Dental blanks, partial dental prostheses, and methods for manufacturing partial dental prostheses

Abstract

This invention relates to a dental blank having an upper surface and a lower surface, comprising a flesh-colored material and a tooth-colored material. The flesh-colored material and the tooth-colored material are bonded together. At the interface between the materials, there are protrusions and depressions formed in or at the interface, the interface extending through an optionally curved plane parallel to or inclined to at least a portion of the surface of the blank. In the blank, a region is reserved for at least one partial prosthesis, extending over one or more protrusions and depressions, and the protrusions and depressions are each circumferentially formed, particularly at least partially circumferentially formed, at the apex of each depression and / or protrusion forming at least one line extending in the form of one or more arithmetic or logarithmic spirals or in the form of one or more circles.

Description

TECHNICAL FIELD

[0001] The invention relates to a dental blank as generally described, to a block having an upper surface and a lower surface as generally described, to a dental partial denture as generally described, and to a method of manufacturing a dental partial denture as generally described. BACKGROUND

[0002] It has been known for a long time to manufacture dentures and teeth using multiple layers of material. Examples in this regard are the solutions disclosed in WO 90 / 13268 A1 and WO 91 / 07141 A1.

[0003] For dentures, on the one hand, it is desirable for the dentures to have good material compatibility, and on the other hand, it is necessary for the dentures or partial dentures to have a slim design. In order to ensure secure anchoring of the dentures in the teeth, they are usually bonded or inserted in an injection molding process. A solution in this regard can be seen in DE 837 288 B1.

[0004] Currently, the production of such partial dentures requires multiple process steps. First, a wax model must be produced. This wax model is then replaced with denture material, for example in a casting process or via a de-waxing process. Finally, the partial denture is finished and polished. Such a multi-step method is known, for example, from WO 2007 / 060142 A1.

[0005] As described above, the partial denture is composed of multiple parts and different materials. The size of the partial denture depends on the respective tooth situation of the patient. This can differ greatly from patient to patient compared to full dentures, since each patient has a different number and extent of tooth gaps.

[0006] Since the models of the gum and tooth parts are made from wax and transferred to the final denture, this is prone to errors and is time-consuming. The use of multiple models thus easily leads to transfer errors. The production of partial dentures is therefore time-consuming and very error-prone due to the large number of materials and process steps involved. SUMMARY

[0007] It is therefore the task of the present invention to produce a blank for a dental partial denture as generally described, a block having an upper surface and a lower surface as generally described, a dental partial denture as generally described, and a method of manufacturing a dental partial denture as generally described, which can be produced inexpensively and quickly on the one hand, has a lower error susceptibility on the other hand, and is also optimized in terms of storage possibilities.

[0008] According to the invention, this task is solved by the embodiments of the present application.

[0009] According to the application, it is proposed that the partial denture is made from a specially designed blank or block. The blank is designed in two colors and consists of a gingiva color (pink to red) material and a tooth color (white to beige) material, in particular based on plastic or ceramic materials, respectively, which are combined together in the form according to the application. This close combination can be achieved, for example, by adhesion or polymerization. The two materials can also be held together only by pressing means, such as one or more screw clamps, but can be separated at any time.

[0010] For example, by pressing the materials against each other at the interface while the materials are still soft or even liquid, so that they penetrate each other microscopically, an integral and inseparable article can be achieved. However, even with this manufacturing method, the transition region is in the sub-millimeter range, for example less than 100 micrometers in thickness.

[0011] This transition region also exists in the same order of magnitude during polymerization, while the adhesive joint can have a small thickness, for example between 40 micrometers and 200 micrometers, during adhesion.

[0012] The materials preferably consist of polymers, in particular PMMA, but other materials such as ceramics, in particular zirconium dioxide, or metals can also be envisaged. It is also possible to use two different materials.

[0013] According to the application, the blank is designed as a bicolored block, or as a bicolored disc or substantially disc-shaped, in particular flat cylindrical blank, with an upper disc-shaped surface and a lower disc-shaped surface. Such a bicolored disc can be, for example, a cylinder whose height is much smaller than the radius. This height of the cylinder can extend along the axis of rotation of the cylinder and is denoted in the notation system of the Cauchy symbol as C∞, where "C" stands for cycle and the index denotes the cardinality, i.e. here ∞ means rotational symmetry. The plane that passes through the interface between the two materials is perpendicular to the height, i.e. to the axis of rotation of the cylinder, and thus corresponds to a surface of revolution or rotation.

[0014] In an advantageous embodiment, a disc-shaped body is realized. This disc-shaped body can be circular, but also non-circular, in particular polygonal. For example, the polygon can be realized by a flat cuboid, in which one edge is shorter than the other two. However, other polyhedra, in particular flat polyhedra, are also possible, such as an equilateral octagonal antiprism or an equilateral decagonal antiprism.

[0015] In the case of a bicolored block, this can be, for example, a cuboid or a polygonal disc, the plane of the interface between the two materials extending parallel to the face of the cuboid with the largest surface area.

[0016] The interface between the materials of the blank extends along the plane, but does not necessarily have to be flat or uniform. In a preferred embodiment, the plane in which the interface lies is parallel to one of the possible flat disc surfaces of the blank, in particular to the surface having the largest surface area. However, this plane can also lie on a diagonal of the blank. If the disc surface is not flat, but for example curved or structured, the plane can extend substantially parallel to or parallel to a portion of the disc surface. It is also possible for the plane to be curved, in particular to conform to a clothoid curve.

[0017] For example, the flesh-colored material can have protrusions and recesses at the interface, each protrusion and recess projecting beyond the plane. Each of the protrusions and recesses is formed (in particular at least partially) within the interface between the materials along a circumferential or curved line, i.e. is helical or annular or sectorial. The course of the protrusions and recesses is chosen such that the protrusions and recesses extend around the inner region or the center of the blank. Partially circumferential extensions (for example with an extension of less than 360 degrees) or multiple circumferential extensions (for example with an extension of more than 1800 degrees, i.e. 5 turns) can also be realized.

[0018] Any angle of rotation is possible.

[0019] Each partial denture is preferably machined, in particular milled, from a region of the blank extending over one or more protrusions and recesses. However, the region can also extend along a line, such that the machined or milled partial denture has a curvature predetermined by the course of the protrusions and recesses. Viewed from the inner region of the disc blank, in particular from the center thereof, the apex of the recesses or protrusions forms a line having a radius r.

[0020] This line can be in the form of an arithmetic or logarithmic spiral, or can form one or more circles.

[0021] The shape of the partial denture itself can be chosen in any suitable manner. Preferably, the shape is curved, corresponding to the dental arch of a person.

