RETAINER AND MANUFACTURING METHOD THEREOF

Abstract

A retainer cooperating with a plurality of teeth and configured to stabilize the plurality of teeth, the retainer including at least one elongated arc which is shaped overall adapted to a natural curvature of a lower jaw or an upper jaw, wherein the at least one elongated arc is locally adapted individually to a surface contour of respective abutting teeth, wherein the retainer is machined from a sheet metal plate and includes two mutually parallel surfaces, wherein the sheet metal plate is made from a nickel titanium alloy, preferably a nitinol, wherein the retainer contacts a tooth surface in an installed condition of the retainer, wherein a machined surface of the retainer faces the tooth surface in the installed condition of the retainer, and wherein an upper side or a lower side of the retainer corresponds to an original surface plane of the sheet metal plate.

Claims

1. A retainer adapted to cooperate with a plurality of teeth and configured to stabilize the plurality of teeth, the retainer comprising: at least one elongated arc which is shaped to a natural curvature of a lower jaw or an upper jaw, wherein the retainer is machined from a sheet metal plate and includes first and second mutually parallel surfaces, wherein a lower side of the retainer corresponds to the first mutually parallel surface, wherein an upper side of the retainer corresponds to the second mutually parallel surface, wherein a front side of the retainer corresponds to a first cut made into the sheet metal plate, wherein a back side of the retainer correspond to a second cut made into the sheet metal plate, wherein the sheet metal plate is made from a nickel titanium alloy, and wherein the at least one elongated arc has a parallelogram-shaped or rectangular cross section.

2. The retainer according to claim 1, wherein the retainer is adapted to connect to respective abutting teeth within bonding portions by a bonding material in a force-transferring manner, wherein the retainer is embedded in the bonding material and is able to adhere to the respective abutting teeth, wherein a position of the retainer is able to be positioned a minimum distance from a respective tooth surface measured perpendicular to the respective tooth surface, and wherein a maximum distance between the respective tooth surface and the position of the retainer, is able to be set at the most 0.1 mm in each of the bonding portions.

3. The retainer according to claim 1, wherein the arc has a local radius of curvature of 1.0 mm or less.

4. The retainer according to claim 1, wherein side lengths of the cross section are at most 0.7 mm.

5. The retainer according to claim 1, wherein the retainer is able to connect to at least three teeth in a force-transferring manner.

6. The retainer according to claim 1, wherein the retainer is configured in one piece.

7. The retainer according to claim 1, wherein the retainer viewed in plane view is enclosable by an inner enveloping parabola and an outer enveloping parabola, and wherein locally in a region of an interdental space a distance measured perpendicular to the inner enveloping parabola between the inner enveloping parabola and the outer enveloping parabola is at least 1.0 mm.

8. The retainer according to claim 1, wherein the retainer has an at least partially roughened surface, and wherein all surfaces extending in the longitudinal direction of the retainer are roughened.

9. The retainer according to claim 1, wherein a surface of the retainer is at least partially treated by electro-polishing or plasma polishing.

10. The retainer according to claim 1, wherein the nickel titanium alloy has an AF temperature between 25° C. and 35° C.

11. A method for producing a retainer comprising the steps: providing a sheet metal plate made from a nickel titanium alloy that includes first and second mutually parallel surfaces; and making a first cut and a second cut in the sheet metal plate via a computer-controlled process; wherein a front side of the retainer corresponds to the first cut made into the sheet metal plate, wherein a hack side of the retainer correspond to the second cut made into the sheet metal plate, wherein a lower side of the retainer corresponds to the first mutually parallel surface, wherein an upper side of the retainer corresponds to the second mutually parallel surface, wherein the retainer has at least one elongated arc including a parallelogram-shaped or rectangular cross section, and wherein the retainer fits a natural curvature of a lower jaw or an upper jaw.

12. The method according to claim 11, wherein the retainer is cut out from the metal sheet by laser cutting or by wire erosion.

13. The method according to claim 11, wherein the sheet metal plate from Which the retainer is machined is curved about at least one axis of curvature, and wherein the at least one axis of curvature extends within a surface plane of the sheet metal plate in a non-curved state of the metal sheet.

14. The method according to claim 11, wherein the retainer after it has been machined from the sheet metal plate is electro-polished or plasma polished, so that edges of the retainer are rounded.

