WO2007128270A2

WO2007128270A2 - Method for the production of a dental brace comprising soft and hard brace zones

Info

Publication number: WO2007128270A2
Application number: PCT/DE2007/000772
Authority: WO
Inventors: Konrad Hofmann
Original assignee: Smh Biomaterial Ag
Priority date: 2006-05-10
Filing date: 2007-04-30
Publication date: 2007-11-15
Also published as: WO2007128270A3; DE102006021955A1

Abstract

The invention relates to a method for producing a dental brace comprising soft and hard brace zones. The materials of the two brace zones have the same plastic base. The soft brace zone (17) of the dental brace (01, 13, 14) is made from a soft, elastic formulation containing at least one monomer or oligomer. Said brace zone is joined to a dimensionally stable, hard brace zone (18) by means of a polymerization process, without using an additional adhesive. The monomer or oligomer is characterized in that the same dissolves in at least one polymer of the hard brace zone, particularly in its own polymer. The inventive dental brace fits perfectly and is very comfortable as a result of the soft brace zone thereof while having a long service life due to the monolithic embodiment thereof. Furthermore, the dental brace can be repaired and can be colored in any color as the same is made from material having the same plastic base.

Description

'Method for producing a toothed rail with soft and hard rail areas'

The invention relates to a method for producing a toothed rail with soft and hard rail areas.

Dental splints are widely used in the dental field and are preferably used in snoring therapy, dental prosthetics or orthodontics. They also serve as night bite protection against unwanted abrasion during sleep. Such splints are preferably used in sleep and snoring therapy, often in conjunction with adjusters, for the treatment of sleep apnea. They serve in this area as Kieferprotrusionsschienen for defined positioning of the tooth jaw.

From the prior art methods for the production of tooth rails are known in which the toothed rail consists of a single material and a single hardness property. Such a dental splint is generally made of a hard plastic material which has dimensionally stable and only limited soft material properties. Such hard splints wear out easily after prolonged use and lose their fit and adhesive property in the dentition. For the better In order to improve the ability to fit and support the adhesive clamping forces of the dental splint on the row of teeth, metallic key springs are used in some designs, which transmit holding forces to the teeth by means of a resilient action at individual points of the splint area. A disadvantage of such an embodiment, the high punctual forces of the metal springs, which attack the tooth surface with frequent changes of the toothed rail or damage any prostheses. Furthermore, the punctual and uneven distribution of the holding forces causes an uncomfortable wearing feeling, and scraping noises occur when inserting and removing the toothed rail.

In alternative methods of manufacturing splints, the splints are constructed of a plurality, preferably two, materials. The interior of the dental splint, which conforms directly to the tooth surface, is made of an elastic plastic. This is glued by means of adhesive with a hard, the outer surface of the dental splint forming plastic rail. Due to the soft interior of the toothed rail, a uniform distribution of holding forces and a gentle treatment of the teeth during insertion and removal of the dental splint are given. However, it shows after prolonged wearing that on the one hand, the adhesive layer, the soft and hard areas of the dental splint connects to each other, easily dissolves, on the other hand in the resulting spaces between the hard and soft area pathogens can arise and ultimately a discoloration of the individual areas to a unsightly shape of the dental splint leads. The production of such a toothed rail of several materials is very complicated, expensive and their life is very limited.

Starting from this prior art, it is the object of the present invention to propose a method for producing a dental splint with soft and hard splint regions, which is the target To allow a high wearing comfort and a long life, while the tooth surfaces to protect when inserting and removing the dental splint, to reduce the possibility of the formation of pathogens in the dental splint and to enable a repair of the dental splint. The rack should be able to withstand temperatures above 50 ° C for effective cleaning, be dyeable as a whole and thereby be as easy and inexpensive to manufacture in the production with the previous means of tooth rail processing.

This object is achieved by a method according to the teaching of patent claim 1.

Advantageous embodiments of the method are the subject of the dependent claims.

