DE102007025164A1 - Methods and apparatus for creating a model of a patient's dentition - Google Patents

Abstract

According to the invention, in order to avoid residual stresses occurring during the molding or pouring out of the molds to be molded, it is proposed that the object whose position and orientation should be transmitted particularly accurately be first excluded from the known from the prior art impression or pouring by a soft placeholder. Thus, the molding or pouring compound is allowed to cure without the possibility of building up internal stresses in the area of the object, since the object does not come into contact with the molding or pouring compound. The remaining space around the object is stiffened in a further step, for example by pouring the space after removal of the placeholder or by curing the placeholder.

Description

The The invention relates to a method and devices for creating a model of a patient's dentition, in particular for production of dentures attachable to implants.

at the creation of dentures in general by dental technicians this one models over one the tooth stump ground tooth stump or implant stump in the previously To be created plaster model a faithful wax model of the Tooth produced. The accuracy of the impression of the patient's dentition However, there are certain limits. This is already the case, for example the impression, d. H. the negative form of the patient's dentition based silicone, polyether or alginate materials are flawed. The aforementioned materials are subject to u. a. thermal reactions during setting, which lead to residual stresses. After taking off lead this Internal stress naturally leads to deformations in the negative impression. Furthermore arise when lifting the straight set impression of the jaw low but irreversible upsets in the impression material, which when removing from the patient's jaw for more Inaccuracies worry, especially since when removing also undercuts to overcome are. The occurring inaccuracies are in wide areas the dental technology uncritical, since after introduction of the denture, z. B. the crown, the bridge etc., which can yield the teeth coming into contact within certain limits.

Especially However, the aforementioned inaccuracies are problematic in the case of Implants. Implanted dentures consists of up to three components: an artificial one Root (implant) inserted into the jawbone by the dentist a connector (implant post) and an artificial one Dental crown or the bridge or Prosthesis manufactured in the dental laboratory. The implant usually consists of the metal titanium and is in the form of a Screw or a cylinder and is between 8 and 16 mm long. On this tooth root is a connector, so the implant post with the tooth crown or bridge or prosthesis stabilized. The connector is also made of titanium or ceramic which becomes a dental crown or bridge like a conventional one Crown made of metal or a ceramic veneer or ceramic. The disadvantage here is that the implant used in the jaw is not to give way or avoid dodges, but rigid is fixed in the bone. Therefore, inaccuracies in the - necessarily double - impression of the patient's dentition can not be compensated and lead to that the prosthesis is useless.

• – Aufsetzen eines Übertragungspfostens auf das im Knochen implantierte Implantat mittels einer durch den Übertragungspfosten geführten Fixierschraube;
• – Anpassen eines individuellen Abdrucklöffels mit Ausnehmungen, so dass die freien Enden des Übertragungspfostens mit der Fixierschraube nach erfolgtem Abdruck zugänglich sind;
• – Befüllen des individuellen Abdrucklöffels mit Abdruckmaterial (meist Silikon).
• – Pressen des mit Abdruckmaterial gefüllten individuellen Abdrucklöffels gegen den Kiefer, so dass die Übertragungspfosten in das Abdruckmaterial einbettet werden.
• – Freilegen von Fixierschrauben durch Entfernen von überschüssigem Abdruckmaterial;
• – Aushärten des Abdruckmaterials.
• – Lösen der Fixierschraube, so dass der Übertragungspfosten nicht mehr mit dem Implantat verbunden ist; und
• – Abziehen des Übertragungslöffels mit Abdruckmaterial und darin eingebetteten Übertragungspfosten.

To create the negative impression (1st impression) of the patient's teeth, the following steps are necessary:

• - placing a transfer post on the implanted bone in the implant by means of a guided through the transfer post fixing screw;
• - Adjusting an individual impression tray with recesses, so that the free ends of the transfer post with the fixing screw are accessible after a successful impression;
• - Fill the individual impression tray with impression material (usually silicone).
• - Pressing the filled with impression material individual impression tray against the jaw, so that the transfer posts are embedding in the impression material.
• - exposure of fixing screws by removing excess impression material;
• - curing the impression material.
• - Loosen the fixing screw, so that the transfer post is no longer connected to the implant; and
• - Removing the transfer tray with impression material and embedded therein transfer posts.

