DK1601303T3 - Apparat til udvælgelse af et område på et dentalt restaureringslegeme, som er vist i 3D-gengivelse, samt en fremgangsmåde dertil - Google Patents

Description

DEVICE FOR SELECTING AN AREA OF A DENTAL RESTORATION BODY, WHICH IS DEPICTED IN A 3D REPRESENTATION, AND METHOD THEREFOR

DESCRIPTION

TECHNICAL FIELD

[0001] The invention relates to an apparatus for the selection of a region of a dental restoration body depicted in 3D representation, and to a method therefor.

PRIOR ART

[0002] The prior art includes CAD/CAM systems for the design and fabrication of tooth restoration bodies, which, by means of a preparation image of a prepared tooth, use teeth from a tooth database in the form of characteristic lines such as the preparation edge, equator line, edge strip, and fissure, in order to design and fabricate a restoration body.

[0003] In order to improve fitting accuracy, provision is also made for at least part of the occlusal surface of a tooth present in the database to be transferred, by copying, to the restoration body to be fabricated.

[0004] For specific modification of a dental design with the help of a CAD system it is always necessary to select those regions that are to be processed with specific design tools.

[0005] In the prior art, selection of the region is executed by way of a menu or dialogue. In addition, the region can be defined by drawing in a boundary line.

[0006] This suffers from the drawback that the boundaries of the regions to be modified and thus the designed tooth shapes, are not dental-specific. Document US 6 049 743 discloses an apparatus and a method for constructing a dental model, in which the dental body is divided into a plurality of regions which can be shaped in a rectangular manner or which can be delimited by dental-specific structures, such as tooth cusps, tooth furrows or tooth edges. In order to deform the dental model, the individual regions can be used as deformation units, wherein a specific region is deformed without modifying the adjoining regions. The regions can also be delimited by auxiliary lines which for example constitute extensions of the natural tooth furrows. In addition, this document discloses that a selected region is modified in a membrane-like manner as far as the boundary of this region, wherein the adjoining regions remain unchanged.

DISCLOSURE OF THE INVENTION

[0007] The invention relates to an apparatus for selecting a region of a dental restoration body represented in a 3D representation according to claim 1. In accordance with the invention the region is defined by selection of dental-specific lines or of dental-specific points or of a preparation edge.

[0008] This has the advantage that the system can be operated in a simple and intuitive manner while working directly on the image to be modified. Therefore the region to be worked on is selected intuitively by selecting a line or a point that is associated with a typically dental region.

[0009] Further embodiments of the invention are defined in the dependent claims.

[0010] It is advantageous if the restoration to be designed, i.e. the tooth that is to be fabricated, is divided into regions that are, at least in part, delimited by dental-specific lines and are indicated in the three-dimensional representation of the restoration.

[0011] Suitable dental-specific lines are the equator line and the edge strip, or alternatively, in the case of front teeth, the labiolingual line, the fissure or again alternatively, in the case of front teeth, the incisal edge, and suitable dental-specific points are the position of one or more cusp peaks, individually or several of them or all together.

[0012] Advantageously, each dental-specific line and/or preparation edge is divided into four parts representing the mesial, distal, buccal, and lingual sides of the tooth respectively. This makes it possible to allocate the region to be selected.

[0013] Advantageously, the selected part of the line determines the part of the tooth in which the region is located. Thus, selection is effected directly with reference to that side of the three-dimensional representation which is displayed.

[0014] In accordance with the invention, the selected line completely determines the region according to the following allocation: preparation edge: the region extends from the preparation edge to the center of the occlusal surface; equator line: the region is located between the preparation edge and the edge strip; edge strip: the region extends from the equator line to the center of the occlusal surface; fissure: the entire occlusal surface is selected as a region which is delimited by the edge strip.

[0015] Selection of a line will clearly define the region assigned to it.

[0016] Advantageously, by selecting a dental-specific point identifying the position of a cusp peak, the region of the corresponding cusp can be selected as far as its cusp borders, whilst the lower border of the region can be formed by the equator line.

[0017] In accordance with a further development, the selected region is depicted in a distinguishable fashion.

[0018] In accordance with a further development, means for evaluating and/or comparing geometrical data of the selected region are provided. This makes it possible to store the selected region in memory or to compare it with a region of another restoration or any other tooth stored in a memory.

[0019] In accordance with a further development, the selected region can be processed with the aid of a design tool of a CAD system. The region to be processed with the design tool is defined by selecting dental-specific lines or dental-specific points or a preparation edge.

