Dental splint as a training aid and method for its manufacture

Description

[0001] The invention is defined in the appended claims and relates to a dental splint as a training means and a method for its manufacture.

[0002] The training of dentists and dental technicians naturally includes practical training sessions in which the dentist's diagnostic skills and "craft" skills, or the dental technician's, are developed. A variety of clinical situations should be simulated as realistically as possible, and the trainees should be given the opportunity to practice actual procedures or practical work. Training situations are usually implemented using phantom heads or articulators, which inadequately simulates the realistic patient situation.

[0003] RU 196 559 U1 discloses a model with upper and lower jaw bases made of a solid, non-shrinkable polymer, featuring model teeth and gums that simulate the condition of a patient's teeth. The model teeth are inserted into the holes in the upper and lower jaw bases that correspond to the shape of the teeth and are secured using collapsible fasteners, allowing for the removal of substitutions and replacements.

[0004] To ensure realistic and effective practical training, natural persons are also included, whose dentition serves as the training object. This has the disadvantage that only defects or jaw misalignments that actually exist in the respective person can be diagnosed. Furthermore, the trainee can only perform very limited manual manipulation of the "test subject's" dentition.

[0005] There is therefore a considerable need for a training tool for dental and dental technician training that offers a wide range of diagnostic and, if possible, practical training opportunities.

[0006] Dental splints have long been a well-known therapeutic method in dental practice, for example for dysfunctions of the temporomandibular joint or for correcting orthodontic misalignments of teeth.

[0007] Various manufacturing processes for dental splints have been established.

[0008] To produce them, an alginate impression of the teeth is usually first taken. This is then cast in super-hard plaster. A hot polymer film is drawn onto the model using a thermoforming machine. Recently, a coordinate-controlled milling process has also become established. The starting point for this process is a dataset of the tooth surface profile of the upper and lower jaws obtained with a 3D scanner on the aforementioned plaster model. Recently, 3D printing processes, also known as additive manufacturing, have also been used to produce occlusal splints. These processes also start with datasets obtained by digitizing the surfaces of dental impression models.

[0009] According to the above-mentioned need, the object of the invention is to provide a versatile training tool for the practical training of dentists and dental technicians.

[0010] This object is achieved by a dental splint having the features of claim 1. Appropriate refinements of the inventive concept are the subject of the dependent product claims. Furthermore, claims 12 and 13 provide methods for producing a training dental splint. Appropriate embodiments of the proposed method are the subject of the dependent method claims.

[0011] The invention includes the concept of a dental splint specifically configured as a training aid, which is placed on a wearer who is available for training purposes, but which offers a different tooth surface configuration and jaw position than the wearer's natural tooth surface configuration and jaw position as the training object. The dental splint according to the invention therefore has a first, concave surface adapted to the tooth and adjacent gum topography of a wearer, and a second, convex surface in which at least sections of a tooth surface configuration are formed that have predetermined defects for the purposes of diagnostics, planning, and treatment.

[0012] This allows for practice to be carried out directly in the mouth of a natural person without permanently changing the person's situation, because the proposed aid can be easily removed and the original natural situation can be restored.

[0013] The training dental splint according to the invention can be temporarily and sufficiently firmly fixed to the upper or lower jaw of the wearer using a suitable adhesive, in a conventional manner. Alternatively, it can be provided with fastening aids that allow it to be clamped onto the corresponding jaw, thus allowing for easy removal. This is particularly advantageous if the training dental splint is primarily intended for diagnostic purposes and is not subject to manipulation that would require significant force to be applied to the dental splint.

[0014] In a first embodiment, the second surface replicates damaged or destroyed teeth and / or malocclusions, such as gaps, caries, broken teeth, defects, and anomalies of all kinds. In particular, a toothless situation can also be replicated, with the second surface being designed as a jaw ridge. In a special embodiment, the surface can be made of an elastic material.

[0015] In a second embodiment, which can be combined with the first, the second surface is designed in such a way that it simulates at least signs of a jaw malposition or bite malposition in the case of dysgnathia or craniomandibular dysfunction of the wearer.

