A device for trimming dental splints.

Abstract

A device for trimming dental splints (1) is described, comprising a spatially displaceable holder (2) for the dental splint (1), a suction device (3), a laser (4) and a computing unit (5). In order to configure the device mentioned at the beginning in such a way that, despite the use of conventional components, precise trimming of the dental splint is possible with minimal control effort and preparation for the user, it is proposed that the laser (4) is in a fixed position, a camera (6) is provided for determining the position of the dental splint (1) and the holder (2) has an at least partially thermostable platform (7) and a stopper (8) for receiving the dental splint (1) released from the deep-drawing mold in a force-connected manner and without play.

Description

[[Technical Field]]

[0001] The present invention relates to an apparatus for trimming a dental splint, comprising a spatially displaceable holder for a dental splint, a suction device, a laser, and an arithmetic unit. [[Background Art]]

[0002] From the prior art, dental splints manufactured from deep-drawing sheets using the deep-drawing method are known. In this process, after the deep-drawing sheet has been drawn over a dental model, the dental splint must be trimmed. In this process, the exposed free deep-drawing edge, that is, the portion of the deep-drawing sheet that is not formed by the model and does not form part of the dental splint, is separated from the dental splint, and deburring is performed along the resulting cut line.

[0003] European Patent No. 2101674 discloses an apparatus in which a dental splint is supported on three posts positioned on a spatially movable platform. In this arrangement, the dental splint is fixed to the posts using negative pressure, whereby the dental splint can subsequently be trimmed with a laser. For this purpose, an arithmetic unit calculates the required cut line for the laser based on a CAD model of the dental splint, and controls the platform and the movable laser such that the laser follows the cut line.

[0004] However, according to the drawbacks of the prior art, for trimming a dental splint, a corresponding CAD model must always be created and loaded into the arithmetic unit. In addition, both laser variables such as beam intensity or spatial directionality and the position of the dental splint must be accurately known and precisely adjusted relative to each other. Additionally, a problem arises in that portions of the deep-drawing edge that have already been cut by the cutting process may suddenly sag, which can cause the dental splint to slip. This results in cutting errors, because the actual position of the dental splint differs from the target position determined in the CAD model.

[0005] It has already been proposed (European Patent No. 2760624) that a dental splint be placed on a platform, thereby allowing the splint to be mounted over a large area with a free deep-drawn edge and supported by a dental arch model. However, this still requires complex dynamic control of the laser intensity, because the intensity must be continuously adjusted to match the local thickness of the deep-drawn sheet, and consequently, the dental arch model may not be welded to the deep-drawn sheet due to an incorrectly set laser intensity, or the device may be damaged by the laser. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] European Patent No. 2101674 [Patent Document 2] European Patent No. 2760624 [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, the fundamental problem of the present invention is to provide a device that enables precise trimming of dental splints with minimal effort and preparation required for the user, despite the use of conventional components. [Means for solving the problem]