By The above steps became the imprint or negative form created.

• – Verbinden eines sog. Modellanaloges, also einem Implantatersatz, der im Gipsmodell das Originalimplantat ersetzen soll und über identische Anschlüsse für den Übertragungspfosten und die Fixierschraube wie ein Original verfügt, mit dem Übertragungspfosten mittels Fixierschraube;
• – Aufbauen einer Zahnfleischmaske, z. B. mittels Silikonmaterial als Zahnfleischersatz in der Negativform, gegebenenfalls nach vorsorglischer Isolierung der Abformmasse;
• – Ausgießen der Negativform, so dass die Zahnfleischmaske und das Modellanalog (Implantatersatz) im Gips eingebettet werden;
• – Aushärten des Gipses und dabei Fixierung der Modellanaloge; und
• – Lösen der Fixierschraube und Abziehen des Löffels zusammen mit Abdruckmaterial und eingebetteten Übertragungspfosten.

To create the plaster model from the negative mold, the following additional steps (2nd impression) are required:

• - Connecting a so-called model analog, so an implant replacement set to replace the original implant in the gypsum model and has identical connections for the transfer post and the fixing screw as an original, with the transfer post by means of fixing screw;
• - Building a gum mask, z. B. by means of silicone material as gum substitute in the negative mold, optionally after pre-isolation of the impression material;
• - pouring out the negative mold so that the gingival mask and the model analog (implant substitute) are embedded in the plaster;
• - hardening of the plaster while fixing the model analogue; and
• - Loosen the fixing screw and remove the tray together with impression material and embedded transfer posts.

The Gypsum model now has the embedded model analogues that are in Recesses in the gingival mask become visible. The dental technician can now use the abutment posts / implant posts and the tooth or model prosthesis or bridge.

There are a number of other analogous Areas of application with comparable accuracy problems, to which the invention can be transferred analogously. In detail:
In particular, the invention also relates to a method and devices for creating a master model of the jaw situation of a patient for the preparation of dental prostheses with double crowns / superstructures on implants.

For the preparation a high-precision Working model by means of elastomers (Thiokolen, siloxanes, polyether gum and vinyl polysiloxanes) a so-called individual spoon is recommended. Be with him Volume changes, caused by thermal expansion coefficients and shrinkage shrinkage, counteract effectively.

at the precision impression with ready-made and torsion-individually made, the tray adapted to the impression object, lead endogenous Stresses in the layer thickness of the impression material to dimensional changes in the impression. This leads to transfer falsified Information of the jaw situation on the master model, thus no longer match, d. H. are no longer in relation. The model is not distortion free and does not represent a dimensional representation of the jaw situation represents.

These Discrepancy is particularly in the impression of implants accordingly problematic because the implant positions are due to a faulty Impression no longer correspond to the jaw condition and with the transfer take a wrong positioning on the master model. It arise not harmoniously corresponding model analogues with the Implants in the jaw.

impression materials shrink concentrically if they are free in space z. B. if they are not on the impression tray by adhesive Stick medium or mechanically. This has a reduction of the negative form result. If the impression material is fixed to the impression tray, it will shrink eccentric to this and leads to enlarge the Negative form; the model is oversized. The bigger the Layer thickness and amount of the impression material compared to the volume of the abformiert body are, the bigger also the absolute increase of the model volume.