[0022] The extension of the partial denture is preferably transverse to the (partially) circumferential extension of the periphery of the protrusions and recesses, i.e. to the apex of the protrusions. For a disc blank, the partial denture can extend substantially radially, but also slightly inclined to the radius, for example deviating from the radius by ± 20 degrees.

[0023] The helix can be described mathematically as a coordinate equation in a plane polar coordinate system, in which the radius r is expressed as a function of the angle in general to infinity, but not only to 2π. However, in the present case only the infinite value is possible. Negative angles are also possible. The general polar coordinate representation of the helix is:​

[0024]

[0025] In the x / y coordinate system this results in a point with the parametric representation

[0026]

[0027] where r is the radius and is the angle of rotation. In particular, the equation of an arithmetic spiral is

[0028]

[0029] where a is a natural number and is the angle of rotation. The polar representation of a logarithmic spiral is

[0030]

[0031] where a and k are real numbers and is the angle of rotation.

[0032] If the parameters of the polar representation of a spiral are set appropriately, i.e. if remains constant, a circle is obtained which is represented by the equation

[0033] r = a,

[0034] where r is the radius and is the angle of rotation. In the x / y coordinate system this equation is

[0035] r 2 = x 2 +y 2

[0036] Preferably, the tooth-colored material has a shape at the interface between the two materials which is exactly opposite to the flesh-colored material. Thus, the interface between the materials has annular protrusions and recesses so that the two materials interlock and can be said to interlock with each other. For example, the flesh-colored material can be polymerized onto the tooth-colored material. In another embodiment, there is a layer of adhesive, bonding or composite material between the two materials to firmly bind the two materials together. It can also be particularly convenient to join the two materials by an additive process or by press-fitting or other joining techniques.

[0037] In a preferred embodiment, the pattern (i.e. the spiral or the one or more circles) has one or more centers concentric with the center of the disc (in particular the center of the blank), i.e. has a common center. Alternatively, also eccentric circles (i.e. circles having different centers) and / or the centers of these circles and / or the starting points of the spirals can be provided in the inner region of the disc-shaped blank (i.e. for example in the inner quarter region, in the inner third region or in the inner half region of the blank).

[0038] When the blank is observed in a cross-section through the two materials (i.e. perpendicular to the plane), it is assumed here that the flesh-colored material is at the bottom and the tooth-colored material is at the top, and this cross-section preferably passes through the center of the blank, the flesh-colored material exhibits protrusions and recesses at the interface, which are preferably asymmetric. The protrusions of the flesh-colored material are rather conical, while the recesses of the flesh-colored material are rather circular. In this respect, when viewed from the side, there is a vertex and a slope extending downward from the vertex, forming a ramp and ending in a valley. This design essentially corresponds to the human gum line, which consists of a string of U-shapes or a chain line.

[0039] In this cross-section, the tooth-colored material exhibits shapes at the interface between the two materials that are exactly opposite to those of the flesh-colored material. This makes the connection (in particular the adhesive joint) between the two materials resistant to forces acting on it, for example during further processing of the blank and during everyday use of the final partial denture.

[0040] In a preferred embodiment, the protrusions and recesses widen and rise outward from the center point. Thus, the ring extends in the cross-section from the inner region of the blank or from the center to the edge with a varying amplitude and / or frequency. Thus, the processed (in particular milled) partial denture in the outer region of the blank naturally has a larger size compared to the processed (in particular milled) partial denture in the vicinity of the center of the blank. However, it is also possible to provide the inner molars and the outer premolars with tooth restorations, i.e. to reverse the size distribution in this respect. Typically, the molars and premolars are more frequently needed than the canines and incisors, and according to the present application, the outer region of the disc-shaped blank provides more space for the arrangement of the molars and premolars, which corresponds to the demand in this respect.

[0041] In another embodiment of the present application, it is proposed to design the tooth-colored material to have a color gradient. In this case, it is envisaged to select a darker shade for the tooth-colored material at the interface between the two materials, and the shade changes in such a way that it becomes lighter as the distance to the flesh-colored material increases.

[0042] In another embodiment, the interface between the materials of the blank is formed in the form of concentric circles, comparable to the pattern created when a drop of liquid falls into a liquid. The radius of the respective annular protrusions and recesses increases from the center point outwards, i.e. towards the edge of the blank. Furthermore, the annuli can increase in size and preferably in width from the center point outwards. It is also possible that the annuli are closer together near the center point, but gradually spread apart towards the outside, i.e. the distance between the annuli gradually increases from the center point towards the outside. In another embodiment, the protrusions and recesses become wider and / or higher from the inside out.

[0043] In another embodiment, the interface between the materials of the blank is helical and three-dimensional. This means that the protrusions and recesses extend helically outwards from the center, i.e. towards the edge of the blank. Furthermore, the helix formed by the protrusions and recesses, i.e. also including the protrusions and recesses themselves, can increase in size, i.e. preferably in width and / or height, from the center point outwards. This design can be comparable to an ammonite or snail shell. As a mathematical equation, this pattern is best described by a logarithmic spiral in polar coordinates The equation is described as:

[0044]

[0045] a function r: R→R and, by means of the representation in polar coordinates, a logarithmic spiral in the Euclidean plane can be described. The parameter k is referred to as the gradient of the spiral. k can also be expressed as tan a, in which case a e [-π / 2, π / 2] is referred to as the spiral angle. In Cartesian coordinates, this leads to:

[0046]

[0047] In another embodiment, the center of the pattern at the interface between the materials of the blank is not centered, i.e. does not coincide with the center of the interface plane. Rather, it is displaced within this plane. The annuli can be unaffected by this, so that this form of embodiment is merely a displacement. However, the displacement of the center point can also involve a compression of the annuli on one side and a simultaneous stretching on the opposite side. In this embodiment, the width of the protrusions and recesses varies automatically, but their height can vary or remain constant.

[0048] In another embodiment, the helix or the concentric circles are wavy or curved. A sawtooth design or a combination of sawtooth and wave is also conceivable. The helix or the concentric circles along which the peaks of the protrusions or recesses of the material run can thus have a wave or a sawtooth pointing sideways, i.e. towards the center and / or the edge of the blank, in the plane in which the respective line lies. In this way, the blank can adapt more closely to the geometry of a natural tooth.

[0049] ​According to the application, it is even possible to produce a number of partial dentures precisely from one blank for different patients without the use of (wax) models. This therefore ensures that transfer errors can be ruled out while ensuring optimum material properties.

[0050] According to the application, the two-color design of the blank means that it is no longer necessary to join the gingival region and the tooth portion.

[0051] The preferred design of the application, i.e. the close connection of the tooth-colored material and the flesh-colored material of the blank, results in the advantage that the milling work can be carried out more quickly. The machining process of the two materials requires only one clamping. Surprisingly, the strength of the connection is also sufficient for the milling operation and the forces applied therein due to the close connection between the tooth-colored material and the flesh-colored material and the form fit between them.

