WO2009137861A1

WO2009137861A1 - Method for producing an orthodontic component

Info

Publication number: WO2009137861A1
Application number: PCT/AT2009/000203
Authority: WO
Inventors: Markus Johannes Hirsch
Original assignee: Pbd, Patent & Business Development Ag
Priority date: 2008-05-15
Filing date: 2009-05-15
Publication date: 2009-11-19

Abstract

The invention relates to a method for producing a bracket (29) from a polyurethane. According to said method, the polyaddition ends at least at body temperature. Once the dimensional stability and the end of the polyaddition of the bracket (29) to be produced have been reached, said bracket is then heated to a temperature between a lower limit of 30°C and an upper limit of 100°C, especially 70°C, or maintained at this temperature. The bracket (29) is then cooled to a maximum temperature of 30°C, whereby a Shore hardness D is set between a lower limit of 80 and an upper limit of 100, especially 90.

Description

Method for producing an orthodontic component

The invention relates to a method for producing an orthodontic component, such as Bracket, and an orthodontic component, as described in claims 1 and 9.

From US Pat. No. 5,653,588 A, an orthodontic component made of a plastic material has become known, in which the plastic is formed by a thermoplastic or a highly crosslinked thermoset, in which the polyaddition is concluded at least at body temperature. To produce the casting mold, at least one reference component of the orthodontic component is fastened on a sprue channel model and an impression model is jointly formed by the same. The impression model is positioned in a mold housing and subsequently the mold housing is closed, after which the mold housing is filled under vacuum with a silicone casting compound and then the silicone casting compound is cured to its shape stability and the formation of the mold. Subsequently, the silicone mold is removed from the mold housing and separated at least a portion of a cross-sectional area of the silicone mold in a predetermined parting plane with a spatially curved parting surface. In this case, the impression model is at least partially arranged in the separation surface or cuts them. Subsequently, the impression model can be removed from the mold, whereby a mold cavity is formed within the mold. Subsequently, in the mold cavity of the mold, the plastic composition intended for the formation of the component is filled under vacuum and the polyaddition is initiated until the dimensional stability of the orthodontic component to be produced is achieved. In this case, hardness values of the component of about 80 Shore D can be achieved.

In known tooth-regulating devices - according to US 1,976,141 A and US 2,045,025 A - the tooth attachments are made of stainless steel and are attached to a stainless steel band which encloses the tooth to hold the tooth cap in the correct position.

Various other tooth-regulating methods and tooth-regulating devices have been developed in which stainless tooth attachments are bonded directly to the tooth surface. These methods and devices did not require a band for attaching the teeth. sentences. Such systems are commonly used. Such known tooth-regulation methods and devices are known inter alia from US Pat. Nos. 4,604,057 A, 4,430,061 A and 4,322,206 A. A disadvantage is the metallic appearance of such made of stainless steel tooth attachments. Therefore, in terms of appearance, tooth-regulating devices which are made of non-metallic material and are transparent or translucent, in particular for adult patients, are desired since such materials give a better, cosmetic appearance. Accordingly, transparent plastic materials usually polycarbonates or transparent or translucent ceramic materials of alumina are used. In known from non-metallic materials existing dental attachments, which are kept to the cosmetic influence as small as possible, very small, it is known - according to US 4,302,532 A - by reinforcing elements to increase the strength of ceramic materials produced from plastic materials.

Furthermore, tooth-regulating devices with a ceramic tooth attachment made of a polycrystalline, ceramic structure with various additives are known. A known ceramic dental attachment - according to US-A-4,954,080 - is made of a polycrystalline ceramic having a light transmittance in the range of visible light, which reduces the visibility of this tooth attachment, so that when it is mounted on the tooth, almost not for an outside third can be seen. This polycrystalline ceramic body for the ceramic tooth attachment is made by pressing a high purity alumina powder, which is then sintered to have nearly zero porosity and an average grain size in the range of 10 to 30 microns. The tooth attachment should preferably be colorless. A light transmission in the range of visible light should be 20 to 60% with a sample thickness of 0.5 mm. The disadvantage of this tooth attachment that this is not recognizable when making x-rays.