The inventive method for producing a toothed rail with soft and hard rail areas is characterized in that the materials of the two rail areas have the same plastic base. Here, the soft rail region of the dental splint is made of a soft elastic formulation containing at least one mono- or oligomer. The soft rail portion is bonded without the use of an additional adhesive with a hard, dimensionally stable design of a plastic dissolved by the formulation described above to form a hard rail portion. Thus, after the polymerization, it is possible to realize an intimate combination of the two rail materials without an intermediate layer and the associated problems outlined above. It is essential that the mono- or oligomer has the property of being able to dissolve in at least one polymer of the hard rail area, in particular in its own polymer. The connection of the soft elastic design of the plastic with the hard design of the plastic is carried out by a polymerization process, so that no connection boundary is recognizable and the areas different degrees of hardness merge together. The different degrees of hardness of the plastic are influenced by the addition of plastic additives, such as plasticizers. The fusion of two embodiments of the same plastic results in an integrally molded plastic rail made of a material without adhesive layer, which may have soft rail areas in the interior, so that a high level of comfort and a comfortable fit are guaranteed. Furthermore, there are no boundary layers within the dental splint, which can be solved by detachment of adhesives and in which pathogens can form. In addition, the plastic rail discolors, if at all, only homogeneously, since only a single plastic base is contained in it. The dental splint is repairable due to its polymerizability and its construction of a material, since broken or chipped parts can either be abraded or re-added using a polymerization process. Thus, the inventive method is also excellent to an already manufactured plastic rail, which was made of a hard, dimensionally stable design of the plastic and eventu also has already been worn, subsequently by applying the soft version of the plastic in their comfort and in improve their passability.

In this case, in a particular embodiment of the present invention, the monomer methyl methacrylate is used as mono- or oligomer. This can be used both in the soft rail area and in the hard rail area. Methyl methacrylate is characterized in that it is easy to process as a thermoplastic, the monomer dissolves in its polymer and is present both in hard and in combination with other mono- or oligomers in soft embodiments. This plastic can be applied, for example, in powder form as a polymer in granular consistency and mixed with a liquid monomer by cold polyols. merization be connected so that depending on the imple mentation form an elastic, soft or dimensionally stable, hard area of a dental splint can be formed. Methyl methacrylate is characterized in that it is resistant to staining, chemically extremely unassailable, is very easy to work, preferably by grinding, polishing or application, and thereby has a high thermal resistance (up to about 100 ° C). Racks made of methyl methacrylate are easy to disinfect and have a high mechanical abrasion resistance. By the polymerization of existing from a plastic base hard, dimensionally stable imple mentation form to form the outer region of the

Dental splint with a soft, elastic embodiment of the same plastic base for lining the dental splint at the contact areas to the teeth, resulting in a very good fit and a comfortable fit. Due to the soft, elastic interior design of the dental splint, the holding forces are distributed over a large area, and the tooth surfaces are protected during insertion and removal of the dental splint. The combination of the polymer MMA in powder form with the monomer MMA in liquid form enables a simple and cost-effective production and repair of broken or chipped parts by a two-component technique. Due to the thermo-elastic properties of the MMA, a repair can be carried out very easily by heating individual regions of the dental splint.

In a particularly preferred form, the hard rail area is> 90 m% and the soft rail area is> 10 m% of methyl methacrylate.

In a particularly preferred form, the soft rail region consists of> 15% methyl methacrylate and in a most preferred form> 20% methyl methacrylate.