[0052] It is particularly advantageous that the one-piece denture can be machined automatically by means of a machining process, in particular by milling in a CAD / CAM device which is integrated with a control device. With the aid of this control device, the exact position of the partial denture in the blank can be determined automatically and / or under user control.

[0053] The CAD / CAM device completes the dental partial denture by determining the exact position of the partial denture in the blank on the basis of patient-specific data, in particular patient-specific tooth sizes and widths, and produces the denture on this basis. In this way, the size of the partial denture is determined in accordance with the specific circumstances of the patient and it is also possible to take into account different shapes of the respective dental arch portion, for example different curvatures of different dental arches, and thus different tooth courses in this range. The necessary patient data are provided as follows:

[0054] Firstly, the patient's tooth situation is recorded by means of a conventional intraoral scan or impression and subsequent three-dimensional scanning and is transmitted to the control device. This marks the anatomical points in the relevant points or regions of interest for the subsequent partial denture. These points serve as reference points. In addition, the control device determines the shape of the individual teeth, the rotation and / or angulation of the teeth and the shape of the base of the partial denture on the basis of the patient's oral situation recorded by the scanning device.

[0055] These data are input into the software of the CAD / CAM device. First, the data of the upper and lower jaw models are imported and correctly positioned relative to each other. On this basis, all parts of the partial denture can be calculated, such as the model cast frame, the retaining elements, the gingival area and the teeth. The design of the blanks according to the application simplifies the modeling of the transition between the gingiva and the teeth and does not require any complex wax models or time-consuming joining. Subsequently, the CAD / CAM device automatically generates a proposal for the partial denture (so-called virtual partial denture) using its control means and gives a recommendation as to which position on the blank can best be used to produce the partial denture. However, the user can modify the virtual partial denture and the recommended position on the CAD / CAM device, for example by a dental technician.

[0056] After the CAD / CAM model of the partial denture has been completed, the completed design is divided into different export contents. On the one hand, there is the CAD / CAM data set for the frame and the associated retaining elements, which can be produced from metal or other materials by additive (e.g. laser melting) or subtractive (e.g. milling) manufacturing. On the other hand, there is the CAD / CAM data set for the flesh-colored parts (gingival parts) and for the tooth parts, which can subsequently be produced or milled from the blanks of the application in a simple manner. Due to the design of the blanks, a number of gingival and tooth parts or data sets for different patients can be produced from one blank.

[0057] In a preferred embodiment, each blank is provided with an individual identification feature, such as a QR code, and also with reference points for allowing precise positioning in the CAD / CAM device. Alternatively, this can also be achieved by means of an RFID chip. Surprisingly, this also applies when the blank is removed from the device and subsequently clamped again. After the partial denture has been produced from the blank, the control means store the precise position of the machined area of the blank by means of the reference points on the blank and the individual identification feature of the blank. As a result, the control means automatically know which area on which blank is still unused and automatically recommend the appropriate blank for the virtual partial denture and the optimal arrangement thereon.

[0058] It is also possible to use the CAM data of the already manufactured blanks for nesting. Furthermore, a camera can be provided in the milling machine, which is aligned to the blank to be machined (possibly partially milled) and provides information about the available area of the blank via image recognition.

[0059] The control device can also perform a so-called nesting of multiple virtual partial dentures on one or more blanks in order to optimize the utilization of material. For this purpose, the control device optimizes the positions of the respective virtual partial dentures, taking into account, inter alia, the partially processed blanks. If an optimal arrangement cannot be achieved or there is not enough new blank, the software issues a corresponding warning signal.

[0060] If the control device has determined an optimal arrangement, this is proposed to the user, for example by means of a pop-up window, so that the user can confirm it. However, it is also possible to automatically forward the arrangement to the CAD / CAM device without confirmation by the user. In this case, the determined data are automatically released for further processing and are transferred to the milling machine of the CAD / CAM device for manufacturing the partial denture, in which the bicolour blank according to the application, in particular the bicolour blank which has already been partially processed, is clamped or will be clamped and the desired partial denture is manufactured.

[0061] In an improved embodiment, the connecting web is kept between the partial denture to be manufactured and the rest of the blank during milling, so that the partial denture is prevented from falling out during milling even if the blank is rotated or tilted in three-dimensional space. This allows the use of any conventional milling machine for processing the blanks according to the application without further special modifications of the milling machine.

[0062] On the basis of the patient data obtained, the control device allows the determination of the shape of the individual teeth, the rotation and angulation of the teeth, and the shape of the base of the partial denture, so that a partial denture can be realized for every conceivable tooth situation of the patient.

[0063] Due to the second design of the application, i.e. the pattern according to the application consists of protrusions and recesses at the interface between the materials, in particular the course of the vertices of the protrusions and recesses in the form of a spiral pattern, a snail shell pattern or a concentric circle pattern, the size of the dental arch portions or the individual teeth is predetermined by the design. Depending on the different radii and distances, and the height and width of the protrusions and recesses in the blank, different tooth heights and widths can be realized in a simple and cost-effective manner. Thus, smaller dental arch portions or teeth can be realized near the centre, since the radii of the concentric circles or spirals are smaller there and the turns of the "circle" or spiral are close together. Furthermore, the protrusions and recesses can be less pronounced compared to the outer regions of the blank according to the application. In this respect, it is advantageous to realize larger dental arch portions or teeth in the outer regions. Thus, many clinical situations, such as different interarch distances, different tooth sizes and different tooth segments, can be realized individually and integrally in the partial dentures from the blank blocks or blank discs, so that the manufacture of the partial dentures can be significantly simplified using these blanks and the automated manufacturing process.

[0064] The innovative interface between the materials can also be in the form of a double helix. In this embodiment, the raised paths of the flesh-colored material, in particular the paths of the apexes of the elevations, form a first helix. The recessed paths of the flesh-colored material, in particular the paths of the apexes of the depressions, form a second helix. Both helices are thus located above and below the plane of the interface between the blanks, preferably offset by the same value.

[0065] In this design, upon completion of the partial denture, the first helix extends between the teeth, and the second helix defines the area of the respective tooth having the highest height in the completed partial denture. Preferably, the two helices converge into each other at a point, in particular in the center. Furthermore, the distance between the two helices is smaller in the inner region of the blank than in the edge region of the blank, and preferably increases continuously from the inside to the outside.

[0066] In another embodiment, it is proposed that the plane of the interface between the materials of the blank itself is not flat, but has a curvature. In this case, the interface between the materials of the blank can be comparable to a vault, a cone or a pyramid. In the case of such an interface configuration, the raised and / or recessed paths of the flesh-colored material can also take all the forms described above, such as logarithmic helices or concentric circles.