Although it is already known - according to EP-BO 189 540 - to produce a micro-filled dental material, which has a good X-ray opacity and good transparency. This dental material used for restorative materials, dental cements, crown and bridge materials, denture materials and for the production of artificial teeth, inlays, implants and finished parts consists of polymerized inorganic binders and compounds of rare precious metals and optionally other inorganic compounds as fillers a fluorinated rare earth metal (elements 57 bis 71 of the Periodic Table of the Elements) or a mixture of these fluorides. Such dental materials are often mixed by kneading to form a paste which cures under various conditions, in particular under the action of light. Although the visible light transmittance for such parts has been sufficient in many instances, it has not been satisfactory for use with dental prescription tooth attachments.

The present invention has for its object to provide a method for producing an orthodontic component and an orthodontic component, in which increases the duration of use and the aesthetics of orthodontic components is improved in their intended use.

This object of the invention is achieved in that after reaching the dimensional stability and the predominant termination of the polyaddition of the orthodontic component to be produced below the orthodontic component to be produced to a temperature in a lower limit of 30 ⁰ C and an upper limit of 100 ⁰ C, in particular 70 ⁰ C, is heated or maintained at this temperature and that subsequently the orthodontic component to be produced is cooled to a temperature of at least 30 ° C or less, and thereby a Shore D hardness in a lower limit of 80 and an upper limit of 100, in particular 90, sets. An advantage of this process is that subsequently after the predominant completion of the polyaddition and the achievement of sufficient dimensional stability of the orthodontic component to be produced is exposed to an additional temperature effect, whereby the total hardness of the component can be further increased. Due to the higher hardness values, however, a firmer and more stable surface is achieved, which offers much greater resistance to abrasion during chewing and use in the mouth area. Due to the increased hardness values, however, the orthodontic components can also be formed with a height reduced by up to 10% to the overall height, since the higher values create a stronger and more stable component. This additionally improves the wearing comfort for the patient, since the supernatant of the orthodontic component can be reduced over the tooth surface. Thus, the pressing and deformation of the inner lip parts can be reduced at the user on the orthodontic component. Also advantageous is a process variant according to claim 2, because the overall hardness of the component can be further increased by the subsequent heat treatment. Due to the higher hardness values, however, a firmer and more stable surface is achieved, which opposes the abrasion during chewing and the use in the mouth area a much higher resistance. Due to the increased hardness values, however, the orthodontic components can also be formed with a height reduced by up to 10% to the overall height, since the higher values create a stronger and more stable component. This additionally improves the wearing comfort for the patient, since the supernatant of the orthodontic component can be reduced over the tooth surface. Thus, the pressing and deformation of the inner lip parts can be reduced at the user on the orthodontic component.

A further advantageous procedure is described in claim 3, because as a result of the material used with its very high inline translucence, a virtually optical inconspicuousness is reached, since the entire component is barely visible on the tooth. The high translucency values up to the crystal-clear training not only facilitates the mounting process of the bracket on the tooth, but also achieves an aesthetic appearance during the treatment.

Furthermore, a procedure in accordance with the features specified in claim 4 is advantageous because, after reaching the dimensional stability as well as the predominant termination of the polyaddition, the homogeneity and the hardness values associated therewith or achievable as a function of the selected period of time can be influenced.

A further advantageous procedure is described in claim 5, whereby the orthodontic components to be produced can be produced with a predeterminable property of hardness values before the additional heat introduction or temperature influencing and the polyaddition can be completely completed. After these processes are completed, only the increase in the hardness values in the desired limits.

Also advantageous is a variant of the method according to claim 6, because so even the heat stored in the silicone mold for temperature influencing be used and thereby a uniform hardening of the entire orthodontic component to be produced is achieved.

Furthermore, a procedure according to the features indicated in claim 7 is advantageous because a more rapid production cycle can be achieved, since the mold can be supplied more rapidly after the removal of the impression model of a further aftertreatment and refilling.

A further advantageous procedure is described in claim 8, whereby the polyaddition and the orthodontic component to be produced can be manufactured more rapidly and, in addition, a more continuous homogeneous microstructure can be achieved thereby.

The object of the invention is, however, independently solved by the features of claim 9. The advantages resulting from the combination of features of this claim are that such an orthodontic component has been created from a plastic which has a sufficiently higher hardness, on the one hand to withstand the stresses during normal use and on the other hand in a lower height than Previously customary orthodontic components can be manufactured. In addition, due to the high translucency up to the crystal-clear formation, an orthodontic component that is almost invisible to the tooth surface is created, which does not have any disturbing optical properties for the wearer of the same.