The precision impression sets the default for the work document on which dentures are made. The accuracy of fit a superstructure is in relation to the specification, however Endoge tension of the impression does not exclude. Thus, the transmission and fixation of a super-construction accurately fitting on the model on the implants in the jaw only by manipulating the design, Impression or model possible.

dentures will be customized according to needs and purpose of the patient manually or more today with use of machines and CAD-CAM in very different Designs and production methods are created, dentures are used as fixed, removable, and conditionally removable constructions made. Are known: crown, bridge and total denture. These are either made of only one material or are combined in combination of several materials. For this purpose, biocompatible materials are preferably used, such as special plastics, precious and non-precious metals, in alloy or as pure metal as well as ceramic and zirconium dioxide. In the preparation of come very different production practices and procedures and special equipment in use, with the conventional dentures of machine Production increasingly replaced becomes.

at the dentures manufacture, z. B. crown, is over a ground tooth stump or implant abutment on a previously created plaster or plastic model a true-to-life model of wax or plastic of the tooth to be produced manually modeled in 1: 1 and then cast in metal, or from ceramic presstechnisch, also stratification technology, or from Plastic press, cast or stratified implemented. adversely to lead Numerous factors of production lead to non-constant results Dentures in all areas of dental laboratory productions. Special Skills and comprehensive material knowledge are in addition to general Expertise needed to make dentures. Physically Conditional negative process developments as well as chemical influences to lead despite many years of experience again and again to errors in manually created dentures. The manual production is limited in the time frame and not Finally, qualified personnel is also expensive. Computer-aided manufacturing is cheaper and very advanced. It caters for all indications of restorative Dentistry variable internal and external systems for manufacturing of modern dental prosthesis products for almost all possible solutions in every imaginable way Materials on.

CAD-CAM Displace procedure increasingly the faulty manual production. trend-like Enable production methods today also the use of special materials with advantageous Properties, such as the pure titanium, which industrially as a block for the CNC production produced no cast contaminants and porosities and of identical nature with inserted titanium implants harmonizes well. In addition, there is no negative ion migration and bone destruction by electrolysis.

metal-free Dentures are a desired goal in dentistry. This requires special, break-resistant, stable ceramics that are compatible with the Zirconia material is the best way to do it. Be hers introduction 1998 permit steadily improving computer systems and software with innovative solutions meaningful constructions and expand the range of dentures. The known advantages of zirconium dioxide were due to already proven hip implants clinically completely safe for years, are successfully used in the dental field. Nevertheless, the relatively short test phase predicts as at the graceful scaffolding good expected results with metal-free dentures.

Especially In the field of implantology offers this ceramic material decisive aesthetic Advantages over metallic, light-absorbing constructions. Has zirconium dioxide excellent material properties and allows stable relative graceful constructions because of enormous strength. The CNC production allows long-span All-ceramic constructions that fit perfectly on the model. In implantology, it has therefore become the drug of choice because it is also unlike titanium plaqueunanfällig.

To come the prefabricated components produced from the metal and novel materials with specially suitable material properties, which are very difficult or impossible to produce in the laboratory. Of decisive advantages are the reproducible results with excellent fit results and exact products alike lasting quality. These production methods are cheaper due to external outsourcing. As here also plasters and plastics for almost all system-related model materials according to customary impression techniques emerge is the real problem of non-corresponding Model analogues and implants still present.

Independent of the way of dental prosthesis production but this fits just fit on the model. When creating dentures in the CAD-CAM, z. B. also in rapid prototyping, of the ground by the dentist Tooth stump or implant abutment on a previously created model made of plaster, plastic or for the respective applied system according to virtual material digital capture by scanning with a lab scanner or externally at the Use of a 3D planning with computed tomography a transmission for a true to original model of the tooth to be produced with appropriate Computer software and hardware designed.

The digital data acquisition and transmission on the working model does not question the impression type, but rather the deformation reactions from the working model creation, because by contractions such as expansions in the material produced Accuracy of dentures not reflected on the jaw is. In the copying process, the transmission is carried out by means of manual Sampling or, as with CEREC System Sirona, with appropriate hardware and software. Again, the production of the dentures after an impression and working model production.

