EP2026711A1

EP2026711A1 - Blank for a dental prosthesis and method for the production of a dental prosthesis

Info

Publication number: EP2026711A1
Application number: EP07725678A
Authority: EP
Inventors: Stephan Holzner; Gerhard Weber
Original assignee: Aepsilon Rechteverwaltungs GmbH
Current assignee: Institut Straumann AG
Priority date: 2006-06-01
Filing date: 2007-05-30
Publication date: 2009-02-25
Also published as: WO2007137837A1; DE102006025660A1; US20070290385A1

Abstract

The invention relates to a blank (1a) for a dental prosthesis comprising a first section (2a) having the shape of a section of a tooth or of a dental prosthesis and a second section (3a) which has a provision of material which by means of machining such as milling can be made into a desired shape. The invention also relates to a method for the production of a dental prosthesis in which a blank is machined by means of a cutting method such as milling or laser machining in order to obtain a desired shape of a dental prosthesis, wherein only parts of the blank are machined and other parts remain unmachined because they already have the desired final shape. The invention also relates to a unit comprising at least one blank as above and at least one counterpiece which has a receptacle for holding the blank which receptacle at least partially conforms to the first section and/or the second section.

Description

Blank for a dental prosthetic item and method of making a dental prosthesis

The invention relates to a blank for a tooth replacement part and to a method for producing a tooth replacement part.

It is known to work out blanks from tooth replacement parts, for example by milling.

The blanks usually have simple geometric shapes, such as the shape of a disc of a given thickness.

To produce the dental prostheses, material is removed from the blanks both from the upper and the underside of the blank (the underside being made accessible, for example, by turning the blank around for machining) so as to give the tooth replacement part the desired shape.

The cost of the blank material is not negligible, so that it is an object of the present invention to provide a blank and a method of manufacturing a dental prosthesis, which requires less blank material.

This object is achieved by a blank according to claim 1, a method according to claim 8 and a set according to claim 13. Preferred embodiments are disclosed in the dependent claims.

The blank has a first portion (such as the top) given by its surface already having the desired shape. The upper part is the part of a tooth that is visible on natural teeth because it is not covered by gums. The blank may thus already have on one side or on a surface or in a section the structure of the purchase surface of a tooth and of adjacent regions thereof. For example, a blank for a dental prosthetic item may have in one section the shape of a portion of a dental prosthesis that is to be clad with a occlusal surface and other visible parts a tooth is provided. This part of a dental prosthesis part is also called upper part.

The remainder (the second portion) of the blank has a simple geometric shape, so that here is a supply of material is given, which can be brought by machining to the desired shape. The shape of the lower part is, for example, columnar, wherein the cross section may be square, rectangular, circular, elliptical, triangular or otherwise. He may also have rounded corners. It is also possible that the cross section corresponds to the outline of the upper part when looking in the direction of the «Auflache.

The blank may include one or more of the materials such as plastic, metal, stainless steel, ceramic, zirconia, etc. Combinations of these materials are possible.

Particularly advantageous is a blank having different colors at different locations. Since natural teeth are usually not monochrome, but have different colors in different places, it is advantageous if the blank also has different colors at different locations. The different colorations need not capture the entire blank, but advantageously only the first section. In this case, for example, such a coloring is relevant in which the upper side has a darker color in depressions and / or grooves and / or cracks, since this is usually the case with natural teeth. The coloring can be both superficial, and it is also possible that the blank is at least partially colored (in particular in the region of the first section).

In an advantageous embodiment, the blank has projections and / or depressions with which the blank can be held. The projections and / or recesses may be attached to the sides, for example, so that machining of both the first and second sections is possible. For this purpose, in particular recesses and / or projections at the transition between the first and the second section are advantageous. At least two, three, four or more recesses and / or protrusions are advantageous, these preferably being attached to different sides of the blank are provided in order to achieve a good grip of the blank. The blank can be held with jaws or other staples or the like on the projections and the recesses.

In the method for producing a dental prosthesis, a blank is brought by a machining process in the desired shape of a dental prosthesis, but only parts or a part of the blank must be processed and another part or other parts can remain unprocessed, as they already have desired final shape.

With this method, both a faster as well as a more effective use of blank material feasible production of a dental prosthesis part is possible.

In this case, in particular, such a method is advantageous in which that part of the tooth replacement part which forms the occlusal surface or points in the direction of the occlusal surface remains unprocessed. However, smaller adjustments are possible here if the need arises, for example, to adapt the tooth replacement part exactly to a tooth gap or to the opposing dentition.

Also advantageous is a method in which the processing of the blank takes place only from a half space out. Even more advantageous is machining only from one direction, as is possible, for example, with a three-axis milling machine. The direction is called feed direction. In particular, such a method is advantageous in which the blank does not have to be re-clamped or turned over and yet can be processed with only one milling head. This is made possible by the fact that a part of the blank already has the desired shape and no longer needs to be processed. As a result, dental prostheses can be produced relatively quickly and the procedure is much easier.

