WO2001082818A2 - Method and device for producing a dental prosthesis using injection impression - Google Patents

Abstract

The invention relates to a method for producing a dental prosthesis, especially models for dental prosthesis, using an injection impression method. The invention also relates to an impression tray, which is specially designed for carrying out the inventive method and to the use of this impression tray as a mouth rinsing device.

Description

 Method and device for producing dentures by means of an injection impression

The present invention relates to an injection impression method suitable for the production of dentures by means of a laser measurement milling system and a device therefor.

It is known to fabricate dentures such as crowns or bridges using a casting process. For this purpose, an impression is made of a patient's dentition or the relevant parts thereof, which serves as a template for the casting process. The blank obtained must then be processed by a dental technician or the dentist in a complex manner and in several work steps in order to grind in the individual details of the desired denture, in particular the corresponding occlusal surface, to suit the respective patient. The creation of functional (gnathological) chewing surfaces is particularly complex.

The production of dentures by means of the casting process not only involves many steps, which have to be carried out by hand, but is also extremely time-consuming, so that it is not possible to produce the desired dentures directly in the same patient session at the dentist. This means that the patient has to do without dentures for a longer period of time with a correspondingly incomplete set of teeth or only with a temporary restoration.

There was therefore generally a need for a method for producing dental prostheses that can be carried out as automatically as possible in the shortest possible time, preferably within one session.

In addition, materials for dentures that have been difficult or impossible to process using conventional casting processes, such as titanium or zirconium oxide, have also recently become a focus of interest. It has been proposed to produce dentures by means of an automated milling system, the milling system using a model of the dentition to produce the corresponding final dentures from the desired material.

So far, however, there have been very few companies that offer crowns nationwide using large, complex and expensive milling systems. These systems are not suitable for use in the dental practice. Furthermore, it is not possible to use these systems to manufacture ceramic crowns and inlays that have precisely simple or, in particular, gnathological occlusal surfaces. The chewing surfaces therefore still have to be grinded in the mouth by the dentist;

Furthermore, a method was known in which the extracted tooth root was measured as such using a laser, copy-milled in titanium and, if possible, implanted in the patient in the same session as an immediate implant. However, this method has proven to be too expensive, cumbersome and too imprecise

Milling processes are also known which use images as a template for the dentures to be created instead of three-dimensional models (“optical impression”). This process is used in particular for the production of ceramic crowns and inlays. However, this process can also be used no precise, in particular no gnathological occlusal surfaces, so that here too the occlusal surfaces have to be ground in by the dentist by hand.

The basic requirement for the fabrication of dentures is that a model of the tooth or tooth area in question that is as true to the image as possible is provided.

A method is known in which an impression of the dentition area in question is taken from a viscous plastic material and then a correction impression is made from a thin plastic material from this first impression by applying the thin material to the impression and the first impression with the thin liquid material is put back in the mouth. If the patient then bites on the impression, the thin material spreads out, whereby possible inaccuracies of the first impression can be compensated for.

In order to obtain the necessary pressure for a good image, there are often no drainage options, with the result that an excess of thin material remains in the impression, which leads to distortion, pronounced press flags, and bite increase. etc. can lead. If a drainage option is provided, the pressure required for good imaging can often not be built up, and the first impression must be processed accordingly, which increases the workload.

It is the object of the present invention to provide a method with which true-to-image models can be obtained which can be used as templates for dentures.

In particular, it is the object of the present invention to provide such a method, with which, using known laser measurement and milling systems, dental prostheses with precise, simple or gnathological chewing surfaces can be quickly and easily fabricated.

Another object of the invention is to provide a method for producing dentures by means of such laser measurement and milling systems, which can be handled by the user himself without special manual skills and with which it is possible to treat a patient in as few sessions as possible, preferably only one session to be able to immediately get the right dentures.

It is a particular object of the present invention to provide a method with which any dental prosthesis with precise, simple or gnathological occlusal surfaces can be largely automatically produced. The present invention makes use of the possibilities of modern laser measurement and milling systems, such as the so-called CAD-CAM-CNC milling machine, which is a multi-axis milling machine with tool changer, and of existing software programs with libraries for tooth modeling, with which The method according to the invention provides improved models for dentures that can serve as a template for such systems.

The present invention relates to a method for producing a model of a denture, comprising the following stages:

1. Production of a preliminary impression with a negative shape of the tooth or tooth area in question, or on a jaw model,

2. Prepare at least one channel in the preprint that extends from the outside into the cavity inside,

3. placing the preliminary impression with the at least one prepared channel on the bit in the corresponding position, if necessary after conditioning the tooth or tooth area,

4. Injecting an impression mass into the negative form of the preprint to form a model, the material of the preprint and the

Do not combine the impression material for the model.

According to one embodiment, the present invention relates to a method for producing a model of a denture, comprising the following stages:

1. Bite registration of the tooth in question with counterbite;

2. Production of a preliminary impression of the tooth with the bite produced in stage 1;

3. conditioning of the tooth, 4. application of the preliminary impression produced in stage 2 to the conditioned tooth obtained in stage 3,

5. Injecting the impression material for the model into the negative form of the preprint, 6. after hardening of the impression compound, removal of the preliminary impression including the hardened impression compound,

7. Detach the tooth model thus obtained with the pre-formed occlusal surface from the pre-impression.

The invention further relates to an impression tray, as is usually used for bite and impression taking, which has been specially adapted for carrying out the method according to the invention, and to a modification of such a tray, which can be used as an oral irrigator.

An impression tray is a curved groove, the shape of which corresponds to the course of the tooth area to be imaged. To take the impression, the impression material is filled into the groove and placed on the relevant tooth area. The channel has an outer buccal (cheek side) and an inner lingual (tongue-side) side wall and a channel bottom that forms the top of the spoon.

When taking the impression, the patient bites on this upper side and thus holds the impression tray in place while exerting pressure.

For the purposes of the present invention, the term “pre-impression” means a finished impression with a negative shape of the tooth or tooth area of interest from which a model is to be made. This pre-impression can be used to produce the model, similar to a casting mold.

For the purposes of the present invention, the term “impression material” means, based on the model, the material from which a desired model is produced.

For the purposes of the invention, the term “conditioning” encompasses measures that are carried out on the tooth for the production of the model, such as roughening, grinding, etc. Figures 1 and 2 show an impression tray for a partial jaw area with two buccally arranged functional bores with threads for the reception of a banjo bolt, also shown.

Figure 3 shows a horseshoe-shaped impression tray in the top view with centrally arranged buccal and lingual functional bores as well as further bores and retention plates with retention pins for attachment. the impression tray.

Figure 4 shows a perforated sleeve with a rubber jacket that can be used for the manufacture of tooth root models.

A special impression tray 1 preferred according to the invention has at least one functional bore 2 on the cheek (buccal) side, the functional bore or the functional bores 2 usually being / are provided at a position of the tray which corresponds to a tooth position when the tray is inserted into the mouth.

A hollow screw 4 can be inserted into one or more of the functional bores 2, the hollow screw 4 and the through-hole 2 preferably having a thread for a secure hold. The cavity in the head of the screw 4 can be designed as a hexagon socket 5. i \

In the method proposed according to the invention, the tooth or tooth area of interest is simulated by injecting an impression material into a pre-impression of the tooth / tooth area in question via an injection channel provided in the pre-impression in a suitable position. The impression material can optimally fill the cavity in the pre-impression, which has the shape of the tooth / tooth area to be reproduced (negative shape), and provides an exact image of the tooth / tooth area after hardening. The images or models obtained show a high degree of accuracy with regard to preparation margins, length of the tooth stumps, bite height, etc. This procedure can generally be used in dental prosthetics to create replicas.

The teeth of a patient himself, any model thereof, a prosthesis or the like can be used as a template for the preprint. It is suitable for the production of dentures such as crowns, inlays, bridges, dental implants, prostheses, working copies made of any materials, temporary restorations and the like.

With the method according to the invention, optimal models can be obtained which can serve as a template for the production of a corresponding tooth replacement from any suitable material. In particular, the method according to the invention provides models of this type which already have the necessary prerequisites for the production of dentures with precise occlusal surfaces.