[0020] Advantageously, the tool adapted to modify the region leaves the boundaries of the region unchanged, whilst a continuous increase in modification takes place toward the point requiring the greatest degree of modification. This enables systematic processing of the selected region whilst allowing for dental-specific requirements.

[0021] Advantageously, the point requiring the greatest degree of modification is located on a dental-specific line. This ensures that processing with the design tool will not make unexpected modifications in regions not receiving the attention of the operator.

[0022] A further subject of the invention is a method of selecting a region of a dental restoration body depicted as a 3D representation, according to claim 10, in which boundaries are assigned to the selected region which are, at least in part, defined by dental-specific lines. This has the advantage that the selection of a region conforms to dental-specific requirements and can easily be consulted for subsequent treatment of the region or for the purpose of comparative analysis. Selection of the region is effected in accordance with the invention by selecting a dental-specific line or a preparation edge associated with the region to be selected. Such a selection has the advantage that it is clear to the user which region he or she is momentarily selecting.

BRIEF DESCRIPTION OF THE DRAWING

[0023] The apparatus according to the invention will be explained with reference to the drawings, in which:

Fig. 1 illustrates a restoration body in the form of a molar, showing its mesial side with a selected region corresponding to the anterior half of the tooth;

Fig. 2 shows the tooth of Fig. 1 but with the right-hand half of the tooth being the selected region;

Figs. 2a and 2b show the tooth of Fig. 2 with the right-hand half of the tooth as the selected region in a comparison of the pre-modified state (Fig. 2a) with the post-modified state (Fig. 2b);

Fig. 3 shows the tooth of Fig. 1 viewed from an oblique angle with the selected region being a lateral surface of the anterior half of the tooth;

Fig. 4 illustrates the tooth of Fig. 1 showing its buccal side with the selected region being the surface of the forward region of the tooth above the equator line;

Fig. 5 illustrates the tooth of Fig. 1 showing its mesial side from above with the occlusal surface as the selected region;

Fig. 6 illustrates the tooth of Fig. 1 showing its buccal side viewed from an oblique angle with a cusp being the selected region;

Fig. 7 illustrates a restoration body in the form of an anterior tooth showing its lingual and distal sides viewed from an oblique angle with one half of the tooth being the selected region;

Fig. 8 illustrates the tooth of Fig. 7 with the occlusal region above the labiolingual line being the selected region, and

Fig. 9 illustrates the fundamental structure of the apparatus.

EXEMPLARY EMBODIMENT

[0024] In a CAD system, dental-specific lines and points are depicted in a 3D representation of the restoration. By clicking on individual elements, a region to be processed using design tools, for example, is selected, and the user can immediately begin work thereon within the representation to be processed. The design tool used can, in particular, be a shaping tool which changes the shape of a surface from the boundary of the region up to the point requiring the greatest degree of modification.

[0025] Fig. 1 shows a restoration body to be fabricated in the form of a molar 1 showing its mesial side, a region 2 corresponding to the anterior half of the tooth being selected. In the 3D representation of the tooth 1, the unselected region is shown as a hatched region, and, in addition, several lines and points are indicated, which will be described below.

[0026] Starting from the lower, cervical end of tooth 1, which is located in the region of the gingiva 3, a first line is shown in the form of the preparation edge 4. The preparation edge 4 represents the boundary between the original tooth surface in its unprepared condition and the prepared part of the tooth.

[0027] In the region of the largest circumference of the tooth 1, the equator line 5 is drawn as one of several dental-specific lines. Progressing to the top of the tooth 1, an edge strip 6 is drawn in, which extends across tooth cusps 7 particularly characterized by dental-specific points 7.1 to 7.4.

[0028] Another dental-specific line is a fissure 8, which extends along the surface of the tooth 1 within an occlusal surface 9 delimited by edge strip 6.

[0029] Another regional boundary is a dividing line 10 between the anterior mesial half and the posterior distal half of tooth 1, which may correspond to the course of a lateral fissure, but may simply represent a way of imparting geometrical information.

The course of this line in the representation described herein is of secondary dental importance.

[0030] The region 2 will be selected by selecting the preparation edge 4, for example by a mouse click, and it will extend from preparation edge 4 up to the center of the occlusal surface 9, which is indicated by the course of line 10. Not in accordance with the invention, it goes without saying that, instead of clicking on the preparation edge 4, provision can also be made for selection to be effected by clicking on the regions between the previously described lines or points. For example, the tooth half represented in Fig. 1 can be selected by clicking on the region between preparation edge 4 and equator line 5. Clicking on other regions in the representation leads to selection of a differently delimited region.