In a particularly preferred embodiment of the method, the production method comprises the following method steps: First, a Gypsum tooth model covered with a spacer material. This spacer material defines the thickness, ie the thickness, of the soft region of the dental splint which bears directly against the row of teeth. After the spacer material has been applied to the row of teeth of the gypsum dental model, the joints between the plaster tooth model and the spacer material can be closed by wax in order to prevent the gypsum from penetrating the cuvette mold. In the subsequent step, the gypsum model with the spacer material is placed in a cuvette, and this cuvette is poured with gypsum to create a cuvette shape. Following this, after the curing of the cuvette mold, the spacer material is removed, and the cuvette is inserted into a plastic injection device, so that a soft execution of the plastic can be pressed into the space between plaster model and cuvette shape. This is followed by curing of the pressed-in plastic to create a soft rail area. In other words, a gypsum tooth model created by a plaster cast of the row of teeth of a patient is coated with a spacer material. This spacer material defines the thickness, ie the thickness, of the soft toothed rail areas. This spacer material serves as a placeholder material in the subsequent

Pour out the cuvette in which the gypsum tooth model with spacer material is inserted. It separates the row of teeth of the plaster tooth model from the poured cuvette shape. After the gypsum in the cuvette has hardened, the gypsum tooth model can be removed and the spacer material removed. Thereafter, the plaster tooth model is again inserted into the cuvette mold, so that now results in a pouring between cuvette and gypsum tooth model. Injected channels are provided within the poured cuvette mold, in which, after inserting the cuvette into a plastic injection device, plastic can flow into the intermediate space between the row of teeth of the gypsum tooth model and cuvette mold. The pressing of the soft version of the plastic takes place at elevated temperatures and under one defined contact pressure.

In an extremely advantageous embodiment of the production method, the gypsum tooth model with the hardened soft rail region are removed from the cuvette after the above-mentioned process steps and the hard rail region is made by applying a hard execution of the plastic to the soft rail region by a polymerization process. That is, after curing of the soft rail portion in the cuvette shape, the gypsum tooth model with this cured rail portion is removed from the cuvette mold and applied to the soft rail portion by a two-component technique by using the powdery polymer and a hard plastic type liquid monomer becomes. For this, the soft rail area is wetted with the monomer and the polymer is sprinkled over it. With the help of a spatula or other shaping aids, the polymer / monomer mixture can be brought into a desired shape. After applying the hard finish of the plastic to form a hard rail area, the finished rail is finished by means of a curing process.

As an alternative to the last method step proposed above, the following method steps can be used to produce the hard rail area. After removal of the gypsum tooth model with the cuvette mold's hardened soft track region, the cuvette mold can be manually reworked to define an additional casting gap between the soft rail region and the cuvette mold. This casting gap defines the space for the post-molding of the hard plastic finish to create a hard rail area. Subsequently, the gypsum tooth model with soft rail area is inserted in the post-processed cuvette mold, and becomes a hard version of the plastic pressed into the space between the soft rail area and cuvette shape using a Kunststoffeinpressvorrichtung, and then a curing of the pressed-plastic hard rail area is performed. This means that instead of applying the hard rail area by means of a two-component technique by reworking the cuvette mold, additional space is created for re-spraying a hard plastic embodiment. Subsequently, in a second press-fitting operation, the thus-manipulated cuvette mold is again inserted into an artificial-substance injection device, and the hard version of the plastic is pressed into the cuvette. This is followed by a second curing process to harden the hard rail area. It is particularly advantageous that before reinserting the plaster tooth model with hardened soft rail area of the joint gap between the soft rail area and the

Gypsum teeth row is sealed by means of a wax layer, so that the pressed-hard plastic can not penetrate into the intermediate joint between the soft rail area and gypsum tooth model.

In principle, the coverage of the row of teeth of the gypsum tooth model with a spacer material is arbitrarily feasible. Conventionally, a wax layer is used as the spacer material. However, it has proved advantageous to cover the row of teeth of a cast dental model with a spacer material by thermoforming a spacer film over the plaster tooth model and then cutting out the spacer film, the thickness of the spacer film defining the thickness of the soft rail area. This means that instead of an irregularly thick coat of wax, a spacer film is drawn by thermoplastic deep drawing over the gypsum tooth model, so that the row of teeth is covered with a film of defined thickness. After deep drawing, the foil must be cut out and thus covers the row of teeth in a form-fitting manner. With regard to the deep-drawing of a spacer film, it has proven to be very favorable if the thermoplastic deep-drawing of the spacer film takes place over the gypsum-tooth model in a temperature range from 200 ° C. to 250 ° C. In this temperature range, the spacer foil used is extremely flexible and adaptable and can even reproduce even the smallest gaps in the teeth of the gypsum tooth model.