[0008] The present invention solves the set problem by having a laser that is in a fixed position and equipped with a camera for locating the position of the dental splint, and a holder having at least partially thermally stable platform and stopper for force-connected, play-free housing of the dental splint released from the deep-drawing mold. Since the dental splint separated from the dental arch model is housed on the platform before trimming, the free deep-drawn edge rests substantially flat on the platform. The stopper force-connected and play-free fixing of the dental splint across its free deep-drawn edge prevents relative movement between the dental splint and the platform, despite the displacement of the holder. The camera captures the orientation and shape of the dental splint housed on the platform and the spatial boundary range between the dental splint and the free deep-drawn edge. From such spatial data, a computing unit determines a cut line for separating the dental splint from the free deep-drawn edge and, accordingly, determines how the holder must be displaced for the laser beam to follow the cut line. In this case, the determination of the cut line can be repeated, including the acquisition of new positional data by the camera at all times during trimming, to determine a suitable cut line. Additionally, the use of the camera eliminates the need for positional marking on the dental splint, which is required in the prior art. Since the laser is stationary, only the holder needs to be displaced to allow the laser to follow the cut line. This reduces positional inaccuracies and makes control easier. The laser intensity can be maintained uncontrolled during trimming, as the excess energy of the laser is absorbed by the thermally stable platform. The laser intensity and platform material can be adjusted at the factory so that the laser intensity is sufficient to trim a normal dental splint but too low to damage the platform. Since the required cut line of the dental splint essentially always extends only across the same portion of the platform, the platform only needs to be thermally stable in this portion.The dental splint is trimmed without a dental arch model, thus eliminating the need to adjust the laser intensity to protect the model. In this case, unexpectedly, even when the free deep-relieving edge is completely separated from the dental splint, the splint remains stably housed by a frictional connection to the separated free deep-relieving edge. In a preferred embodiment, the platform is not only thermally stable but also thermally conductive so that excess laser energy can be derived from the dental splint, and no heat reservoir is formed on the platform that heats the dental splint. For this purpose, the platform may be formed from, for example, anodized aluminum. To determine the position of the dental splint and the required cut line from camera data, the computing unit may implement a self-learning algorithm or a neural network. The computing unit may be trained to acquire only the spatial orientation of the dental splint, the free deep-relieving edge and the boundary range between them, and not process other detailed image information. To determine the position, the holder may be displaced together with the dental splint to the acquisition position where the camera records an image of the dental splint. The acquisition position is selected so that the camera used can record high-quality images of the dental splint and its surrounding deep-diameter edges with respect to the relative position of the holder to the camera, as much as possible without autofocus or other technical aids, so that these images can be easily processed by the computing unit. Therefore, the dental splint may be oriented, for example, approximately perpendicular to the optical axis of the camera at the acquisition position. The image processing steps by the computing unit may include fragmentation, normalization, and segmentation so that the computing unit can determine the progression of the required cut line from the processed image. After the image is normalized at the acquisition position, the surrounding deep-diameter edges can be recognized by the computing unit via their pixel values ​​and distinguished from the dental splint, thereby determining the required cut line. Optionally, the computing unit may compare the acquired and processed image with a computer model of the dental splint. A reference point may be determined at the detection position so that the relative position of the dental splint can still be recognized even after the holder has been displaced.

[0009] When the camera is positioned within the laser's field of view, the effort required for calculations to determine the necessary cut line is reduced, and holder control is simplified. The closer the camera is positioned to the laser, the closer the laser's optical path and the camera's optical path become, so the computing unit does not have to perform complex conversion steps to translate the camera's data into instructions to displace the holder. When the computing unit uses a neural network, this also simplifies the training of the computing unit itself, because the training images do not require complex conversion steps, thereby reducing training time. In one preferred configuration, the camera is an RGB camera, because the image quality of such a camera is high enough to generate reliable image data for further processing in the computing unit, despite its low cost.

[0010] If the platform has at least one through-hole, which is in fluid communication with the inlet of a suction device mounted on the side of the platform opposite the laser, the dental splint can be more firmly secured on the platform without other means. Based on these measures, the suction device not only aspirates particles and / or vapors generated during trimming, but also applies negative pressure to the dental splint through at least one through-hole. The negative pressure promotes the adhesion of the dental splint on the platform. Since the required cut line of the dental splint essentially always extends only over the same subregion of the platform, in one preferred embodiment, multiple through-holes are arranged in this subregion, thereby aspirating particles and / or vapors where they are generated and the dental splint is additionally secured by negative pressure at its cut edge. Since the laser beam can also pass through the through-hole of the platform and be incident on a portion of the holder located below it, thermally unstable portions of the holder must be located outside the beam path, and / or portions reachable by the laser beam must likewise be configured to be thermally stable. The platform may occupy various relative positions to the laser based on its displaceability, but in terms of the present invention, the platform is intended to be on the side opposite to the laser when processing the dental splint. In addition to localized high precision during trimming, it is proposed that the platform be displaceable in at least partially five spatial directions to facilitate deburring of the dental splint. Thus, the holder and, consequently, the dental splint can rotate around two axes in addition to three translational motions, thereby changing the cutting angle of the laser. This allows for post-processing or removal of the cut edges of the dental splint, and thus better deburring of the dental splint.

