METHOD FOR PRDUCING A POSITIONING TRAY AND THE DEVICE THEREFOR

Abstract

The present invention relates to a method for producing a positioning tray for brackets of dental braces, wherein the positioning tray has a positioning aid and one or more associated brackets, wherein the positioning aid is formed as one piece with the associated bracket(s), comprising the following steps: obtaining original data which describe the present geometry of one or more teeth of at least one jaw of a patient; obtaining target data which describe the geometry of the one or more teeth of the at least one jaw of the patient after treatment with dental braces; calculating tray configuration data which describe the geometry of brackets with respect to the present geometry of the one or more teeth of the at least one jaw of the patient and the positioning aid arising from the original data and the target data, wherein the calculation of the tray configuration data is carried out such that using the described brackets of this type, the positioning aid is connected such that it can be used in order to position the brackets with respect to the teeth of the patient such that the bracket(s) can be connected to the surface of the teeth of the patient, and that, together with an ideal curve (basis for planning), previously determined and to be connected to (one of) the bracket(s), a correction of a malocclusion can be carried out; producing, on the basis of the tray configuration data, a corresponding positioning tray through a generative or ablative manufacturing method. The invention further relates to a corresponding device, a computer-readable storage medium and a corresponding positioning tray.

Claims

1. Method for producing a positioning tray (10) for brackets of dental braces, wherein the positioning tray has a positioning aid (12) and one or more associated brackets (14), wherein the positioning aid (12) is formed in one piece with the associated brackets (14), comprising the following steps: Obtaining source data which describe the present geometry of one or more teeth of at least one jaw of a patient, Obtaining target data which describe the geometry of the one or more teeth of the at least one jaw of the patient after treatment with dental braces; Calculating tray configuration data which describe the geometry of brackets (14) with respect to the present geometry of the one or more teeth of the at least one jaw of the patient and the positioning aid (12), arising from the source data and the target data, wherein the calculation of the tray configuration data is carried out such that, using the described brackets (14) of this type, the positioning aid (12) is connected such that it can be used to position the brackets (14) with respect to the teeth of the patient, in such a way that the brackets (14) can be bonded to the surface of the teeth of the patient, and that, together with an arch wire to be connected to the brackets, a malocclusion can be corrected, Producing, on the basis of the tray configuration data, a corresponding positioning tray (10) by means of a generative manufacturing process, preferably a 3D printing process, or an ablative manufacturing process.

2. Method according to claim 1, wherein the method is designed such that a point with reduced breaking strength (20), which serves as a predetermined breaking point, is formed in the positioning tray (10) at the transition between the brackets and the associated positioning aid to make it easier to separate the brackets (14) from said positioning aid (12).

3. Method according to one of the preceding claims, in which for producing the positioning trays (10), at least for that portion which forms the brackets (14), a generative manufacturing process is used which uses a composite that is mixed with ceramic particles and that preferably contains admixtures which meet the demands for strength and oral compatibility of the bracket (14).

4. Method according to one of claims 1-2, in which for producing the positioning trays (10), the positioning trays are manufactured from a ceramic or composite blank by means of an ablative process.

5. Apparatus for the production of a positioning tray (10) for brackets of dental braces, wherein the positioning tray (10) has a positioning aid (12) and one or more associated brackets (14), wherein the positioning aid (12) is formed in one piece with the associated brackets (14), with: a device for obtaining source data which describe the present geometry of one or more teeth of at least one jaw of a patient, in particular a device which is equipped to capture an oral cavity of a patient, a device for obtaining target data which describe the geometry to be achieved for the one or more teeth of the at least one jaw of the patient after treatment with dental braces, and which permit positioning of the brackets according to the curve of an ideal arch wire which is available and previously determined by the device, a device for calculating tray configuration data which describe the geometry of brackets (14) with respect to the present geometry of the one or more teeth of the at least one jaw of the patient and the positioning aid, arising from the source data and the target data, wherein the calculation of the tray configuration data is carried out such that, using the described brackets (14) of this type, the positioning aid (12) is connected such that it can be used to position the brackets (14) with respect to the teeth of the patient in such a way that the brackets (14) can be bonded to the surface of the teeth of the patient, and that, together with an ideal arch wire previously selected on the target model with the aid of the device and to be connected to the brackets (14), a malocclusion can be corrected, and a device for producing, on the basis of the tray configuration data, a corresponding positioning tray by means of a generative manufacturing process, preferably a 3D printing process, or an ablative manufacturing process.