Depending on the choice of material, the model itself can represent the denture, for example a temporary.

The injection channels are located in the preprint in positions that correspond to the tooth positions in the dentition, so that a targeted injection is possible.

The number of injection channels is freely selectable per se. Injection channels that are not required for the application in question can be closed with suitable closures and / or serve to drain excess impression material.

If necessary, separate drainage channels, preferably lingually, can also be provided. By closing the corresponding drainage channel or injection channels that are not required for the injection, pressure can be built up which supports the filling of the negative mold. For larger work, for example when imaging a tooth area that comprises several teeth, the cavity to be filled by injection in the preprint is correspondingly larger, with a correspondingly larger number. Injection channels can be provided. In this case, part of these channels can serve as a drain.

In order to build up pressure during the injection, it is also sufficient to close some of these channels, since the larger injection volume means that the risk of image distortion is correspondingly lower.

0 A material that contrasts with it is selected as the material for the impression material, ie a material that does not match the material of the preprint

I i connects so that the image, the model, can be taken from the preprint.

5 Before the model is removed, the impression can first be cast for a master model or for the production of an image of the jaw, for example with plaster, plastic or another suitable material. The model is then preferably taken from the preliminary impression together with the jaw image, whereby the repositionability of the model from impression material can be ensured.

According to a variant, a bite can first be made from a contrasting material in the preprint, removed from the preprint and then, if desired, a final impression can only be taken with an identical, ie connecting, material.

With this procedure, a more robust impression is obtained, which can easily be poured out several times, whereby bite registration remains possible.

To take the impression, the impression tray should be fixed with so-called stops on the 0 tooth row at a suitable distance. A suitable distance is approx. 4 mm, but this can vary if necessary.

Appropriate stops should also be made on the opposite teeth row. Only then should the impression material be loaded onto the spoon. This ensures that the dental impression is reproduced correctly and that the patient can securely fix the impression tray when additional material is placed on the tray. Kerr or a light-curing, high-viscosity plastic can be used as the material for the stops.

The method according to the invention is particularly suitable for the production of dental implants, tooth crowns, inlays and fixation holding devices, so-called abutments, and attachments.

The present invention is described below on the basis of various concrete examples for a tooth replacement, the reference to the individual examples merely serving to better illustrate the principle according to the invention without restricting the invention to these specific embodiments.

In principle, the bite and pre-impression can be taken in accordance with conventional procedures known per se for this purpose with the usual materials.

The principles of the method according to the invention are explained in more detail below using the example of producing a crown with a simple and a gnathological occlusal surface.

For the production of a model of a crown, the method according to the invention is carried out in accordance with the further embodiment described above.

For the manufacture or reconstruction of a chewing surface, it is necessary to take a bite of the tooth or tooth area in question with detection of the opposing bite. Bite registration in the first stage creates the conditions for the simple or gnathological chewing surface to be produced.

The usual plastic materials for the bite can be used, such as those used for temporary restorations. These are usually soft, quickly solidifying, easy to process and as little shrinking plastic materials that can be applied with spray cartridges.

An example of a suitable material is sold under the name Pro-Temp.

Before the bite is taken, the tooth to be crowned can be lightly ground or roughened to enable the plastic material to be applied to hold the bite better. Here, some of the height of the tooth can be removed or unevenness, for example slight depressions, can be applied, which improve the adherence of the material to the tooth (retention).

The material for the bite registration is applied to the tooth to be crowned in such a way that in the area of the planned crown the occlusal surfaces of the opposing teeth are completely covered by this bite. After the bite material has set, the bite is removed from the mouth and excess areas of no interest that do not belong to the bite of the tooth to be crowned are ground back.

The gnathological contacts of the opposing teeth are shown on the plastic of the bite.

For the production of a simple occlusal surface, the gnathological contacts are preferably marked, for example with a colored pencil, before the plastic material is applied to the corresponding opposing tooth. These markings rub off on the bite and thus serve to better identify and locate the contact points for the later production of the occlusal surface. For further clarification, the contact points shown can be drilled with a fine drill, for example a rose drill. For the second stage, the conditioned bite is placed back on the tooth to be ^• crowned and, if necessary, corrected while maintaining the color markings or the holes, for example by grinding it in again with articulation paper. _,

Now a preliminary impression is taken of the tooth to be crowned, including the bite.

A material is used for the preprint which does not bond or stick to the material of the bite, so that the bite can be removed from the preprint obtained.

If, for example, Pro-Temp is used as the material for the bite, a customary thioether impression compound can be used for the preliminary impression.

After the pre-impression material has set, the pre-impression including the bite is removed from the mouth and the tooth to be crowned is ground back to the required extent.

To carry out the fourth stage, the bite is first removed from the preliminary impression, a negative form (cavity) of the crown model to be produced remaining in the preliminary impression.

For the subsequent injection, an injection channel is punched out in the pre-impression, which connects the cavity with the negative shape of the tooth to be crowned to the outer surface of the pre-impression and which is used to inject the impression material for the crown model.

The injection channel should be installed in such a way that the injection can also take place in the mouth of a patient as freely as possible. For reasons of space, it is suitably attached in the buccal position in the present example.

A further channel, for example lingually (on the tongue side), but preferably opening above the tongue, is preferably stamped into the preliminary impression, which can be used to remove excess impression material. During the injection of the impression material, this drainage channel should be kept closed in order to have control over the complete filling of the cavity created by the preparation. As soon as pressure becomes noticeable, which indicates an adequate filling, the channel is released and excess material can drain off.

The pre-impression prepared in this way is now placed on the tooth stump and injected via the injection channel into the cavity of the negative mold.

The impression material fills the cavity in the form of the tooth to be imaged, including the bite shape. The cavity, and thus the fabrication of the crown model, can be filled with a special silicone, as is commonly used in dental prosthetics. A suitable material is sold, for example, under the name Bite Jet by Coltene.

In order that the model for the crown obtained from the impression material can be removed from the pre-impression without damage, the materials selected for the pre-impression or for the impression material should not bond or stick together.

For the use of a laser measurement system, as is preferred according to the invention, the impression material used should be suitable for scanning with a laser.

After the impression material has hardened, the pre-impression is removed from the mouth together with the hardened impression material.

The model in the form of the tooth to be crowned can now be taken from the preliminary impression and used as desired, for example measured directly with a laser. The model is preferably taken from the preliminary impression, including the sprue pins, which have formed in the position of the channels as a result of excess impression material. These pouring pins can be used for further processing as a holder and / or for fixing. The buccal sprue pin can serve as a holder when the model is subsequently scanned in using a laser measurement system.

The crown model with the preformed occlusal surface obtained as described above can be scanned into a computer with the aid of a laser measurement system as it was taken from the preprint.

The crown, including the occlusal surface, can now be designed using a computer using suitable graphics programs and tooth libraries, as they already exist.

In the computer-controlled processing of the tooth data, print proofs or the like, which may be present on the model due to the process, can also be retouched, so that it is not necessary to edit the model before scanning it.

To increase the contrast, the model can be provided with a suitable contrast agent, for example titanium dioxide powder, before scanning.

When spraying with contrast medium, care should be taken to ensure that the markings on the contact points are captured exactly by the scanner. For this purpose, they can be covered, for example, with a varnish that is not recognized by the laser and / or that repels the contrast medium. The contact points can also be reworked with a drill.

The model obtained provides the essential data for the approximal contact zones, that is to say the contact zones to the neighboring teeth and the contact points to the opposing teeth, and the preparation margin on the underside of the crown for the crown to be produced. Corrections and modifications to the other areas of the crown to be made, such as the lateral tooth curvatures, can be carried out using software libraries that are customary for this purpose.

The occlusal surface of the model obtained naturally does not correspond to the occlusal surface of the tooth to be crowned, but represents the negative impression of the tooth with the marked contact points. The negative counter tooth impression basically forms the maximum volume of the possible crown shape. Based on the negative counter-tooth impression and the marked contact points, the best possible purchase area for the tooth to be crowned can now be determined, for example, using appropriate software and computer-assisted processing.

