WO2009026943A1

WO2009026943A1 - Production of a dental prosthesis

Info

Publication number: WO2009026943A1
Application number: PCT/EP2007/007480
Authority: WO
Inventors: Andreas Hoffmann; Tim Uferkamp
Original assignee: Dentales Service Zentrum Gmbh & Co. Kg; Gerd Uferkamp Dental Gmbh
Priority date: 2007-08-27
Filing date: 2007-08-27
Publication date: 2009-03-05

Abstract

To produce a dental prosthesis, the following steps are performed: mechanical and/or optical scanning of a mucous membrane structure in a toothless area of a lower jaw or upper jaw in order to determine a data record (2) describing the three-dimensional shape of the mucous membrane structure; determination of a data record (6) describing the three-dimensional shape of a removable dental prosthesis (8), wherein the three-dimensional shape of the dental prosthesis (8) has a mucous membrane area (9), complementing the three-dimensional shape of the mucous membrane structure, and an adjoining tooth area (10); and control of a machine (7), using the data record (6) describing the three-dimensional shape of the dental prosthesis (8), in order to machine the three-dimensional shape of the dental prosthesis (8) from a plastic preform which has an area with a first colour and an adjoining area with a second colour, wherein the mucous membrane area of the three-dimensional shape of the dental prosthesis (8) is formed in that area of the plastic preform with the first colour, and the tooth area (10) thereof is formed in that area of the plastic preform with the second colour.

Description

MANUFACTURE OF DENTISTRY

TECHNICAL FIELD OF THE INVENTION

The invention relates to a method and an apparatus for the production of dental prostheses. Dentures are dental prostheses which have a mucous membrane area and a tooth area adjacent thereto. The mucosal area serves to support and attach the dental prosthesis to a tooth-free area of a mandible or maxilla, while the tooth area replaces the missing teeth of the respective jaw. A dental prosthesis can replace part of the teeth of a mandible or maxilla, or all teeth of a jaw.

STATE OF THE ART

The common way to make dentures is to take one or more impressions from the affected and opposing jaws of each patient and make a model based on those impressions. The model is then the basis for the formation of the denture both to the mucosal area of the denture to the tooth-free area of the respective jaw, as well as to the tooth area on teeth of the opposite jaw and possibly adjacent teeth of the jaw for the denture is intended to adapt. For the formation of the tooth area prefabricated computer-milled ceramic denture teeth can be used, which provide a perfect basis for a gearing among each other in a full denture, ie a denture for both the lower jaw and the upper jaw. In partial dentures, however, these advantages of the use of finished prosthetic teeth are hardly usable because they are not adapted to the teeth still present in the mouth. Corresponding If necessary, the teeth must be made individually by hand. The known method is very laborious and time consuming and accordingly associated with relatively high costs. It can be automated in parts at most.

For the three-dimensional navigation of implants to be anchored in a jaw, it is known to perform a computed tomography of the skull to which the affected jaw belongs. The data obtained for the spatial form of the jaw are visualized three-dimensionally for the planning and the conception of a drilling scheme for the implantation of a dental implant.

For the production of dental inlays, it is known to optically scan the cavity in a tooth with a scanning device and to obtain a data record describing the spatial shape of the cavity. At the same time, the spatial shape of the adjacent tooth surfaces can be detected. From the records thus obtained is with the help of a computer

Data record determined, which describes the spatial form of a matching in the cavity inlay.

Subsequently, the data record describing the spatial form of the inlay is displayed on a screen three-dimensionally together with the data sets of the scanned spatial forms to allow a dentist to rework the space shape of an outer surface of the inlay automatically determined by the computer as appropriate. Subsequently, with the data thus obtained a machine for material decreasing working out of

Room shape of the inlay driven from a ceramic body. The inlay is then cemented into the cavity of the respective tooth. The ceramic body can be selected for its color on the color of the tooth into which the inlay is to be cemented.

OBJECT OF THE INVENTION

The invention has for its object to provide a method and an apparatus for the production of dental prostheses, which allow the cost-effective production of individual dental prostheses.