[0067] In the case of such a curved interface in combination with a raised and / or recessed helix configuration of the flesh-colored material, the configuration of the interface can be comparable to the upper side of a snail shell.

[0068] Blanks of different sizes can also be realized, i.e. blanks having different overall dimensions, comparable to ready-made sizes such as "L", "M" or "S".

[0069] It is particularly advantageous that, due to the ring design according to the invention and the alternating elevations and depressions in the cross section, in the completed partial denture, each elevation of the tooth-colored material follows the visible edge of the tooth neck opposite the gum formed by the flesh-colored material. The similarity to a natural tooth and gum is surprisingly simple, since the flesh-colored material is at least partially removed, in particular by milling, to such an extent that, on the vestibular side, the dividing line between the tooth-colored material after the coronal milling and the flesh-colored material recedes to the gum line, in particular opposite both the flesh-colored material and the tooth-colored material. In this way, the completed partial denture is hardly distinguishable from the surrounding teeth.

[0070] According to the application, by designing the interface between the tooth-colored material and the flesh-colored material, it is possible to manufacture a plurality of partial dentures of different (tooth) sizes from one blank. The smaller the teeth are required (especially for partial dentures for children or adolescents), the closer the partial denture is to the center of the blank according to the application, since the pattern is narrower there and the height and width of the protrusions and recesses are less pronounced there than at the edge of the blank. If non-uniform tooth sizes are required, for example in order to achieve a transition from molar to incisor teeth, it is also possible to arrange the virtual partial dentures obliquely (i.e. radially) in the blank. If very large tooth sizes are to be achieved, the outer edge of the blank is preferred. Surprisingly, this makes it possible to provide dentures that are particularly successful aesthetically, even if there is a large difference in the size of the teeth.

[0071] According to the application, it is particularly advantageous if, in the course of the manufacturing process, the individual teeth of the partial denture are held connected to one another via connecting points made of tooth-colored material. Surprisingly, this can improve the resistance to masticatory forces, i.e. in particular to lateral shear forces, compared to conventional partial dentures in which the individual teeth are cemented into the base.

[0072] After the final polishing, the finished partial denture can be delivered to the dentist for insertion.

[0073] While teeth that are manufactured and made independently are usually accommodated in tooth cavities of denture bases manufactured according to the prior art and are subjected to considerable shear stresses due to the leverage of the masticatory forces during mastication, which also exert a great load on the bonding surfaces, the present application intends to minimize these shear forces by the design of the partial denture according to the application, in particular the special design of the interface between the tooth-colored material and the flesh-colored material, and the connection of the teeth to form a bridge extending over the entire partial denture. According to the application, the feared loosening of the bond of individual teeth is eliminated, since the connection of at least two adjacent teeth of the partial denture exhibits lower shear stresses during mastication due to the increased bonding surface.

[0074] According to the application, the flesh-colored material and the tooth-colored material are tightly bonded together by adhesive bonding, polymerization or one-piece manufacturing.

[0075] In the case of two-part manufacturing, it is advantageous if the two materials can be bonded together at any time and can be matched to one another in any selection. The individual parts can also have matching geometries, so-called positioning elements. They can be recommended and arranged on the virtual partial denture automatically by a CAD / CAM device equipped with a control device, or they can be determined on the CAD / CAM device by the user, for example by a dental technician.

[0076] The first or "wavy" design according to the present application has a pattern in the form of concentric circles at the interface between the materials, whereby the size of the arch or individual teeth is predetermined by the design. This pattern design at the interface between the two materials corresponds to the wave pattern created when a drop of water hits the surface of water.

[0077] According to the present application, other circular patterns can also be employed in which the distance between the circles increases towards the edge of the interface, or the centre of the innermost circle among the circles is displaced towards the edge of the interface and the distance between the circles is "compressed" in this direction and "stretched" in the other direction.

[0078] The second or "snail shell" design according to the present application has a spiral pattern at the interface between the materials. The spiral can be arithmetic or logarithmic, i.e. corresponds to the pattern of a snail shell.

[0079] The blank according to the present application thus makes it possible to produce partial dentures in a simple and cost-effective manner according to the patient-specific requirements without the aid of expensive wax models. Transfer errors are thus avoided from the outset and the manufacturing process is optimised.

[0080] Further advantages, details and features of the present application will become apparent from the following description of embodiments of the present application and with reference to the accompanying drawings.

[0081] In the drawings: BRIEF DESCRIPTION OF DRAWINGS

[0082] Figure 1 a is a schematic cross-sectional view of a partial denture part or tooth / gum part manufactured according to the present application in a first embodiment consisting of a gum-coloured material and a tooth-coloured material;

[0083] Figure 1 b is a schematic cross-sectional view of a partial denture part or tooth / gum part manufactured according to the present application in another embodiment consisting of a gum-coloured material and a tooth-coloured material,

[0084] Figure 2 is a schematic view of a possible embodiment of the innovative interface between tooth-coloured material and flesh-coloured material;

[0085] Figure 2 a is a schematic view of a first embodiment of the innovative interface between tooth-coloured material and flesh-coloured material;

[0086] Figure 2 b is a schematic view of another embodiment of the innovative interface between tooth-coloured material and flesh-coloured material;

[0087] Figure 2c is a schematic view of another embodiment of the innovative interface between tooth- and flesh-colored materials and possible positioning of teeth of different sizes;

[0088] Figure 2 d is a schematic view of another embodiment of the innovative interface between tooth- and flesh-colored materials;

[0089] Figure 2 e is a schematic view of another embodiment of the innovative interface between tooth- and flesh-colored materials;

[0090] Figure 2 f is a schematic view of another embodiment of the innovative interface between tooth- and flesh-colored materials and possible positioning of teeth of different sizes;

[0091] Figure 3 is a schematic view of possible designs of the innovative interface between tooth- and flesh-colored materials and possible positioning of teeth of different sizes;

[0092] Figure 3 a is a schematic view of a first embodiment of the innovative interface between tooth- and flesh-colored materials and possible positioning of teeth of different sizes;

[0093] Figure 3 b is a schematic view of another embodiment of the innovative interface between tooth- and flesh-colored materials and possible positioning of teeth of different sizes;

[0094] Figure 3 c is a schematic view of another embodiment of the innovative interface between tooth- and flesh-colored materials and possible positioning of teeth of different sizes;

[0095] Figure 4 is a perspective view of a schematic section of a blank according to the present application in a possible embodiment;

[0096] Figure 4 a is a perspective view of a schematic section of a blank according to the present application in a first embodiment;

[0097] Figure 4 b is a perspective view of a schematic section of a blank according to the present application in another embodiment;

[0098] Figure 5 is a perspective view of a schematic section of a blank according to the present application in a possible embodiment, in which possible arrangements of various virtual partial dentures are shown;