For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

Each shows in a highly schematically simplified representation:

1 shows an impression model for orthodontic components with the associated mold housing in a simplified, perspective exploded view;

Fig. 2 shows a mold for the production of orthodontic components, in view and simplified, schematic representation; Fig. 3 shows the shape of Figure 2 in plan view.

4 shows the shape of FIGS. 2 and 3 cut in front view, according to the lines IV-

IV in Fig. 2;

5 shows the shape of FIGS. 2 to 4 cut in front view, according to the lines V-

V in Fig. 2;

6 shows a system for carrying out the method according to the invention for the production of orthodontic components;

7 shows an orthodontic component produced by the method according to the invention in a simplified perspective view;

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component names, wherein the disclosures contained in the entire description can be mutatis mutandis to the same parts with the same reference numerals or component names. Also, the location information chosen in the description, such as above, below, laterally, etc. related to the directly described and illustrated figure and are mutatis mutandis to transfer to a new position to the new situation. Furthermore, individual features or combinations of features from the different exemplary embodiments shown and described can also represent independent, inventive or inventive solutions.

All statements on ranges of values in representational description are to be understood as including any and all sub-ranges thereof, eg the indication 1 to 10 should be understood to encompass all sub-ranges, starting from the lower limit 1 and the upper limit 10 are, ie all sub-areas begin with a lower limit of 1 or greater and end at an upper limit of 10 or less, eg 1 to 1.7, or 3.2 to 8.1 or 5.5 to 10. In Fig. 1, a mold housing 1, consisting of a mold upper part 2 and a lower mold part 3 and arranged in the upper mold part 2 Spritzöffhung 4 is shown, which opens into a mold cavity 5 of the mold housing 1.

Furthermore, FIG. 1 shows an impression model 6 which is necessary for producing the casting mold and which is formed from a sprue channel model 7 and at least one reference component 8 arranged thereon. So it is e.g. It is possible to produce the entire impression model 6 or individual parts thereof from an original model and / or to use as an impression model 6 or even individual parts thereof already a precisely produced original part or else an exact casting from the original model. The sprue channel model 7, in turn, consists of a distributor channel model 9 and a respective feed channel model 10 assigned to the reference component 8. The distributor channel model 9 usually has a larger cross section or diameter 11 than a diameter 12 of the feed channel model 10. This ensures, as will also be described in more detail later, that the casting compound can be distributed without great resistance in the casting cavities of the casting mold formed by the sprue channel model 7.

The reference member 8 may be accurately prefabricated in the desired shape and thus connected at a minimum joint to the feed channel model 10, such as e.g. be glued, welded, etc. The reference component 8 corresponds in its outer shape exactly to be manufactured orthodontic component. For the production of this reference component 8, a wide variety of materials, such as e.g. Metal, non-ferrous metal, plastic, gypsum or wood can be used.

To produce the mold 13, the mold housing 1, consisting of the upper mold part 2 or lower mold part 3 is closed, wherein in the mold cavity. 5 In the non-illustrated system, the production of a simplified form shown in Figs the entire impression model 6 is positioned. Between the upper mold part 2 and lower mold part 3 of the mold housing 1, a mold parting plane is formed. In order to facilitate the manipulation of the mold housing 1 in the system, it is possible to provide a lift or the like. For the production of the mold 13, which preferably consists of a silicone rubber and therefore can also be referred to as silicone mold, it is necessary to carry out the potting of SiIi- konkautschukes under vacuum. For this purpose, it is necessary to equip the system in such a way that the interior of the system can be evacuated, that is to say both the molded housing 1 and the supply lines and storage containers for the silicone casting compound are evacuated. This ensures that the amount of supplied silicone rubber enters the mold housing 1 free of voids and without trapped air. Furthermore, it is possible to dose the amount of silicone rubber supplied by means of a control device, wherein the control device is in communication with an input terminal, from which, for example, the amount supplied, the feed rate and other parameters can be preset.

After the potting of the silicone rubber is carried out in the mold cavity 5, the mold 13 thus produced is cured in a heat chamber.

The silicone rubber used for the mold 13 is advantageous because it has a high flowability during the casting process and then has a well-crosslinked rubber with high Shore hardness A and high tear and tear propagation resistance after curing. For example, the Shore hardness A of the form Ϊ3 from the cured silicone rubber according to DIN 53 505 at 25 ° C. in about 50. Furthermore, the tensile strength is about 4.5 MPa and the elongation at break 220%.

FIGS. 2 to 5 show the mold 13 after removal of the molding model 6.

