Dental multi-colored milling blank

Abstract

A dental multi-colored milling blank having at least two layers (16), a transition zone, where material from both layers is present. In the transition zone, a transition geometry exists that extends three-dimensionally. The transition geometry comprises round surfaces facing towards both directions of extension of the layers.

Claims

1. A dental multi-colored milling blank comprising at least two layers of materials having different color and/or brightness which are adjacent to each other and are bonded to each other, wherein a transition zone (22) exists therebetween across at least a part of an extent of the at least two layers and comprises both a material of a first layer and a material of a second layer, and at least one transition geometry (32) of the layers extending three-dimensionally in the transition zone (22), wherein the transition geometry (32) comprises round surfaces (30) which are adjoined by slopes (36) obliquely facing towards two directions comprising an X-direction and a Y-direction (24, 26) based on a Cartesian coordinate system in a plane in which the layers extend, wherein each round surface (30) is the center of a base member, which base member is in the shape of a half-torus, regularly recurring across the extent of the transition zone (22) of the layers, the base members merge into one another by intersections of the round surfaces forming a grid of hexagonal structure which remains constant across the entire transition zone (22), each base member comprises a crest (32) and an associated circumferential valley (34), and wherein the round surfaces (30) comprise pitches at 45 degrees or less to the two directions (24, 26) in which the layers extend.

2. The multi-colored milling blank according to claim 1, wherein the transition zone (22) exists between the first layer of material and the second layer of material, wherein the first layer of material comprises a dentin material and the second material comprises an enamel material.

3. The multi-colored milling blank according to claim 1, wherein the first layer comprises a dentin material, wherein the second layer comprises a center material, wherein a third layer comprises an enamel material, wherein the transition zone is formed between the dentin material and the center material and wherein a second transition zone (22) is formed between the center material and the enamel material.

4. The multi-colored milling blank according to claim 1, comprising a plurality of transition zones (22, 24), each transition zone located between adjacent layers and extending three-dimensionally.

5. The multi-colored milling blank according to claim 1, wherein each round surface (30) has a radius of curvature which is constant across more than half of the round surface (30) or across the entire round surface (30).

6. The multi-colored milling blank according to claim 1, wherein the multi-colored milling blank is used to fabricate dental restoration parts, wherein the round surfaces (30) are formed on knobs which extend away from a basal side of the dental restoration parts to be subsequently fabricated or towards an occlusal (52) and/or oral and/or vestibular direction.

7. The multi-colored milling blank according to claim 1, wherein the milling blank comprises one or more transition zones, each one or more transition zone (22) extends in a plane which is parallel to or is at most at an angle of less than 40 degrees to an occlusal plane or at an angle of less than 20 degrees to the occlusal plane.

8. The multi-colored milling blank according to claim 7, wherein each transition zone (22) extends along a dental arch having an arc geometry with a crest line adjacent to the occlusal plane and with arc flanks descending orally or vestibularly from the crest line in a basal direction.

9. The multi-colored milling blank according to claim 1, wherein the round surfaces (30), as viewed from a basal direction, are designed as a surface having round recesses, and/or wherein the round surfaces (30) merge into one another at round recesses, as viewed from an occlusal direction (52).

10. The multi-colored milling blank according to claim 1, wherein the first layer, the second layer and a third layer are different with respect to the color and/or brightness.

11. The multi-colored milling blank according to claim 1, wherein two transition zones (22) extend substantially parallel to each other, and each comprise round surfaces (30) which are offset to each other.

12. A dental multi-colored restoration part made by additive manufacturing, comprising at least two layers which include materials of different color and/or brightness which adjoin each other and are connected to each other, wherein a transition zone (22) exists therebetween across at least part of an extent of the at least two layers and comprises both a material of a first layer and a material of a second layer, and a transition geometry (32) of the at least two layers extending three-dimensionally in the transition zone (22), wherein the transition geometry (32) comprises round surfaces (30) which are adjoined by slopes (36) obliquely facing towards two directions comprising an X-direction and a Y-direction (24, 26) based on a Cartesian coordinate system in a plane in which the layers extend, wherein each round surface (30) is the center of a base member, which base member is in the shape of a half-torus, regularly recurring across the extent of the transition zone (22) of the layers, the base members merge into one another by intersections of the round surfaces forming a grid of hexagonal structure which remains constant across the entire transition zone (22), each base member comprises a crest (32) and an associated circumferential valley (34), and wherein the round surfaces (30) comprise pitches at 45 degrees or less to the two directions (24, 26) in which the layers extend.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages, details and features will arise from the following description of an example embodiment while make reference to the drawing, wherein:

(2) FIG. 1A is a side view partially broken away across a multi-colored milling blank according to the invention, in one embodiment;

(3) FIG. 1B is an enlarged detailed representation of the embodiment of FIG. 1A;

(4) FIG. 2A is a perspective bottom view across the milling blank of FIG. 1A;

(5) FIG. 2B is an enlarged detailed view of FIG. 1A, in top view;

(6) FIG. 3 is a schematic representation of 3 base elements as to the transition geometry for the milling blank of one of the figures;

(7) FIG. 4 is another view of the detailed structure of FIG. 3;

(8) FIG. 5 is an enlarged view of a part of a dental restorative section, made of a milling blank according to the invention; and

(9) FIG. 6 is an enlarged view of FIG. 5.