[0099] Figure 5 a is a perspective view of a schematic section of a blank according to the present application in a first embodiment, in which possible arrangements of virtual partial anterior dentures of the lower jaw are shown;

[0100] Figure 5 b is a perspective view of a schematic section of a blank according to the present application in another embodiment, wherein a possible arrangement of virtual maxillary anterior partial dentures is shown;

[0101] Figure 5 c is a perspective view of a schematic section of a blank according to the present application in another embodiment, wherein a possible arrangement of virtual maxillary and mandibular anterior partial denture parts is shown;

[0102] Figure 5 d is a perspective view of a schematic section of a blank according to the present application in another embodiment, wherein a possible arrangement of a plurality of virtual maxillary and mandibular anterior partial denture parts is shown;

[0103] Figure 6 is a top view schematic of a possible design form of a posterior blank according to the present application, and shows possible positioning of partial dentures of different sizes;

[0104] Figure 6 a is a top view of a first design of a posterior blank according to the present application, and shows possible positioning of partial dentures of different sizes;

[0105] Figure 6 b is a top view schematic of another design form of a "L" size posterior blank according to the present application, and shows possible positioning of partial dentures of different sizes;

[0106] Figure 6 c is a top view schematic of another design form of a "M" size posterior blank according to the present application, and shows possible positioning of partial dentures of different sizes;

[0107] Figure 6 d is a top view schematic of another design form of a "S" size posterior blank according to the present application, and shows possible positioning of partial dentures of different sizes;

[0108] Figure 7 is a top view schematic of a possible design form of an anterior blank according to the present application, and shows possible arrangement of partial dentures of different sizes;

[0109] Figure 7 a is a top view schematic of a first design of an anterior blank according to the present application, and shows possible positioning of partial dentures of different sizes;

[0110] Figure 7 b is a top view schematic of another design form of an "L" size anterior blank according to the present application, and shows possible positioning of anterior partial denture arches;

[0111] Figure 7 c is a plan view of another design form of a front tooth blank of "S" size according to the present application and shows possible positioning of a front partial denture arch;

[0112] Figure 7 d is a plan view of another design form of a front tooth blank of "S" size according to the present application and shows possible positioning of a front partial denture arch;

[0113] Figure 8 is a top view of a possible design form of a posterior tooth blank according to the present application and shows possible positioning of partial dentures of different sizes;

[0114] Figure 8 a is a top view of a first design of a posterior tooth blank of "L" size according to the present application and shows possible positioning of partial dentures of different patient data;

[0115] Figure 8 b is a top view of another design form of a posterior tooth blank of "M" size according to the present application and shows possible positioning of partial dentures of different patient data;

[0116] Figure 8 c is a top view of another design form of a posterior tooth blank of "S" size according to the present application and shows possible positioning of partial dentures of different patient data;

[0117] Figure 8 d is a top view of another design form of a posterior tooth blank according to the present application and shows possible positioning of partial dentures of different sizes;

[0118] Figure 8 e is a top view of another design of a posterior tooth blank according to the present application and shows possible positioning of partial dentures of different sizes relative to a disc-shaped blank according to the present application;

[0119] Figure 9 is a top view of a design form of a disc-shaped blank according to the present application and shows possible positioning of partial dentures of different sizes. DETAILED DESCRIPTION

[0120] Figure 1 a and Figure 1 b shows a schematic cross-section of a tooth / gum portion 1 according to the present application. Here, the tooth 2 is composed of a tooth-colored material 4 and a gum portion 8 of a flesh-colored material 10. The two materials are tightly bonded to each other at their interface 12, in particular polymerized or adhered to each other. Figure 1 a shows a multi-part, in this case four-part, tooth / gum portion, whereby the teeth 2 can be connected to each other by connection points 6, whileFigure 1 b shows a single-part tooth / gingival portion, i.e., a so-called single-tooth denture.

[0121] like Figure 1 The tooth / gingival portion 1 shown is made of a flat, cylindrical or disc-shaped two-tone blank. This is, for example, disc-shaped, extending perpendicularly to its height through the plane 13 of the interface 12 between the two materials, and thus perpendicular to the axis of rotation C∞ of the disc. Figure 1 In diagram a, plane 13 is shown in side perspective. (And...) Figure 1 Contrary to the illustration in a, plane 13 can also extend at an angle or even be curved. The billet can also be block-shaped. In this case, plane 13 passing through interface 12 between the two materials preferably extends horizontally in a flat billet. In another embodiment, plane 13 is realized to pass through interface 12 and extend obliquely in the billet, thereby also realizing interface 12 extending obliquely in the billet.

[0122] The interface 12 between the materials of the blank has a series of annular protrusions 32 and recesses 34, which may have the same center as the center of the plane, and each protrusion and recess protrudes beyond the plane. At the interface 12 between the two materials, the tooth-colored material 4 has a shape completely opposite to that of the flesh-colored material 10. Therefore, the interface 12 between the materials has annular protrusions 32 and recesses 34, in which the two materials interlock. A transition portion extends between them, forming an inclined surface, or a ramp.

[0123] If the blank is observed in a cross-section passing through both materials (i.e., a plane perpendicular to the interface 12) (assuming flesh-colored material 10 is at the bottom and tooth-colored material 4 is at the top, and the cross-section preferably passes through the center of the blank), at the interface 12 (i.e., when reflected at plane 13), the protrusions 32 and recesses 34 of the flesh-colored material 10 are asymmetrical. Instead, the protrusions 32 are more conical, while the recesses 34 are more circular. This design of the interface 12 corresponds to the human gingival line, and therefore appears chain-like when viewed from the side, comparable to a series of U-shapes.

[0124] The interlocking gives the connection between the tooth-colored material 4 and the flesh-colored material 10 the strength and resistance to forces acting upon it, especially when joined via adhesive joints, such as during further processing of the blank and during daily use of the final partial denture. On the other hand, the asymmetry of the interface makes it easy to manufacture the tooth / gingival portion 1 with a particularly natural appearance, as the tapered protrusion 32 of the flesh-colored material 10 automatically resembles the natural path of the gingiva in the interdental region. The circular recesses 34 of the flesh-colored material 10 (i.e., the circular protrusions of the tooth-colored material 4 in negative form) provide a natural tooth shape. Therefore, to achieve a natural appearance, it is only necessary to mill the tooth / gingival portion 1 from the blank at the optimal point, thus requiring only fine milling of the gingival margin in the transition area between the flesh-colored and tooth-colored materials (4, 10) as the final finishing step.

[0125] Figure 2 a, Figure 2 b、 Figure 2 c and Figure 2 Figure d shows a schematic diagram of a possible embodiment of an innovative interface 12 between tooth-colored material 4 and flesh-colored material 10.