In order to be able to remove the impression model 6 from the mold 13, it is necessary to separate the mold 13 along a predeterminable parting plane 14 in a spatially curved parting surface 15. The separation of the mold 13 takes place from an upper side 16, which is associated closer to the distribution channel model 9.

Due to the separation and the high elasticity of the silicone rubber, it is possible in a simple manner to remove the mold in the form of an embedded distribution channel model 9, whereby after removal thereof in the mold 13, a distribution channel 17 is formed. By further separation of the mold 13 to a depth 18 starting from the Upper side 16 into the region of a schematically indicated dividing line 19, it is now possible to successively remove both the Zuführkanalmodell 10 and the reference or the reference components 8 from the mold 13. Due to the separation of the mold 13 along the parting line 14 and the resulting separation surface 15 form from the top 16 to the region of the parting line 19 mold halves 20, 21 from.

The removal of a plurality of supply channel models 10 with the reference components 8 supported on them now proceeds as follows. First, as already described above, the mold 13 is separated along the desired parting plane 14 into the region of the distributor channel model 9 and this is removed from the mold 13. In a further separation of the mold 13 to the depth 18, starting from an end face 22 and a unfolding of the resulting mold halves 20 and 21, it is possible, the end face 22 nearest Zuführkanalmodell 10 and remove the reference component 8 held thereon from the mold 13. After removing this first impression unit 23, consisting of the Zuführkanalmodell 10 and the reference member 8, there is a further separation of the mold 13 along the parting plane 14 in the direction of this adjacent arranged further impression unit 23 by a distance 24, resulting in a further unfolding the two mold halves 20, 21 can be seen from the mold 13, the further impression unit 23. This process of stepwise separation takes place until one of the end face 22 opposite further end face 25 is reached. By removing the individual impression units 23, a feed channel 26 is formed in the region of the feed channel model 10, and a mold cavity 27 in the region of the reference component 8 for the production of an orthodontic component 29 shown below. The feed channel 26 and the mold cavity or form 27 form within the mold 13 a so-called mold cavity for receiving the potting compound to form the component or components 29.

In order to fill a casting compound with closed mold halves 20, 21 of the mold 13 into the distributor channel 17, it is necessary, starting from the top side 16, to arrange a runner 28 in the mold 13, which extends into the distributor channel 17. This can for example be retrofitted in the mold 13, or, as indicated in Fig. 1 in thin lines, already be arranged as a channel model on the distribution channel model 9. As a result, a mold 13 for the production of orthodontic components is now provided in a simple manner. Due to the undulating separation of the mold 13 along the parting line 14 results in a collapse of the two mold halves 20, 21 already an exact mutual self-centering, whereby the arrangement of further centering can be avoided. The resulting mold 13 can be produced with relatively simple means, resulting in a low mold cost for the production of such components 29 results. Furthermore, the casting of the mold 13 under vacuum results in an exact and void-free image of the reference component 8 in the mold 13.

FIG. 6 shows a schematically indicated system 30, which serves to cast orthodontic components 29 in the mold 13.

In order to support the mold 13, in particular the two mold halves 20, 21, which is partially divided by the parting surface 15 in the parting plane 14, for the potting process or to clamp the two mold halves 20, 21 against each other, this can be schematically indicated Tenter 31 inserted and held there. In order to handle heavier forms 13 with the associated clamping frame 31 easier, it is of course also possible again to provide a lift in the system 30.

As potting compound is a casting resin in the form of a liquid two-component material based on a non-foamable urethane casting resin. The two components of the casting resin are stored in containers 32, 33, wherein in the container 32, a schematically indicated binder 34 is contained as a resin main component, which is based on a polyol. The container 33, on the other hand, contains the further constituent, namely a hardener 35, which is e.g. is formed on the basis of a diphenylmethane-4,4-diisocyanate.

The two components stored in the containers 32, 33, namely the binder 34 and the hardener 35 of a casting resin 36 are fed via their own supply lines of a mixing device 37 and by means of each supply line associated control devices which via Leitun-. gene with the input terminal in connection, dosed in their amount supplied. The mixing of the binder 34 with the hardener 35 is carried out after the supply in the appropriate amount and composition in the mixing device 37. The feed of the mold 13 with casting resin 36 via a supply line 38 from the mixing device 37 and is monitored by means of another control device which is also connected via a line to the input terminal. In order to again achieve an exact casting result for the orthodontic components 29, it is necessary to evacuate the interior of the system 30 by means of a schematically indicated vacuum pump, which in turn achieves a perfect and void-free result.