SOLUTION

The object of the invention is achieved by a method having the features of independent claim 1 and a device having the features of independent Patent claim 11 solved. Preferred embodiments of the new method are described in the subclaims 2 to 9. The claim 10 relates to the use of a plastic preform in the new method. Preferred embodiments of the new device are described in the subclaims 11 to 13. The independent claim 14 additionally describes a novel process for the production of dental prosthesis substantially corresponding new process for the production of epithetics. Claim 15 accordingly describes one of the new device for the production of dental prosthesis substantially corresponding new device for the production of epithetics

DESCRIPTION OF THE INVENTION

In the new manufacture of dental prostheses, the pressure of impressions is replaced by a mechanical and / or optical scanning of a mucosal structure in a tooth-free region of a mandible or maxilla, in order to directly determine a record describing the spatial shape of the mucosal structure. In principle, the same algorithms can be used as have been used heretofore for the optical scanning of a cavity in a tooth for the production of a lays. However, it is also possible to mechanically scan the mucosa structure into the tooth-free region in order to determine the data record describing the spatial form of the mucosal structure, for example with a contact probe. Which exact scanning method is used, for example, which exact optical technique is irrelevant. For example, three-dimensional recording techniques in which the spatial form of interest is recorded from multiple directions and optical scanning methods using spot or strip light may be employed. In the latter case, for example, one speaks of so-called Lichtschnittabtastung.

The data record describing the spatial shape of the mucosal structure is used in the invention to describe a spatial form of a removable denture

Determine the data record. Here, the spatial shape of the denture has a to the spatial form of

Mucosal structure complementary mucosal area and adjacent thereto

Teeth. The spatial form of the mucous membrane area facing the respective jaw can, in a first approximation, have the same spatial form, ie. H. the same surface course, albeit with a different sign, as the mucous membrane structure, in which he in the use of the

Denture should come to rest. The adjacent to the mucous membrane area Tooth area may be generated automatically using additional data or customized by a performer of the new method.

In the already concluding step of the new method, the machine thus obtained, which describes the spatial form of the dental prosthesis, drives a machine for removing material from the working space of the dental prosthesis from a plastic preform. The plastic preform has a region of a first and an adjacent region of a second color. The two colors are adapted to form the mucous membrane area of the dental prosthesis in the area of the plastic preform of the first color and the tooth area in the area of the plastic preform of the second color. That is, the first color is usually a pink tone, while the second color is a pale yellow hue. To adapt to individual peculiarities, plastic preforms with different pink and white-yellow shades can be selected. The size of the plastic preform can be selected to avoid unnecessary processing costs in terms of its shape and size matched to the spatial shape of the dental prosthesis. Also for this purpose, a plurality of plastic preforms are available for selection. The material decreasing working out can be done for example by grinding and / or milling of the plastic preform. It can also be carried out first a milling step, which then followed by a grinding step for finishing. This can be followed either already in the machine or manually followed by a polishing step. The denture, however, is in any case substantially completed by the machine. Despite the design of the new dental prosthesis exclusively made of plastic, it can be sufficiently stable for long-term use. Incidentally, it is possible with the new method easily and with little effort, either immediately or after a certain time to make a double denture to have a replacement, should the denture initially produced fail. When using, for example, reinforced plastics for the plastic preform such a failure, for example, by breaking the denture, however, relatively unlikely. It is even less likely than with a dental prosthesis made by a conventional method, since the new denture builds on a continuous coherent plastic preform.

If in the new method, in addition, the spatial shape of adjacent to the tooth-free area teeth of the lower jaw or upper jaw scanned and the spatial shape of the Denture descriptive record is determined with additional consideration of the spatial shape of the adjacent teeth, the process of adaptation of the spatial form of the denture descriptive record on remaining teeth of the respective jaw can be largely automated.

The same applies to the adaptation of the dental prosthesis to remaining teeth of the opposite jaw. For this purpose, in addition, the spatial shape of a portion of a jaw opposite to the tooth-free portion of the lower jaw or upper jaw is to be scanned, and the spatial shape of the denture descriptive record is to be determined taking into account the spatial shape of the area of the opposing jaw.

Furthermore, a relative position of a jaw, which lies opposite the tooth-free region of the lower jaw or upper jaw, can also be scanned in order to use this relative position of the opposing jaw in the determination of the data set describing the three-dimensional shape of the dental prosthesis. Thus, a spatial form for the dental prosthesis can be determined automatically, which ensures a toothing with the remaining teeth of the opposite jaw.