6. Apparatus according to claim 5, which is designed such that a point with reduced breaking strength (20), in particular a point with a weakened material thickness, which serves as a predetermined breaking point, is formed in the positioning tray (10) at the transition between the brackets (14) and the associated positioning aid (12) to make it easier to separate the brackets (14) from said positioning aid (12).

7. Apparatus according to claim 5 or 6, which is designed, for producing the positioning trays (10), at least for that portion which forms the brackets (14), to use a generative manufacturing process which uses a composite that is mixed with ceramic particles and that preferably contains admixtures which meet the demands for strength and oral compatibility of the bracket (14).

8. Apparatus according to one of claims 5-6, in which the device for producing, on the basis of the tray configuration data, a corresponding positioning tray is a device which can perform an ablative manufacturing process.

9. Machine-readable storage medium which contains a computer program that can control a method according to one of claims 1-4.

10. Positioning tray (10) for brackets of dental braces, wherein the positioning tray (10) has a positioning aid (12) and one or more associated brackets (14), wherein the positioning aid (12) is formed in one piece with the associated brackets (14).

11. Positioning tray according to claim 10, in which a point with reduced breaking strength (20), which serves as a predetermined breaking point, is formed at the transition between the brackets (14) and the associated positioning aid (12) to make it easier to separate the brackets from said positioning aid.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0052] FIG. 1 shows schematically a positioning tray according to the invention.

[0053] FIG. 2 shows schematically a method according to the invention.

[0054] FIG. 3 shows a view of a modeled corrected dental arch with brackets attached to it and an ideal arch wire.

[0055] FIG. 4 is a plan view onto the teeth illustrated in FIG. 3 with attached brackets and ideal arch wire.

[0056] FIG. 5 is a front view of a computer model of uncorrected teeth with positioning trays mounted on them and associated brackets.

[0057] FIG. 5a is a plan view onto the arrangement according to FIG. 5.

[0058] FIG. 6 is a sectional view of a tooth which is illustrated in FIG. 5.

DETAILED DESCRIPTION OF THE DRAWINGS

[0059] An embodiment of the invention is described in the following with reference to FIGS. 1 and 2. FIG. 2 shows a positioning tray 10 which can only be produced according to the method illustrated in FIG. 1 for positioning the brackets on the ideal target model. This positioning tray 10 comprises a positioning aid 12 which is joined to a bracket 14. This bracket 14 can be attached to a tooth, not shown, of a patient by providing it with an adhesive on the rear (not shown) which is cured as soon as the bracket is in contact with the tooth of the patient. The bracket 14 has a slot 16 into which an arch wire can be inserted. As soon as this arch wire has been inserted, it can be attached to the bracket 14 by means of a rubber band or by another means. An appropriate rubber band (not shown) is pulled over the protrusion which is created by the different width of bracket base 18 and bracket foot 19 such that it holds the arch wire in the groove 16.

[0060] In addition, a predetermined breaking point 20 can be formed between the positioning aid 12 and the bracket 14. This is formed by a selective weakening of the material at this point such that the positioning aid 12 can easily be snapped off the bracket 14 once this bracket 14 has been attached to the tooth of a patient.

[0061] FIG. 2 shows schematically a method for producing such a bracket. For this, source data are first imported in step S100. This importing can take place, for example, by means of a device which scans the oral cavity of a patient (intraoral scanner).

[0062] Based on this, target data are created (step S102) which illustrate how the teeth or the jaw of the patient should look after the treatment. That is to say, while the source data represent the actual state, the target data represent the target state.

[0063] In step S104, an appropriate ideal arch wire, which most closely corresponds to the curve of the target state of the dental arch created by the orthodontist using the software and further specific criteria (minimum distance to tooth surfaces, etc.), is then selected from the virtual arch wire library. Only after this are appropriate brackets determined or calculated. Calculation of “appropriate brackets” is understood as identifying the bracket positions which are able to passively accommodate the ideal arch wire already selected in their bracket slots. Thus later, after several successive changes of arch wire, the teeth of the patient can be translated from the actual configuration to the target configuration. In other words, when calculating the appropriate brackets this is part of the planning which the orthodontist only carries out after determining the ideal arch wire where, with the help of the software, he determines the exact position of the brackets in relation to the selected ideal arch wire (orientation of the bracket slot) and the teeth (height and inclination of the bracket foot).

