured, in particular scanned, and transferred in this way generated three-dimensional jaw data using a suitable computer unit and a corresponding processing program in a virtual articulator 10, so that results in the arrangement shown in Fig. 1. 1 shows a virtual articulator 10 in which a virtual upper jaw model 12 and a virtual lower jaw model 14 are arranged, the spatial allocation of the virtual upper jaw model 12 relative to the virtual lower jaw model 14 corresponding to that spatial assignment in the actual articulator.

Based on the acquired dimensional data of the virtual maxillary model 12 and the virtual mandibular model 14 and based on the spatial mapping data of the virtual jaw models 12 and 14 relative to each other, the data processing program now selects a set of artificial teeth from a plurality of sets of teeth based on criteria predefined in the data processing program which is best suited in size and shape of the individual teeth for the production of the full denture. After selection of the set of teeth, as shown in Fig. 2, the individual virtual teeth 16 of the selected set of teeth are positioned and aligned according to defined algorithms in the virtual jaw models 12 and 14, whereby a virtual prosthesis 18 is generated. The algorithms used were created on the basis of dental / dental technical parameters and stored in the data processing program.

Based on the virtual prosthesis 18, more precisely based on the position data of the virtual teeth 16, a virtual positioning aid 20 is now automatically generated on the basis of corresponding algorithms, as shown in FIG. 3. The virtual erection aid 20 is substantially plate-like and has tooth partial impressions of the virtual teeth 16. The virtual tooth partial impressions 22 shown in FIG. 3 are those of the virtual teeth 16 of the virtual upper jaw 12. In the same plate 20, the virtual tooth part impressions 36 of the virtual mandible 14 are formed (not visible in FIG. 3). The impressions include the positioning of the future occlusion. The virtual erection aid 20 can optionally have both the virtual tooth partial impressions 22 of the virtual upper jaw model 12 and those of the virtual lower jaw model 14. Alternatively, for each of the virtual tooth partial impressions 22 of the virtual upper jaw model 12 and for those 36 of the virtual inner jaw model 14, a separate erection aid can be generated. The three-dimensional data of the virtual positioning aid 20 generated in this way are now fed to a three-dimensional printing device, preferably a rapid-prototyping device, which generates an actual positioning aid 24 from the data of the virtual positioning aid 20 in a layered construction. The aforementioned devices for generating the actual erection aid 24 are known in the prior art and are therefore not explained in detail below. Alternatively, it is of course also possible to supply the three-dimensional data of the virtual erection aid 20, for example, to a milling center or the like, which mills out the actual erection aid 24 from a block of material.

Taking over the exact spatial arrangement of the virtual erection aid 20 in the virtual articulator 10, which is shown in Fig. 3, the actual erection aid 24 is inserted into an actual articulator 26, which is carried out using a positioning device in the form of a holder 28, the separately is shown in Fig. 7 and Fig. 8. The holder 28 has a base plate 38 which can be detachably connected to the articulator foot. On the base 38 sits a telescopic connector 40 with a Zyliπderstift 42, which is provided in millimeter intervals with annular grooves for axial adjustability. With a fixing screw 44, the determination of the height position takes place. At the upper end of the holder 28, a seat for fixing the plate-shaped positioning aid 24 is provided, which is fixed by means of a locking screw 46 on the holder in an exact position, see Fig. 8. In the actual partial tooth impressions for upper and lower jaw of the actual Aufstellhilfe 24, which are shown in Fig. 8 above for the teeth of the upper jaw and below for the teeth of the lower jaw, now actual artificial teeth 30 are arranged, the actual teeth 30 by insertion into the actual tooth partial imprints of the actual erection aid 24th be automatically positioned and aligned, see Fig. 4.

As shown in FIG. 5, an actual upper jaw model 32 is then inserted into the actual articulator 26, and the actual deployment aid 24 and actual upper jaw model 32 are moved toward each other such that the actual teeth 30 are attached to the actual upper jaw model 32 using adhesive material become. In the same way and As a result, the corresponding actual lower jaw model 34 is also provided with actual teeth, which is shown schematically in FIG.

Starting from the actual jaw models provided with actual teeth, a full denture can now be produced in a conventional manner.

An advantage of the method according to the invention for producing a complete prosthesis is that essential method steps are performed computer-assisted. In particular, the time-consuming positioning and alignment of the teeth in the upper or lower jaw model, which is normally done manually by the dental technician, and without the expertise and the dexterity of the same is hardly possible, is automated according to the invention by computer-controlled an erection is generated, which shape and size the teeth, the positioning and the alignment of the teeth in the corresponding jaw models. In order to be able to produce a full denture with the aid of the method according to the invention, the corresponding person need only be able to properly position the jaw models produced by the dentist in the articulator and to operate the corresponding data processing program. In other words, the method according to the invention can also be carried out by a person who does not have the skills of a dental technician.

It should be understood that the above-described embodiment of the inventive method is in no way limiting. Rather, modifications and changes are possible without departing from the scope of the present invention, which is defined by the appended claims.