[0126] Figure 2 a and Figure 2 b shows a schematic diagram of the innovative interface 12 between materials 4 and 10, in which arithmetic is shown ( Figure 2 a) or logarithmic ( Figure 2 b) Spiral line pattern. Figure 2 The illustration in b can be compared to the shape of an ammonite or snail shell. The spiral 24 spirals outward from a point 26 (specifically, the center of the plane 13 containing interface 12) towards the edge of the blank. The flesh-colored material protrusions 32 extend along the lines of the spiral 24, while the flesh-colored material recesses 34 extend between these lines. Furthermore, the protrusions 32 and recesses 34 of the flesh-colored material 10 can become larger and / or wider outward from the center point 26. Figure 2 b illustrates the slightly wavy route of the spiral, i.e., the spiral 24 which is not a perfectly geometric shape. This allows for further dimensional variations in the tooth / gingival portion 1 in a simple manner, especially in partial denture routes to accommodate irregular deviations in tooth size—a common feature of natural teeth.

[0127] Figure 2c shows a schematic view of the innovative interface 12 between the materials 4 and 10, in this embodiment the course of the elevations 32 of the flesh-colored material 10, in particular the course of the apexes of the elevations 32, is shown in solid lines 24, while the course of the depressions 34 of the flesh-colored material 10, in particular the course of the apexes of the depressions 34, is shown in grey dashed lines 25. It is shown here how the exemplary tooth / gum portion 1, in this case 1 which comprises three teeth 2 as an example, is arranged in the blank. Thus, the lines 24, which represent the course of the elevations 32 of the flesh-colored material 10, in particular the course of the apexes of the elevations 32, extend between the teeth 2 of the tooth / gum portion 1. The lines 25, which represent the course of the depressions 34 of the flesh-colored material 10, in particular the course of the apexes of the depressions 34, define the area of the respective tooth which has the highest height in the finished partial denture.

[0128] Furthermore, the lines 24 and 25 make it possible to shape or design chain lines or U-shapes in a simple manner, thus realistically imitating the shape of natural human gum, in particular the gum line.

[0129] Figure 2 d shows a schematic view of the innovative interface 12 between the materials 4 and 10, which is designed here in the form of concentric circles 28 around a common center point 26. This corresponds to the pattern that is created when a drop of liquid falls into a liquid. The elevations 32 of the flesh-colored material extend here along the lines of the shown concentric circles 28, while the depressions 34 of the flesh-colored material extend between these lines. Furthermore, the distance between the two circles can gradually increase with increasing distance from the center point 26, and the elevations 32 and depressions 34 along or between the circles can also gradually increase and / or widen, respectively, towards the outside.

[0130] Figure 2 e shows a schematic view of the innovative interface 12 between the materials 4 and 10, which is designed here in the form of shifted-up circles 28 around the center point 26 of the innermost circle, whereby the center point is not located here in the center of the interface, but is shifted towards the edge of the blank.

[0131] Figure 2 f shows a schematic view of the innovative interface 12 between the materials 4 and 10, which takes here the form of a plurality of curves 27 around the center point 26 of the blank, whereby the curves 27 here neither join to form a circle nor form a complete spiral over the entire interface 12 of the blank.

[0132] Figure 3 a to Figure 3 c shows a schematic view of the possible design similar to a to 2c, whereby the possible positioning of the teeth 2 is now drawn into the view of the boundary layer 12. Figure 2 a to 2c, whereby the possible positioning of the teeth 2 is now drawn into the view of the boundary layer 12.

[0133] Figure 3 a shows a helix 24 which indicates the course of the highest points of the protrusions 32. This helix 24 can for example be an arithmetic or logarithmic helix. Furthermore, according to the invention, the helix 24 can also not extend completely geometrically, but can have slight undulations 15, like Figure 3 a shown, with Figure 2 b the undulating course of the helix, and with the same advantages.

[0134] In Figure 3 a and Figure 3 b, the possible tooth sizes of the tooth / gum portion to be produced increase from the center 26 of the helix 24 (in Figure 3 a) or the concentric circle 28 (in Figure 3 b) outwards, i.e. towards the edge of the blank. According to the invention, the smaller the teeth 2 required are, the closer they are to the center 26 of the blank, since the pattern there is narrower and the height and width of the protrusions 32 and recesses 34 are less pronounced than at the edge of the blank. If non-uniform tooth sizes are required, for example in order to achieve a transition from molars to incisors, it is also possible to arrange the virtual tooth / gum portions obliquely, i.e. radially, in the blank. If very large tooth sizes are to be achieved, the outer edge of the blank is preferred. Surprisingly, this makes it possible to provide tooth / gum portions which are particularly successful aesthetically, even if there is a large difference in the size of the teeth 2.

[0135] In the embodiment shown in Figure 3 c, the center point 26 is not in the center of the interface 12, but is offset towards the edge of the blank. In this case, smaller tooth sizes can in particular be arranged on the side of the center point 26 which is further from the edge, i.e. the compression side. Larger tooth sizes, on the other hand, can be arranged on the stretch side.

[0136] Figure 4 a and Figure 4 b show a schematic cross-section of a blank according to one embodiment of the invention in perspective view.

[0137] In Figure 4 a, a schematic cross-section of a blank according to the invention is shown in perspective view, in which the embodiment of the interface 12 takes the form of a helix 24. In Figure 4 the upper view in a, a possible arrangement of a plurality of virtual tooth / gum portions (24 portions) is shown. The teeth 2, in particular the teeth 2 connected by the joints 6, consist of a tooth-colored material 4 and a denture base 8 of flesh-colored material 10. The two materials are tightly bonded to one another at their interface 12, in particular polymerized or bonded to one another.

[0138] Figure 4The lower drawing of a shows in perspective the design and arrangement of the interface 12 in the form of a spiral 24 in the blank according to the invention. Here, the three-dimensional configuration of the flesh-colored material 10 at the interface between the materials 4 and 10 is shown.

[0139] The protrusions 32 and recesses 34 of the flesh-colored material 10 are similar in configuration to Figure 2 the protrusions and recesses shown, where the tooth-colored material 4 can form a negative for the production of the flesh-colored material 10. The protrusions 32 and recesses 34 of the flesh-colored material 10 are alternating with each other, viewed in the direction from inside to outside. The protrusions 32 form a top, which is followed by a slope or inclined surface. Viewed in this view, the interface 12 forms a chain line or a string of U-shapes. When viewed from above, the apexes or protrusions 32 form concentric circles. The distance between the circles can be the same, but in the embodiment shown it is different, for example, the distance on the outside is greater than the distance on the inside.

[0140] In Figure 4 b, a schematic cross-section of a blank according to the invention is shown in perspective, which has a configuration of the interface 12 in the form of concentric circles 28 similar to Figure 2 b or 3b. In Figure 4 b, a possible arrangement of a plurality of virtual tooth / gum portions is shown. The teeth 2, in particular the teeth 2 connected by the joints 6, consist of the tooth-colored material 4 and the denture base 8 of the flesh-colored material 10. The two materials are tightly bonded to each other at their interface 12, in particular polymerized or adhered to each other.