An even more perfect automatic adaptation of the dental prosthesis to the individual conditions can be achieved if the relative position of the opposing jaw in different positions of the jaw is scanned to each other. For example, grooves in the chewing surfaces can be matched to the possible relative positions of the jaws.

Specifically, the data set describing the spatial shape of the dental prosthesis can be determined taking into account an occlusal plane and / or an occlusion direction between the opposing pines.

Since a mucous membrane, even if it covers a jaw bone only in a thin layer, is neither rigid nor has a uniform thickness nor uniform deformation properties, it is preferred in the new method if the mucosal structure in the tooth-free region of the mandible or maxilla in scanned various oral situations to determine the descriptive of the spatial shape of the mucosal structure record. These different oral situations, for example, by blowing, sucking and / or by Muscular rest of or be adjusted by the respective patient. Changing spatial forms of the mucous membrane structure provide important information on the local thickness and deformability of the mucous membrane.

Although this is not absolutely necessary in the new method, especially when comprehensive data sets are obtained by palpation in the oral cavity, the

Spatial form of the mucosal structure descriptive dataset together with the through

Scanning determined data sets are visualized in a three-dimensional representation, before the machine is driven. This allows a control of the space shape automatically determined for the dental prosthesis. With a three-dimensional representation for visualization is meant here usually no holographic representation, but the reproduction of a perspective view with a variable direction of view, which gives a three-dimensional impression even when displayed on a two-dimensional screen.

In the case of the new method, it is particularly preferred if the data record describing the spatial form of the mucosal structure can be changed by means of graphical tools that act on this three-dimensional representation. Performing the new method can then make changes to the three-dimensional representation to optimize the spatial shape of the denture, which automatically affect the record of the denture, which is then used to drive the machine for working out the denture from the plastic preform.

The new method is not only suitable for the production of dentures. It is also suitable for the production of epithetics for the mouth and facial area. In this particular application of the new method, it comprises the steps of: mechanically and / or optically scanning a surface structure in a region of a head to determine a data set describing the spatial form of the surface structure; Determining a data set describing the spatial form of an epithesis or an opturator, wherein the spatial form of the epithesis or of the opturator has an abutment region that is complementary to the spatial form of the surface structure and regions facing away from it; and driving a machine with the spatial form of the epithesis or of the opturator descriptive record for material decreasing working out of the spatial form of the epithesis or the opturator of a plastic preform having a region of a first and an adjoining region of a second material, wherein the deformability and / or the color of the first and second materials differ from each other. For example, one material may be hard to replace a missing bone area while the other material is soft to replace soft tissue overlying the replaced bone structure.

Advantageous developments of the invention will become apparent from the claims, the description and the drawings. The advantages of features and of combinations of several features mentioned in the introduction to the description are merely exemplary and can come into effect alternatively or cumulatively, without the advantages having to be achieved by embodiments according to the invention. Further features are the drawings - in particular the illustrated geometries and the relative dimensions of several components to each other and their relative arrangement and operative connection - refer. The combination of features of different embodiments of the invention or of features of different claims is also possible deviating from the chosen relationships of the claims and is hereby stimulated. This also applies to those features which are shown in separate drawings or are mentioned in their description. These features can also be combined with features of different claims. Likewise, in the claims listed features for further embodiments of the invention can be omitted.

BRIEF DESCRIPTION OF THE FIGURES

In the following the invention will be further explained and described with reference to preferred embodiments shown in the figures.

Fig. 1 is a flowchart illustrating the implementation of the new method for

Production of dentures outlined with the new device; and

Fig. 2 shows a plastic preform as used in the new method. DESCRIPTION OF THE FIGURES

The new method for the production of dental prostheses sketched in FIG. 1 on the basis of the new device used here begins with the step of scanning in which a scanning device 1 scans at least one mucosal structure in a tooth-free region of a lower jaw or upper jaw by mechanical and / or optical scanning the spatial form of the mucosal structure descriptive record is determined. In addition, the spatial shapes of adjacent to the tooth-free area teeth of the lower jaw or upper jaw or a portion of a jaw, which is opposite to the tooth-free area of the lower jaw or upper jaw, scanned. The relative position of the opposing jaw relative to the lower jaw or upper jaw with the tooth-free area can also be determined. Preferably, at least the mucosal structure in the tooth-free region of the lower jaw or upper jaw is scanned in different oral situations, which are caused, for example, by suction, bladder or muscle rest from or in the respective patent. The scanning can be done by a variety of such as common optical methods for detecting three-dimensional structures. It can also be a mechanical scan. As a rule, it will be a scanning scanning with an optical or mechanical probe that detects the spatial shape of the mucosal structure point or line by line.