[0064] As soon as these brackets have been appropriately determined or calculated, after using the software to reset the teeth, including the brackets now correspondingly positioned on the teeth, appropriate positioning trays are calculated. That is to say, a positioning aid is determined which is joined to the brackets and which is designed such that it can guarantee secure retention of the positioning tray on the dental arch by modeling it virtually over occlusal surfaces or incisal edges of individual teeth. Based on these calculated positioning trays, that is to say based on the calculated three-dimensional configuration data, appropriate positioning trays are produced, for example by means of a 3D printer,

[0065] The method schematically and briefly illustrated in FIG. 2 will now be described again in detail with reference to FIGS. 3 to 6.

[0066] FIG. 3 shows a modeled arrangement of the brackets 14, 14′ on the lingual side of the teeth 25, 25′. These brackets 14, 14′ are attached on the inside of the teeth 25 (i.e. on the side which is directed towards the tongue) and are connected by an ideal arch wire 23. This arrangement is the configuration of the teeth 25, 25′ and the brackets 14,14′ to be achieved after correction of the malocclusion and is obtained after the third virtual planning step, as is described in the present application.

[0067] FIG. 4 shows a corresponding plan view onto this configuration from which further details can be seen. The teeth 25, 25′ which are connected by the virtual ideal arch wire 23 are also shown here. This plan view, which can also be described as a view along the incisal direction towards the teeth 25, 25′, shows the brackets 14, 14′ which are joined to the teeth 25, 25′ via a bracket base or bracket foot.

[0068] The fourth virtual planning step will now be described with reference to FIG. 5 which in particular is understandable by looking at it together with FIG. 3. In this drawing, the brackets 14, 14′, which are in turn attached to the teeth 25, 25′, are shown together with the positioning aid 12 attached thereto. In this case, this Figure shows the modeled arrangement of the brackets 14, 14′ together with the positioning aid 12 attached thereto in a state which corresponds to the uncorrected state of the teeth 25, 25′. This arrangement is calculated by a transformation of the teeth 25, 25′ from the target state to the actual state and the accompanying transformation of the brackets 14, 14′ joined thereto to this actual state. In other words, in the computer model the brackets 14, 14′ are appropriately attached to the teeth 25, 25′, the teeth 25, 25′ are then rotated and moved in such a way that they are translated to the actual state (which includes the malocclusion to be corrected), and the brackets 14, 14′ are moved and rotated together with the teeth 25, 25′. In this state, a positioning aid 12 is then determined which can hold the brackets 14, 14′ in this position determined in this way.

[0069] This positioning aid 12 which holds the brackets 14 is formed in one piece with said brackets 14. The positioning aid 12 is planned such that it attaches the brackets 14 at the position relative to the tooth at which they are to be attached such that by means of the positioning aid the teeth 25 are translatable into the configuration shown in FIG. 3 (as was described in other words above). Thus, for example, in the illustration shown in FIG. 5, the tooth 25′ would have to be moved downwards with respect to the teeth 25 located to the right and left of it so that it maintains the configuration shown in FIG. 3. So that the bracket 14 to be attached to said tooth maintains the right position relative to this tooth 25′, it must be positioned “further up” in the positioning tray 10 than the adjacent brackets 14 which is why the positioning tray 10 is offset in the middle, as is shown in FIG. 5. For easier understanding and to be able to differentiate the positioning aid 12 more easily from the brackets 14/14′, the positioning aid 12 is shown in a black and white pattern while the brackets 14/14′ are shown in solid black.

[0070] FIG. 5a shows a detailed view, namely a plan view onto the configuration shown in FIG. 5. The positioning aids 12 which are joined to the brackets 14 are shown here. The bracket foot 19 and the bracket body 18 can be seen.

[0071] FIG. 6 illustrates a longitudinal sectional view of a single tooth, which is shown in FIG. 5. A positioning aid 12 which extends over the incisal edge of the tooth 25 is also illustrated here as black with white dots. A bracket 14 with a bracket incision 16 is joined to the tooth 25 via the bracket foot 19 which joins the bracket base 18 directly to the tooth 25. Here, a “protrusion” between the bracket base 18 and the bracket foot 19 is used to accommodate rubber ligatures for immobilizing the ideal arch wire. It is preferable here for the material of the positioning aid to be selected from a less expensive material than the bracket material. As a result, costs can be reduced. In general, the materials of the positioning aid 12 and the brackets 14/14′ may differ, it being possible, for example, to make the brackets 14/14′ of a material that is more durable in the oral cavity than the positioning aid 12. This results in a cost saving as a more durable material such as this is generally more expensive and more difficult to machine than a corresponding less durable material.