[0031] Using a processing tool, the entire region 2 can be processed, and, by entering keyboard commands, for example, its size can be enlarged or reduced horizontally, vertically, or normal to the plane of display. The region can therefore be modified in all six directions in space, suggested by the lines 11.1 and 11.2 indicating reduction and enlargement of the width of the tooth respectively.

[0032] The same applies, of course, to the height of the tooth and its spatial dimensions extending towards and away from the user. Such modifications will also change the course of the fissure 8.

[0033] In Fig. 2, tooth 1 is represented from the same direction as in Fig. 1, but in this case the right-hand lingual half of the tooth is the selected region 22. In this representation it is particularly easy to recognize that a boundary line 23 of the selected region 22 is not a typical dental design line but only an auxiliary line for demarcation of the region 22. The line 23 runs approximately through the center of the tooth 1 and thus approximately within the region of the lateral fissures. The lateral fissure can, of course, also be used as a dental-specific line for delimiting the region 22 if it has been allocated for this purpose by the measuring data or in some other way.

[0034] If the selected region 22 is processed with a tool for CAD purposes, then the preparation edge 4 and auxiliary line 23 will remain unchanged.

[0035] Figs. 2a and 2b show the tooth of Fig. 2 with its right-hand half being the selected region and provide means of comparison between a pre-modified state (Fig. 2a) and a post-modified state (Fig. 2b), modifications having been made in the direction of the arrows. The course of the preparation edge 4 and line 23 have not changed, but the equator line 5, edge strip 6, and the fissure have changed their position in the direction of the arrows.

[0036] In Fig. 3, tooth 1 is represented in an oblique view, whilst the selected region 32 of interest represents the lateral surface of the anterior half of tooth 1 of Fig. 1. The occlusal surface 9, in contrast to Fig. 1, is therefore no longer part of the selected region 32. The selected region 32 is delimited by preparation edge 4, auxiliary line 10, and edge strip 6.

[0037] If the region 32 is now processed with the design tool, only the lateral surface will expand in the mesial direction, for example without edge strip 6, auxiliary line 10, or preparation edge 4 being modified.

[0038] Modifications in the course of the surface will take place in such a way that the modification, starting from modification "zero" at the previously described boundaries of region 32 up to the point of greatest modification, indicated by the hatched circle 33, gradually increases in the mesial direction during the shaping operation, so that the surface within the entire region 32, with exception of the boundary region, is modified. The region 32 is selected, for example, by clicking on the equator line 5.

[0039] In Fig. 4, the tooth 1 of Fig. 1 is illustrated showing its buccal side and the selected region 42 covers only the surface of the anterior region of the tooth above the equator line 5. The boundaries of the selected region 42 are therefore defined by the equator line 5 and auxiliary line 10. The auxiliary line 10 approximately coincides with the lateral fissures, but its exact course is not of crucial importance in this case. Selection of the region 42 is effected, for example, by clicking on the right-hand part of edge strip 6.

[0040] In Fig. 5, the tooth 1 of Fig. 1 is illustrated showing its mesial side viewed obliquely from above, and the selected region 52 is the occlusal surface 9. The occlusal surface 9 is delimited by the edge strip 6. Modifications only affect the position, but not the course, of the fissure 8. This means that the spatial relationship between the points forming the fissure 8 does not change, i.e., in particular, that the line is not stretched or bent. The entire line will be raised or lowered, for example, as the occlusal surface 9 is modified.

[0041] Fig. 6 illustrates the tooth of Fig. 1 showing its buccal side from an oblique angle, and a cusp, identified by a point 7.2, is represented as the selected region 62. The selected region 62 including the cusp is delimited at the bottom by equator line 5 and laterally by the cusp borders 63 and 64. The boundary 64 runs along fissure 8 and an extension thereof and merges with the lateral fissure, and the cusp boundary 63 consists of the lateral fissure and its extension.

[0042] The cusp peak 7.2 can be processed together with the rest of the surface in all six directions in space. Thus it can be raised or lowered, shifted in the distal and mesial directions, and likewise in the buccal and lingual directions. Here again, the boundaries of the region 62 remain unchanged. Selection of the region 62 is effected, for example, by clicking on the point 7.2.