DETAILED DESCRIPTION

(10) The milling blank 10 shown in FIGS. 1A and 2A is disc-shaped in a manner known per se and has a diameter of almost 100 mm. The height of the milling blank 10 is 20 mm.

(11) In a manner also known per se, it comprises a circumferentially projecting edge 12, which is for clamping into an appropriate holder in the milling machine.

(12) In the embodiment shown, the milling blank comprises three layers, namely an enamel layer 14, a center layer 16 and a dentin layer 18.

(13) Between the three layers 14 to 18, a transition zone is located, between the enamel layer 14 and 16 the transition zone 20 and between the center layer 16 and the dentin layer 18 the transition zone 22.

(14) Each transition zone 20 and 22 has a specific transition geometry according to the invention, which is three-dimensional and, according to the invention, comprises round surfaces 30 facing towards both directions of extension, as is will be further explained in FIG. 1B below.

(15) Herein, the direction of extension 24 runs in the X direction and the one crossing the drawing plane is the Y direction 26.

(16) In both transition zones 20 and 22, the transition geometry is similar, wherein it is to be understood that, depending on the example embodiment, different transition geometries, e.g. different grid dimensions, can also be realized.

(17) Round surfaces 30 are formed at crests 32 and valleys 34. Between the crests 32 and the valleys 34 inclined slopes 36 are located, which extend diagonally towards both directions of extension 24 and 26, but still facing towards both directions of extension 24 and 26.

(18) The crests 32 are formed as such peaks, and in this respect, each forming a knob having an essentially circular cross-section.

(19) The valleys 34, on the other hand, are connected with each other around the crests 32, so that they also essentially extend circularly around the crests 32.

(20) The slopes 36 have a slope gradient that is at its maximum in the center thereof and that starts from the top of the crest 32 and smoothly ends in the valleys 34.

(21) In this respect, the radius of curvature of the valleys 34 is slightly larger than the radius of curvature of the crests 32.

(22) In the example shown, the crests 32 and valleys 34 extend in a grid, and each combination of a crest 32 with the associated circumferential valley 34 forms a base element 40 having the associated transition geometry 44 and 42, respectively.

(23) In the example shown, the grid dimension is about 2.5 mm, being the distance between the peaks of adjacent crests 32. The height, i.e. the vertical distance between crests 32 and valleys 34, is about half the grid dimension.

(24) Furthermore, the distribution of the layers is provided as shown in the following example embodiment:

(25) Height of melting material layer 14: 8 mm

(26) Height of center layer 16: 3 mm

(27) Height of the dentin layer 18: 9 mm

(28) From FIG. 2A it can be seen that the back side of the milling blank 10 is also structured, in the example having a knob structure 45.

(29) Such a structure comprises a hexagonal base structure; in this respect, this base structure corresponds to a possible structure of the transition geometries 32 and 34, which can be seen in the top view of FIG. 2B. It is to be understood that any other base structure, especially polygonal, is allowed instead.

(30) In the example embodiment, the transition geometries 44 and 42 are congruent, so that in the position where crests 32 are provided in the transition geometry 44, such crests are also found in the transition geometry 42.

(31) Other arrangements for the elevations are possible. For example, it is possible to arrange the elevations in an annular form, i.e. with a central starting point and surrounded by rings with an increasing number of elevations.

(32) It is to be understood that an offset is also possible instead, which may be favorable for reduction of reflection.

(33) FIG. 3 shows how a base element 40 can be implemented. For clarification, three base elements 40a, 40b and 40c are shown herein, and in the example embodiment represented herein, they are shown merging into each other.

(34) The view of FIG. 3 corresponds to the sectional view of FIG. 2B, but basically as viewed from an angle at the bottom. In addition, the crests 32 in FIG. 3 are below and the valleys 34 in FIG. 3 above.

(35) The valleys 34 surround each of the downwardly knob-shaped crests 32.

(36) The slopes 36 between the crests 32 and the valleys 34 intersect each other in adjacent base elements 40, so that gentle transitions result having a plurality of round surfaces 30, which are partly inclined, partly also having a vertical surface normal.

(37) The slopes 36 are inclined in the directions 24 and 26. The inclination of the slope increases from crest 32 and decreases again at a turning point 48 until it reaches zero at the center of each valley 34.

(38) Herein, the slope inclination at the turning point 48 is about 35 degrees, wherein it is understood that the inclination as mentioned is adaptable to the requirements in wide ranges.

(39) From FIG. 4, another perspective view of the base elements 40a and 40b according to the invention is shown. The crests 32 extend in a rounded conical shape from the surrounding valleys 34. Thus, at the transition point 50, the imaginary center between two crests 32, i.e. the valley incision, is a little less deep.

(40) FIG. 5 shows a center layer 16 of a dental restoration part, which has the unique transition geometry 42 towards the dentin layer 18. In the occlusal direction 52, a cutting mass layer extends, not shown herein.

(41) As can be seen in this example, the crests 32 face towards the occlusal direction 52, whereas the valleys 34 opposite the crests 32 are shifted away from the occlusal side 52.

(42) It is to be understood that a modified embodiment is also possible instead, in which the sequence of crests 32 and valleys 34 is reversed.

(43) From FIG. 6, the structure of the crests 32 and valleys 34, each forming base elements 40, is enlarged.

(44) It can be seen that the base structure of the base elements 40 is hexagonal and the base elements 40 extend symmetrically to each other.