Method of producing a dental prosthesis

Abstract

The invention relates to a method of producing a dental prosthesis from a one-piece or multi-piece prosthesis blank which is constructed from a gum-colored material and a tooth-colored material (32), in particular in each case on a plastic base. It is characterized by being connected to each other at connecting surfaces, having an interface between the gum-colored and tooth-colored materials. This interface, when viewed along the connecting surfaces has an undulating shape and viewed in the vestibular direction has a radial shape. In order to finish the dental prosthesis, a CAD/CAM device determines the exact course of a gingival line, based on patient-specific data, and produces the prosthesis.

Claims

1. A method of producing a dental prosthesis comprising providing a one-piece or multi-piece prosthesis blank having a gum-colored material and a tooth-colored material connected to each other at connecting surfaces and having an interface between the gum-colored and the tooth-colored materials, the interface, when viewed along the connecting surfaces, has an undulating shape and when viewed in a vestibular direction has a radial shape, using a CAD/CAM device to determine an exact course of a gingival line based on patient-specific data in order to produce and finish the dental prosthesis.

2. The method of producing a dental prosthesis according to claim 1, comprising supplying the CAD/CAM device with the patient-specific data, where anatomically relevant points are marked and serve as reference points.

3. The method of producing a dental prosthesis according to claim 2, comprising obtaining the patient-specific data from an intraoral 3D scan or an impression.

4. The method of producing a dental prosthesis according to claim 1, comprising using the CAD/CAM device to automatically produces a suggestion for the prosthesis.

5. The method of producing a dental prosthesis according to claim 4, comprising using the CAD/CAM device to produce the prosthesis as a virtual prosthesis.

6. The method of producing a dental prosthesis according to claim 5, comprising changing the virtual prosthesis by a user at the CAD/CAM device.

7. The method of producing a dental prosthesis according to claim 1, comprising using the CAD/CAM device having a design function to constructs and produce a vestibular border line of the interface based on the patient-specific data.

8. The method of producing a dental prosthesis according to claim 1, wherein the gum-colored material (10) is removed by milling.

9. The method of producing a dental prosthesis according to claim 1, wherein a plurality of dental arches or dental parts can be produced from one input material blank.

10. The method of producing a dental prosthesis according to claim 1, wherein the radial shape ensures that, when the width increases as viewed from the vestibular direction, the height of the teeth and wave crests increases at the same time.

11. The method of producing a dental prosthesis according to claim 1, wherein in smaller arches, smaller teeth are produced automatically, due to the radial shape of the dental prosthesis, as the distance between two crests or between two troughs corresponds to the grid dimension of the teeth.

12. The method of producing a dental prosthesis according to claim 1, wherein the data is fed to a rapid prototyping device in which the shapes of the tooth arch blank and the prosthesis base blank are stored virtually.

13. The method of producing a dental prosthesis according to claim 12, wherein the tooth arch blank and the prosthesis base blank comprise a radial/wave-shaped interface.

14. The method of producing a dental prosthesis according to claim 1, comprising providing the one-piece or multi-piece prosthesis blank having the gum-colored material and the tooth-colored material are fabricated of a plastic material.

15. The method of producing a dental prosthesis according to claim 1, comprising providing the one-piece or multi-piece prosthesis blank having the gum-colored material and the tooth-colored material intensively connected to one another.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages, details and features may be taken from the following description of several exemplary embodiments of the invention in conjunction with the drawings, in which:

(2) FIG. 1 shows a schematic perspective view of a blank for producing a dental prosthesis, namely a circular disc-shaped gum-colored blank;

(3) FIG. 2 shows the illustration according to FIG. 1 in a sectional view;

(4) FIG. 3 shows a modified embodiment of the blank according to FIG. 1;

(5) FIG. 4 shows a further modified configuration of a dental arch blank for providing an inventive dental prosthesis;

(6) FIG. 5 shows a view of the prosthesis base blank showing indicated possible border lines of the interface to form the gingival margin;

(7) FIG. 6 shows a further modified configuration of the dental arch blank according to FIG. 4;

(8) FIG. 7 shows a finished dental prosthesis in one embodiment in a sectional view;

(9) FIG. 8 shows a further embodiment of a prosthesis according to FIG. 7;

(10) FIG. 9a show further embodiments of inventive dental prostheses in the finished state;

(11) FIG. 9b show further embodiments of inventive dental prostheses in the finished state;

(12) FIG. 10 show schematic illustrations of the blanks for providing an inventive prosthesis, also illustrating the tooth-colored blank;

(13) FIG. 10a show schematic illustrations of the blanks for providing an inventive prosthesis, also illustrating the tooth-colored blank; and

(14) FIG. 11 shows a schematic illustration of the blank according to FIG. 10 wherein various dental arch sizes are indicated alternatively.

