WO2010043419A1 - Method for producing a multi-layer dental splint in a deep-drawing device and dental splint - Google Patents

Abstract

The invention illustrates and describes a method for producing a multi-layer dental splint in a deep-drawing device. According to the invention, a first deep-drawing film (1) and at least one second deep-drawing film (2, 7), and optionally at least one third deep-drawing film (9) are connected to each other on a jaw model (3) in the deep-drawing device, wherein the first deep-drawing film (1) and the second deep-drawing film (2, 7), or the third deep-drawing film (9) have a hard layer (4, 5, 10) made from a first plastic material, and at least one deep-drawing film (2, 7) has a soft layer (6, 8) made from a second plastic material, and wherein the deep-drawing films (1, 2, 7, 9) are connected to each other to obtain a layered composite having a hard exterior layer (4, 5, 10) on each of the two exterior sides, and having a soft interior layer (6, 8) that is embedded between the hard layers (4, 5, 10).

Description

 Method for producing a multilayer dental splint in a thermoforming device and dental splint

The invention relates to a method for producing a multilayer dental rail in a thermoforming tool. Moreover, the present invention relates to a dental splint.

Dental splints are used in orthodontics as bite splints, stretching plates, positioners or retention rails for retention after completion of the active treatment phase, for correction of minor malocclusions or as other removable orthodontic treatment apparatus. Dental splints are used for intraoral protrusion devices for the treatment of obstructive sleep respiratory regulation disorders, which prevent the pharyngeal soft tissue from falling back and thus obstructing the airways by altering the position of the mandible. In order to absorb the forces occurring during sleep and to ensure the mandibular advancement over the duration of the entire sleep, the protrusion devices require a maximum retention on the teeth. The retention of the devices is achieved through hard-soft thermoforming slides. Additional brackets incorporated into the rail can increase retention. In the treatment of craniomandibular dysfunctions (CMD) plastic occlusion splints are used. The point of attack of occlusion splints is to cancel the existing contact relationship of the teeth with each other. Other intraoral plastic splints have a carrier function and act as carriers of drugs and fluoride. They facilitate, for example, the application of carbamide or hydrogen peroxide-containing gels in the external bleaching therapy and at the same time prevent rapid rinsing or wiping of the substances by the saliva or the intraoral soft tissues. A protective function is achieved by dental splints when used as compression or dressing plates after surgical interventions or as a mouthguard in some dental trauma endangered sports.

For the production of the aforementioned dental splints, a thermoforming technique known in the dental field can be used, in which thermoplastic films are heated in thermoforming machines and shaped on a jaw model made of gypsum. Thermoforming films are available in a wide variety of shapes and sizes as well as in different colors. The film shape depends on the recommended for processing thermoforming device, the thickness of the film according to the intended design form and the application of the rail and is often also dependent on the preferences of the practitioner. From the films, the desired processing form can be punched out, which is applied in the laboratory by heating and by pressure in the desired shape or on the respective model. Various thermoforming devices are used, the differences being among others in the heating and thermoforming technology. A distinction is made between vacuum and compression molding technology.

Dental rails made of polycarbonate are known from the prior art, which are characterized by their crystal clear appearance, which also has no discoloration with appropriate care. A disadvantage of the known rails made of polycarbonate, however, is that they are very hard, especially since they are superficially reinforced with acrylic and / or attached to the surface with acrylic auxiliary parts. The known dental splints are mechanically stressed when inserted into the mouth and when removing it from the mouth and while wearing, which can lead to breakage of the dental splint.

In addition, known from the prior art dental splints, which have a two-layer structure, which is formed of a hard carrier layer of polycarbonate and a soft bonded to the carrier layer polyurethane layer. The soft surface facilitates the insertion of the splint and improves the grip on the teeth. The disadvantage here, however, is that after a few months discoloration of the soft polyurethane layer occurs. Supporting or auxiliary elements, for example for feed rods of intraoral prion extrusion devices, such as those used for snoring therapy, can be attached to the surface of the carrier layer of polycarbonate with self-curing or light-curing plastics, after the polycarbonate layer has been coated several times with a bonding agent. Often a reinforcement of the dental splint is achieved here by applying acrylate. The applied acrylate surfaces must be worked with rotating instruments and then polished, which is labor-intensive. The object of the present invention is to provide a method for producing a multilayer dental splint which makes possible the simple and cost-effective production of dental splints, wherein the thus available dental splints have improved mechanical properties and are easily integrated and removed by a patient should let. In addition, it is an object of the present invention to provide a dental splint which has improved mechanical properties, can be produced inexpensively and can be easily inserted and removed by the patient.