[0141] Figure 4 b, the design and arrangement of the interface 12 in the form of concentric circles 28 in the blank according to the invention is shown in perspective. In Figure 4 b, the three-dimensional configuration of the flesh-colored material 10 at the interface between the materials 4 and 10 is shown here, in particular corresponding to a string of U-shapes 30.

[0142] Figure 5 b, a schematic cross-section of a blank according to the invention is shown in perspective, which has a configuration of the interface 12 in the form of concentric circles 28 similar to Figure 5 d, a schematic cross-section of a blank according to the invention is shown in perspective, which has a configuration of the interface 12 in the form of concentric circles 28 similar to Figure 5 a shows the lower anterior segment from teeth 33 to 43, Figure 5 b shows the upper anterior segment from teeth 13 to 23, Figure 5 c shows a disc, in which the lower anterior segment from teeth 31 to 33 and the upper anterior segment from teeth 23 to 21 are arranged next to each other. By rotating the virtual tooth / gum portions by 180 degrees (in Figure 5 d), the tooth segments can be made from all four anterior segments in the same blank. Of course, this applies not only to the examples as Figure 5 a toFigure 5 c the front tooth segment shown, also for any other desired tooth segment made from one blank.

[0143] In Figure 5 a to Figure 6 c, the plane 13 in which the interface 12 between the tooth made of tooth-colored material 4 and the denture base 8 made of flesh-colored material 10 lies is shown in each case as a straight line in the side view.

[0144] Figure 6 a to Figure 6 d shows a schematic representation of possible embodiments of the rear tooth block according to the application in a top view. The possible positioning of the teeth 2 or tooth / gum portions, here in particular the rear teeth, in the boundary layer 12 between the tooth-colored material 4 and the flesh-colored material 10 is drawn in two dimensions. The cross sections are chosen such that in Figure 6 a to Figure 6 d the area of the block, in particular the converging area 21 in which the center of the fan-shaped direction lines 38 lies, is in each case on the upper side of the figure, while the edge of the block is on the lower side of the figure. The fan-shaped direction lines 38 correspond to the height of the flesh-colored material 34 and lie at the connecting points 6, i.e. the papillae, between the individual teeth 2.

[0145] The fan-shaped direction lines 38 converge into one another, and the central area formed by these lines can also be referred to as the converging area 21. The direction of the direction lines 38 allows the appropriate dimensioning of the tooth / gum portion to be selected depending on the position of the tooth / gum portion in the block. From Figure 6 a to Figure 6 d it can be seen that the tooth / gum portion that is machined, in particular milled, in the upper area of the block thus automatically has a smaller dimension than the tooth / gum portion that is machined, in particular milled, at the bottom.

[0146] Figure 6 b to Figure 6 d shows that the blocks according to the application can be produced in different sizes in order to achieve a more fine-tuned adjustment of the dimensions. For example, an "L" size block can be produced for very large tooth / gum portions, an "M" size block for medium-sized tooth / gum portions, and an "S" size block for very small tooth / gum portions.

[0147] Figure 6 a to Figure 7 d also shows an exemplary holder 36 for clamping the tooth / gum to clamp the block according to the application in the clamping device of the CAD / CAM apparatus.

[0148] Figure 7 a to Figure 8d shows a schematic view of a possible design of a block according to the application in a top view. The possible arrangement of a tooth 2 or tooth / gum portion (here in particular a front tooth) in a boundary layer 12 between a tooth-colored material 4 and a flesh-colored material 10 is drawn in two dimensions. These cross sections are chosen such that in Figure 7 a to 8d in each case the center is on the lower side of the figure, while the edge of the block is on the upper side of the figure. The directional lines 38 shown in the block are thus segments of an imaginary spiral or of an imaginary concentric circle which are much larger than the block. The directional lines 38 serve to show that the size of the segments of the spiral 24 or of the concentric circles 28 which lie in the area of the block increases from the center 26 outwards, i.e. towards the edge of the block. From Figure 7 a it can be seen that the machined, in particular milled, gum portion in the upper side area of the block thus automatically has a greater size than the machined, in particular milled, gum portion in the lower side area of the block.

[0149] Figure 7 b to Figure 7 d shows that the blocks according to the application can be produced in different sizes, so that in Figure 7 a the arrangement of three tooth-gum portions shown on one block can also be produced on individual blank blocks which are narrower than the blank block.

[0150] Figure 7 a to Figure 8 d also shows an exemplary rod 36 for clamping the blocks according to the application in the clamping device of a CAD / CAM device.

[0151] Figure 8 a to Figure 8 c shows a schematic view of a possible design of a block according to the application in a top view. The possible positioning of a tooth 2 or tooth-gum portion (here in particular a back tooth) in a boundary layer 12 between a tooth-colored material 4 and a flesh-colored material 10 is drawn in two dimensions. These cross sections are chosen such that in Figure 8 a to 8c in each case the center is on the left side of the figure, while the edge of the block is on the right side of the figure. The course of the concentric circles 28 according to the application in the innovative interface 12 between the materials 4 and 10 is schematically drawn in the form of dashed lines.

[0152] In the illustration of the drawing, the common center 26 of the concentric circles 28 is on the left side of the blank. In this embodiment, the distance between the concentric circles 28 increases from the inside, i.e. from the side of the block where the imaginary center point is located, outwards, i.e. in the direction of the edge of the blank. From Figure 8As can be seen in a to 8c, the machined, in particular milled, gum portion in the outer region of the block thus automatically has a greater dimension than the machined, in particular milled, gum portion near the center of the block.

[0153] Figure 8 a to Figure 8 c also shows that the blocks according to the application can be produced in different sizes in order to achieve a more fine adjustment of the dimensions. For example, it is conceivable here that for very large gum portions or overall tooth dimensions, the size of the block is "L", for average-sized gum portions or tooth dimensions, the size of the block is "M", and for very small gum portions or overall tooth dimensions, the size of the block is "S".

[0154] Figure 8 a to Figure 8 c also shows an exemplary rod 36 for clamping the block according to the application in the clamping device of the CAD / CAM device. In this embodiment, the rod is attached to the side which preferably enables smaller tooth dimensions, i.e. near the imaginary center of the interface.

[0155] Figure 8 d and Figure 8 e in combination show that the orientation of the block can also be rotated. Thus, the rod 36 for clamping the blank of the application in the clamping device of the CAD / CAM device is in Figure 2 d on the other side of the blank, unlike in Figure 9 a to 8c.