The optimized data can be used for the production of the corresponding dentures using the milling machine.

To create a gnathological occlusal surface, a bite with a simple occlusal surface is first produced, as described above.

A so-called functional bite is then taken, the patient performing functional movements with the teeth when taking the bite.

For the production of the functional bite, customary special wax is applied to the previously created "simple" bite.

So that the simple bite does not interfere with the execution of the functional movements, it is ground back accordingly.

Care must also be taken to ensure that the contact point markings are not glued or subsequently removed. This can be prevented, for example, by making the contact point markings sufficiently deep! marked with a drill after taking the simple bite.

The functional bite is significantly larger than the "simple" bite and represents a grated chewing surface, so to speak. The preprint is now taken over the functional bite including the simple bite.

Then proceed as described above for a simple chewing surface.

After laser detection, the occlusal surface is calculated using modified software libraries of tooth shapes and corresponding modification programs. In this way, crowns with perfect occlusal surfaces can be obtained, which do not have to be reworked, as in the conventional methods.

For example, the calculation of the purchase area can be done as follows:

For a crown with a simple occlusal surface, the contact line / area (equator) to the neighboring teeth is checked, starting from the occlusal contact points, which is also possible over the entire area. Then the buccal and lingual tooth arches are determined using characteristic proportions as offered in the library. This usually deviates the most from the shape specified by the model.

The subsequent determination of the cusp inclination (cusp slopes) can be done using averages when designing a simple crown. Taking into account the specified contact points, the fissures are taken from a library of ideal occlusal surfaces according to the models of optimal occlusal surfaces, depending on the tooth type. ,

For a crown with a gnathological occlusal surface, after checking the occlusal contact points, the registered chewing tracks are initially set to mean values. Bumps traversed with the help of a functional program. The deviations from the registered quay can be independently optimized by the computer program. With this program, an asymptotic approximation to the optimal limit can be achieved. With the help of the model obtained according to the invention for the crown, including a negative impression of the opposing tooth (s) with contact points, the relevant data for the design of an optimal occlusal surface are made available by means of existing tooth shape libraries, by means of which the design of an optimal crown with a milling cutter system is made possible , Post-processing of the crowns obtained in this way is no longer necessary, so that the crowns can be used directly.

10 Since the production of the model for laser detection can be carried out in a simple manner using materials and measures that are generally known per se, the method can be carried out easily on site in the dental practice. The processed data is then fed into a compact milling system, for example a five-axis compact system with tool change.

15 ben who can mill the corresponding crowns in different materials.

The next example for the application of the method according to the invention is the production of an immediate implant for an extracted tooth.

! wrote. The root must be designed in addition to the crown.

20

For the production of the root, care should be taken to ensure that the replication of the root utilizes the cavity, also known as the “alveolus”, which the extracted root has left in the bone, as optimally as possible.

25 Furthermore, the gumline should be sufficiently sealed to prevent epithelial overgrowth from the sulcus, since the artificial root cannot be connected to the existing bone epithelially but only via connective tissue.

30 In addition, the teeth to be extracted are often damaged, so that a mere copy of the existing, extracted root would only result in insufficient support and the implant would not be sufficiently stable. Adequate connection strength between the root and crown (abutment) must be ensured. The abutment on an implant for a single tooth must also be rotationally stable so that it cannot break out due to rotary movements when chewing. With the method according to the invention, it is now possible to obtain immediate implants for complete teeth, ie roots including crowns, which can meet the above requirements. ; .

Before the extraction of the tooth with root will; As described above, the crown situation is preserved by a preprint, for example! made from thioether

For the preparation of a root egg implant, it may be necessary, before inserting the implant into the cavity that the extracted root has left in the bone, to bring it into a shape that ensures an optimal hold for the implant. For this expansion of the alveoli, the bone situation must be carefully examined in advance.

Previously, this required a surgical intervention, whereby the corresponding jaw region had to be made accessible for the examination by opening the gums. According to a special embodiment of the invention, the planning of the bone enlargement can be carried out by means of an X-ray analysis with a measuring ball and measuring cylinder, in that both a panoramic picture and a transverse picture in the posterior region are carried out. Of course, several recordings can also be made. By combining these two types of recording, an exact 3D acquisition of the tooth to be extracted is possible, the surrounding bone being able to be measured precisely using the measuring ball or the measuring cylinder. Based on the data provided by the images obtained, an optimal expansion of the expected bone cavity can be planned without the need for a surgical intervention.

In particular, the possible precise measurement of the distance to the mandibular nerve and the maxillary sinus enables planning and thus implementation of an optimal expansion of the bone cavity resulting from the extraction. For the manufacture of the implant, an image of the bone cavity, which should have the best possible resistance form for a good hold of the implant, must be created.

For this, an impression mass is entered into the bone cavity obtained. This impression material is shaped in advance so that a protrusion the size of the removed tooth stump protrudes from the tooth compartment. This then serves as a fastening for the crown to be put on. The extracted tooth can be used as a template.

It is also possible to insert a sleeve, for example made of metal, into the impression material such that the sleeve protrudes from the tooth compartment. The sleeve should also be filled with impression material in order to achieve a stronger connection. The crown can then be placed on the sleeve. An example of a sleeve and its application is described below.

A thermoplastic material usually used for this purpose can be used as the impression material for the root, which should be sterile for the application described. Suitable materials are, for example, thermoplastic impression materials, which are sold under the name stents or Kerr.

After removal from the bone cavity, the root impression obtained on the part protruding from the tooth compartment is designed so that the model for the root implant can be repositioned into the model for the crown. The model for the root implant is then put back into the bone cavity.

However, it is often undesirable for imaging root areas, for example for hygienic reasons, to fill the impression material directly into the alveolus, the area of the extracted tooth root.

According to the invention, a perforated sleeve with an elastic sleeve is used for taking the impression of the tooth root, which is inserted in the root area and filled with the impression material, as shown in FIG. 4. The perforated sleeve 20 according to the invention tapers towards the tip and is thinner and longer than the tooth roots.

In the area of the perforated sleeve tip, one or more openings 22, 23 are provided, of which at least one of the openings 22 sits exactly on the tip, or the tip is open.

The perforated sleeve 20 preferably has three to four small holes 23 in its tip region, one of which sits exactly on the tip.

The perforated sleeve 20 can be formed from any bendable and / or elastic material. A bendable metal is preferably used.

The perforated sleeve 20 is surrounded by a thin elastic sleeve 21, which at least envelops the area that is inserted into the alveolus. The sleeve can be made of a rubber material or a similar elastic material, preferably it is a rubber sleeve.

In the upper area of the perforated sleeve, that is to say the area which protrudes from the alveolus, the elastic sleeve 21 is fastened all around tight to the perforated sleeve. For this purpose, a sealing collar 24 or the like can be used.

In order to image the root, after extracting the tooth, perforated sleeves 20 are pushed in according to the number of roots down to the lowest point of the exposed socket. If necessary, the perforated sleeves can be bent to fit. t. ' i j

One after the other, elastic impression material is then injected into the perforated sleeves 20 by means of an impression compound syringe 29 such that the syringe cannula seals the volume of the perforated sleeve 20 flush. Impression mass is first pressed into the most distal, apical root tip area, the impression mass penetrating through the openings 22, 23 in the sleeve tip in the area of the elastic sheath and completely filling the space of the alveolus there. Air and blood that are still in the socket are thus completely pushed out of the socket from bottom to top, which ensures that an accurate representation of the socket shape can be obtained without malformations due to possible air and / or or blood inclusions.

Since the cannula tip 28 preferably remains in the perforated sleeve 20, disposable syringes are preferably used, the cannula tips 28 of which can be easily cut off from plastic, for example with a knife 30, as indicated in FIG. 4.

The impression is left in the socket until the other perforated sleeves 20 have also been filled, tied off and, if necessary, the cannula tips 28 have been separated.