When using the method, it is particularly advantageous that, before inserting the plaster tooth model with spacer material in the cuvette joints between gypsum tooth model and spacer material are sealed by applying a wax layer. The sealing prevents penetration of the gypsum compound to form the cuvette shape. Thus, a well-defined and contour-matched cuvette shape can be created.

Furthermore, when the method is used, it is particularly recommendable that the thickness of the soft rail area be adjusted after removal of the spacer material by manual reworking of the cuvette mold. Thus, sharp edges and corners in the cuvette shape can be rounded off, and in particularly critical areas, the size of the injection mold can be increased in order to allow a sufficiently thick and contoured shaping of the soft rail area.

When using the method described above, it is particularly recommended that the injection of the plastic into the cuvette with the help of Kunststoffeinpressvorrichtung takes place under a pressure range of 3 to 10 bar. If the pressure range is set too low, there is a risk that individual areas of the cuvette shape will not be sufficiently filled with plastic. If, however, the pressure is too high, there is a risk on the other hand that the cuvette shape or the gypsum-tooth model will be damaged or leakage will cause filling compound to penetrate into intermediate joints. After pressing the plastic into the cuvette mold, the plastic must harden. It has proven to be particularly advantageous if the curing of the pressed plastic in the cuvette in a temperature range of 70 ° C to 120 ° C for a period of 30 to 120 minutes. By such a temperature range and such a period of time it is ensured that the resin homogeneously hardens homogeneously without impurities, so that the toothed rail has a particularly regular structure.

After hardening of the soft splint region of the dental splint, the hard splint region must be connected to the soft splint region by a polymerization process. To prepare the application of the hard rail area on the soft rail area, it is again particularly favorable if joints between gypsum tooth model and the soft rail area are sealed by applying a wax layer before applying the hard rail area on the soft rail area. Again, the wax layer serves to prevent ingress of unwanted mass, in this case the plastic hard version, and to create well-defined areas of the soft and hard dental splint.

If one follows the method in which the hard rail area is applied to the soft rail area by manual application, it is extremely favorable if the hard rail area is applied to the soft rail area by a cold polymerization process in which a powdery polymer version of the hard Plastic version is powdered on the soft rail area and grows by adding a liquid monomer version, the hard version of the plastic by cold polymerization on the soft rail area, so that a hard rail area arises. In the course of such an application by means of a two-component technique by fusion of the powdery polymeric plastic with the liquid monomeric plastic, it is possible by means of Rule and custom design of the hard rail area a well-formed and special circumstances considering rail area are formed. Thus, a targeted strengthening of the hard rail area at critical points or a particularly thin shaping of the hard rail area in other places is possible.

If a hard rail area is formed according to the method described above, it has proven to be particularly advantageous that after applying the hard rail area to the soft rail area, the rack rail in a water bath in a pressure range of 2 to 3 bar and a temperature range of 30 to 60 ° C hardens. The hard rail area is not yet cured immediately after manual application, i. the polymerization process is still ongoing. In order to complete this polymerization process as homogeneously as possible in the entire rail area, the curing under the given pressure and temperature range leads to particularly advantageous designs of the toothed rail.

As a rule, the plastic used in the construction of a dental splint is colorless. However, the method described above makes it possible to produce a dental splint with hard and soft splints made of a single type of plastic. By coloring the plastic, it is in principle possible and advantageous to use colored plastic to adapt the rack to desired requirements. Thus, tooth rails can be produced in different colors or achieve special effects, for example, by the addition of phosphorescent materials.

The method will be explained in more detail below with reference to drawings showing some embodiments.

Show it: Fig. 1 in perspective schematic representation of a resulting from the process rack;

FIG. 2 is a perspective view of a plaster tooth model; FIG.