The above object is achieved in a method of the type mentioned in that in the thermoforming a first thermoforming sheet and at least a second thermoforming sheet and optionally at least a third thermoforming sheet are connected to each other by deep drawing on a jaw model, wherein the first thermoforming sheet and the second thermoforming sheet or the third thermoforming sheet has a hard layer of a first plastic material and at least one thermoforming sheet has a soft layer of a second plastic material and wherein the thermoforming sheets are bonded together such that a laminate with a hard outer layer on each of the two outer sides of the dental rail and with a soft between the hard layers embedded inner layer is obtained. The dental splint thus obtained has an at least three-layered construction with two hard outer layers and with a soft inner layer embedded between the hard layers. It is understood that the dental rail according to the invention may have more than three layers with different hardness, but the two outer layers should have a higher hardness and rigidity than the at least one soft layer in the interior of the dental rail. The properties "hard" and "soft" in the sense of the invention relate to different Shore hardnesses of the layers. The dental splint according to the invention has an increased breaking strength and a better insertion and Auslourungsverhalten by increased elasticity of the dental splint, which is effected by the inner soft layer with higher elasticity. In addition, the inventive dental splint preferably has a smooth surface on both outer sides, which leads to a reduced plaque infestation. In a preferred embodiment of the invention, a thermoforming film with a hard layer of a polyester Plastic, preferably made of polycarbonate (PC) or polyethylene terephthalate (PET), selected. The outer layer of the hard outer layers of the polyester plastic are stable against discoloration and allow a crystal clear appearance of the dental splint according to the invention. In addition, the hard layer is sufficiently resistant to fracture, so that a breakage of holding or auxiliary elements, such as anchoring parts for advancing or guiding rods of intraoral Protrusionsgeräten not to be feared. The dental rail according to the invention preferably has hard layers of the same plastic material.

In a further preferred embodiment, a thermoforming sheet having a soft layer of a thermoplastic polyurethane (TPU) or ethylene-vinyl acetate (EVA) is selected. The aforementioned plastic materials lead to a sufficiently high elasticity of the dental rail according to the invention, so that a fracture of the dental rail during insertion and removal and when wearing must not be feared.

To produce the dental splint according to the invention, a thermoforming sheet can be used which has an at least two-layered construction with at least one hard layer and at least one soft layer. The aforementioned thermoforming sheet can then be thermoformed with another thermoforming sheet, which has a preferably single-layer structure with a hard layer, so that a layer composite with two outer hard layers and a soft layer embedded between the hard layers results. For example, a first thermoforming sheet made of polycarbonate and have a single-layer structure. This thermoforming sheet is first deep drawn on a jaw model, so that a single-layer rail is obtained. This rail then initially remains on the jaw model and is connected by deep drawing with a second thermoforming sheet, wherein the second thermoforming sheet may have a two-layer structure with a hard layer of polycarbonate and with a second soft layer of polyurethane. In order to obtain the intended layer structure, the second thermoforming sheet is placed with the soft layer of polyurethane on the obtained from the first thermoforming sheet of polycarbonate rail and deformed over the first rail and deep drawn on the jaw model, so that there is a three-layer structure. Optionally, a primer on the first polycarbonate rail are applied to ensure a full-surface connection of the layers. In principle, of course, several slides can be deep-drawn in one operation at the same time on the jaw model.

The hard layer of thermoforming film may have a layer thickness of less than or equal to 3.0 mm, preferably from 1.0 to 1.5 mm, more preferably less than or equal to 0.5 mm, in particular from 0.2 to 0.5 mm , The soft layer may have a layer thickness of 0.5 to 2.0 mm, in particular from 1.0 to 1.3 mm. It should be understood that all intermediate values of the foregoing intervals are disclosed, although not specifically described. Moreover, it is understood that during deep drawing, the layer thickness of the thermoforming sheet is reduced. The layer thicknesses of the thermoforming films used according to the invention ensure very good mechanical properties of the dental splint according to the invention.

In addition, particularly good mechanical properties are achieved when a first thermoforming sheet of polycarbonate with a layer thickness of about 0.5 mm is bonded to a two-layer thermoforming sheet by deep drawing, the two-layer thermoforming sheet comprising a hard layer of polycarbonate with a layer thickness of 0, 8 to 1.2 mm and a soft layer of polyurethane with a layer thickness of 1.0 to 1.3 mm. Accordingly, the three-layered dental splint thus obtained has a hard layer on one outer side with a layer thickness of less than 0.5 mm and a second hard layer on the other outer side with a layer thickness of less than 1.2 mm to less than 0.8 mm , The layer thickness of the soft layer of the dental splint according to the invention is less than 1.3 mm to less than 1.0 mm.