The injected impression material fills the elastic sleeve 21, for example one. Rubber sleeve, in the socket and bulges it more or less strongly above the socket. In this way it is possible that the gumline is also precisely mapped for the optimal design of the later implant. At the same time, this sensitive area is protected against possibly non-sterile impression material, such as is used for taking an impression of the tooth or for producing a tooth model according to the inventive method.

For the production of a tooth model including the root, a previously made impression of the crown can be placed on the root model located in the alveolus and the cavity formed as a template for the crown, as described above, can be filled with impression material for the crown, for example with special silicone.

After the special silicone has set, the pre-impression with the crown impression, including the root impression, is removed from the mouth and the procedure described above for the production of a crown is carried out. If necessary, modifications can be made to the model before scanning the tooth model obtained with crown and root.

To improve retention, transverse grooves and longitudinal troughs near the root tips can be provided. Furthermore, a bevel for the thickened gumline seal - a so-called bevel - can be created, which usually has a length of about 2 mm. A prefabricated screw implant can of course also be used for single-root teeth. The individually milled implants can also be provided with a screw thread.

The tooth stump on which the crown is to be placed can also be designed as desired. For example, it can be provided with a thread, whereby rotation stability should also be provided here.

The tooth model, which may have been modified, can now be scanned in - as described above for the crown - and the data recorded for processing in the computer and the subsequent replication using the milling system. The optimal shape of the dentures to be created can now be calculated on the basis of the recorded data and with the help of appropriate libraries on the computer.

On the basis of the data, corresponding replicas of the tooth can be created from any material via the milling system. It is therefore also possible to first make a temporary if necessary.

The finished final implant can take a slightly different position than the one determined by the impression. To determine the final overall shape, a lavish cut out of the crown model, which is made of silicone, for example, so that it lies loosely - with play - on the abutment or crown stump, together with the preliminary impression, a “correction relining” with silicone or the crown model with the implant post are taken together again.

With the methods described above, it is in particular possible to provide an optimal single tooth restoration.

According to a special embodiment, wax models of the final tooth shape and position can also be made and additionally scanned in order to improve the data acquisition in order to obtain a broader data acquisition.

To optimize the final shape, working scans can be made in advance from the scanned data from softer or cheaper materials, on the basis of which the fit and shape of the dentures can be checked and corrected if necessary.

These corrected models can in turn be scanned so that the finished dentures made of the more expensive and / or more difficult to process final material fit optimally and no further corrections are required.

It is also sensible to make such working copies from softer or cheaper material if the completion is to take place in the laboratory, for example with more complicated and / or larger constructions.

Of course, the present invention can also be combined with industrially prefabricated implants.

If required, a so-called wax-up, an image of the final tooth shape and position in wax, can be made, which can be recorded together with the working copies using the laser if necessary.

The injection impression method according to the invention can also be modified for the production of inlays. Inlays are dental fillings which, in contrast to dental fillings applied directly in the mouth, are made from a permanent material using an image and inserted into the tooth.

Bite registration can generally be dispensed with in inlay production, since the occlusal surface can be reconstructed on the basis of residual bumps or cusp inclinations on the diseased tooth.

To produce the pre-impression, the cavity in the tooth to be supplied with an inlay is first filled and ground in with a conventional filling that is to be applied directly into the mouth.

Then, as described above, with the exception that a bite can be dispensed with, the preliminary impression is taken.

After the pre-impression material has set, the pre-impression is removed from the mouth and punched through at a location suitable for the injection channel, so that the optimal injection channel and also a holder for the laser fixation are possible for the inlay impression. For the production of the inlay mold, the preliminary impression is set back on the tooth to be imaged and the imaging material is injected into the tooth cavity via the injection channel.

The preprint can be fixed during the setting as usual by biting the patient.

Due to the smaller space available in contrast to the depiction of crowns, a lingual drainage channel should be avoided here.

After the impression material has set, the pre-impression is removed from the mouth and the inlay model is preferably removed from the pre-impression with a sprue pen, optionally processed and recorded with a laser.

In contrast to the manufacture of crowns, inlay production must ensure that the break-off edges, the so-called preparation margin, of, are respected. It has proven useful to turn the direction of the laser by 90 ° in addition to the usual laser detection so that the main direction of the preparation (from mesial to distal) can be better represented. In this case, it is sufficient for the construction of an inlay to measure the cavity, that is, it is sufficient to detect only the areas of the inlay model with the laser measuring system that reflect the shape of the cavity, so to speak, the underside of the inlay impression. The molding edges of the inlay impression then simultaneously represented the actual inlay edges.

According to a preferred embodiment of the method according to the invention, the negative form of the pre-impression to be filled with the impression compound is evacuated before the injection of the impression compound. This measure prevents possible air ingress, which could lead to inaccuracies in the model of the tooth area in question.

For this purpose, at least one channel is punched out at a suitable location in the initially produced pre-impression of the tooth area in question, via which the evacuation takes place by connecting the channel to a vacuum device. Any additional channels that are present in the preprint and that are not used for evacuation are sealed tightly.

The tightness of the pre-impression used in the relevant mouth area required for the evacuation results from the accuracy of fit of the pre-impression. The tightness is also supported by the pressure exerted by the patient on the pre-impression placed in the mouth.

After the evacuation, the impression material is injected into the negative form. For this purpose, an additional channel can be provided at a suitable point in the preprint or a prepared channel can be opened after evacuation. In principle, the injection can also take place via the evacuation channel itself. - Due to the vacuum, the filled impression material is distributed evenly and without air bubbles in the cavity of the negative mold.

If the injection takes place via a separate injection channel, the distribution of the mass can additionally be supported by the suction exerted by the vacuum device used for the evacuation, for example a pump or the like.

According to a further preferred embodiment, the impression material is injected by exerting a holding pressure on the filled impression material.

For example, the impression material can be injected using a syringe. It can then be re-pressed using the syringe plunger.

The channel, which is connected to the vacuum device, must be closed to build up the post-pressure. For example, a closure can be used for this purpose, the line to the vacuum device can be disconnected, or the closure itself can be done by means of impression material sucked into the evacuation channel.

In principle, any means suitable for this purpose can be used to exert the holding pressure and to close the channel for evacuation.

The repressing not only improves the impression accuracy, but also supports the resetting of the preprint. Particularly in the case of large cavities in negative molds, the pre-impression can be deformed as a result of the evacuation, which must be eliminated by resetting in order to achieve the greatest possible model accuracy.

The channel (s) for the evacuation and injection of the impression material are preferably arranged buccally (cheek side) in the pre-impression, since the buccal cale arrangement allows better handling than a lingual (tongue-side) arrangement.

If a vacuum is provided for the injection, drainage channels can be dispensed with.

With the injection method according to the invention, precise models for the most varied types of dentures can be produced in a simple manner, avoiding time-consuming and laborious laboratory work. The models can form the basis for data acquisition for the production of precisely fitting denture shapes, so that additional corrections to the completed dentures can be avoided. They can also be used as dentures themselves or for any other desirable purpose.

To facilitate the implementation of the injection impression method according to the invention and its configurations, specially adapted impression trays were developed, which are also the subject of the invention.

The use of conventional impression trays is common in dental technology for the production of dental impressions.

These are curved metal or plastic splints that are adapted to the jaw shape and, when taking the impression, encompass the corresponding jaw area, including the patient's teeth, and absorb the impression material. When taking the impression, the patient thus bites into the impression material, which is located in the impression tray, and with the opposing teeth on the upper side of the tray, whereby this can be fixed. The spoon including the impression is then removed from the mouth and the impression is taken from the spoon.

Since, for the method according to the invention, a further impression mass has to be injected through the preliminary impression in order to fill the cavity in the preliminary impression, the preliminary impression being placed in an impression spoon for fixing an impression tray was developed according to the invention, which allows an injection of the impression compound through the tray wall.

As shown in FIGS. 1 and 2, holes 2 are provided in the impression tray according to the invention for injection and evacuation, which are referred to below as “functional holes”. These functional holes 2 are usually arranged in the impression tray 1 according to the invention in such a way that they correspond to the normal position of the teeth in the jaw. Functional bores 2 for anterior teeth can have a smaller diameter than functional bores 2 for the other teeth.