Of the However, accuracy of the impression of a patient's dentition are certain Set limits. For example, the imprint d. H. the Negative form of a patient's dentition, based on irreversible elastomers Impression materials such as, A-silicones and polyether based, as well as for reversible hydrocolloids and alginates, which are water-based build up, with mistakes. The aforementioned materials and almost all known impression materials are subject to thermal Reactions that lead to residual stresses during the setting process. During the Abbindprozesses and after lifting these residual stresses naturally to deformations in the negative impression. Furthermore arise when lifting the straight Bound impression of the jaw low but equally irreversible Deformations in the impression material, which when pulling off the jaw of the Patients for make further inaccuracies. Especially because when peeling too Undercutting and non-parallelism are to overcome, which also in best possible Compliance with the recommended 4 mm space between teeth and Impression tray wall can not prevent this as well. The deformation of the impression material must not exceed 30%. Otherwise it comes to an irreversible compression. That from the literature taken speaks for yourself.

Also if the maximum recovers of impression material is given up to 98% so put the 2% non-provision as well a dimension change which impact three-dimensionally and in implant prosthetics to the greatest difficulties in the transmission of fits leads. The occurring inaccuracies are also natural tooth not uncritical in dental technology, even after insertion of the Dentures, z. As a crown, bridge, etc., the contact with it kicking teeth within certain limits yield because of the elastic periodontium apparatus can. So can too short and too long crowns, as too narrow or too wide Marginal conclusion resulting from the aforementioned 2% non-provision. The above inaccuracies are particularly problematic in implant prosthetics.

On implants worn dentures, so-called superstructure consists of several Components. A superstructure is superimposed on the implant. The number of implants determines the extent and construction type, which also requires appropriate construction in connection with natural tooth roots, or prepared natural dental abutments. The implant is inserted into the jawbone by the dentist or surgeon, surgically inserted or implanted. Multi-part implants are connected via a connector (implant post or abutment) to the tooth crown, bridge or denture.

implants usually consist of the metal titanium, which is especially for this well-suited and clinically well proven. Provide aesthetic benefits made of zirconium oxide implants, the technical reasons with the implant structure in one piece are made. One differentiates with implants one-piece and multi-part components, wherein one-piece so-called single-phase implants consist of one part, namely the artificial one Tooth root with tooth stump. Multi-part or multi-phase implants consist of several components and are partly in combination with titanium and zirconium dioxide or other combinations with biocompatible Material components assembled.

at The implant types exist several systems that vary greatly are designed; these can be made in the form of a screw or a cylinder and are between 4 to 16 mm long.

at multiphase implants, the tooth root is over a titanium screw inside over a joint fixed with the implant post. Other systems fix by snap closure. About the Abutment, the denture is the crown, bridge or denture firmly, or even removable from the patient or only conditionally in the dental office detachably attached.

The joint can also be made of titanium or zirconium dioxide. Of the Dentures crown, bridge or prosthesis is in conventional Made in a manner and on the implant or implants assembled.

adversely is, however, that while the implant inserted in the jaw is not to be able to give way or avoid at loads, but rigid in the Bone stores. Therefore, you can Inaccuracies in the - necessarily two - fold impression of the Patient dentition can not be compensated.

It can not, custom-made constructions that are on the model or via CNC are made exactly with non-corresponding model analogues and implants of a patient's jaw to integrate easily. The implant systems lead to overcome the fit problem special, very precise Ausbelichteile with Composite on the model or in the mouth glued the individual elements connect. Prostheses and bridge constructions be done by appropriate consideration in the production for this coincidence prepared.

to solution the well-known fit problem are in the implant technology also very expensive processes, such as the SAE-Secotec spark erosion process used in the dental laboratory. The spark erosion is for elimination of metallic interfering contacts when dentures. Field of application of the method are primarily the superstructures and bars for implant blocking. This and the Cresco method, in which the fit - accurate basal surfaces of the Construction to be separated and after fixation by means of laser corrected again attached will clarify the topic of fit difficulties. This Effort like all other techniques does not have the real problem the inaccuracy between model and jaw situation, the relation help. If on the model dentures fit exactly, so it does not fit in the mouth, if not identical specifications to disposal stand.

So represents the oral contraception For years, the only alternative dar to achieve uncomplicated useless Results. The established method originally came from electroplating and allows the joining the construction elements orally. This is the superstructure with tilt-free clearance built with the so-called secondary parts the tertiary structure Glued in the patient's mouth with special adhesives, composite adhesive. The bond and the composite seal the glue joints. Of the so-called tricolor effect in the field of adhesive bond is ever after construction unavoidable.