[0043] Fig. 7 depicts an anterior tooth 71 as an oblique view of its lingual and distal sides. One half of the tooth 71 is represented as a selected region 72. Proceeding from the preparation edge, the equator line S and the labiolingual line 76 are found again instead of the edge strip. At the tip of the tooth 71 there is shown the incisal edge 78, which encompasses the region of the incisor edge.

[0044] In addition, the auxiliary line 10 that divides the tooth 71 into two halves is shown. The selected region 72 is thus delimited by the preparation line 4 and auxiliary line 76, and the surface of the region 72 can be modified in all six directions in space, whilst no change takes place at the regional boundaries and, again, a constantly increasing modification up to the point of greatest modification, as indicated by the hatched circle 73, takes place when making modifications in the distal direction.

[0045] The region 73 requiring the greatest degree of modification lies on a dental-specific line, i.e., on the equator line 5. Even if other regions 73' are present that are further removed from a center or a central axis, they are deformed to a lesser extent by use of the design tool. This also applies to the other exemplary embodiments.

[0046] Fig. 8 shows the tooth 71 of Fig. 7 from the same viewpoint, but in this case the occlusal region 79 above the labiolingual line 76 is selected.

[0047] Modifications within this region 72 also affect the incisal edge 78, as has already been explained with reference to the modification of the occlusal region in respect of Fig. 5. The position of the incisal edge 78 can be changed, but not its course as such.

[0048] In principle, the dental-specific design lines are proposed by the CAD system on the basis of the existing 3D data set and can also be adapted by hand to account for dental-specific problem definitions. This applies to dental-specific points as well as to the positions of cusp peaks.

[0049] Each line 4, 5, 6 is divided into four parts which respectively represent the mesial, distal, buccal and lingual sides of the tooth. By selecting a subregion of the line, for example by clicking, that half of the tooth is specified in which the selected region lies.

[0050] Depending on which of the lines is selected, a corresponding region of the tooth is selected. Selection of the preparation edge 4 causes the region 2; 22 extending from the preparation edge 4 to the center of the occlusal surface 9 to be selected. Selection of the equator line 5 causes the region 32 located between the preparation edge and edge strip 6 to be selected. Selection of the edge strip 6 causes the region 42 extending from equator line 5 to the center of the occlusal surface to be selected, and selection of the fissure 8 causes the entire occlusal surface 9 to be selected as region 52, delimited by edge strip 6.

[0051] As has already been noted in the description of Fig. 1, a region can also be selected by clicking the surface of the tooth representation in places other than the dental-specific lines or dental-specific points. Clicking on a tooth cusp in the region of its peak can result in selection of the tooth cusp. Clicking on a region between two cusps can lead to the selection of the entire occlusal surface. Clicking on the surface between the equator line and the edge strip can result in selections as shown in Fig. 3 or Fig. 4, depending on whether the region is selected closer to the equator line or to the edge strip. Here again, it is necessary for the surface to be divided into mesial, distal, buccal, and lingual sides of the tooth, so that the respective region of interest will be clearly defined.

[0052] Similarly, in the case of an anterior tooth, selection of the region represented in Fig. 7, for example, can be followed by clicking on a region below the labiolingual line, which will result in a selection as shown in Fig. 8. If, then, a region below the labiolingual line is selected, a selection ensues as shown in Fig. 7.

[0053] Fig. 9 illustrates the fundamental configuration of the apparatus. The apparatus comprises a CAD system 91 having a display unit 92 for representing the restoration body 1 and for selecting a design tool 93 represented by symbols. Furthermore, an input unit in the form of a computer mouse 94 is available for the control of a pointer 95 displayed on the display unit 92. In addition or alternatively, a keyboard 96 is provided for inputting control commands into the CAD system.

Claims (10)

1. Apparat til udvælgelse af et område (2; 22; 32; 42; 52; 62; 72; 82) på et i 3D-gengivelse vist dentalt restaureringslegeme (1; 71), omfattende et CAD-system (91) med en display-enhed (92) til gengivelse af restaureringslegemet (1; 71) og med en input-enhed (94), ved hjælp af hvilken den på display-enheden (92) viste pointer (95) kan styres, hvorved i det mindste dele af områdeafgrænsningen er dannet som dentalspecifikke linjer (5, 6, 8), hvorved apparatet er således udformet, at området (2; 22; 32; 42; 52; 62; 72; 82) kan defineres ved udvælgelse af dental-specifikke linjer (5, 6, 8) eller en præpareringsrand (4), som er vist på 3D-gengivelsen, hvorved udvælgelsen sker ved at klikke på de dental-specifikke linjer (5, 6, 8) eller restaureringsranden (4) ved hjælp af input-enheden (94) via pointeren (95), hvorved den udvalgte linje fuldstændigt bestemmer området (2; 22; 32; 42; 52; 62; 72; 82) i henhold til den følgende allokering: - Præpareringsrand (4): område (2; 22) strækker sig fra præpareringsrand (4) til midten af okklusalfladen (9); - ækvatorlinje (5): område (32) ligger mellem præpareringsrand (4) og randliste; - randliste (6): område (42) strækker sig fra ækvatorlinjen (5) til midten af okklusalfladen (9); - spalte (6): hele okklusalfladen (9) udvælges som område (52), der er afgrænset af randlisten (6).