In addition to the functional bores 2, the bucket 1 can have any number of further bores 7. These bores 7 serve to retain the impression compound on the tray and are therefore also referred to as “retention bores”. Their diameter is usually significantly smaller than that of the functional bores 2.

Functional bores 2 can have a diameter of approximately 3 mm and those of the additional bores 7 of approximately 2 mm.

For reasons of better handling, the functional bores 2 are preferably arranged buccally, in particular buccally in the center, as shown in the figures. Their number is not critical, there may be one, two or more functional bores 2 as required. For example, a corresponding functional bore 2 can be provided for each tooth position. ι

It is essential that the upper side 6 of the impression tray is freely available, so that the patient can bite freely on this upper side 6. For this purpose, it is necessary that there are no functional bores 2 for injection or evacuation or the like on this upper side, which no longer allow a corresponding counterbite or could be impaired in their function by the counterbite. This configuration ensures that the same situation can be created for the production of the model as in the production of the preprint and the preprint can also be positioned as precisely as possible for the illustration of the model, in particular the height, that is to say the vertical dimension to get the model exactly. For this purpose, the patient should be able to exert pressure by bite on the spoon or the preprint in exactly the same way as in the production of the preprint.

For the production of a model or impression, functional bores 2 that are not required can be provided with a closure, for example to prevent clogging by the impression compound. Suitable closures can be, for example, plugs or screws.

Functional bores 2, which are not required for the injection, or further functional bores 2 at a suitable location can serve as a drainage channel for excess injected mass if required.

For the production of channels for injection, evacuation, drainage etc. in a pre-impression, which fit the corresponding perforations in the impression tray, it has proven useful to place the pre-impression in the tray and to insert the desired channel, for example by inserting one Punch the hollow sleeve into the corresponding hole in the spoon. In this way, a channel can be obtained for each tooth position that corresponds optimally with the perforation in the tray.

The functional bores 2 can have means for connecting necessary supply lines, such as for the injection of the impression material or for the vacuum device, threads, for example, for receiving these means, closures, sleeves etc. According to a special embodiment, a hollow screw 4 is provided for the functional bore via which the injection is to be carried out, which contains an inner channel 5 which is available for the injection, as is also shown in FIG. 1.

Corresponding plug connections are also suitable. If required, banjo bolts 4 and plug connections can also be used together.

It is also advantageous if the inner channel 5 has a thread, at least in part, preferably in the region of the outer wall, which makes it possible, by means of an appropriate insert, to securely close or open the cavity if necessary without changing the entire screw have to. The channel 5 in the hollow screw 4 can advantageously be used to insert a punch, a plug-in sleeve or the like for punching out the injection channel into the preliminary impression.

After removing the punched impression material, the punch for the injection can be repositioned in the screw and serve as an injection nozzle.

In the hollow screw 4, a cross screw can in the outer area

Fixation of closures or the punch etc. are provided.

The banjo bolts and plug connections can be seated or designed to be retractable in the bucket wall.

For acquisition with a scanner, the models received for calibration should be aligned and fixed appropriately.

According to a particularly preferred embodiment, the hollow screws 4 are therefore designed such that they simultaneously fit for use on the scanner and can serve as calibration points or fixation of the respective model. Identically designed screws / plug connections can also be used. It is essential that the inner channels 5 correspond to one another, so that the model can be precisely fixed using the sprue.

An example of such a screw configuration is described below. However, it goes without saying that the screw design can vary depending on the scanner used. For the selected example, the head of the banjo bolt 4 is square.

As an example of an embodiment of the square head of the screw, the head can have a thickness of 3 mm and an edge length of approximately 8 mm, the edge length being approximately twice as long as the length of the inner hollow cylinder.

The channel area in the head can be designed as a hexagon socket. The hexagon socket can serve as a fixation for the scanning process and at the same time enables the screw to be removed without damaging the outer surface of the bucket.

The scanner can be calibrated using the edges of the square screw, using the edges to align the model to be measured.

For scanning, the model of the desired dental prosthesis produced according to the invention is inserted into the punching sleeve via the sprue, which was created by the injection, and is fastened to the hollow screw with the latter. This enables the model to be optimally aligned for scanner acquisition.

For the present example, one side of the square banjo head is aligned parallel to the chewing plane, so that when scanning this surface serves as an orientation for the scans to be taken. In this setting, one scan can be taken at an angle of + 30 ° and another at an angle of - 30 ° to the resulting scan plane to record the occlusal surface of the planned crown. Then the prepared lower surface opposite the occlusal surface is recorded with the so-called preparation margin of the future crown by rotating through 180 °. The underside can also be scanned with two 30 ° angled scans. This means that the scans of the occlusal surface and the scans of the lower surface can be positioned exactly perpendicular to one another, so that the image of the entire crown can be determined from the acquired data.

For example, an impression tray for a complete jaw can have 14 holes or screws corresponding to the number of teeth.

It goes without saying that the design of an impression tray according to the invention can be applied to any conventional form of an impression tray. The invention is suitable, for example, for entire impression trays or one-sided impression trays

The wall thickness of the spoon should be adequate retention and sufficient

Allow space for a screw thread.

A wall thickness of preferably at least 3 mm has proven itself for these purposes.

The screw threads with screws in the buccal and occlusal (possibly also lingual) areas can, if they are not required for the injection, also serve to better fix and retain the impression material.

It has been shown that the preprint for removing the model has to be destroyed in many cases. However, it is often desirable to use the preprint several times, for example to create control models.

To do this, it is necessary to place the pre-impression in the impression spoon as exactly as possible in the same position as for the first impression. According to the invention, this problem is solved by so-called retention plates, which are placed on the impression tray, as shown in Figure 2. The retention plates 9, 10, 11 have retention pins 12 which can be inserted into the functional bores 2 and possibly further holes 7 of the impression tray 1 and protrude into the interior of the groove of the impression tray 1.

If there is impression material in the tray, the ends of the pins 12 penetrate into the material and form depressions in it. It is important to ensure that the pins 12 do not protrude into the cavity of the negative mold. Therefore, the length of the pins 12 is to be selected such that they penetrate the wall of the preprint but do not penetrate it to the cavity of the negative mold.

To remove the model from the preprint, the retention plates 9, 10, 11 are removed from the spoon 1, the preprint is removed and, if necessary, disassembled to remove the model.

To reconstruct and reuse the preprint, the individual parts of the preprint are put back into the spoon and the retention plates are put back on. Due to the recesses in the wall of the preprint, the shape of the preprint can be reconstructed by plugging in the corresponding retention plates and used for the production of further models.

A distinction is made here between buccal retention side plates 9, frontal retention side plates 10, an upper retention plate 11 for placement on the top of the spoon and lingual retention side plates (not shown in the figure).

The retention plates 9, 10, 11 preferably contain a number of retention pins 12 corresponding to the functional bores 2 and possibly further bores 7 of the impression tray 1. This can prevent bores 7 or bores 2 impression material penetrates to the outside and makes it difficult to remove the preprint from the impression tray.

The retention pins 12 are preferably made of a rigid material. They preferably have a diameter which is flush with that of the holes 7 and functional bores 2, that is to say in the plugged-on state they close the holes 7 and functional bores 2 tightly.

As shown in Figure 3, pins 12 may taper forward. By protruding into the mass of the preprint, they serve as retention for the preprint mass.

The frontal retention side plate 10 is bent at the two ends (towards the "distal") and is preferably somewhat elastic. As a result, the - usually rigid - pins 12 in the functional bores 2 and further bores 7 of the curved front part of the impression tray 1 can be lighter be introduced.

Only the retention pins 12 in the area of the ends of the elastic retention front plate 10 are slightly inclined towards the main orientation of all other pins 12 of the retention front plate 10.

A type of handle can be attached to a front panel for better handling, as shown in Figure 2. In the event that a facebow transfer is to be carried out simultaneously for possible laboratory work, for example, two tubes can form the lateral boundary. The tubes can expediently be chosen to be approximately 4 cm long and 5 mm wide on the inside.