[0011] During deep drawing, the free deep-drawn edge of the dental splint may deform, which can make it difficult to secure the dental splint on the platform. This prevents the dental splint from being accommodated on the platform in a force-connected manner in all directions, because the dental splint transmits the deformation of the free deep-drawn edge to the splint during force connection, potentially leading to the formation of an incorrect cut line. To enable accurate cut line determination despite such deformation, a stopper may be annular and, together with the platform, can form a accommodating section for the free deep-drawn edge of the dental splint. As a result of this measure, force connection is formed along the entire free deep-drawn edge and optionally supplemented by shape connection. That is, if the free deep-drawn sheet is placed flat on the platform, the dental splint can be accommodated on the platform regardless of the orientation of the dental splint, across the free deep-drawn sheet. This allows the wavy deformation that often occurs on the free deep-drawn edge to be flattened. In one preferred embodiment, the stopper is connected to the holder via a hinge and can be swung downward and locked before trimming.

[0012] If the holder has a cross slide, the holder can be easily and accurately displaced. The cross slide, based on its simple operating principle, can be easily operated via an adjustment spindle and requires no calibration. Furthermore, the holder can also be rotated via one or more guides of the cross slide guide.

[0013] To create a compact configuration, the holder has a rotating base, to which a platform that is at least partially thermally stable is assigned. This allows the dental splint, along with the platform, to be easily and space-savingly displaced without restricting access to the laser. A particularly favorable configuration is obtained when the rotating base is positioned on a cross slide.

[0014] The drawings illustrate the scope of the present invention. [Brief explanation of the drawing]

[0015] [Figure 1] A front view of the apparatus according to the present invention is shown. [Figure 2] A cross-sectional view along line II-II in Figure 1 is shown. [Figure 3] A plan view of the holder of the apparatus according to the present invention is shown at an even larger scale. [Figure 4] Figure 3 shows a cross-sectional view along the line IV-IV. [Modes for carrying out the invention]

[0016] An apparatus according to the present invention for trimming a dental splint 1 (shown only schematically) comprises a displaceable holder 2 for the dental splint 1 and a suction device 3 mounted on the holder 2 for aspirating particles and vapors generated by the trimming process. The apparatus further comprises a laser 4, a computing unit 5 mounted in the housing of the laser 4 in the illustrated embodiment, and a camera 6. The holder 2 has a platform 7 that is at least partially thermally stable and on which the dental splint 1 can be accommodated. Since the dental splint 1 is accommodated on the platform 7 for trimming without the deep drawing model attached to the dental splint 1, the thermally stable platform 7 must be able to absorb the excess energy of the laser beam of the laser 4 without damage and derivate it in a suitable manner. The laser 4 is configured in a fixed position, and therefore the platform 2 must be configured to be displaceable in multiple spatial directions, preferably five spatial directions, in order to perform the trimming process using the laser 4. Therefore, to ensure secure accommodation of the dental splint 1 on the platform 7 of the holder 2 in any position, the holder 2 has a stopper 8 for the dental splint 1, and the stopper 8 allows the dental splint 1 to be accommodated by force connection. To enable precision machining by the laser 4 in any position, the accommodation of the dental splint 1 must be performed without any play.

[0017] The camera 6 transmits necessary image data. Based on the image data, the arithmetic unit 5 determines the cutting line required for trimming the dental splint 1, and displaces the holder 2 such that the laser beam can follow the required cutting line. In this case, since the camera 6 is arranged in the region of the laser 4, both the optical axis of the camera 6 and the optical axis of the laser 4 are thereby located in the same region, whereby a change in the position of the holder 2 required for trimming can be obtained more easily by the arithmetic unit 5.

[0018] As can be particularly seen from Figure 3, the platform 7 has one or more through holes 9, and the suction device 3 may be connected to the holder 2 via the inlet 10 on the side of the platform 7 opposite the dental splint 1. Thereby, fluid communication between the inlet 10 and the at least one through hole 9 can be established, and the fluid communication allows vapor to be suctioned, which is generated directly around the dental splint 1 during the trimming process by the laser 4, to be suctioned on the side of the platform 7 opposite the dental splint 1. This increases the freedom of movement of the holder 2 and enables a reduction in the distance between the inlet 10 and the dental splint 1. Furthermore, this facilitates the generation of negative pressure by the suction device 3. The generation of negative pressure promotes accommodation of the dental splint 1 on the platform 7.