2. Apparat ifølge krav 1, kendetegnet ved, at der som dental-specifikke linjer (5, 6, 8) anvendes ækvatorlinjen (5), randlisten (6) eller, som alternativ dertil, for fortænders vedkommende, den labiolinguale linje (76), spalten (8) eller, som alternativ dertil, for fortænders vedkommende, skærekanten (78), såvel som dental-specifikke punkter positionen af en eller flere knopspidser, og nærmere betegnet enkeltvist eller flere af dem eller alle tilsammen.

3. Apparat ifølge krav 1 eller 2, kendetegnet ved, at hver dental-specifik linje (5, 6, 8) og/eller præparationsranden (4) er opdelt i fire dele, som henholdsvis repræsenterer de mesial-linguale, mesial-bukkale, distal-linguale og distal-bukkale hjørner af tanden.

4. Apparat ifølge et af kravene 1 til 3, kendetegnet ved, at den udvalgte del af linjen (4, 5, 6, 8) bestemmer halvdelen af tanden, i hvilken området (2; 22; 32; 42; 52; 62; 72; 82) ligger.

5. Apparat ifølge et af kravene 1 til 4, kendetegnet ved, at det udvalgte område (2; 22; 32; 42; 52; 62; 72; 82) er vist, så der kan skelnes mellem dem.

6. Apparat ifølge et af kravene 1 til 5, kendetegnet ved, at vurderings- og/eller sammenligning smidleme er tilvejebragt for geometriske data for det udvalgte område (2; 22; 32; 42; 52; 62; 72; 82).

7. Apparat ifølge et af kravene 1 til 6, kendetegnet ved, at det udvalgte område (2; 22; 32; 42; 52; 62; 72; 82) kan bearbejdes ved hjælp af et konstruktionsværktøj i et CAD-system.

8. Apparat ifølge krav 7, kendetegnet ved, at værktøjet til ændring af området (2; 22; 32; 42; 52; 62; 72; 82) lader områdegrænserne uændrede, hvorved der hen imod punktet (33; 73) med den største ændring er tilvejebragt et kontinuerligt forløb af ændringen.

9. Apparat ifølge krav 8, kendetegnet ved, at punktet (33, 73) med den største ændring ligger på en dental-specifik linje (5, 6, 8).

10. Fremgangsområde til udvælgelse af et område (2; 22; 32; 42; 52; 62; 72; 82) på et i 3D-gengivelse vist dentalt restaureringslegeme (1; 71), omfattende et CAD-system (91) med en display-enhed (92) til gengivelse af restaureringslegemet (1; 71) og med en input-enhed (94), ved hjælp af hvilken en på display-enheden (92) viste pointer (95) kan styres, hvorved der er tilordnet områdegrænser til det udvalgte område, og som i det mindste til dels er udformet som dental-specifikke linjer (5, 6, 8), hvorved udvælgelsen af området (2; 22; 32; 42; 52; 62; 72; 82) sker ved udvælgelse af en dental-specifik linje (5, 6, 8) eller en præpareringsrand (4), hvorved udvælgelsen sker ved at klikke på de dental-specifikke linjer (5, 6, 8) eller restaureringsranden (4) ved hjælp af input-enheden (94) via pointeren (95), hvorved den udvalgte linje fuldstændigt bestemmer området (2; 22; 32; 42; 52; 62; 72; 82) i henhold til den følgende tilordning: - Præpareringsrand (4): område (2; 22) strækker sig fra præpareringsranden (4) til midten af okklusalfladen (9); - ækvatorlinje (5): område (32) ligger mellem præpareringsrand (4) og randliste; - randliste (6): område (42) strækker sig fra ækvatorlinjen (5) til midten af okklusalfladen (9); - spalte (8): hele okklusalfladen (9) udvælges som område (52), der er afgrænset af randlisten (6).