[0016] In further embodiments, only individual teeth are reproduced on the second surface, which can be individually manufactured from a material that can be processed with dental instruments or devices, such as a hard plastic, and can be attached to a dental splint carrier.

[0017] In another embodiment, the dental splint is a lower jaw splint for fixation on the patient's lower jaw, wherein the tooth surface configuration on the second surface is contoured based on the overall tooth surface profile of the patient's lower jaw. In an alternative embodiment, it is an upper jaw splint for fixation on the patient's upper jaw, wherein the tooth surface configuration on the second surface is contoured based on the overall tooth surface profile of the patient's upper jaw. In each case, the natural dentition situation of a jaw is copied in essential parts in the tooth surface configuration of the bite splint.

[0018] From a material and manufacturing perspective, the dental splint in a first embodiment is made of a hard plastic with milled tooth surface configurations on the first and second surfaces.

[0019] In an alternative embodiment, the dental splint is made of a fused thermoplastic powder or granules or light-curing liquid polymers, wherein the tooth surface configurations on the first and second surfaces are formed by additive molding.

[0020] In a further alternative embodiment, the dental splint is made of a thermoplastic film, wherein the tooth surface configurations on the first and second surfaces are formed by a pressure / heat forming process and optionally by means of an attached adaptation element manufactured by a milling process or additive forming on at least one of the first and second surfaces.

[0021] Furthermore, a set of dental splints is proposed, comprising at least one lower jaw splint and one upper jaw splint, wherein the lower jaw splint and upper jaw splint are configured to match one another in such a way that they simulate a jaw misalignment or craniomandibular dysfunction.

[0022] Please note that a set of dental splints can also include multiple lower jaw splints and / or multiple upper jaw splints, whose first, concave surface is designed to match the tooth surface and adjacent gum topography of the same wearer, but which have different second, convex surfaces to simulate various malocclusions or damaged teeth, etc., and / or signs of jaw misalignment or dysfunction. A single wearer can then advantageously realize completely different training situations.

[0023] When producing the proposed training aid, it is advantageous to avoid the time-consuming and costly intermediate step of obtaining an impression of the tooth surface profile and a corresponding hard plaster model. For this purpose, the tooth surfaces are directly scanned intraorally using a suitable intraoral scanner. Such intraoral scanners are known per se, and their use is described, among other things, in the applicant's patent publications, such as DE 10 2014 111 643 A1.

[0024] Provided the appropriate technical sophistication and precision are achieved, direct imaging of the tooth surfaces to obtain data sets of the tooth surface profile can avoid the inaccuracies and susceptibility to errors inherent in the process of taking impressions of the tooth surfaces using a registration and then transferring them to a hard model. Above all, however, the labor required, at least in the dental technology field and possibly also in the dental field, and the resulting cost burden on the production of the aligner is reduced.

[0025] In principle, indirect scanning of the tooth surfaces using a dental impression is also possible within the scope of the invention - however, at the expense of the above-mentioned advantages of intraoral scanning.

[0026] According to a further method aspect of the invention, various possible positional relationships or movement sequences between the lower jaw and upper jaw are recorded "automatically" using a position determination system, and the data sets obtained during the position determination are linked to the tooth surface profile data sets obtained intraorally. The determination of the positional relationship between the lower jaw and upper jaw in fixed dentition positions or during movement sequences is also known per se; see, for example, DE 10 2014 102 111 B4 of the applicant.

[0027] In the context of the present invention, this method particularly advantageously enables the recording of jaw relationships from a physiological opening movement. This allows the patient to simply drop the lower jaw due to gravity while the closing muscles are relaxed, without the stressed or painful muscles of a closing movement being activated. The goal is to determine a physiological jaw relationship acceptable to the test subject, in which the training occlusal splint can occlude the opposing teeth in the mouth or establish a bite.

[0028] The step or process of position / movement determination can include simultaneous, continuous intraoral scanning of the upper and lower jaw teeth, with the teeth sliding against each other or against an inserted support pin or spacer. However, the scanning of the tooth surfaces can also be performed separately. The measuring system used for position / movement detection operates, in a conventional manner, with cameras and reflective or active marker elements, or with ultrasonic sensors based on the time-of-flight principle, or with magnetic or inertial sensors, or it comprises a combination of the various sensor types mentioned here.