15. A retainer adapted to cooperate with a plurality of teeth and configured to stabilize the plurality of teeth, the retainer comprising: at least one elongated arc which is shaped to a natural curvature of a lower jaw or an upper jaw, wherein the retainer is machined from a sheet metal plate and includes first and second mutually parallel surfaces; wherein a lower side of the retainer corresponds to the first mutually parallel surface, wherein an upper side of the retainer corresponds to the second mutually parallel surface, wherein a front side of the retainer corresponds to a first cut made into the sheet metal plate, wherein a back side of the retainer correspond to a second cut made into the sheet metal plate, and wherein the at least one elongated arc has a parallelogram-shaped or rectangular cross section.

16. The retainer according to claim 15, wherein the retainer is adapted to connect to respective abutting teeth within bonding portions by a bonding material in a force-transferring manner, wherein the retainer is embedded in the bonding material and is able to adhere to the respective abutting teeth, wherein a position of the retainer is able to be positioned a minimum distance from a respective tooth surface measured perpendicular to the respective tooth surface, and wherein a maximum distance between the respective tooth surface and the position of the retainer, is able to be set at the most 0.1 mm in each of the bonding portions.

17. The retainer according to claim 15, wherein the arc has a local radius of curvature of 1.0 mm or less.

18. The retainer according to claim 15, wherein side lengths of the cross section are at most 0.7 mm.

19. The retainer according to claim 15, wherein the retainer is able to connect to at least three teeth in a force-transferring manner.

20. The retainer according to claim 15, wherein the retainer is configured in one piece.

21. The retainer according to claim 15, wherein the retainer viewed in plane view is enclosable by an inner enveloping parabola and an outer enveloping parabola, and wherein locally in a region of an interdental space a distance measured perpendicular to the inner enveloping parabola between the inner enveloping parabola and the outer enveloping parabola is at least 1.0 min.

22. The retainer according to claim 15, wherein the retainer has an at least partially roughened surface, and wherein all surfaces extending in the longitudinal direction of the retainer are roughened.

23. The retainer according to claim 15, wherein a surface of the retainer is at least partially treated by electro-polishing or plasma polishing.

24. A method for producing a retainer comprising the steps: providing a sheet metal plate that includes first and second mutually parallel surfaces; and making a first cut and a second cut in the sheet metal plate via a computer-controlled process; wherein a front side of the retainer corresponds to the first cut made into the sheet metal plate, wherein a back side of the retainer correspond to the second cut made into the sheet metal plate, wherein a lower side of the retainer corresponds to the first mutually parallel surface, wherein an upper side of the retainer corresponds to the second mutually parallel surface, wherein the retainer has at least one elongated arc including a parallelogram-shaped or rectangular cross section, and wherein the retainer fits a natural curvature of a lower jaw or an upper jaw.

25. The method according to claim 24, wherein the retainer is cut out from the metal sheet by laser cutting or by wire erosion.

26. The method according to claim 24, wherein the sheet metal plate from which the retainer is machined is curved about at least one axis of curvature, and wherein the at least one axis of curvature extends within a surface plane of the sheet metal plate in a non-curved state of the metal sheet.

27. The method according to claim 24, wherein the retainer after it has been machined from the sheet metal plate is electro-polished or plasma polished, so that edges of the retainer are rounded.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Hereinafter, the invention described above is explained in detail with reference to an exemplary embodiment illustrated in drawing figures, wherein:

[0061] FIG. 1 is a plan view of a retainer according to the invention for use in the upper jaw;

[0062] FIG. 2 is similar to FIG. 1, but is used on a mod& of the upper jaw;

[0063] FIG. 3 is a sketch of a retainer used on a model of a lower jaw;

[0064] FIG. 4 is similar to FIG. 1, but is illustrated as a three-dimensional lattice model;

[0065] FIG. 5 is a cross section through a teeth provided with a retainer according to the invention;

[0066] FIG. 6 is an enlarged view of the retainer of FIG. 5;

[0067] FIG. 6a is an enlarged view of an alternatively formed retainer; and

[0068] FIG. 7 is a plan view of a nitinol sheet with a worked out retainer.