During the processing of the binder 34, care must be taken to ensure that it is absolutely protected from absorption of moisture, since carbon dioxide will otherwise be liberated during the mixing with the hardener 35 during the reaction. This resulting carbonic acid is in gaseous form and leads to foaming in the casting resin 36, whereby no flawless

Cast results are achievable. Therefore, it is advantageous, in order to obtain the lowest possible moisture or water content, to add a desiccant before use, whereby a dehydration to about 0.1% is achieved. Since the hardener 35 also reacts with moisture, it must also be treated with care. The mixing ratio between the binder 34 and the hardener 35 is preferably 10: 9, wherein a pot life of the mixture of the two components is between 2 and 5 min., Preferably 3 to 4 min. is. Until the removal of the component 29, it is necessary, the mold 13 over a period of about 30 min. a temperature of about 7O ⁰ C suspend. Subsequent to this curing time, a hardness of approximately 80 Shore D and even moreover up to 100 Shore D, a tensile strength of approximately 60 to 70 N / mm ² and a bending strength of between 100 N / mm ^{2 are} achieved for the component 29 and 110 N / mm ² . It may prove advantageous if the curing process also takes place under vacuum.

As casting resins for the different applications different solid, elastic see or see transparent types are used and are easily varied for adaptation to certain applications. In order to significantly increase the life of the mold 13 and thus the number of molding operations, it is advantageous to store the mold 13 in the air for a few hours after each casting or to briefly bake it out at an elevated temperature between 50 ° C and 100 ° C or to temper. As a result, the cast resin constituents which have penetrated into the surface of the mold 13 can in turn escape, as a result of which a contaminant-free mold is again available for the next casting process and thus an exact casting for the components 29 is achieved. FIG. 7 shows a possible form of the component 29 produced according to the invention in a simplified perspective view. As already described above, the component 29 consists of the casting resin 36, which forms a plastic 39, which is preferably formed by a thermoplastic or a highly crosslinked thermoset, in which the polyaddition at least at body temperature, ie at about 32 - 36 ° C. , already completed. Furthermore, it is advantageous if the component 29 is formed from a highly crosslinked duroplastic, for example from a polyurethane, as has already been described above.

A bearing surface 40 of the component 29, which in the application case faces the tooth surface of a user or patient, has surface-enlarging depressions 42 in the direction of a supporting body 41, which are formed, in particular, by dovetail-shaped and / or C-shaped slots. The depressions 42 extend from the bearing surface 40 in the direction of a viewing side opposite this arranged into the support body 41 and are preferably aligned parallel to a slot 43 arranged in the visible side. But it is also possible to form the depressions 42 spherical cap.

The slot 43 has side flanks 44, 45 oriented approximately vertically to the support surface 40 and extends from the visible side in the direction of the support surface 40 as far as a bottom surface 46 into the support body 41. A transition region 47 between the side edges 44 and 45 and the bottom surface 46 is rounded, in particular be executed undercut.

Seen in the vertical direction to the longitudinal extension of the slot 43 are arranged on both sides of the slot 43 hooks 48 and 49, wherein the hook 49 is shown that this with respect to the support surface 40 has a convex curvature.

As described in the preceding FIGS. 1 to 8, the orthodontic component 29 produced in the mold 13, after attaining its dimensional stability as well as predominantly terminating the polyaddition, subsequently reaches a temperature in a lower limit of 30 ° C. and an upper limit of 100 ° C, especially 7O ⁰ C heated or maintained at this temperature. In practice, it has been found that the temperature is preferably greater than 80 ° C to be selected and a temperature range in limits between 80 ° C and 100 ⁰ C. has been found to be particularly favorable. Due to this subsequent high temperature influence on the plastic for the formation of the component 29, only the complete completion of the polyaddition can be achieved, as a result of which the hardness values which can be achieved in comparison with known components can be increased as a result. Hardness values of more than 80 Shore D, in particular 85 Shore D, up to 100 Shore D are achieved. Thus, the already present in its form orthodontic component 29 is exposed to an additional subsequent temperature action, which can be carried out over a period of time in a lower limit of 2 hours and an upper limit of 12 hours. This relatively long period of time achieves the previously stated complete completion of polyaddition.