As well have become so-called transmission keys for Prevention of oral contraception proven in the patient's mouth for the connection and transmission of fixed individual components serve a superstructure. These from the Doppelkronentechnik known transmission method is also with joining material Plastic applied orally and in the lab is the current situation play on a newly created model. These, in principle Proper approach can also provide useless models, because here too by contraction and or expansion, the respectively used Model materials it comes to deformations and thus to the position change. Tensions in the constructions are noticeable in the mouth.

The goal of a master model is to enable precise dental prosthesis production. This must be The conditions for correct impression taking and exact model production meet the requirements.

Of the The invention is therefore based on the object, an improved method and devices for creating a model of a patient's dentition to accomplish.

These Task is by a method or devices with the features of the independent claims. advantageous Embodiments of the invention are the subject of the dependent claims.

According to the invention is for Prevention of residual stresses when molding or pouring the forms to be molded suggest that the object whose position and orientation is to be transferred particularly accurately, first by a soft placeholder known from the prior art Impression or pouring is excluded. Thus, one allows the impression or Ausgießmasse a curing, without that can build up in the area of the object residual stresses because the object not with the impression or Ausgießmasse comes into contact. According to the invention is thus make sure to wear that while of curing the impression or pouring material remains a free space around the object. The remaining space around the object is in another Stiffened step, for example, by pouring the space after removal of the Platzhalter or by curing of the placeholder. Because the volume of the free space is very small in relation to to the volume of the total impression or spout is, can only comparatively low residual stresses and thus potential Build inaccuracies. The inevitably associated with each hardening As a result, deformations acting on the object are smaller than in an impression or spout of the known type. There may be several Objects are simultaneously selected on a shape to be formatted and transferred according to the method become.

• – eine erste Abformung, bei der das Patientengebiss die abzuformende Form bildet und ein Übertragungspfosten als Objekt vorgesehen ist, welcher auf einem Knochen des Patientengebisses fixierten Implantat lösbar befestigt ist, und
• – eine zweiten Abformung, bei der die in der ersten Abformung abgeformte Negativform die abzuformende Form bildet und ein sogenanntes Modellanalog als Objekt vorgesehen ist, welches auf einem in der Negativform fixierten Übertragungspfosten lösbar befestigt ist.

To carry out the method, it may be necessary for the object to be permanently but detachably connected to the mold to be shaped, since it is fixed in the impression or pouring material after the free space has been stiffened. Therefore, the method according to the invention is particularly suitable for the creation of a model of a patient's dentition for the preparation of dental prostheses that can be fixed on implants. Two impressions are made, namely

• A first impression, in which the patient's dentition forms the form to be shaped and a transfer post is provided as an object, which is detachably fastened on a bone fixed to the patient's denture fixed implant, and
• A second impression in which the negative mold formed in the first impression forms the mold to be formed and a so-called model analog is provided as an object which is detachably fastened on a transfer post fixed in the negative mold.

These Steps have the goal that the implant in the jaw same position and alignment as the model analog has in the model, or correspond identically. Accordingly leaves the teaching of the invention also on other situation impressions for the creation of dentures, z. B. crowns, double and multiple crowns transferred. This forms the Patient dentition with scaffold the shape to be shaped and the framework crown detachably connected thereto the object.

The in the embodiment described fixation by means of fixing screws (in the so-called open Mouth impression with spoon with recess) is only one way of refinement a detachable one Fastener between abformed form and object. It can also be one-click, Push-on or snap-in connections can be selected. These allow a so-called closed mouth impression, in which the form attachable transfer caps be embedded in the impression mass using a conventional Impression tray. This needed no recesses.

If a reactive material is used as a placeholder, which only hardens when the impression or pouring material has already hardened, the impression tray need not contain any recesses, ie the placeholder need not be accessible. It thus eliminates work steps. The reactive material is preferably activatable in such a way that it begins to cure with a time delay upon contact with the impression or pouring material. The time delay is to be selected such that after contact first the impression or pouring material hardens and the placeholder only then hardens. As a result, each primary structure can be accurately embedded by the impression according to the invention:
The method is suitable for embedding any object or primary structure which is permanently but detachably connected to the mold to be molded.