In the production of the dental splint according to the invention can be provided according to the method that the first thermoforming sheet is first deep-drawn onto the jaw model, the resulting single-layer rail then remains on the jaw model. Subsequently, the second thermoforming sheet is then positioned on the jaw model and thermoformed over the first rail on the jaw model, resulting in the composite of the second thermoforming sheet with the previously formed first rail, so that obtained at least two-layer rail becomes. If a third thermoforming sheet is provided for producing the dental splint according to the invention, the two-layered splint formed from the first thermoforming sheet and the second thermoforming sheet remains on the jaw model and then the third thermoforming sheet is positioned on the jaw model and deep-drawn on the two-layered rail on the jaw model , which leads to a dental splint with three layers.

If the first deep-drawing film has a hard layer of polycarbonate or consists entirely of polycarbonate, the rail obtained by deep-drawing the first deep-drawing film can be at least partially, preferably completely, coated with an acrylate solvent, in particular a preparation of a methacrylic acid methylester (MMA) and dichloromethane become. This improves the bond of thermoforming films during deep drawing.

If holding or auxiliary elements are required in the dental splint according to the invention, such as for guiding, advancing and / or anchoring bars between two rails of an intraoral protrusion device, at least one holding or auxiliary element can be applied to the surface of the first obtained after thermoforming the first thermoforming foil Rail are attached, wherein, preferably, the surface of the first rail at least partially coated with an acrylate, in particular with a preparation of a methyl methacrylate (MMA) and dichloromethane, and the holding or auxiliary element is attached with a self-polymer. The first rail obtained from the first deep-drawing film remains on the jaw model. Then, a further thermoforming sheet can then be positioned on the jaw model and deep drawn over the first rail on the jaw model, so that the holding or auxiliary element between the first rail and the second thermoforming sheet is securely embedded and the holding or auxiliary element does not over the surface of the Dental rail according to the invention protrudes and the dental rail has a smooth surface. This also leads to a reduced plaque infestation during days of the rail.

The invention will be described by way of example with reference to exemplary embodiments, wherein the invention is not limited to the described features of the exemplary embodiments. In the drawing show: 1 shows schematically the process sequence in the production of a dental rail according to the invention in a first embodiment of the method according to the invention,

Fig. 2 shows schematically the procedure in the production of a dental rail according to the invention in a second embodiment of the method according to the invention and

3 schematically shows the process sequence in the production of a dental rail according to the invention in a third embodiment of the method according to the invention.

In Fig. 1, a method for producing a multilayer dental rail in a thermoforming device, not shown, is shown schematically. The dental rail produced in this way can be used, for example, for a snore therapy device, as described in DE 203 19 088 U1 or DE 201 02 432 U1. The thermoforming device may, for example, be a universal pressure molding device for all applications of dental thermoforming technology and orthodontics, as marketed under the trade name BIOSTAR® by Scheu-Dental GmbH. Also, a compact printing forme device with the trade name MINISTAR S® of the Scheu-Dental GmbH can be used for the production of the dental splint. In the thermoforming apparatus, a first thermoforming sheet 1 and at least one second thermoforming sheet 2 are joined together by deep drawing on a jaw model 3 made of gypsum, wherein the first thermoforming sheet 1 consists of polycarbonate. For example, a polycarbonate thermoforming film with the trade name IMPRELON® "S" of Scheu-Dental GmbH can be used. The thermoforming sheet 1 preferably has a layer thickness of 0.5 mm, but may also have a smaller layer thickness.

In the first step, a wafer-thin insulating film, which does not connect to the first thermoforming sheet 1 and is only required for insulation to the jaw model 3, deep-drawn. Subsequently, the first thermoforming sheet 1 is deep-drawn. After deep-drawing of the first thermoforming sheet 1, the film excess of the first splint thus obtained, which is single-layered, is removed shortly below the equator of the teeth with a milling machine to the final length vestibular and gingival / palatal. separates without the first rail obtained by deep-drawing the first thermoforming sheet 1 is removed from the jaw model 3.

Thereafter, the entire surface of the first rail arranged on the jaw model is coated with a bonding agent, with an acrylate solvent, namely a preparation of methyl methacrylate (MMA) and dichloromethane, obtainable under the trade name PERLIBOND® from Scheu-Dental GmbH, being used as adhesion promoter can. Subsequently, holding elements for feed rods, as provided for example in intraoral snoring therapy devices, or other auxiliary parts on the surface of the drawn on the jaw model 3 thermoforming sheet 1 are fixed with acrylic.