The lingual retention side plates (not shown in the figure) close the functional bores 2 and further bore 7 of the inner lingual side wall of the impression tray. The lower retention pin row of the lingual retention side plates should be shorter than the other pins for easier removal. Due to the strong curvature of the impression tray 1 in the front lingual region is preferably dispensed with pins 12 in the region of the central incisors.

Preferably the lingual plate to be removed first is shorter than the other. The retention pins 12 of this plate are slightly inclined forward (mesial).

To improve the retention of the pre-impression or the pre-impression mass, an outstanding mount can be provided on the impression tray 1 in the lower region of the front curvature of the lingual retention plate, which compensates for the reduced retention due to the lack of some retention pins in this region.

Additional means can be provided on the retention plates, in particular the buccal and lingual ones, which increase the retention of the retention plates on the impression tray 1.

Thus, as shown in Figure 2, a spring 13, here a burr-shaped bar, can be provided on the upper edge of the retention plates.

The upper edge is curved so that the plate engages over the upper side edge of the spoon 1 when it is attached. A groove 8 can be provided along the outer edge of the upper side of the spoon 1, in which the tongue 13 can engage.

In this case, the retention side plates are wider than the spoon sides so that they can grip around the top of the spoon. The resulting circumferential bar can also serve as a fixation aid for the impression tray while the impression material is being bonded by the row of opposite teeth.

No retention spring 13 is usually provided for the front panel.

To remove the retention side plates 9, 10, as may also be required in the mouth, the retention springs 13 are released from the groove 8, for example by means of thumb pressure. For this purpose, a release fork can be pushed between the retention side plates 9, 10 and the spoon outside the retention pins 12 can be lifted from the impression material and the impression tray 1.

The upper retention plate 11 can have additional retention elements 14 on the side opposite the side with the retention pins 12.

These can be pyramid-shaped, as shown in Figure 2. But they can also have any other suitable shape.

These additional retention elements 14 serve to fix impression-> mass, which can be applied to the spoon back. This may be necessary to provide orientation aids, for example to align a so-called Herrlan bite pillow. As already mentioned, it is desirable for the patient to exert the same pressure on the spoon 1 as possible when producing the preprint and in the subsequent steps. For this purpose, a Herrlan bite cushion can be provided on the back of the spoon. This pillow then measures the pressure the patient exerts when biting.

According to a preferred embodiment, the retention side plates have bores whose position corresponds to the functional bores 2 in the impression tray 1 described above. In this case, the method according to the invention can also be carried out without difficulty even with attached retention side plates.

Since - as stated above - the injection / evacuation is preferably carried out buccally, the buccal retention side plates 9 in particular have corresponding bores. As in the impression tray, these are preferably positioned in the center, with the middle row of pins being replaced by the corresponding holes.

To facilitate connections for, for example, evacuation and injection, the through-holes can each be surrounded by a sleeve which protrudes somewhat outwards in the direction of the vestibule. These sleeves can have an annular thickening at the outer end, so that there is something between the thickening and the outer surface of the retention side plate narrower shaft is created. If, for example, the sleeve protrudes outwards by approx. 5 mm and the ring-shaped thickening has a length of 2 mm, this results in an approx. 3 mm long shaft.

These sleeves are used to attach the evacuation hose and the impression syringe.

It goes without saying that, instead of these sleeves, other elements can also be provided which facilitate the connection of the evacuation hose and the injection syringe.

Since the injection and evacuation take place in the patient's mouth and the space available there is very limited, it may be necessary to provide means, for example adapters, that take this lack of space into account and easier handling of the necessary equipment in the mouth allow the patient.

A so-called evacuation adapter, such as a curved adapter, to which the evacuation hose is attached can be applied to the retention sleeve, which is provided for the evacuation. This can be a tube bent downwards and forwards, for example at 90 ° in each case.

Often it is also necessary that the injection of grout since then ^', borrowed done must, for example, in the back teeth. .

According to the invention, an adapter for the injection can be provided for this. According to a special embodiment, this adapter has suitable cutouts on its flat underside for receiving the retention sleeve and lies flush against the outer surface of the retention side plate. At the top, it has an expediently semi-tubular, preferably elastic clamping device, onto which the syringe can be attached laterally (syringe holder adapter). A preferred procedure according to the invention is explained below using an example.

The preparation of the impression tray for carrying out the method according to the invention is expediently carried out outside the mouth.

The preprint previously made is in the spoon and the corresponding retention side plates are attached. In the area where the injection is to be carried out, a retention side plate with perforations is used.

An evacuation channel is provided for the evacuation at the corresponding point in the preprint.

This can be done by inserting a lancing sleeve at the appropriate position. This piercing sleeve can also remain in the channel. In this way the canal is stabilized and a possible collapse during evacuation is prevented. This piercing sleeve can be funnel-shaped towards the tip.

An adapter for the evacuation, as described above, can be placed on the retention sleeve, which is provided for the evacuation. For better sealing, the retention sleeve can be provided with an appropriate seal, such as a rubber ring. The evacuation hose is then plugged onto this adapter. This is preferably transparent in order to be able to observe when the sucked-in impression material emerges from the evacuation channel. The evacuation hose is connected to a vacuum device, preferably to a vacuum pump customary in dental technology.

To prepare for the injection, a puncture sleeve is also provided at the corresponding point in the preprint. Since the injection channel should still be closed during the evacuation, this piercing sleeve should not yet reach the cavity. Only when the syringe is put on can the piercing sleeve be completely penetrated in the subsequent process by means of the syringe tip and the prepared injection channel can be opened. On the retentive On the sleeve, which is intended for injection, the syringe holder adapter, as described above, is attached.

The impression tray with pre-impression prepared in this way is now placed in the patient's mouth and evacuated. After the evacuation has taken place, the syringe filled with the impression compound, which for better handling may have a correspondingly bent tip, is pushed into the lancing sleeve, the syringe snapping into the clamping device of the syringe adapter. At the same time, the lancing sleeve is pressed into the pre-impression mass while opening the cavity of the negative mold and the punched-out impression mass pin is sucked into this cavity by the evacuation suction that is now discharging. This extremely small spigot is encased by the flowing impression material and does not affect the accuracy of the impression. The impression material is also sucked into the evacuation hose through the cavity. This process can be stopped by disconnecting the hose accordingly.

The repressing is now carried out via the syringe plunger. According to a preferred embodiment, the post-compression with the syringe plunger is supported by building up a counter pressure.

The counterpressure can be built up by pushing the impression compound into the evacuation tube, removing it from the adapter, and pressing the impression compound back into the evacuation adapter by means of finger pressure. ^'•

The same effect can be achieved by kinking the evacuation hose.

According to a variant of the method, a lower-viscosity second impression material, which differs from the actual impression material, can already be placed in the pre-impression in the pre-impression area and also in the sulcus, the area around the patient's teeth, before insertion into the mouth. This is possible because the evacuation takes only a few seconds claimed. The pre-impression is then placed in the mouth and proceed as described above.

After the injected impression material has hardened, the impression spoon is removed from the mouth and the model is taken from the preliminary impression.

This model can now be used directly as a template for producing the relevant tooth replacement from the desired material, for example by means of a scanning process, or the model itself can be used as a tooth replacement, for example as a temporary. As already mentioned above, the pre-impression, even if it had to be cut for the removal of the model, can be fixed in the impression tray again by placing the retention side plates on it and used for further use if necessary.

According to a further embodiment of the method according to the invention, a copy of the model can be made with the preprint in order to obtain correction models or plastic copies that can be used directly as a provisional if the corresponding material is used.

For this, the preprint, which still contains the model, is used with a suitable one

Material such as plaster or a corresponding plastic material, poured out.

The image of the jaw obtained in this way is referred to below as a cast model.

The cast model is removed from the preprint and reworked if necessary.

To make copies of the model from the impression material, the preparation boundaries can be ground free in the cast model, if necessary the tooth stumps can be blocked out with wax and isolated. After the prototype of the model has been removed from the preliminary impression, the preliminary impression, if necessary after being fixed in the impression tray with, for example, the retention plates, is placed on the cast model and - as described above - a suitable impression compound is formed with a copy of the prototype model in the Cavity of the negative mold injected.