The dental prosthetic item made by the method may be an inlay, an overiay, a coping, a crown, a trim, a bridge, or other component of a dental prosthetic item, such as a portion of an implant. For a dental prosthesis part for a given tooth position, such as the foremost or another molar tooth, the canine or a particular incisor, different blanks are usually required. However, even for a particular tooth position (for example, for the first molar tooth), there may be various blanks from which one is selected. These may differ both in their shape and additionally or alternatively by their color.

The selection of a blank from a plurality of blanks for a particular tooth position, wherein the different blanks differ in shape, usually allows the selection of a suitable shape of the counter-bite blank with a corresponding top.

In the method, a denture part finished with respect to the mold can also be dyed or colored accordingly.

For example, one set includes one of the blanks described above. The kit further comprises at least one counterpart that matches the first section or the second section. Thus, the blank can be held with the counterpart to edit the accessible part of the blank, z. B. by milling.

It can be provided for a blank different counterparts to always have access to different parts of the blank for editing. Thus, for example, two, three or more counterparts can be provided, which are adapted to the shape of the first or second section and thereby leave access to different parts of the first and / or the second section.

In the accompanying figures, advantageous embodiments of the invention are disclosed. Showing:

Figure 1 is a schematic three-dimensional representation of various blanks;

Figure 2 is a schematic three-dimensional representation of a dental prosthesis part; Figure 3 is a schematic three-dimensional view of a second dental prosthesis part;

Figure 4 is a schematic three-dimensional representation of a blank for a two-part bridge;

Figure 5 is a schematic view of a bit and various blanks;

Figure 6 is a schematic three-dimensional representation of a blank having a recess and a projection;

Figure 7 is a schematic three-dimensional representation of a counterpart.

FIG. 1a shows a blank 1a for a tooth replacement part. The blank 1a has an upper surface 2a, which has the shape of a chewing surface of a molar tooth. Furthermore, the blank 1a has a lower part 3a which has a rectangular cross section and is columnar.

In Figure 1b, a blank is shown, as it may be suitable for a canine. The blank 1b here has a top 2b, which corresponds to the occlusal surface of a canine. The lower part 3b has a columnar shape, wherein the cross section is here round or irregular. When viewed from above (in Figure 1b from above) on the upper part 2b results in an approximately semicircular cross-section with rounded corners.

FIG. 1c shows a blank for a tooth replacement part which can replace two teeth (here two incisors). Generally, the blank may be formed for the manufacture of a dental prosthetic item for replacement of one, two, three, four or more teeth. The upper part 2c here has the shape of two juxtaposed incisors. The lower part 3c of the blank 1c has a substantially rectangular cross-sectional shape but is slightly bent. This shape results from the top view of the chewing surfaces 2c.

FIG. 2 shows a finished tooth replacement part as it was produced from the blank 1a (see FIG. 1a). The upper part 2a is unchanged, only at the bottom of the blank 1a was processed, so that the desired shape 5 results. This form here has a recess 6, with which the dental prosthesis part can be placed on a bridge or an implant post.

In FIG. 3, a tooth replacement part, as can be produced from the blank 1c, is correspondingly illustrated. The upper part 2a is unchanged in shape, only the lower part 7 has been processed.

FIG. 4 shows a blank 1d for the production of a bridge. The bridge has on its top two frusto-conical elevations 8a, 8b. On these increases panels can be applied, which resemble optically teeth. These panels then have the chewing surfaces.

The lower part 3d has a columnar shape which has an approximately elliptical cross section.

FIG. 4 shows a blank 1d for a two-part bridge. However, it is also possible to provide three, four, five or more unit bridge blanks.

FIG. 5 a shows schematically a series of teeth 11 which correspond to a maxillary dentition. Reference numeral 12 denotes the associated teeth of the mandibular dentition. At position 9, a tooth is missing, which is to be replaced by a dental prosthesis. The tooth gap is at the position of the second molar tooth. For the position of the second molar tooth blanks can be provided with shapes, as shown in Figure 5b. The blank 10a has on its upper side two differently high bumps, while the blank 10b has approximately two equal height bumps. Blank 10c results at least in its upper side in approximately mirror image of blank 10a and also has two different heights on hump. The blank 10d has a substantially flat upper side while the blank 10e has an outwardly curved upper side.

For the tooth gaps 9 in FIG. 5 a, for example, a blank with the upper side of the blank 10 a would offer itself, since it would fit well with the counterbite 11.

FIG. 6 shows a blank 1 which is provided, for example, with a projection 16 and a recess 17. Advantageously, a blank 1, which has only projections 16 or only depressions 17, since thus a holder of the blank 1 is easier. In Fig. 6, only two holding elements (one recess and one projection) are shown, both of which are on the same page. On the two sides facing away from in FIG. 6 or only on one of these sides, one or more holding devices are provided in each case. In a blank having a substantially triangular cross section, one, two or three holding devices may be provided on one, two or three sides. Correspondingly, in the case of a blank having a substantial square cross-section, one, two or three holding devices can be provided on one, two, three or four sides. Also advantageous is an arrangement of retaining elements on opposite sides.