The second thermoforming sheet 2 has a two-layer structure with a hard layer 5 made of polycarbonate and a soft layer 6 of a thermoplastic see polyurethane. The thermoforming sheet 2 is a composite sheet with a hard layer and a soft layer with the trade name DURASOFT® of Scheu-Dental GmbH. The hard layer can be combined with an autopolymer, it being possible to use an autopolymer of Scheu-Dental GmbH with the trade name DURASPLINT®. The hard layer 5 may have a layer thickness of 0.8 mm and the soft layer 6 a layer thickness of 1.0 mm. It is equally possible that the hard layer 5 has a layer thickness of 1.2 mm and the soft layer 6 has a layer thickness of 1.3 mm. The second thermoforming sheet 2 is then placed with the soft polyurethane layer 6 on the first deep-drawn first thermoforming sheet 1, which is mounted on the jaw model 3, and then deep-drawn on the jaw model 3 on the thermoforming sheet 1. In this case, the second thermoforming sheet 2 connects to the first thermoforming sheet 1. Thus, a dental splint is obtained with a three-layer structure of two outer hard layers 4, 5 and a soft layer 6 arranged therebetween, which has an increased breaking strength and improved integration and Ausgesungsverhalten by has an increased elasticity.

After forming the second thermoforming sheet 2, the excess film is separated from the resulting three-layer dental splint without the layer composite being removed from the jaw model 3. The dental splint is only then removed from the jaw model 3. Finally, a Smoothing the edges of the dental rail. Further processing or polishing of the dental splint is not provided.

FIG. 2 shows an alternative embodiment of a method for producing a multilayer dental splint. In the embodiment shown in Fig. 2, the thermoforming sheet 1 of Fig. 1 is connected to a second thermoforming sheet 7, which has only a soft layer 8 of polyurethane. As in the case of the method described in FIG. 1, the thermoforming film 1 is first deep-drawn onto the jaw model 3. Subsequently, this first rail thus obtained from the thermoforming sheet 1 remains on the jaw model 3 and it is the second thermoforming sheet 7 deep drawn on the first rail on the jaw model 3, so that a two-layer rail is obtained. In turn, at least one holding or auxiliary element can be embedded between the thermoforming film 1 and the thermoforming film 7. In order to obtain the desired layer composite, a third deep-drawing film 9, which is single-layered and has a hard layer 10 made of polycarbonate, is subsequently deep-drawn onto the jaw model 3 via the two-layered rail, so that a three-layered dental splint according to the invention is obtained. According to the method illustrated in FIG. 1, the excess film of each rail obtained by forming the thermoforming sheets 1, 7, 9 is removed before thermoforming of the next deep-drawing sheet 7, 9, without the rail being detached from the jaw model 3. Incidentally, before deep-drawing a next deep-drawing film 7, 9, a coating of the previously obtained rail may be provided with a bonding agent.

Finally, FIG. 3 shows that a three-layered dental splint according to the invention can also be obtained in a single-stage deep-drawing process by deep-drawing a deep-drawing foil 11 having a three-layered structure with two outer hard layers 12, 13 made of polycarbonate and one between the hard layers 12, 13 embedded soft layer 14 of polyurethane has up.

The layer thickness of the hard layer 10, 12 of the thermoforming films 9, 11 corresponds to the layer thickness of the hard layer 5 of thermoforming film 2. This results from a comparison of Figures 1 to 3. The layer thicknesses of the hard layer 13 of the thermoforming film shown in Figure 3 11 corresponds to the layer thickness of the hard layer 4 of the thermoforming film 1 from FIG. 1. The layer thickness of the soft layer 8 of the second deep-drawing film 7 from FIG. 2 and the layer thickness of the soft layer 14 of the deep-drawing film 11 from FIG. 3 correspond to the layer thickness of the soft layer 6 of the deep-drawing film 2 from FIG. 1.

It is not shown, moreover, that due to the material properties of polycarbonate, predrying is indispensable in order to avoid the formation of bubbles due to moisture during heating in the thermoforming apparatus. Moreover, before the thermoforming of the first thermoforming sheet 1, an insulating film for gypsum / plastic can be raised as a blank sheet on the jaw model 3. Here, for example, an insulating film with the trade name ISOFOLAN® the Scheu-Dental GmbH can be used. The insulating film can be removed from the dental rail in a simple manner after the production of the dental splint.