DETAILED DESCRIPTION OF THE INVENTION

[0069] A first exemplary embodiment, shown in FIG. 1, includes a retainer 1, which is adapted for use in a upper jaw. The retainer 1 is configured as a 6-point retainer and is connected to six teeth in a force-transmitting manner after it has been inserted into the respective patient. The retainer 1 is shown in FIG. 1 in a plan view, so that an upper surface 2 of the retainer 1 is visible.

[0070] The retainer 1 includes an arc 3, the global shape of which is parabolic. This global shape of the arc 3 is determined by the shape of the respective upper jaw, into which the retainer 1 is to be inserted. The arc 3 includes locally individual formations 4, which can be divided into two categories. The first category refers to formations 4 in the form of “shallow waves” 5 which are configured to adapt the retainer 1 to an individual topography of the adjacent teeth. These shallow waves 5 are therefore correspondingly adapted to an individual tooth shape of a patient. The second category describes “tips” 6 which form the points of the arc 3, which enter into interdental spaces between adjacent teeth. In the tips 6 the arc 3 has small radii of curvature, which are here in the range of 0.5 mm to 1.0 mm. These tips 6 are different from the waves 5 by means of their amplitudes relative to the global shape of the arc 3.

[0071] This can be shown on the basis of two enveloping parabolas 7, 8 enclosing the arc 3 and shown in dashed lines in FIG. 1. These enveloping parabolas 7, 8 describe an inner boundary line and an outer boundary line of the retainer 1, wherein the inner enveloping parabola 7 includes those points that are located innermost relative to the shape of the retainer 1 and the outer enveloping parabola includes those points that are located outermost relative to the shape of the retainer 1, Thus, the outer enveloping parabola 8 extends substantially through maximum points of the tips 6. In the example shown a distance as measured perpendicular to the enveloping parabola 7 between the same and the outer enveloping parabola 8 is continuously about 2 mm. This value describes at the same time the above-mentioned amplitude of the tips 6. A parabola which would be laid substantially through maximum points of the shallow waves 5 would have a much smaller distance from the inner enveloping parabola 7. That is, the amplitude of the waves 5 in comparison to the tips 6 is small. This is clearly visible in the form of the retainer 1 shown.

[0072] The retainer 1 is formed from the material nitinol and was cut out from a corresponding nitinol sheet by a laser cutting process. Prior to this step it is always necessary to detect the respective contour to be reproduced of teeth to be stabilized. This is typically implemented by the scan of an impression that reproduces a dental impression of the upper jaw or lower jaw, or by means of a so-called “intraoral scan” which is made by means of an intraoral scanner. In the latter method, the shape of the teeth is detected directly in the patient's mouth. Here, it is advantageous that this method is possible comparatively quickly and allows greater precision than an impression process.

[0073] The result of the respective scan of the teeth is then processed by means of a CAD software and a three-dimensional model of the retainer 1 is created, which is adapted very well to the scan and consequently to the real topography of the respective teeth. Based on the model subsequently the laser is programmed, by means of which the retainer 1 is cut out. This process step is also referred to as computer aided manufacturing (CAM).

[0074] The retainer 1 is shown in FIG. 2 in an inserted state in which the retainer 1 is initially loosely applied to the teeth. The retainer 1 is formed such that a distance between a tooth surface at which the retainer 1 abuts and a point of the retainer 1, the distance of which measured perpendicular to the tooth surface is the smallest, is at most 10 μm, i.e. 0.01 mm. Such a precision cannot be realized with retainers according to the prior art. The resulting advantages are explained in detail above.

[0075] FIG. 3 shows another example of a retainer 1′ according to the invention, wherein the retainer 1′ is adapted for use in a lower jaw. The retainer 1′ like the retainer 1 is connected to six teeth in a force-transmitting manner, however, the retainer is shown in FIG. 3 in its inserted state, i.e. without the junctions necessary for a connection. Here, tips 6 ‘of the retainer 1’ protrude into interdental spaces between the teeth such that shifting the retainer 1′ relative to the teeth is blocked at least in a transverse direction. From the figure it is clear that the amplitude of the tips 6′ are significantly larger in the retainer 1′ than is the case in the retainer 1. This results from the natural shape of the teeth.