[0156] Figure 9 e shows one example of a region of a virtual disc-shaped blank which can be formed as a rectangular block according to the application. As described above with reference to ​ e, the virtual disc-shaped blank has here an eccentric circle formed by protrusions and recesses. It is understood that it is not necessary to actually produce a disc-shaped blank, in particular a rectangular blank, in order to machine the blocks, but rather the desired regions can be produced directly as block-shaped blanks. The figure also shows a possible arrangement of exemplary teeth 2 or tooth-gum portions.

[0157] ​ A schematic view in plan view shows possible design forms of a disc-shaped blank according to the application. The figure shows various layers of tooth-gum portions in a blank according to the application, which are determined automatically by the control device and / or under user control. In this example, the virtual tooth-gum portions are arranged partly obliquely, partly radially in the blank. A single tooth-gum segment 44 is provided here, but any other type of tooth-gum portion is also possible. ​Examples of two-unit (48) and five-unit (46) tooth-gum portions are shown.

[0158] It is conceivable that during milling, the connecting web 40 remains between the tooth-gum portion 1 to be produced and the rest of the blank (i.e. in the area of the milling joint 42), so that even if the blank is rotated or tilted in three-dimensional space, the tooth-gum portion 1 can be prevented from falling out during milling. This allows the use of any conventional milling machine for machining the blank according to the application without further special modifications to the milling machine.

Claims

1. A dental blank, comprising: an upper surface and a lower surface, composed of a flesh-colored material and a tooth-colored material, wherein the flesh-colored material and the tooth-colored material are bonded to each other, and wherein an interface between the materials has protrusions and recesses formed in or at the interface, the interface extending through a curved plane that is parallel or inclined to at least a portion of a surface of the blank, characterized in that the protrusions and the recesses are each at least partially circumferentially formed in the interface between the materials, a vertex of each recess and / or protrusion forming at least one line that extends in the form of one or more arithmetic or logarithmic spiral or in the form of one or more circles, wherein the line has a radius r, as viewed from a center point of the blank, wherein: or or ， where a and k are natural numbers, respectively , and is a rotation angle.

2. The blank according to claim 1, characterized in that the course of the recesses and / or the protrusions is the first derivative of the equation of the line, wherein the radius r is greater than or equal to zero and the radius r increases with increasing rotation angle .

3. The blank according to claim 2, characterized in that the course of the recesses and / or protrusions has the form of concentric circles.

4. The blank according to claim 2, characterized in that the course of the protrusions and the recesses are closer together near the center of the blank and further apart towards the outside, or the course of the protrusions and the recesses are further apart near the center of the blank and closer together towards the outside.

5. The blank according to claim 2, characterized in that the center of the one or more lines is not located in the center of the plane of the interface between the materials, but is slightly offset towards the edge of the plane of the interface, and / or the course of the protrusions and the recesses has different distances on different sides of the center.

6. The blank according to claim 2, characterized in that the tooth-colored material and / or the flesh-colored material is designed to have a color gradient and / or to be continuously more transparent with increasing distance from the interface between the materials.

7. A dental partial denture made from a blank according to any one of the preceding claims 1 to 6.

8. The dental partial denture according to claim 7, characterized in that the teeth of the partial denture are at least partially connected to each other integrally via the tooth-colored material to form a partial dental arch.

9. A blank, having an upper surface and a lower surface, composed of a flesh-colored material and a tooth-colored material, wherein the flesh-colored material and the tooth-colored material are bonded to each other, and wherein an interface between the materials has protrusions and recesses formed in or at the interface, the interface extending through a curved plane that is parallel or inclined to at least a portion of a surface of the blank, characterized in that the protrusions and the recesses extend through the blank, as viewed in a plan view of the interface, and one or more lines are parallel to each other, in the form of a circle, a spiral or a curve.

10. The blank according to claim 9, characterized in that the one or more lines extend in the form of a sector, a circle or a spiral, and converge to form a convergence area.

11. A method for manufacturing dental partial dentures from blanks or blocks using a CAD / CAM device, the blanks or blocks being manufactured with an upper disc-shaped surface and a lower disc-shaped surface, the blanks or blocks being composed of a flesh-colored material and a tooth-colored material, wherein the flesh-colored material and the tooth-colored material are bonded to each other, and wherein the interface between the materials has protrusions and recesses formed in the interface, which interface extends through a plane, which is parallel, or curved or inclined, with respect to one of the disc-shaped surfaces of the blank or block, characterized in that a region is reserved in the blank or block for at least one partial denture, which region extends over one or more protrusions and recesses, and wherein the protrusions and the recesses are each formed at least partially circumferentially in the interface between the materials, the apex of each recess and / or protrusion forming at least one line, which line extends in the form of one or more arithmetic or logarithmic spiral lines or in the form of one or more circles, and wherein a plurality of partial dentures are manufactured from the blank or block, wherein the line has a radius r, as viewed from the center point of the blank, wherein: or or ， where a and k are natural numbers, respectively , and is a rotation angle.

12. The method for producing dental partial dentures according to claim 11, characterized in that after the scanning, the virtual production and the virtual positioning in the blank of the dentures, a plurality of partial dentures are produced for different patients by milling from the blank.

13. The method for manufacturing dental partial dentures according to claim 11, characterized in that the blanks have a reference point and / or an individual identification marking for positioning in the CAD / CAM device, and / or the control device stores the position of the dentures manufactured for each blank and determines the blank and / or the positioning in the blank for the new partial dentures to be manufactured by a nesting method in order to achieve maximum utilization of the raw material.

14. The method for manufacturing dental partial dentures according to claim 13, characterized in that the individual identification marking comprises a QR code or an RFID tag.

15. A method for manufacturing dental partial dentures from blanks or blocks using a CAD / CAM device, the blanks or blocks being manufactured with an upper disc-shaped surface and a lower disc-shaped surface, the blanks or blocks being composed of a flesh-colored material and a tooth-colored material, wherein the flesh-colored material and the tooth-colored material are bonded together, and wherein the interface between the materials has protrusions and recesses formed in the interface, which interface extends through a plane, which is parallel, or curved or inclined, with respect to one of the disc-shaped surfaces of the blank or block, characterized in that a region is reserved in the blank or block for at least one partial denture, which region extends over one or more protrusions and recesses, and the protrusions and the recesses are each formed at least partially circumferentially in the interface between the materials, the apex of each recess and / or protrusion forming at least one line, which line extends in the form of one or more arithmetic or logarithmic spiral lines or in the form of one or more circles, and Said CAD / CAM device defines the partial denture from the spatial shape of the partial denture and has a control device which positions the partial denture in the blank in such a way from the desired dimensions and tooth widths and also recommends the shape of the individual teeth, the rotation and / or angling of the teeth after user intervention, wherein said line has a radius r, viewed from the center point of the blank, wherein: or or ， where a and k are natural numbers, respectively , and is a rotation angle.

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