From the scanning device 1 of the spatial form of the mucosal structure descriptive record 2 is transferred to a computer 3, which is provided with a screen 4 and an input device 5. The computer 3 calculates with a software designed for this purpose from the data set 2 a data record 6 which describes the spatial form of a removable dental prosthesis 8 for filling the tooth-free region of the lower jaw or upper jaw. Then, this data set 6 is displayed together with the data set 2, which describes the spatial shape of the mucosal structure, on a screen 4 in a three-dimensional representation. Three-dimensional representation means that the respective spatial forms are displayed under selectable viewing direction with the course of their boundary lines in space. The spatial form of the dental prosthesis 8 can be manipulated on the screen 4 via the input device 5, which may comprise a keyboard as well as, for example, a mouse, as shown here. Thus, at the same time a manipulation of the associated data set 6. Thus, a perform the new method intervention in the determination of the spatial shape of the dental prosthesis 8. The spatial form of the denture 8 descriptive record 6 is then transmitted to a machine 7, the a plastic preform, which will be described in more detail in connection with FIG. 2, decreasing material, the denture 8 works out. In this case, the dental prosthesis 8 has a mucosal area 9 and a tooth area 10, which are worked out of areas of the plastic preform with different colors.

2 outlines the preform 1 1, which has a pink area 12 for forming the mucous membrane area and a white-yellow area 13 for forming the tooth area 10 of the dental prosthesis 8. In this case, the preform 11 preferably consists throughout of plastic of the same composition, which is colored differently in the regions 12 and 13, but which is connected in a closed manner over the boundary between the regions 12 and 13. The spatial form of the preform 11 may be adapted to the denture 8 in order to remove as little material as possible from the preform. The colors of areas 12 and 13 may also be individually selected depending on the circumstances of the individual patient by offering a plurality of preforms 11 of different colors and different color combinations.

LIST OF REFERENCE NUMBERS

scanning

record

computer

screen

input device

record

machine

dentures

mucosal area

posterior region

preform

Area

Claims

1. A method for the production of dental prostheses comprising the steps of: - mechanically and / or optically scanning a mucosal structure in a tooth-free region of a mandible or maxilla to determine a spatial shape of the mucosal structure descriptive record (2), - Determining a spatial form of a removable Denture (8) descriptive record (6), wherein the spatial shape of the dental prosthesis (8) to the spatial shape of the mucosal structure complementary mucous membrane area (9) and an adjoining tooth area (10), and - driving a machine (7) with the The dental prosthesis spatial form (6) for reducing the working out of the spatial form of the dental prosthesis (8) from a plastic preform (11) having a region (12) of a first and an adjoining region (13) of a second color the mucous membrane area (9) of the three-dimensional shape of the dental prosthesis in the region (12) of the plastic molded article (11) from the first and the tooth region (10) in the region (13) of the plastic preform (11) of the second color is formed.

2. The method according to claim 1, characterized in that in addition scanned the spatial shape of adjacent to the tooth-free area teeth of the lower jaw or maxilla and the spatial form of the denture (8) descriptive record (6) is determined taking into account the spatial shape of the adjacent teeth.

3. The method according to claim 1 or 2, characterized in that in addition the spatial shape of a region of a jaw, which is the tooth-free region of the lower jaw or upper jaw, scanned and of the spatial shape of the dental prosthesis (8) descriptive record (6) taking into account Spatial shape of the area of the opposite jaw is determined.

4. The method according to any one of claims 1 to 3, characterized in that in addition a relative position of a jaw, which is opposite to the tooth-free region of the lower jaw or upper jaw, scanned and the spatial shape of the dental prosthesis (8). descriptive data record (6) is determined taking into account the relative position of the opposing jaw.