[0029] The direct, "automated" position detection of the wearer's jaw during relevant movement sequences is significantly superior to the conventional simulation using an articulator in several respects. In particular, it is performed with reference to the specific anatomy of the actual wearer and not on a non-specific device. Furthermore, data sets can be obtained directly that can be used as control data sets in the manufacturing process (with predetermined modifications). Furthermore, the direct acquisition of the coordinate data sets can be linked to feedback from the wearer; see below.

[0030] On the manufacturing side, the scan data sets or data sets processed based on the data obtained with the positioning system can be fed into any of the manufacturing processes mentioned above under device aspects. Specifically, the concave first surface of the dental splint according to the invention can be machined from a dental splint base body using an abrasive machining process, in particular a milling process, or built up from a material powder using an additive manufacturing process, or formed from a thermoplastic film using a pressure / heat forming process. The scan data set (possibly processed with position data) is the control data set in each case.

[0031] To shape or construct the second surface that forms the actual training object, the respective scan data set is preferably processed with digitized data of predetermined defects. Using the thus processed data set, the convex second surface is machined from the dental splint base body using the coordinate-controlled, abrasive machining process, or constructed using the additive manufacturing process, or embossed onto the thermoplastic film during the pressure / heat forming process. In principle, however, the second, convex surface of the training dental splint can also have a different topography that is not based on the actual tooth surface and adjacent gum topography of the wearer.

[0032] Advantages and usefulness of the invention will become apparent from the following description of an embodiment with reference to the figures. These show: Fig. 1A to 1D bottom view, top view, front view and detail view of a training dental splint according to the invention, Fig. 2 a principle sketch (functional block diagram) of a system for obtaining and using intraoral scans of the tooth surfaces and associated position data and Fig. 3 a perspective view of a paraocclusal bracket to be used in such a system.

[0033] Fig. 1A shows a concave first surface 1a of a training dental splint 1, into which a molded configuration of the tooth surfaces and adjacent gum sections of a wearer is molded. The dental splint 1 can be manufactured according to one of the method solutions specified in the method claims based on a scan of the tooth surface and gum topography of the wearer and is thus precisely adapted to the wearer.

[0034] Fig. 1B shows a convex second surface 1b of the dental splint 1 with a simulated tooth surface configuration 3 in which predetermined defects are provided. Specifically, a tooth gap 3a, a tooth fracture 3b on one of the front teeth, and a tooth misalignment 3c are schematically shown here.

[0035] Fig. 1C und 1D show the dental splint 1 fixed between the natural teeth 4 and 5 of the wearer or in cross section to the teeth 4 with an adhesive 6.

[0036] As mentioned in the method claims and above, the tooth surface configuration 3 on the second surface of the dental splint can generally be generated based on the scan data of the carrier, whereby suitable data of the predetermined tooth defects for shaping the second surface are combined with the scan data set. However, the configuration on the second surface can also be generated in its entirety independently of the scan data set of the tooth surface topography of the carrier, or individual tooth replicas can be placed on a geometrically undefined base surface of the second surface.

[0037] Fig. 2 shows, as a schematic diagram, essential parts of a system 100 for the moving image capture / representation of a patient’s dentition using a special paraocclusal bracket 10, as in Fig. 3 shown in sketchy form.

[0038] The system comprises a position signal acquisition unit 101 and a position calculation unit 102, which evaluate the position signals from a position marker part 15 of the bracket 10 when inserted into a patient's mouth. The result is a position data set of the bracket that precisely represents the position of the bracket relative to a spatially fixed coordinate system in which scans of the lower and / or upper jaw were generated.

[0039] Using an intraoral scanner 103, the tooth surfaces are optically scanned in a portion of the entire extension of the bracket defined by the scanner's detection range 103a, and the associated image data set is saved. It includes image data of the markings (not fully shown in this figure) on the edges of the coupling tray located within the detection range 103a. A previously generated and saved image data set of the entire bracket is loaded from a database 104 into a comparison processing unit 105, where it is subjected to comparison processing with the image data set of the detection range. The markings located within the detection range are identified as a subset of all markings provided on the coupling tray. Based on this identification, the detection range and thus the impressions located within it can be precisely assigned to the position of the bracket 10.