Claims

Claims: 1. A process for producing a multilayer dental splint in a thermoforming apparatus, wherein in the thermoforming apparatus a first thermoforming sheet (1) and at least one second thermoforming sheet (2, 7) and optionally at least a third thermoforming sheet (9) by deep drawing on a jaw model (3) with each other wherein the first thermoforming sheet (1) and the second thermoforming sheet (2, 7) or the third thermoforming sheet (9) comprises a hard layer (4, 5, 10) of a first plastic material and at least one thermoforming sheet (2, 7 ) has a soft layer (6, 8) of a second plastic material and wherein the thermoforming sheets (1, 2, 7, 9) are joined together in such a way that a layer composite with a hard outer layer (4, 5, 10) on each of the two outer sides and with a soft between the hard layers (4, 5, 10) embedded inner layer ( 6, 8) is obtained. 2. The method according to claim 1, characterized in that a thermoforming sheet (1, 2, 9) with a hard layer (4, 5, 10) of a polyester plastic, preferably polycarbonate (PC) or polyethylene terephthalate (PET), selected becomes. 3. The method according to claim 1 or 2, characterized in that a thermoforming sheet (2, 7) with a soft layer (6, 8) of a thermoplastic polyurethane (TPU) or ethylene vinyl acetate (EVA) is selected. 4. The method according to any one of the preceding claims, characterized in that a thermoforming sheet (2) having an at least two-layer structure with at least one hard layer (5) and at least one soft layer (6) is selected. 5. The method according to any one of the preceding claims, characterized in that a first thermoforming sheet (1) and a second thermoforming sheet (2) are interconnected, wherein the first thermoforming sheet (1) consists of polycarbonate and wherein the second thermoforming sheet (2) has a two-layer Structure having a hard layer (5) made of polycarbonate and with a second soft layer (6) made of polyurethane. 6. The method according to any one of the preceding claims, characterized in that a thermoforming film (1, 2, 9) with a hard layer (4, 5, 10) with a layer thickness of less than or equal to 3.0 mm, preferably of 1.0 to 1.5 mm, more preferably less than or equal to 0.5 mm, in particular from 0.2 to 0.5 mm. 7. The method according to any one of the preceding claims, characterized in that a thermoforming film (2, 7) with a soft layer (6, 8) with a layer thickness of 0.5 to 2.0 mm, in particular from 1.0 to 1, 3 mm, is selected. 8. The method according to any one of the preceding claims, characterized in that first the deep-drawn thermoforming film (1) on the jaw model (3) is deep-drawn and that the thermoformed first thermoforming sheet (1) remains on the jaw model (3) and then the second thermoforming sheet ( 2, 7) is deep-drawn onto the jaw model (3). 9. The method according to any one of the preceding claims, characterized in that the first thermoforming sheet (1) after deep drawing at least partially, preferably completely, with an acrylate, in particular a preparation of a methyl methacrylate (MMA) and dichloromethane, coated. 10. The method according to any one of the preceding claims, characterized in that after deep-drawing of the first thermoforming sheet (1) at least one Supporting or auxiliary element is attached to the surface of the first thermoforming sheet (1), wherein, preferably, the surface of the first thermoforming sheet (1) at least partially coated with an acrylate, in particular with a preparation of a methyl methacrylate (MMA) and dichloromethane, and the Holding or auxiliary element is attached with a self-polymer. 11. Dental splint having an at least three-layer structure, in particular produced according to one of the preceding claims, with two outer hard layers (4, 5, 10, 12, 13) and with an inner one between the hard layers (4, 5, 10, 12, 13) embedded soft layer (6, 8, 14). 12. Dental splint according to claim 11, characterized in that two hard layers (4, 5, 10, 12, 13) of a polyester plastic, preferably polycarbonate (PC) or polyethylene terephthalate (PET), and an inner soft layer (6 , 8, 14) of a thermoplastic polyurethane (TPU) or ethylene vinyl acetate (EVA) are provided. 13. Dental splint according to claim 11 or 12, characterized in that a hard layer (4, 13) on a wear state of the dental track tooth surfaces of the patient facing outside of the dental splint has a layer thickness of less than 0.5 mm, in particular less than 0, 2 mm, and a hard layer (5, 10, 12) on a side facing away from the tooth surfaces outside of the dental rail has a layer thickness of less than 1.2 mm, in particular less than 0.8 mm. 14. Dental splint according to one of claims 11 to 13, characterized in that the soft layer (6, 8, 14) has a layer thickness of less than 1.3 mm, in particular less than 1.0 mm. 15. Dental rail according to one of claims 11 to 14, characterized in that between the soft layer (6, 8) and a hard layer (4, 5, 10) at least one holding or auxiliary element is embedded.