Furthermore, it is advantageous if the holding devices are provided at the transition between the first and the second section. In a holder at these locations, the first and / or second section remains substantially accessible for editing substantially.

The projections 16 may be removed in a finishing step.

In Fig. 7, a counterpart 11 is shown that can form a set together with a blank. The counterpart 11 has a receptacle 12 which is adapted to the shape of the blank. FIG. 7 shows a counterpart whose receptacle is adapted to the first section of the blank of FIG. 1b or 6. The receptacle 12 does not have to be an exact negative mold of a part of the shape of the blank, but merely needs to be adapted to allow holding of the blank. Optimal for this, however, is such a negative form.

The recording can be adapted to both the first and the second section or only one part of each. The respective exposed part can then be processed accordingly.

In Fig. 7, the counterpart 11 has a bracket 13 which is pivotally mounted about the axis 18. This bracket 13 can be pivoted to the side of the counterpart, on which the receptacle 12 has an opening. For holding a blank, the blank may, for example, have projections 16 (see Fig. 6) on its periphery which, when the blank is inserted into the receptacle, rest on the surface of the counterpart 11 or are slightly spaced therefrom with the blank inserted. The clip 13 can be pivoted after insertion of the blank due to the recess 14 on the blank over to the opening of the receptacle 12 out (in Fig. 7 down). It then presses the blank on the projections into the receptacle 12, whereby a firm grip is ensured. Other shapes and types of staples or the like are possible to hold the blank in the counterpart 11. Thus, brackets can be provided which can be pivoted into recesses on the blank side in order to hold the blank.

The counterpart 11 in Fig. 7 surrounds the blank at least partially fully. However, it is also possible that the counterpart 11 has recesses and / or holes, with which a machining of that portion of the blank is held by the counterpart is possible. So z. B. the front third of the counterpart in Fig. 7 are missing, so that the receptacle 12 is also accessible from the front side. The blank is then still held by the counterpart 11, however, the corresponding portion of the blank is accessible for processing. With other counterparts, in which compared to FIG. 7, for example the top, bottom or back third or right half is missing (so that the top of the blank looks out to the right of the counterpart hole) other sections of the blank may be accessible, although the blank is always held at the same (first) section.

Claims

claims:

1 blank (1a, 1b, 1c, 1d, 10a, 10b, 10c ₁ 10d, 10e) for a dental prosthesis, with:

a first portion (2a, 2b, 2c) having a shape of a portion of a tooth or a dental prosthesis, and

- A second portion (3a, 3b, 3c), which has a supply of material, which can be brought by machining such as Wegfräsen in a desired shape.

2. blank according to claim 1, characterized in that the first portion (2 a, 2 b, 2 c) corresponds to the upper part of a tooth or a dental prosthesis.

3. blank according to claim 1 or 2, characterized in that the second portion (3a, 3b, 3c) has an approximately columnar shape, wherein the cross section corresponds to the outline of the first portion in a plan view, or square, rectangular, circular, elliptical or triangular, and possibly has rounded corners.

4. Blank according to one of claims 1 to 3, characterized in that the blank (1a, 1b, 1c, 1d) comprises at least one of the materials, plastic, metal, stainless steel, ceramic or zirconium oxide.

5. blank according to claim 1 to 4, characterized in that the blank (1a, 1b, 1c, 1d) has different colors at different locations.

6. blank according to claim 5, characterized in that in the first portion (2 a, 2 b, 2 c) in recesses (4) and / or grooves (4) and / or cracks (4) darker colors are present than at other locations.

7. Blank according to one of claims 1 to 6, characterized in that the blank (1) holding elements, such as projections (16) and / or recesses (17), preferably on one or more sides corresponding to tooth sides and / or at or at the transition between the first and second sections (2a, 2b, 2c).

8. A method of manufacturing a dental prosthesis, wherein a blank (1a, 1b, 1c, 1d) is machined by an ablation process, such as milling or laser machining, to obtain a desired shape of a dental prosthesis, wherein only parts of the blank (1a , 1b, 1c, 1d) and other parts remain unprocessed, since they already have the desired final shape.

9. The method according to claim 8, characterized in that the upper side (2a, 2b, 2c, 2d) of the dental prosthesis remains unprocessed.

10. The method according to claim 8 or 9, characterized in that the processing of the blank (1a, 1b, 1c, 1d) takes place only from one direction.

11. The method according to any one of claims 8 to 10, characterized in that the tooth replacement part is an inlay, an overlay, a coping, a crown, a cover, a bridge or other component of a dental prosthesis such as an implant.

12. The method according to any one of claims 8 to 11, characterized in that the blank (1a, 1b, 1c, 1d) from a plurality of blanks (10a, 10b, 10c, 10d, 10e) is selected.

13th sentence comprising:

- At least one blank (1) according to one of claims 1 to 7 and

- At least one counterpart (11) that at least partially the first portion (2b) and / or the second portion adapted receptacle (12) for holding the blank (1).

14. Set according to claim 13, characterized in that the counterpart (11) holding devices (13), such as Klammem, which can engage the blank, in particular on projections (16) and / or depressions (17) to the To hold blank (1) in the counterpart (11).