DETAILED DESCRIPTION

(15) FIG. 1 shows a gum-colored blank 10 as a primary product of an inventive dental prosthesis in an embodiment in a perspective view. The basic structure of the blank is disc-shaped and consists of gum-colored material which may also be referred to as gingival material. At its upper side—in the illustration according to FIG. 1—it comprises a recess 12 which is configured in a particular manner. Basically, the recess 12 extends in the form of a semicircle, that is to say in the shape of an arch. One of the characteristic features of the arch is the wave shape of the bottom side of the recess 12 which extends towards the arch. In the radial direction, that is to say from the center 17 of the arch towards the outside, that is to say towards the vestibular side, a radial shape is provided.

(16) The arch 16 consists of alternating wave crests 18 and wave troughs 20. They extend isogonically such that the same wave crest exists at the same angular position of the arch 16, and the same wave trough 20 exists at another consistent angular position.

(17) It is apparent from FIG. 1 that the wave shape 14 of the arch 16 deviates slightly from a sine shape. Indeed, the wave shape simulates the gingival margin and, in this respect, assumes some elements of a catenary and some elements of a sine shape.

(18) The arch-shaped recess 12 is intended to receive a blank made of tooth-colored material which is shaped such that it fits the recess. Accordingly, the side of the blank made of tooth-colored material which faces the blank comprises a negative shape relative to the wave shape 14 at the bottom of the recess 12. In this respect, the shape of the tooth-colored blank exactly matches the recess 12, possibly by leaving an adhesive gap having a thickness of between 50 μm and 150 μm.

(19) Accordingly, the tooth-colored blank may be bonded into the recess 12 of the blank 10 easily.

(20) Alternatively, it is also possible to produce a connection between these blanks by polymerization.

(21) By means of the joining operation, the blank 10 in turn obtains the shape of a circular disc altogether due to the filling of the recess 12, wherein in a way known per se an annular protrusion 24 is configured circumferentially and serves to be mounted in the workpiece holder of a dental milling machine.

(22) In this connection, it is provided to mount the blank 10 at an exactly predetermined position by means of a positioning device which enables to mount the blank such that rotation is prevented. Thus, the blank which has possibly been machined partially may be removed for inspection purposes if necessary, and may then be reinserted in the correct position.

(23) According to the invention, after the two blanks have been connected with one another intensively in the described manner or in any other suitable manner, the milling process which is predetermined by CAD/CAM is performed. The blank produced in this way makes it possible to realize any design of prostheses, that is to say prosthesis bases and teeth. The entire dental prosthesis may be produced in one go by milling, and the gingival line 26 makes possible that the gingival margin provided in this way may not be differentiated from a natural gingival margin at first glance.

(24) Even if the recess 12 is described as a circular arc-shaped recess, it is to be understood that any other configurations of the shape are possible. As is indicated in FIG. 1 the wave shape 14 is indeed lowered slightly in the vestibular/incisal area, and raised slightly in the vestibular/molar area, in accordance with the human gingival margin.

(25) A possible distribution of the wave crests and wave troughs is apparent from the sectional view of the blank 10 illustrated in FIG. 2. The radial shape of the wave crests 18 or wave troughs 20, respectively, produces an asymmetric distribution of the wave crests and wave troughs, as can be seen from FIG. 2.

(26) The arch width of the arch 16—as viewed in the radial direction—is considerably larger than the vestibular/lingual or vestibular/palatal extension of a prosthesis tooth.

(27) In this way, it is initially possible to determine any desired radial position of the dental arch to be provided for by CAD. Thus, the size of the prosthesis, but also of the associated teeth, may be adapted to the requirements of the human jaw of the patient to a large extent. Due to the radial shape, in case of smaller arches smaller teeth are produced automatically as the distance between two crests 18 or between two troughs 20 corresponds to the grid dimension of the teeth, respectively.

(28) According to the invention, it is particularly favorable that the inserted teeth will not be separated even after the milling process but are present in the form of a dental arch. The interdental spaces are preferably configured to be positioned deeply and the bridges of material between the individual teeth are shifted towards the lingual/palatal side. In this way, it is ensured that the optical impression of the inventive dental arch may not be differentiated virtually from a set of teeth with individual teeth.

(29) Realizing the dental arch additionally allows for considerably increased strength.

(30) This makes it possible to manage with teeth without tooth roots, that is to say teeth which are only held in position by means of the intensive connection with the gingival blank 10.

(31) It is favorable to realize the recess 12, as is illustrated in FIG. 1 and FIG. 2, in order to precisely position the tooth blank relative to the gingival blank.

(32) In a modified embodiment, however, the arch 16 extends until the outer circumference of the blank 10, as is apparent from FIG. 3. This embodiment, too, is suitable for forming a prosthesis base which fits many different sizes and shapes, wherein this embodiment also enables slightly enlarged dental arches.