In this way, any copies of the tooth or the tooth area to be formed can be obtained.

In a further embodiment, the special impression spoon according to the invention can simultaneously be used as an oral irrigator.

For this purpose, the impression tray contains an impression of the dentition of the lower jaw or upper jaw, the impression having buccal and lingual bores corresponding to the bores or injection channels of the impression tray.

A supply and drain line system for the cleaning liquid are also provided.

The insert consists of a rubber-like, permanently elastic material that should be relatively soft, for example a relatively soft silicone with a preferred Shore hardness of 30 to 50, which should be very durable, preferably addition-crosslinked.

The insert is preferably designed to be removable from the impression tray, so that the tray can be used by different users, for whom an individually adapted insert is made in each case.

The cleaning fluid is injected into the interdental spaces via the delivery system via the buccal injection channels and discharged through the lingual bores.

In a preferred embodiment, the buccal injection channels are supplied via a feed line (inflow tube) which is in communication with the injection channels. muniert, the feed line having openings or branches to the individual injection channels.

A corresponding system ensures that the cleaning fluid is drained off. The drainage system is preferably designed as a mirror image of the inflow system, the individual lingual bores opening into a drain which runs parallel to the feed line.

The supply line as well as the discharge line for the two jaw halves unite in the front area of the jaw to form a single line, which can leave the mouth via a corresponding hole in the handle of the impression tray.

The diameter for the supply and the discharge is not critical in itself, but should ensure an adequate supply and removal of detergent without being uncomfortable for the user. A diameter of approx.8.0 mm fulfills these purposes, for example.

The impression tray used for an oral irrigator preferably contains an injection channel (bore) for each tooth. If necessary, it can of course also be more or less.

The injection channels can have different diameters. For example, the diameter can be 2.5 mm for molar teeth, 2 mm for premolar and canine teeth and 1.5 mm for front teeth.

To increase the cleaning effect, the cleaning liquid is preferably moved.

For this purpose, the feed line can be connected to a connecting rod-translated electric motor, which moves the liquid back and forth by means of a pump piston. The speed can be selected variably. For example, cleaning concentrate can be drawn into the displacement of the pump cylinder via a supply hose and backflow can be prevented by a check valve. The concentrate supply can be controlled as required. Due to the back and forth flooding of the liquid, an additional cleaning and massage effect is achieved - and depending on the frequency of the pump stroke.

The continuous inflow of cleaning agent ensures that the interdental deposits are removed.

The cleaning agent can be chosen arbitrarily and can be added if necessary. Water can be used as a cleaning agent, for example. Here, a hose connected directly to the water line can lead the water directly into the supply line. A possible additive is a fluoride.

Since the user bites on the spoon, a bite, for example made of silicone, is preferably provided on the back of the spoon.

For this purpose, a circumferential retention bar at a suitable height, for example approx. 3 mm, can be provided on the spoon.

The provision of a bite can prevent a lifting leg of the impression tray due to the hoses and / or the internal pressure generated by the liquid.

Along the inside (ie lingual) of the bite block, a bulge can be provided, which is formed by the bite block and the spoon back to accommodate the drainage, which increases the wearing comfort

An impression of the dentition is used as the insert, which contains bores at positions that match the injection channels in the impression tray, or preferably correspond in analogy to the injection channels in the impression for the injection process.

A suitable insert for a user can be produced using a conventional plaster model of the bit, depending on the lower or upper jaw. For the production of the plaster model, for example, a denture impression that extends to the fold of the envelope can be poured out with plaster. The denture impression can be made of silicone or a thioether, for example.

Wax is applied to the interdental spaces of the plaster model in such a way that a later cavity for the cleaning liquid is created.

From the plaster model prepared with wax in this way, an impression is made completely down to the envelope fold, which is used for the application. After the wax has been driven off, the desired cavity is created at precisely defined points and in the desired thickness.

If necessary, the plaster model can be revised to ensure that the insert is sealed so that no fluid escapes and to protect certain areas, such as the gum line, if necessary.

This increased adaptation can be brought about, for example, by appropriate etchings on the plaster model.

Alternatively, the denture impression itself can be used for the production of the insert for the oral irrigator, by punching out corresponding parts for the cavities and depicting the waxed-up changes by relining them with easily flowing impression material.

The oral irrigator according to the invention can also be used for bleaching teeth. Due to the aggressive nature of bleaching agents, precautions must be taken to protect sensitive areas or areas that should not be bleached from the bleaching agent.

In particular, care should be taken to ensure that the insert is sealed tight, for example to protect the gumline from the bleaching liquid. Furthermore, in this case, the gum spaces should not be used for lingual drainage, unlike when cleaning with non-aggressive liquids.

The procedure for producing a bleaching insert that meets the above requirements can be as follows.

Specially for bleaching the teeth, a film (plastic splint) is first deep-drawn on the plaster model approx. 1 to 2 mm over the teeth to be bleached and the gum line is sanded clean to prevent irritation of the gums.

In the area of the gumline, an approx. 0.5 mm deep etching is ground in on the plaster model. The connection to the lingual drainage channels is specified with the help of wax sticks.

An impression for use, for example made of silicone, is taken from the plaster model prepared as described above using these wax sticks and the plastic splint. The plastic splint should only cover the lingual tooth surfaces in the upper third.

The plastic splint is first checked for exact fit in the patient's mouth. Then a kind of "correction impression" can be made with thin-flowing material, for example silicone, to ensure that the gum line is covered by the silicone impression. The plastic splint is then removed from the impression and the wax is expelled to create the drainage channels, which is why If necessary, silicone residues are removed from the buccal injection channels as well as the drain channels. With the device described above, bleaching is possible in a closed system, bleaching with effective concentrations and thus being able to be carried out quickly without any particular expenditure.

This closed system is thus clearly superior to the simple plastic splints previously used for bleaching, which were used for example by the patient himself at home, since the bleaching agent is only kept at the place of action by this plastic splinch, which only covers the teeth, and is not avoided bleach may leak into the gum areas or oral cavity.

In order to prevent or minimize damage, the concentration of bleach and therefore its effectiveness must be reduced. This in turn increases the required application time.

Bleaching in the dentist's office is also very expensive, since not only are several hours required, but also a rubber dam must be placed in addition to other measures. The patient must also be supervised.

The implementation of bleaching with the closed system possible according to the invention is described below using an application example.

After cleaning has been completed, a flavor-intensive liquid is injected into the impression used as an insert in the closed process. In this way, the patient can check the tight fit of the impression. For example, the patient can determine in this way how firmly he has to press the spoon into place so that no liquid escapes. Then, starting with a weak concentration, the bleach is added in batches.

In order to achieve a better effect, it should not be rinsed, but the bleach should only be transported to the place of action and remain there for a short time, for example a few minutes, until it is replaced by fresh agent. Few drainage channels are sufficient for this. Also, not all teeth have to be bleached, for example in general the so-called 7s do not necessarily have to be bleached. This leaves sufficient drainage channels, which can be available for a quick removal of the bleaching agent if necessary, in order to stop the bleaching in an emergency.

So that the bleach does not drain prematurely, the drain can be closed outside the mouth, for which a clamp can be used, for example.

Furthermore, the discharge line can be connected to a water line, for example, so that in the event that the bleaching is to be stopped or interrupted, water or another suitable liquid can be passed in counterflow via the discharge line and thus the bleaching agent via the injection channels is driven out.

An impression tray, which can also be used in a suitable manner for use as an oral irrigator or for bleaching, can be designed as follows:

As described above, the injection channels can be formed by hollow screws which are screwed in on the buccal side of the impression tray and can have a diameter of approximately 6 mm and a length of approximately 10 mm. In the normal position, the banjo bolts in this embodiment protrude approximately 4 mm buccally beyond the outer surface of the spoon. With a bucket thickness of approx. 3 mm, the banjo bolts protrude 3 mm into the interior of the bucket. The minimum distance between the teeth shown and the tray should be at least 3 mm, preferably 4 to 5 mm.