5. The method according to claim 4, characterized in that the relative position of the opposing jaw is scanned in different positions of the jaw to each other.

6. The method according to claim 4 or 5, characterized in that the spatial form of the dental prosthesis (8) descriptive record (6) is determined taking into account an occlusal plane and / or an occlusion between the opposing pines.

7. The method according to any one of claims 1 to 6, characterized in that the mucosal structure is scanned in the tooth-free region of the lower jaw or upper jaw in different oral situations to determine the spatial shape of the mucosal structure descriptive record (2).

8. The method according to any one of claims 1 to 7, characterized in that the spatial form of the dental prosthesis (8) descriptive record (6) is visualized together with the determined by scanning data sets (2) in a three-dimensional representation before the machine (7 ) is driven.

9. The method according to claim 8, characterized in that the spatial form of the dental prosthesis (8) descriptive record (6) is changed by acting on the three-dimensional representation graphical tools.

10. Use of a plastic preform (11) having a region (12) of a first and an adjoining region (13) of a second color, in the manufacture of dental prosthesis according to one of claims 1 to 9, wherein the mucous membrane area (9 ) of a dental prosthesis from the region (12) of the plastic preform (11) from the first and its tooth region (10) from the region (13) of the plastic preform (11) is formed from the second color.

11. A device for the production of dental prostheses comprising: - a mechanical and / or optical scanning device (1) for scanning a mucosal structure in a tooth-free region of a mandible or maxilla, which determines a spatial shape of the mucosal structure descriptive record, - a computer (3) for Determining a spatial form of a removable denture (8) descriptive record (6) due to the the spatial shape of the mucous membrane descriptive record processing program, wherein the spatial shape of the denture (8) to the spatial shape of the mucosal structure complementary mucous membrane area (9) and an adjacent thereto Tooth area (10), and - a machine (7), which is controlled by the computer with the spatial form of the denture descriptive record (6) for material decreasing working out of the spatial shape of the dental prosthesis (8) from a Kunststoffvorfomnling (11) the plastic preform (11) a A region (12) of a first and an adjoining region (13) of a second color, wherein the mucous membrane region (9) of the spatial shape of the dental prosthesis in the region (12) of the plastic preform (11) from the first and the tooth region (10 ) is formed in the region (13) of the plastic preform (11) of the second color.

12. The device according to claim 11, characterized in that a screen (4) to the computer (3) is connected, on which the computer (3) the spatial form of the dental prosthesis (8) descriptive record (6) together with by scanning detected data sets (2) in a three-dimensional representation visualized before he controls the machine (7).

13. The device according to claim 12, characterized in that input devices are provided to change the spatial form of the dental prosthesis (8) descriptive record (6) by acting on the three-dimensional representation of graphical tools.

14. A method for the production of epithetics comprising the steps of: - mechanically and / or optically scanning a surface structure in a region of a head in order to determine a data record describing the spatial form of the surface structure, Determining a data record describing the spatial form of an epithesis or obturator, the spatial form of the epithesis or of the obturator having an abutment region complementary to the spatial form of the surface structure and adjacent regions facing away from it, and driving a machine having the spatial form of the epithesis or of the obturator descriptive data set for the material decreasing working out of the spatial form of the epithesis or the obturator of a plastic preform having a region of a first and an adjoining region of a second material, wherein the deformability and / or the color of the first and the second material from each other differ.

15. An apparatus for the production of epithetics comprising: a mechanical and / or optical scanning device for scanning a surface structure in a region of a head which determines a data record describing the spatial shape of the surface structure, a computer for determining a spatial form of an epithesis or an obturator descriptive dataset based on a program describing the spatial form of the surface structure processing program, wherein the spatial form of the epithesis or the obturator complementary to the spatial form of the surface structure contact area and this abgekehrte adjacent areas, and - a machine that the computer with the spatial form The epithesis or the obturator descriptive record for material decreasing working out of the spatial shape of the epithesis or the obturator is driven from a plastic preform, wherein the plastic preform a region of a first and a dara n adjacent region of a second material, wherein the deformability and / or the color of the first and the second material differ from each other.