(33) FIG. 3 shows a homogeneous distribution of the wave troughs 20 and the wave crests 18. In a still further modified embodiment it is provided to realize the wave crests and troughs to be narrower and smaller in the area of the incisors, and accordingly to realize them broader and of a larger height in the area of the premolars and above all the molars. This accounts for the different tooth sizes and tooth widths along the course of a human set of teeth.

(34) However, a human set of teeth is typically not exactly shaped like a circular arc, but recedes slightly in the incisal area, that is to say in particular in the area of the teeth I, which have an almost plane labial surface, compared to a circular arc. Then, the radial shape of the crests 18 and troughs 20 automatically leads to smaller grid dimensions thereat.

(35) On the other hand, human upper jaw teeth II are typically slightly narrower than the upper jaw teeth I. This can also be taken into account by correspondingly adapting the width of the troughs and crests to the respective angular position, particularly in the case of upper jaw prostheses.

(36) In comparison, an even further modified dental arch blank 32 is apparent from FIG. 4. The shape of the wave crests and wave troughs extending radially and apparent from the FIG. 4 fits the prosthesis base blank 10 in a manner true to shape, into the recess 12 disposed thereat.

(37) In this embodiment the rays 28 extend towards a central point which is considerably lowered relative to the height of the gingival line. In this way, the rays 28 are caused to tilt relative to the horizontal which is favorable in particular embodiments and enables a better mounting of the dental arch in the palatal/lingual region.

(38) FIG. 5 shows an accordingly exposed, partially machined prosthesis base blank 10 which illustrates the tilt of the radial line 28 described in connection with FIG. 4. Moreover, various border lines 27, 29 and 31 are indicated in FIG. 5 which exemplify the milling line of the interface 33 with respect to the dental arch blank 32 which is to be seen as the prosthesis gingival margin, in this respect.

(39) Its position may be adjusted by the control device in a patient-specific manner wherein in case of rather triangle-shaped jaw structures the mesial region protrudes in accordance with the arrow 35, and the line structure apart from that may be adapted to the requirements to a large extent.

(40) FIG. 6 shows how a dental arch 32 which is to be mounted in a recessed manner in a circular arc recess in the partially machined prosthesis base blank 10 may be built in layers.

(41) It is apparent schematically that the dental arch blank 32 is built from 5 layers 35a, 35b, 35c, 35d and 35e which become increasingly dark and opaque towards the interface 33, corresponding to the dentin of a human tooth. It is to be understood that considerably more or also fewer layers may be used.

(42) Here, the layer transition 35e-35d follows the course of the rays, wave crests and wave troughs of the interface in an extenuated manner, while this characteristic becomes more and more extenuated towards the layer 35a. Examples of tooth shapes and sizes, 37a and 37b, are shown in dashed lines.

(43) It is to be understood that here the two blanks are preferably each produced separate from one another by milling and are then joined together and connected with one another intensively by adhesive bonding. During milling, the side flanks of the circular arc recesses to be seen thereat form stops of the inventive dental arch in the mesial/distal direction likewise. This enables a particularly good anchorage of the dental arch as is particularly important with comparatively small prostheses.

(44) By milling off the outer side of the prosthesis base blank 10 the inventively particularly favorable gingival line between red and white material can be made visible, in turn.

(45) FIG. 7 shows how a finished prosthesis 30 may be configured in cross-section.

(46) It is apparent that the tooth-colored material 32 extends along the prosthesis base 10 produced in this way according to the gingival margin, but without perforating the gum-colored material 10, according to the natural dental arch. It is also apparent that in this preferred embodiment the material 32 is also held positively in the material 10 in the radial direction.

(47) FIG. 8 shows the finished dental prosthesis 34 with the aid of a wire model. By reference to the rearmost molar 36 as part of the inventive dental arch 38 it is apparent that it is embedded intensively in gingival material or connected with it intensively, respectively.

(48) FIGS. 9a and 9b show prostheses produced accordingly in different directions of view in perspective.

(49) FIG. 10 and FIG. 10a show how the arch-shaped tooth-colored material 32—still in the shape of a blank in this illustration—is inserted into the recess 12 of the blank 10 and accommodated therein. The subsequent shape of the prosthesis 34 is illustrated schematically in FIG. 10 and FIG. 10a, respectively.

(50) FIG. 11 shows a section according to FIG. 10 wherein different prostheses 34, 34a and 34b are illustrated with alternative sizes. It is apparent that the blank 10 leaves sufficient free space for the largest possible combinations of prosthesis bases and teeth both towards the occlusal/incisal side, that is to say in the region of the dental arch 32, and in the central region towards the bottom, wherein it is to be understood that the dimensions of the blank are known as boundary conditions to the control device.