In addition, it would also be possible to cool the produced orthodontic component 29 after reaching its dimensional stability and stopping the polyaddition to a temperature of a lower limit of 20 ° C and an upper limit of 50 ⁰ C and only then again the additional temperature effect suspend in the limits specified or described above. During this additional temperature effect after the completion of the polyaddition of the component 29 forming plastic is increased in its hardness values. In this case, a Shore hardness D can be achieved in a lower limit of 80 and an upper limit of 100, in particular 90. As a result, it is also possible to produce smaller components which, in particular with respect to the height or the thickness with which they protrude from the tooth surface, can be produced, since in conjunction with the higher hardness, a higher strength of the entire component 29 can be achieved. The height or thickness reduction of the component 29 may be about 10% compared to conventional components. This value is then split to 5% per page, thus reducing the total. However, it is an advantage if the orthodontic component 29 to be produced is cooled to a temperature of at least 30.degree. C. or less after the additional application of temperature, and thus the hardness values can be set within the limits specified above. Under at least 30 ° C is understood here that the cooling is cooled from the above values to at least 30 ° C or less.

This additional effect of temperature on the produced orthodontic component 29 after reaching the dimensional stability as well as the predominant termination of the polyaddition can still be in the form of 13 component 29 is stirred. Regardless of this, it would also be possible to carry out the additional effect of temperature only after the removal of the orthodontic component 29 to be produced from the mold 13.

However, to improve the polyaddition, it is also possible to heat the entire mold 13 together with the produced or orthodontic devices 29 during the polyaddition reaction at a temperature of a lower limit of 20 ° C and an upper limit of 80 ⁰ C.

Polyurethane (PU) has proven to be advantageous as a plastic because it can be produced with a very high degree of translucence right through to complete transparency with high strength and abrasion resistance. In addition, this material is also very resistant to UV radiation and thus has here also a high resistance. The plastic may be a thermoplastic or thermoset in which the polyaddition is completed at least at body temperature. It is advantageous if the thermoset is highly crosslinked and is a polyurethane.

Translucency refers to the partial translucency of a body. So there are many substances that are translucent because they allow light to pass through but are not transparent. In contrast to transparency, one can describe translucency as translucency and transparency as transparency of image or sight. The higher the value for the translucency is chosen, the closer it comes to transparency. Transparency is the effect of transmission, whereby physics understands the ability of matter to transmit electromagnetic waves. If the waves - especially those of visible light - fail to penetrate the matter, then the electrons of the medium absorb energy from the light wave and the waves are absorbed on the way through. The material is therefore opaque. But if the waves manage to penetrate the material or the material, then there is no interaction between the light and the atoms and the waves can not give off any energy to the atoms. The material is thus transparent. Transparency is therefore not only a property of the material, but is also related to the electromagnetic wavelength to be considered. Transparency is thus an optical property of a material or material. In general, a material or material is referred to as transparent or transparent, if one What is lying behind can be seen relatively clearly. A complete transparency can also be called glass clear.

In order to reduce the visibility of the orthodontic component 29 during the intended use on a tooth of a patient, it is advantageous if the material for forming the support body 41, in particular if it is selected from a plastic, an inline translucency with a lower limit of 90%, in particular 95%, and an upper limit of 100% at a thickness of 0.5 mm. As a result, it is achieved that light rays which enter the orthodontic component 29 can penetrate to the tooth surface and be reflected by it. Then, a reflection beam corresponding to the color of the tooth emerges from the component 29. Due to the fact that only a small portion of the light beams entering the component 29 do not emerge from it again, the optical impression is obtained that the orthodontic component 29 assumes the tooth coloration of the tooth which is unique to each user. Thus, an orthodontic component 29 has been created in a simple manner, which on the one hand is easy to manufacture and on the other hand represents an optical inconspicuousness for the user of the same.

If the composition of the material of the component 29 is changed accordingly, the exit of reflected beams can be reduced or prevented. As a result, the natural coloring of the component 29 is placed in the foreground and there is a clear optical visibility towards the tooth.

The transmittance of radiation through a material is defined by the degree of transmittance, which is the ratio of the intensity of the transmitted beam and the intensity of the incident beam, and is related to the radiation of a certain wavelength and a sample of a predetermined thickness.

These variables are given by the following formula

I / Io = ke ^ad in which

"I / Io" are the intensities of the transmitted beam and the incident beam; "d" is the thickness of the sample;

"a" is the absorption coefficient and

"k" is a constant determinable from the refractive index of the material,

which are related to each other. The cone angle of the incident beam and the cone angle of the transmitted beam must be specified.