Ideally, the banjo bolts point exactly at the buccal surfaces of the teeth, whereby they are preferably vertical in the middle. This position is most suitable for both prosthetic impressions and bleaching. For the oral irrigator, the banjo bolts should be aimed as precisely as possible at the interdental spaces. This can be achieved by simply placing the tray forward by approx. 4 mm and by dispensing with distance stops, which can normally be used to ensure that an impression is free of distortion. The buccal channels can be used to insert interdental brushes for interdental cleaning.

It is understood that the above description for the design of a spoon is only exemplary and the spoon including the bores for the injection and drainage channels can be modified according to the respective requirements of the specific application.

This applies in particular to the design, such as dimensions and the position of the bores for the injection and drainage channels, and the banjo bolts that are preferably used.

The number of injection and drainage channels can also be determined as required.

In addition to the specific application examples described above, the injection impression method according to the invention and the impression tray according to the invention can be used in a variety of ways in dental technology, in particular for the production of dentures in any configuration and in prosthetics.

LIST OF REFERENCE NUMBERS

Abdrucklöffel

Bore (functional bore)

Handle

Hohlschraube

Allen

top

retention holes

Groove (on top of spoon)

Buccal retention side plate

Frontal retention side plate

Upper retention plate

retention pin

feather

retention element

Tubes for holding a ι 9 free

hole sleeve

elastic cover

Opening in tip

Holes at the tip end of a tight cuff

measurement mark

impression material

bone

Tip of syringe

syringe

knife

Claims

claims

1. A method for producing tooth models comprising the following steps: - Production of a preprint with a negative form of the relevant one

Tooth or the relevant tooth areas,

Preparing at least one injection channel in the preprint,

- placing the preliminary impression with the at least one prepared injection channel on the bit in the corresponding position, if necessary after conditioning the tooth or tooth area concerned or on a jaw model (also called a cast model),

- Injecting an impression mass via the injection channel into the negative form of the preprint with the formation of a model, the material of the preprint and the material of the impression mass for the

Do not connect the model.

2. The method according to claim 1, characterized in that the cavity of the negative mold is evacuated in the pre-impression before injection of the impression compound.

3. The method according to any one of claims 1 or 2, characterized in that a post-pressure is exerted on the injected impression material.

4. The method according to any one of the preceding claims, characterized in that at least one evacuation channel is provided in the preliminary impression.

5. The method according to any one of the preceding claims, characterized in that the channels for the injection and the evacuation are arranged buccally in the preprint.

6. The method according to any one of claims 1 to 5, characterized in that before the preparation of the pre-impression of the tooth to be treated, a bite with a counter bite is taken, the tooth to be treated is conditioned, the bite is placed on the conditioned tooth and then a Pre-impression is taken from the conditioned tooth including the bite.

7. The method according to claim 6, characterized in that an additional functional bite is taken.

8. The method according to any one of the preceding claims, characterized in that at least one bore is also provided in the preliminary impression for removing excess impression material.

9. The method according to any one of the preceding claims, characterized in that in addition a root model of the tooth in question is made.

10. The method according to claim 9, characterized in that before extraction of the root, the bone situation in the root area is detected by means of X-ray analysis by combining a panoramic image with a transverse image in the posterior region.

11. The method according to any one of claims 9 to 10, characterized in that a perforated sleeve according to one of claims 33 to 37 is used for the production of the root model.

12. The method according to any one of claims 9 to 11, characterized in that on the model for the root implant in the cavity provided in the jaw, the pre-impression for the crown is placed on it and by injecting the impression material into the negative form of the pre-impression, a model of the whole tooth including root is produced.

13. The method according to any one of the preceding claims, characterized in that the models obtained for dentures are recorded by means of a laser measurement system and the data obtained thereby are used as the basis for the production of a corresponding denture.

14. impression tray suitable for use in a method according to one of claims 1 to 13, characterized in that the impression tray (1) has at least one functional bore (2) for connecting injection means and / or a vacuum device, the at least one functional bore ( 2) is arranged on the side surfaces of the impression tray (1).

15. impression tray according to claim 14, characterized in that the at least one functional bore (2) is arranged buccally.

16. impression tray according to one of claims 14 or 15, characterized in that the functional bores (2) are arranged centrally on the side surfaces, the position of the individual functional bores (2) essentially corresponding to a tooth position in the dentition.

17. impression tray according to one of claims 14 to 16, characterized in that the impression tray (1) additionally has bores for removing excess impression material.

18. impression tray according to one of claims 14 to 17, characterized in that a hollow screw (4) and / or a plug connection is provided for the injection in the at least one functional bore (2).

19. impression tray according to claim 18, characterized in that the inner channel of the hollow screw (4) or the plug connection has a thread at least partially in the region of the outer wall.

20. impression tray according to one of claims 18 or 19, characterized in that the head of the hollow screw (4) and / or plug connection is designed as an internal hexagon (5).

21. impression tray according to any one of claims 14 to 20, characterized in that at least the functional holes (2) provided for the injection and / or connection of the vacuum device have a thread and / or a plug connection.

22. impression tray according to one of claims 18 to 20, characterized in that the banjo bolt (4) and / or the plug connection for calibration and fixing is designed for a scanner.

23. impression tray according to one of claims 14 to 17, characterized in that the impression tray (1) is provided with a supply and discharge system for a liquid and a denture impression as an insert, the insert having bores at positions which correspond to the bores in the Correspond to the impression tray (1).

24. Use of an impression tray according to claim 23 as an oral irrigator and / or for bleaching teeth.

25. Retention plate to be placed on an impression tray, characterized in that the _. Retention plate (9, 10, 11) has a multiplicity of retention pins (12) which can be inserted flush through the bores (7) and possibly functional bores (2) provided in an impression tray (1).

26. Retention plate according to claim 25, characterized in that the retention plate is a buccal or lingual retention side plate (9), the upper edge of which is curved and on its underside a spring (12) for fastening in a running on the outer edge of an impression tray (1) Has groove (8).

27. Retention plate according to one of claims 25 or 26, characterized in that the retention plate is a retention side plate (9, 10) which has at least one bore which corresponds to a functional bore (2) of the impression tray (1).

28. Retention plate according to claim 27, characterized in that the at least one bore is provided with a sleeve which projects to the outside of the retention plate.

29. Retention plate according to claim 28, characterized in that the sleeve has an annular thickening at its outer end which points outwards.

30. Retention plate according to claim 25 or 26, characterized in that the retention plate is an upper retention plate (11) for the top of the spoon, which has additional retention elements (14) on the side facing away from the spoon (1).

31. Evacuation adapter for placement on a bore or sleeve of a retention plate according to one of claims 25 to 29, characterized in that the evacuation adapter is a tube which is bent downwards and forwards.

32. Syringe holder adapter for placement on a bore or a sleeve of a retention plate according to one of claims 25 to 29, characterized in that the syringe holder adapter has a planar underside with recesses for planar placement on a sleeve of a retention plate and on the top a semi-tubular elastic clamping device for the side Attaching an impression mass syringe.

33. Perforated sleeve for producing a root model, characterized in that the perforated sleeve (20) is narrower and thinner than a tooth root, tapers downwards and has an opening (22) at least on its tip, the perforated sleeve (20) at least in the area that projects into the root cavity (alveolus) is provided with an elastic sleeve (21), and the elastic sleeve (21) above the area that projects into the root cavity is tightly connected to the perforated sleeve (20).

34. Hole sleeve according to claim 33, characterized in that the hole sleeve (20) in addition to the tip opening (22) has further holes (23) in the region of the tip end.

35. perforated sleeve according to one of claims 33 or 34, characterized in that the elastic sleeve (21) with a sleeve (24) is tightly connected to the sleeve body.

36. Perforated sleeve according to one of claims 33 to 35, characterized in that the perforated sleeve (20) consists of a bendable material, preferably a bendable metal.

37. Perforated sleeve according to one of claims 33 to 36, characterized in that the perforated sleeve (20) has measurement markings (25) along its body.