FIG. 3 shows a perspective view of a cuvette; FIG.

4 is a schematic sectional view of a plastic injection device with inserted cuvette;

5 shows a plaster tooth model with adapted toothed rail;

Fig. 6 is a schematic sectional view of the structure of a toothed rail with hard and soft rail areas.

Fig. 1 shows a schematic perspective view of a toothed rail 01 with hard and soft rail areas, which emerges from the method according to the invention.

FIG. 2 shows a plaster tooth model 02, which represents the starting point of the method. A spacer material, for example a wax layer or a deep-drawn spacer foil, can be applied to the row of teeth of the plaster tooth model 02, the thickness of which then defines the thickness of the soft toothed rail area.

FIG. 3 shows a cuvette 03, in the interior region 04 of which a plaster tooth model 02 provided with a spacer material can be inserted. Thereafter, the cuvette 03 is filled with gypsum, so that at least the area of the teeth coated with the spacer material tooth row is filled with gypsum. After removal of the spacer material of the gypsum teeth row results after insertion of the gypsum tooth model 02 in the inner region of the cuvette 04 an ejection mold, which has a space between gypsum tooth row and cuvette shape and which can be ejected from a soft version of the plastic. The Kunststoffeinpressvorrichtung 05 necessary for introducing the plastic is shown in Fig. 4 in a schematic sectional view. In the Kunststoffeinpressvorrichtung 05 a plastic capsule 06 is inserted, in which a pressing cylinder 07 is located. By pressing the pressing cylinder 07 with a predefined pressure of the still liquid plastic is passed through injection channels 09 in the cuvette mold 1 1 and fills there the ejection between plaster model and cuvette mold 11. The cuvette 1 1 is held in a clamping frame 10, which receives the press-in pressure of the pressing cylinder 07.

After the formation of the soft splint regions of the dental splint, the hard splint region is achieved either by application, i. powdered sprinkling, a hard version of a plastic and cold polymerization applied by addition of a liquid monomeric plastic hard version or injected by post-processing of the cuvette shape by creating an additional ejection space.

After hard and soft rail area have been formed, the outer hard rail area can be brought by grinding, polishing or other processing measures in a well-rounded shape. In the final inspection, the rail 13, as shown schematically in FIG. 5, is inserted, for example with the aid of an articulator, into the plaster tooth model 12 in order to check the fit and the seat and to be able to carry out fine mechanical work.

In Fig. 6 the structure of the dental splint 14 according to the invention is shown in a schematic sectional view. The tooth 16 is in

Gums 15 embedded. The tooth 16 is enclosed by the soft rail area 17, and this in turn is surrounded by the hard rail area 18. The hard rail area 18 essentially determines the shape of the toothed rail 14 and the soft rail area 17 surrounds the tooth 16 and serves to fix the rail by transmitting contact forces.

Claims

claims

1. Method for producing a dental splint with soft and hard

Rail areas, characterized in that the materials of the two rail areas have the same plastic base, wherein the soft rail area (17) of the toothed rail (01, 13, 14) made of a soft, elastic formulation containing at least one mono- or oligomer and this is connected by a polymerization process and without the use of an additional adhesive with the dimensionally stable hard rail area (18), for which purpose the mono- or oligomer has the property of itself in at least one polymer of the hard rail area, in particular in its own Polymer, to dissolve.

2. A method for producing a dental splint according to claim 1, characterized in that as a mono- or oligomer methyl methacrylate (MMA) is used.

3. A method for producing a dental splint according to claim 1 or 2, characterized in that the hard rail area to> 90 m% and the soft rail area to> 10 m% consists of methyl methacrylate.

4. A method for producing a dental splint according to one of the preceding claims, characterized in that the soft splint region amounts to> 15 m%, in particular to

> 20 m%, consists of methyl methacrylate.