LIST OF REFERENCE NUMBERS

10 virtual articulator

12 virtual maxillary model

14 virtual mandible model

16 virtual teeth

18 virtual prosthesis

20 virtual installation aid

22 virtual tooth partial impressions

24 actual erection aid

26 actual articulator

28 positioning device

30 actual teeth

32 actual upper jaw model

34 actual lower jaw model 6 virtual dental partial impressions lower jaw 8 base plate 0 telescopic connector 2 cylindrical pin 4 fixing screw 6 locking screw

Claims

Patent claims

1. A method for the computer-aided production of a full denture as a dental prosthesis for edentulous patients with the following method steps:

Molding of the toothless upper jaw and lower jaw, preparation of corresponding models and assignment of these to one another, in particular in a manner known per se in an articulator,

Determination of the geometry of the models in their association with each other in a measuring device, preferably by 3D scanning, and creation of a three-dimensional representation or a corresponding digital data set in the form of virtual models,

Inputting the data set into a computer program whose database contains the usable tooth forms for the complete prosthesis to be produced and which, taking account of the individual geometries according to dental parameters, selects the teeth of the prosthesis and sets them up virtually to the total prosthesis,

Computer-aided construction of a virtual positioning aid, in which the tooth arrangements are designed in the form of partial tooth recesses or partial dental impressions,

Production of a real erection aid,

Inserting the artificial teeth into the corresponding recesses or impressions of the erection aid,

Connecting the freestanding areas of the artificial teeth projecting from the erection aid over a soft wax layer or similar adhesive mass with the associated jaw model or both jaw models,

Removing the installation aid and Completion of the full denture in a conventional dental technique.

2 Method according to claim 1, characterized in that the metrological detection of the model geometries by 3D scanning or by the method of the striped light projection is made.

3 Method according to claim 1 or 2, characterized in that the calculation of the position and the orientation of the teeth for the virtual total prosthesis is carried out on the basis of algorithms stored in the computer unit.

4. Method according to claim 1, characterized in that the alignment of the upper jaw and lower jaw models with respect to one another is carried out using an articulator, that all measurement data are determined by 3D scanning and the resulting data set is taken over into a software containing a having virtual articulator and according to dental and dental technical parameters makes the tooth selection and determines the tooth positions for the full denture and then constructed the erection.

5. The method according to any one of claims 1 to 4, characterized in that the actual erection aid is generated using a three-dimensional printing technique or a rapid prototyping technique

6. The method according to any one of claims 1 to 5, characterized in that the actual erection aid is made of a plastic material

7. positioning aid for positioning of artificial teething in the manufacture of a full denture, in particular for carrying out a method according to one or more of claims 1 to 6, characterized by a mounting plate (24), in the Zahnteilausnehmungen (22) or dental partial impressions of at least one Gebißhalfte forming artificial teeth (30) are formed such that the artificial teeth (30) are used in their desired position and target orientation in this

8. positioning aid according to claim 7, characterized in that the mounting plate (24) with a holder (28) for positionally accurate arrangement in an articulator (26) is releasably connectable.

9. installation aid according to claim 8, characterized in that the holder (28) is axially adjustable and via a screw (46) carries the mounting plate (24).

10. erection aid according to one of claims 7 to 9, characterized in that the mounting plate (24) with inserted artificial teeth (30) in the articulator (26) with the upper jaw or lower jaw model (32, 34) in a predetermined positioning in particular with the help of Wax or other adhesive mass is connectable.

11. erection aid according to claim 10, characterized by a movement device which moves the erector and the jaw model relative to each other to press the protruding from the erection aid tooth portions in a predetermined manner in the adhesive mass of the model.

12. erection aid according to one of claims 7 to 1 1, characterized in that it consists of a plastic material.

13. erection aid according to one of claims 7 to 12, characterized in that it is constructed in layers by way of 3D printing or rapid prototyping.

14. A method for producing an erection aid according to one of the preceding claims, characterized by the following method steps:

Molding the maxilla and mandible of a patient;

Creating an upper jaw model and a lower jaw model; Aligning the upper jaw model and the lower jaw model with each other;

Capture the positions of the aligned upper jaw model and the aligned lower jaw model using position coordinates;

Inserting the upper jaw model and / or the lower jaw model into a measuring device for scanning the corresponding jaw model;

Creating a virtual jaw model;

Identifying the position coordinates in the virtual jaw model;

Calculating the position and orientation of the teeth for the corresponding virtual jaw model based on algorithms stored in a computer unit;

Generating a virtual erection aid based on the virtual jaw model and the calculated position and orientation data of the teeth;

Generating an actual erection aid based on the data generated for the virtual erection aid.

15. The method according to claim 14, characterized in that based on stored in a computer unit algorithms further a set of teeth from a plurality of corresponding sets is selected.

16. The method of claim 14 or 15, characterized in that the alignment of the upper jaw model and the lower jaw model to each other using an articulator.

17. The method according to any one of claims 14 to 16, characterized in that the jaw model is detected using a Laserscaππers or a strip light projector.

18. The method according to any one of claims 14 to 17, characterized in that the actual erection aid is generated using a three-dimensional printing technique or rapid prototyping technique.

19. The method according to any one of claims 14 to 18, characterized in that the actual erection aid is made of a plastic material.

20. Erection aid according to one of claims 1 to 7, characterized by a virtual mounting plate (20) in the form of an individual, the patient geometries corresponding virtual construction, in which the tooth positions are in the form of partial Zahnausnehmungen or partial dental impressions and a based thereon identical real Aufstellplatte (24) with corresponding Zahnteilausnehmungen (22/36) or Zahnteilimpressionen in which the artificial teeth (30) can be used.