The measurement of the transmittance can be performed, for example, with a laser beam at a wavelength of 0.63 mm, so that the cone angle of the incident beam is very close to zero. The cone angle of the transmitted beam used to determine the intensity of the transmitted beam may be, for example, 60 °. In this way, a transmittance, ie an inline translucency can be defined.

Thus it is possible to determine the inline translucency with a Perkin Elmer Lambda spectrophotometer, e.g. Type 9UV / VIS / NIR perform, for example, the wavelength range between 400 nm and 800 nm may be.

Preferably, a thickness of the test specimen is 0.5 ± 0.005 mm, wherein a high-quality surface treatment is provided, so a very fine polishing must take place to avoid reflection of the light due to irregularities in the surface of the specimen, which can significantly affect the measurement result , Basically, it has to be taken into account that the measurement of the in-line translucency is a difficult problem because the amount of light with which a specimen is irradiated is set in relation to the amount of that light of a given wavelength coming from the specimen exit. The difference in these two amounts of light is that the incident light is deflected and therefore scattered by irregularities in the sample, such as grains, grain boundaries and the like. This distraction and scatter depends largely on the size and

Shape of the irregularities and measurement of the distribution of the light becomes difficult if their size in the range of the wavelength, for this measurement experiment Ver- was turned, comes. Therefore, each specimen is to be made with two surfaces that are plane-parallel to each other and that are to be polished to a predefined surface roughness.

For the measurement of the inline translucency, the specimen is illuminated with a directed or parallel bundled light beam with low divergence, which is aligned perpendicular to the surface of the specimen. A partial loss of the radiation intensity is caused by the transition of the radiation of air to the specimen due to the different refractive index between the air and the specimen. The light intensity entering the specimen is then deflected by irregularities in different directions. Therefore, the allowed angle of incidence of the radiation relative to the meter is an important factor in determining the in-line translucency. The larger the allowed angle of incidence on the meter, the greater the measured in-line translucency for the same specimen.

Therefore, the light incidence angle of the incident light beam on the test specimen, as well as the light exit angle of the exiting light beam should be kept the same for all samples.

Preferably, for example, an angle of 3 ° can be accepted as the entrance angle. It is advantageous to use a directed onto the test specimen beam with a width of 0.2 mm and a height of 0.5 mm and to provide a diaphragm with a diameter of 1 mm or 0.5 mm.

But it is also possible to set the angle of incidence of the transmitted beam at about 60 °.

It is now essential that a color acceptance of the bracket according to the color of the underlying tooth is optically achieved when a translucency is very high, for example between 70% and 90% up to 100%, as this is a major part of the irradiated light impinges perpendicularly on the tooth and is reflected from this outwards, so that for a viewer essentially only the color of the tooth can be seen and the orthodontic component 29 or the bracket apparently assumes the color of the tooth. If a completely transparent or transparent component 29 is used, this also has the further advantage that during the assembly process of the component 29 on the tooth surface of the tooth, the operator receives unimpeded insight through it all the way to the tooth surface. As a result, the distribution of the connecting means in the recesses 42 described above in the region of the support surface 40 can be better controlled. In addition, however, it is also much easier for a curing process of the bonding agent, if this example is performed by UV light or similar electromagnetic waves that the waves or radiation can penetrate through the material of the component 29 therethrough. This can be achieved over the entire connection surface of the support body 41 or body with the tooth uniform curing and thus an improved adhesion result.

The exemplary embodiments describe or show possible embodiments of the method sequence for producing an orthodontic component 29 and the orthodontic component 29 itself, wherein it should be noted at this point that the invention is not limited to the specifically illustrated embodiments of the same, but rather also various combinations of the individual Embodiment variants are mutually possible and this possibility of variation due to the doctrine of technical action by objective invention in the skill of those working in this technical field expert. So are all conceivable embodiments, which are possible by combinations of individual details of the illustrated and described embodiment variant, includes the scope of protection.

For the sake of order, it should finally be pointed out that for a better understanding of the structure of the orthodontic component 29 and of the described method sequence, these or their components have been shown partially unevenly and / or enlarged and / or reduced in size.

The object underlying the independent inventive solutions can be found in the description.

Above all, the individual in Figs. 1; 2, 3, 4, 5; 6; 7 embodiments form the subject of independent solutions according to the invention. The related, Tasks and solutions according to the invention can be found in the detailed descriptions of these figures.