[0040] Together with the associated (relative) position coordinates, the image obtained in the detection area 103a is sent to an overall image synthesis stage 106, in which it is processed together with the images (partial images) obtained by the scanner in other partial areas to form an overall image of the tooth surface based on the respective relative position coordinates.

[0041] Both the partial image provided with the relative position coordinates and the overall tooth surface image can be related to a spatially fixed coordinate system using the (absolute) position coordinates of the bite fork obtained in the position calculation unit 102. This is illustrated in the figure for the overall tooth surface image, which is provided at the output of the overall image synthesis stage 106. It is subjected to a combined processing in an image / coordinate assignment stage 107 with the position coordinates available at the output of the position calculation unit 102. The result is a coordinate-accurate overall tooth surface image, which is used in the method according to the invention for producing the molding configuration 2 in the first, concave surface of the dental splint 1.

[0042] The system 100 further comprises a storage unit 108, in which image data of predetermined tooth defects or malpositions are stored, which were previously recorded on patients or "synthetically" obtained and stored. The output of the storage unit 108 is connected to a tooth surface data combination stage 109, which is connected via a further input to the output of the image / coordinate assignment stage 107. In the combination stage 109, the scan data of the person wearing the dental splint 1, processed with the position signals, are combined with the data characterizing the tooth defects or malpositions from the storage unit 108 in such a way that an image data set representing the defective tooth surface configuration 3 on the second surface 1b of the dental splint 1 is obtained.This is used in the formation of the second surface according to one of the methods specified in the method claims and mentioned above.

[0043] Fig. 3 shows the paraocclusal bracket 10 placed frontally on the entire row of teeth of the lower jaw of a patient, which is fixed to the teeth by means of a preferably elastic or hard-elastic, sufficiently adhesive registration material or adhesive 13. In the central position of the bracket base body 11, a mounting sleeve 11a is arranged, projecting forward at a right angle, which fits a mounting pin 15a of the sensor part 15 to be attached to the bracket base body 11. In this simplified version, the attachment is achieved by inserting the pin 15a into the sleeve 11a and frictionally (or positively) fixing the pin in the sleeve. In practice, the pin-sleeve arrangement is expediently provided with formations for specifying a defined angular position of the sensor part 15 with respect to the bracket base body 11 (for example a tongue and groove arrangement), which, however, is not shown in the figure.

[0044] Different markings 11b are provided on the top and front of the bracket base body 11. These markings are easily legible for an intraoral scanner and easily distinguishable during scan evaluation. The markings, which are shown here as different symbols but can also be colored or designed as elevations / depressions, etc., allow sections of the bracket base body 11 captured during a scan to be clearly assigned to a position relative to the lower jaw, and thus to the teeth imaged.

[0045] The bracket base body 11 is manufactured as a molded part, such as a plastic injection-molded part (e.g., made of polyamide, ABS, or another physiologically safe polymer) or as a metal casting (e.g., made of an aluminum alloy). It can also be a plastic molded part with an inlaid metal reinforcement or another type of molded part. The molded part can be partially or entirely made of a transparent material, which allows it to simultaneously absorb the markings on tooth surfaces.

[0046] The measuring sensor part 15 is in Fig. 3 represented merely symbolically; it may comprise an arrangement (known as such) of transmitters or sensors or reflectors of an ultrasonic positioning system.

Claims

1. A dental splint (1) as an training tool for dentistry and dental technology, having a first, concave surface (1a) adapted to the teeth (4) and adjacent gingival topography of a wearer, and a second, convex surface (1b) having formed therein at least portions of a tooth surface configuration (3) having predetermined defects for the purpose of diagnosis, planning and restoration.

2. The dental splint of claim 1, wherein damaged or destroyed teeth and / or tooth malpositions, such as gaps, caries, fractures, or other abnormalities are replicated in the second surface.

3. The dental splint of claim 1 or 2, wherein the second surface is configured to at least mimic signs of jaw malposition or dental malposition in a dysgnathia or craniomandibular dysfunction of the wearer.