5. A method for producing a dental splint according to one of the preceding claims, characterized in that the method comprises the following method steps:

a) Overlapping the to-shining areas of a gypsum tooth model

(02, 12) with a spacer material;

b) placing the plaster tooth model (02, 12) with the spacer material in a cuvette (03, 08) and pouring the cuvette (03, 08) with gypsum to create a cuvette mold (11);

c) after curing of the cuvette mold (11) removing the spacer material and pressing the soft execution of the plastic in the space between plaster model (01, 12) and cuvette mold (11) by means of a Kunststoffeinpressvorrichtung (05) and then curing the pressed-in plastic to create a soft rail area (17).

6. A method for manufacturing a dental splint according to claim 5, characterized in that the method further comprises the following method step:

d) removal of the gypsum tooth model (02, 12) with hardened soft rail area (17) from the cuvette mold (11) and manual application of the hard rail area (18) on the soft rail area (17) by means of a polymerization process.

7. A method for manufacturing a dental splint according to claim 5, characterized in that the method further comprises the following method steps:

a) After removal of the gypsum tooth model (02, 12) with hardened soft rail region (17) from the cuvette mold (11) manual processing of the cuvette mold (11) to provide an additional casting gap between soft rail region (17) and cuvette mold (11) for the post-injection the hard design of the plastic to provide a hard rail portion (18);

b) reinserting the plaster tooth model (02, 12) with a soft rail area (17) in a reworked cuvette mold (11) and pressing the hard version of the plastic into the intermediate space between soft rail area (17) and cuvette mold (11) by means of a plastic injection device (05) and then curing the pressed-plastic of the hard rail area (18).

8. A method for producing a dental splint according to claim 5 to 7, the adur ch ek nz ei chn et, that the coverage of the row of teeth of a gypsum tooth model (02, 12) with a spacer material by thermoforming a spacer film on the gypsum tooth model (02, 12 ) and subsequent cutting out of the spacer film, the thickness of the spacer film defining the thickness of the soft rail region (17).

9. A method for producing a dental splint according to claim 8, characterized in that the thermoplastic thermoforming of the spacer film on the gypsum tooth model (02, 12) in a temperature range of 200-250 ° C follows.

10. A method for producing a dental splint according to claims 5 to 9, characterized in that before inserting the gypsum tooth model (02, 12) with Abstandsma- material in the cuvette (03, 08) joints between gypsum tooth model (02, 12) and spacer material be sealed by applying a wax layer.

11. A method for producing a dental splint according to claims 5 to 10, characterized in that after the removal of the spacer material by manual post-processing of the cuvette mold (11), the thickness of the soft rail portion (17) is adjusted.

12. A method for producing a dental splint according to claims 5 to 11, characterized g ek ennzei chn et that the pressing of the plastic into the cuvette (03, 08) by means of Kunststoffeinpressvorrichtung (05) under a pressure range of 3 to 10 bar ,

13. A method for producing a dental splint according to claims 5 to 12, characterized in that the curing of the pressed-in plastic in the cuvette (03, 08) in a temperature range of 70 to 120 ⁰ C takes place during a period of 30 to 120 minutes.

14. A method for producing a dental splint according to claims 5 to 13, characterized in that prior to the application of the hard rail portion (18) on the soft rail portion (17) joints between gypsum tooth model (02, 12) and the soft rail portion (17) Applying a wax layer to be sealed.

15. A method for producing a dental splint according to claim 6, characterized in that the application of the hard rail portion (18) on the soft rail portion (17) by a cold polymerization process in which a powdery polymer design of the hard version of the plastic on the soft rail area ( 17) is powdered and by adding a liquid monomer of the hard

Execution of the plastic in a cold polymerization process on the soft rail area (17) grows, so that a hard rail area (18) is formed.

16. A method for producing a dental splint according to claim 15, characterized in that after the application of the hard rail portion (18) on the soft rail region (17), the toothed rail (01, 13, 14) in a water bath in a pressure range of 2 to 3 bar and a temperature range of 30 to 6O ⁰ C hardens.

17. A method for producing a dental splint according to one of the preceding claims, characterized in that the plastic is dyeable.