REFERENCE NUMBERS

1 mold housing 41 supporting body

2 Formoberteil 42 recess

3 mold base 43 slot

4 sprue opening 44 side flank

5 mold cavity 45 side flank

6 Impression Model 46 Floor area

7 runner model 47 transition area

8 Reference component 48 Hooks

9 distribution channel model 49 hooks

10 feed channel model

11 diameter

12 diameters

13 form

14 parting plane

15 separation area

16 top

17 distribution channel

18 depth

19 dividing line

20 mold half

21 mold half

22 front side

23 impression unit

24 distance

25 front side

26 feed channel

27 mold nest

28 sprue

29 component

30 attachment

31 clamping frame

32 containers

33 containers

34 binders

35 hardener

36 Giesharz

37 mixing device

38 supply line

39 plastic

40 contact surface

Claims

Patent claims

1. A method for producing an orthodontic component (29), such as bracket, made of a polyurethane, in which at least one reference component (8) of the orthodontic component (29) mounted on a runner model (7) and formed by them together an impression model (6) Positioning the impression model (6) in a mold housing (1) and then closing the mold housing (1), after which the mold housing (1) is filled with a silicone casting compound under vacuum and then the silicone casting compound until its dimensional stability and the formation of a silicone mold ( 13), subsequently removing the silicone mold (13) from the mold housing (1) and at least a portion of a cross-sectional area of the silicone mold (13) in a predetermined parting plane (14) with a spatial curved parting surface (15) in which the impression model (6) is arranged at least in regions or intersects the separation surface (15), is separated and then the impression model (6) the silicone mold (13) is removed and a mold cavity is formed in the silicone mold (13), whereupon the mold cavity of the silicone mold (13) is filled with the polyurethane to form the orthodontic component (29) under vacuum and the polyaddition is initiated; until a dimensional stability of the orthodontic component (29) to be produced is achieved, in which the polyaddition is terminated at least at body temperature, characterized in that after achieving the dimensional stability as well as the predominant termination of the polyaddition of the orthodontic component (29) to be produced, then the orthodontic component to be produced (29) to a temperature in a lower limit of 30 ° C and an upper limit of 100 ° C, in particular 70 ⁰ C, heated o- is held at this temperature and that subsequently the produced orthodontic ■ see component (29) is cooled to a temperature of at least 30 ° C or less and thereby one Shore hardness D in a lower limit of 80 and an upper limit of 100, in particular 90 sets.

2. The method according to claim 1, characterized in that the orthodontic component (29) is heated to a temperature in a lower limit of 80 ⁰ C and an upper limit of 100 ° C or maintained at this temperature.

3. The method according to claim 1 or 2, characterized in that the material of the orthodontic component (29) with an inline translucency at a thickness of 0.5 mm in a lower limit of 90%, in particular 95%, and an upper limit 100% is formed.

4. The method according to any one of the preceding claims, characterized in that the temperature effect on the produced orthodontic component (29) after reaching the dimensional stability and the predominant termination of the polyaddition over a period of time in a lower limit of 2 h and an upper limit of 12 h is performed.

5. The method according to any one of the preceding claims, characterized in that the produced orthodontic component (29) cooled after reaching the dimensional stability and the termination of the polyaddition to a temperature in a lower limit of 20 ° C and an upper limit of 50 ⁰ C. becomes.

6. The method according to any one of the preceding claims, characterized in that the temperature effect on the produced orthodontic component (29) after reaching the dimensional stability and the predominant termination of the polyaddition even in the silicone mold (13) befindlichem to be produced orthodontic component (29) becomes.

7. The method according to any one of claims 1 to 5, characterized in that the effect of temperature on the produced orthodontic component (29) after reaching the dimensional stability and the predominant termination of the polyaddition after removal from the silicone mold (13) is performed.

8. The method according to claim 1, characterized in that during the polyaddition, the silicone mold (13) is heated together with the orthodontic component (29) to be produced to a temperature in a lower limit of 20 ° C and an upper limit of 80 ° C.

9. Orthodontic component (29), in particular bracket, made of polyurethane, in which the polyaddition is terminated at least at body temperature, characterized in that the polyurethane has a Shore D hardness in a lower limit of 80, in particular 85, and an upper limit of 100, in particular 90 and an inline translucence at a thickness of 0.5 mm in a lower limit of 90%, in particular 95%, and an upper limit of 100%.