[0019] If the stopper 8 of the platform 7 is configured in an annular shape, the dental splint 1 can be accommodated on the platform 7 on the peripheral side over the free deep-drawn edge 11 thereof, whereby a play-free force-fit accommodation of the dental splint 1 independent of a change in position of the holder 2 can be achieved. In this case, the platform 7 together with the stopper 8 forms a receiving portion 12 for the free deep-drawn edge 11 of the dental splint 1.

[0020] If the holder 2 has a cross slide 13 and a rotary table 14, and at least partially heat-stable platform 7 is assigned to the rotary table 14, the holder 2 can be easily controlled, displaced in a space-saving manner and at low cost.

[0021] The five degrees of freedom of motion are represented by the coordinate system indicated in FIG. 2. In addition to the three translational degrees of freedom, the platform 7 is rotatable at least partially. This can be achieved, for example, via the rotary table 14. A further rotational degree of freedom can be achieved, for example, in that the slide of the cross slide 13 functions as a shaft support, and the longitudinal axis of the platform 7 is guided by the shaft support. Thereby, the platform 7 is slidable in the axial direction and is supported rotatably about the axis. This application relates to the invention described in the claims, but also includes the following other embodiments. 1. A device for trimming a dental splint (1) comprises a spatially displaceable holder (2) for the dental splint (1), a suction device (3), a laser (4), and a computing unit (5), The apparatus is characterized in that the laser (4) is fixed in position, a camera (6) is provided for identifying the position of the dental splint (1), and the holder (2) has at least a partially thermally stable platform (7) and a stopper (8) for force-connecting and securely accommodating the dental splint (1) released from the deep-drawing mold. 2. The apparatus according to claim 1, characterized in that the camera (6) is positioned in the region of the laser (4) such that the dental splint (1) is oriented laterally with respect to the optical axis of the camera (6) at the detection position. 3. The apparatus according to the 1 or 2, wherein the platform (7) has at least one through hole (9), and the through hole (9) is in fluid communication with the inlet (10) of the suction device (3) mounted on the platform (7) opposite to the laser (4). 4. The platform (7) is characterized in that it is displaceable in at least part in five spatial directions, one of the devices described in 1 to 3 above. 5. The device, any one of the above 1 to 4, is characterized in that the stopper (8) is annular and together with the platform (7) forms a receiving portion (12) for the free deep-drawn edge (11) of the dental splint (1). 6. The holder (2) is characterized by having a cross slide (13), one of the devices described in 1 to 5 above. 7. The device, any one of the above 1 to 6, is characterized in that the holder (2) has a turntable (14), and the platform (7) which is at least partially thermally stable is assigned to the turntable (14).

Claims

1. A device for trimming a dental splint (1) comprises a spatially displaceable holder (2) for the dental splint (1), a suction device (3), a laser (4), and a computing unit (5), The apparatus is characterized in that the laser (4) is in a fixed position, a camera (6) is provided for identifying the position of the dental splint (1), and the holder (2) has at least a partially thermally stable platform (7) and a stopper (8) for pressing and securely housing the dental splint (1) released from the deep drawing mold.

2. The apparatus according to claim 1, characterized in that the camera (6) is positioned in the region of the laser (4) such that the dental splint (1) is oriented laterally with respect to the optical axis of the camera (6) at the detection position.

3. The apparatus according to claim 1 or 2, characterized in that the platform (7) has at least one through hole (9), the through hole (9) is in fluid communication with the inlet (10) of the suction device (3) mounted on the platform (7) opposite to the laser (4).

4. The apparatus according to claim 1 or 2, characterized in that the platform (7) is at least partially displaceable in five spatial directions.

5. The apparatus according to claim 1 or 2, characterized in that the stopper (8) is annular and together with the platform (7) forms a receiving portion (12) for the free deep-drawn edge (11) of the dental splint (1).

6. The apparatus according to claim 1 or 2, characterized in that the holder (2) has a cross slide (13).

7. The apparatus according to claim 1 or 2, characterized in that the holder (2) has a turntable (14), and the platform (7) which is at least partially thermally stable is assigned to the turntable (14).

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