4. The dental splint according to one of the preceding claims, wherein only individual teeth are reproduced on the second surface, in particular are manufactured individually from a material which can be processed with dental instruments or devices, such as a hard plastic and are fastened to a dental splint carrier.

5. The dental splint according to any one of the preceding claims, formed as a mandibular splint for fixation on the patient's mandible, wherein the tooth surface configuration on the second surface is contoured based on the total tooth surface profile of the patient's mandible.

6. The dental splint according to any one of claims 1 to 4, formed as a maxillary splint for fixation on the patient's maxilla, wherein the tooth surface configuration on the second surface is contoured based on the total surface profile of the patient's maxilla.

7. The dental splint according to any one of the preceding claims, formed substantially of a hard plastic material having milled tooth surface configurations on the first and second surfaces.

8. The dental splint according to any one of claims 1 to 6, made of a fused thermoplastic powder or granules or light-curing liquid polymers, wherein the tooth surface configurations on the first and second surfaces are formed by additive molding.

9. The dental splint according to any one of claims 1 to 6, made of a thermoplastic sheet, wherein the tooth surface configurations on the first and second surfaces are formed by a pressure / heat molding process and optionally by means of an attached conforming element fabricated by a milling process or additive molding on at least one of the first and second surfaces.

10. A set of dental splints according to any one of the preceding claims, comprising at least a mandibular splint and a maxillary splint, wherein the second surfaces of the mandibular splint and maxillary splint are configured in such a way that they simulate a jaw malposition or craniomandibular dysfunction.

11. A set of dental splints according to any one of claims 1 to 9, comprising a plurality of dental splints having identical first concave surfaces and different second convex surfaces in which different predetermined defects are replicated.

12. A method of manufacturing a dental splint (1) according to any one of claims 1 to 9, wherein the tooth surface and adjacent gingival topography of the lower jaw or upper jaw of the wearer is directly scanned by means of an intraoral scanner and the scan data set is used to produce the concave first surface (1a) out of a dental split base body using a machining process, in particular a milling process, or from a material powder using an additive manufacturing process or from a thermoplastic film subjected to a pressure / heat forming process, wherein the scan data set of the tooth surface and adjacent gingival topography is subjected to processing with digitized data of predetermined defects and with the processed data set the convex second surface (1b) is machined out of the dental splint base body by means of the coordinate-controlled, ablative machining process or in the additive manufacturing process or imprinted on the thermoplastic film in the pressure / heat molding process.

13. A method of manufacturing a dental splint (1) according to any one of claims 1 to 9, wherein from the tooth surface and adjacent gingival topography of the lower jaw or upper jaw of the carrier person, a dental impression model is obtained by means of a dental fork or coupling bucket filled with a registration material, and the dental impression model is scanned, and the concave first surface (1a) is machined out of a dental splint base body with the scan data set by means of an ablative machining process, in particular a milling process or built up from a material powder by means of an additive manufacturing process or formed by means of a pressure / heat molding process of a thermoplastic film, wherein the scan data set of the tooth surface and adjacent gingival topography is subjected to processing with digitized data of predetermined defects and with the processed data set the convex second surface (1b) is machined out of the dental splint base body by means of the coordinate-controlled, ablative machining process or in the additive manufacturing process or imprinted on the thermoplastic film in the pressure / heat molding process.

14. The manufacturing method according to claim 12 or 13, wherein by means of a position determination system a positional relationship between the lower jaw and upper jaw of the wearer are determined and the scan data set of the tooth surface and adjacent gingival topography is processed with the position determination system data and the formation of the convex second surface based on the processed data set. is performed in such a way that these signs of jaw malalignment or craniomandibular dysfunction.

15. A method manufacturing a dental splint set according to claim 10 comprising a method according to claim 12 or 13, wherein scan data sets of the lower jaw and upper jaw of the wearer person are taken and both scan data sets are subjected to a processing with the data of the position determination system and the respective processed data sets are used to form the respective second surface of the mandibular dental splint and maxillary dental splint, wherein the second surfaces are formed in such a way that, in combination with each other, they form a jaw malposition or occlusal malposition, respectively simulate a dysgnathia or craniomandibular dysfunction.