[0076] The retainer 1 is finally shown in FIG. 4 in a three-dimensional lattice model. From the illustration it is clear that the retainer 1 has a square cross-section, wherein a side length of the cross section is 0.3 rm. Likewise, in FIG. 4 both a front surface 9 and a rear surface 10 of the retainer 1 are shown. These are arranged parallel to one another, wherein the front surface 9 faces a tooth surface of the respective abutting tooth in an installed state of the retainer 1. Perpendicular to the front surface 9 and the rear surface 10 the upper surface 2 and a lower surface 11 of the retainer 1 are oriented.

[0077] The upper surface 2 and the lower surface 11 of the retainer 1 each extend in one plane. These planes define a metal sheet (not shown) from which the retainer 1 was originally machined, wherein the metal sheet has a thickness of 0.3 mm. This means that a machining tool (laser, water jet, erosion wire, etc.) has been traversed parallel to the upper surface 2 of the retainer 1 over the metal sheet corresponding to the contour of the retainer 1 in order to machine the retainer 1 from the metal sheet. By means of this process step the front surface 9 and the back surface 10 of the retainer 1 have been obtained. These are therefore to be understood as processing planes 12 or machining surfaces 13 because they represent the planes that have been processed or where the retainer 1 has been machined. After machining the retainer 1 is provided directly in the illustrated form and may be applied to the patient's teeth without further adaptations.

[0078] FIG. 5 shows a cross section through an incisor 14 which is provided with the retainer 1 according to the invention of FIG. 1, wherein only the area of the incisor 14 is shown, which is located above the gums 15. For the sake of clarity, FIG. 6 shows an enlarged view of the retainer 1 in FIG. 5. In a bonding portion—in which the retainer 1 is bonded with the incisor 14—the retainer 1 is embedded into a bonding material 16, which previously has been applied onto an inner tooth surface 17 and abuts quasi directly the tooth surface 17. The surface with which the retainer 1 abuts the tooth surface 17 corresponds to the machining surface 13 of the retainer 1, i.e. a cutting edge 18 which was formed during the production of the retainer 1. The upper surface 2 of the retainer 1 corresponds to an upper metal sheet surface 19 and the lower surface 11 of the retainer 1 corresponds to a lower metal sheet surface, wherein said upper and lower sheet surface 19 are parallel to each other. The upper and the lower sheet surface correspond to an original metal sheet plane. The upper surface 2 and the lower surface 11 of the retainer 1 extend perpendicular to the inner tooth surface 17.

[0079] FIG. 6a shows an alternative formed retainer 1″ which has a square cross section and is mounted in its bonding portion by means of the bonding material 16 at the incisor 14 such that it is completely surrounded by the bonding material 16.

[0080] Finally, FIG. 7 shows a plan view of a nitinol sheet 20, wherein the process of working out the retainer 1 according to the invention in FIG. 1 has just been completed and the finally cut out retainer 1 is still disposed within the nitinol sheet 20. The surface of the nitinol sheet 20 and the retainer 1 which extends in the drawing plane corresponds to the upper nitinol sheet surface 19 or the upper side 2 of the retainer 1. The cutting edge 18 of the retainer 1, of which only a line 21 is visible in the figure, extends perpendicular to the drawing plane. It corresponds to the machining surface 13 of the retainer 1, which comes to abut the inner tooth surface 17. A cutting edge 22 extending parallel to the cutting edge 18, which again is only visible as a line 24 in FIG. 7, is also to be regarded as a machining surface 23, which faces away from the inner tooth surface 17 in the inserted state.

REFERENCE NUMERALS AND DESIGNATIONS

[0081] 1″ retainer [0082] 2 upper surface [0083] 3 arc [0084] 4 formation [0085] 5 wave [0086] 6, 6′ tip [0087] 7 enveloping parabola [0088] 8 enveloping parabola [0089] 9 front surface [0090] 10 rear surface [0091] 11 lower surface [0092] 12 processing plane [0093] 13 machined surface [0094] 14 incisor [0095] 15 gums [0096] 16 bonding material [0097] 17 inner tooth surface [0098] 18 cutting edge [0099] 19 upper metal sheet surface [0100] 20 nitinol sheet [0101] 21 line [0102] 22 cutting edge [0103] 23 machined surface [0104] 24 line