There are also so-called functional imprints feasible. In this case, a primary structure, for. As a crown frame, initially placed in the mouth on the tooth stump or the implant and taken a first impression. The primary structure serves as an object, which is provided with a placeholder before the impression. Since it is a closed impression, the inaccessible placeholder must consist of the above-described reactive material. He stays soft during the Impression hardens and hardens only then. In the second spout of the newly formed negative mold, in which the primary structure is embedded, the primary structure is first with a suitable fixation z. B. the common double pin provided. The latter serves as an object and is provided in accordance with the invention with a corresponding placeholder.

For a better understanding, the individual process steps and advantageous embodiments will be described later on the basis of 1 to 4 exemplified with implants.

The Procedure can also be performed when the object is solid and indissoluble with the shape Form is connected. A prepared tooth stump or implant-attached abutment may be such an object be. After the stiffening of the free space can then the impression together with the stiffened space be deducted.

According to the invention also for implementation claimed the necessary apparatus devices. The usage an elastic sleeve as a wildcard it to the dentist or dental technician quickly and without much work the placeholder on the object, so usually the transfer post or to apply the model analog. An industrially manufactured prefabricated Sleeve as Placeholder offers about it In addition, the advantage of big Regularity, so that later to be cured Volume very even, in particular is rotationally symmetric. The spout is thus around the object a substantially equal wall thickness.

The low remaining residual stresses or shrinkages Contraction or expansion during expansion therefore essentially occurs symmetrical so that caused by shrinkage or expansion Inaccuracies remain very small. This is an advantage over that individual modeling of a wax sleeve on the object. The elastic Embodiment of the sleeve allows a slight pushing on the object and further the unproblematic Pull out the cast in placeholder. This must namely between the object and the potting compound are pulled out.

In In another advantageous embodiment, the placeholder is self-centering designed in relation to the object. This compensates when curing occurring residual stresses. A self-centering sleeve can For example, be realized by the fact that fins inside, in particular pointed inward Lammellen, z. In triangular form, extend. After putting on the object, for example a transfer post, Model analog or a scaffold in crowning, and short twisting of the sleeve, this is symmetrical on the object. Allow slats at correspondingly resilient outer walls of the sleeve also such a placement on objects with irregular cross section (eg oval, rectangle, triangle, any cross section). The outer walls follow the form.

A Another advantageous embodiment provides a rotation in Terms of the outer surface of the Placeholder before. This prevents the sleeve from accidentally twisted. An anti-rotation can also consist in that the Cross section of the applied placeholder deviates from the circular shape, ie or triangular or oval. The cross section can be a property of the placeholder or arise only after touchdown. As a result, the spout thus essentially has one around the object same wall thickness

advantageously, The placeholder is made as an endless tube, that is all Elements, such as fins, recesses or notches run evenly parallel to the longitudinal axis. this makes possible an economical manufacture as an endless tube z. B. by means Extruder. Also, an economical production by injection molding is possible, so that the necessary during extrusion section is eliminated.

Out View of the dentist or dental technician changes comparatively Little in the known process of molding when the objects, for example, transfer post and model analogs already exist with placeholders, so factory be made with them. This also has the advantage that through appropriate measures, for example, detachable Gluing, etc., the placeholder particularly precisely symmetrical is aligned to the object.

A particularly user-friendly design provides for a curable placeholder. This is so soft in the ground state that during curing of the impression or pouring hardly, or no voltages can be transmitted to the object surrounded by the placeholder. Only after the curing of the impression or pouring material, the curable placeholder is activated and hardens. Known activations are in particular chemical activation and UV irradiation. The big advantage in terms of application technology lies in the fact that hardly anything changes for the dentist or dental technician during implant impression. The intermediate step "curing by UV irradiation" is only necessary after curing of the impression or pouring compound, and for the patient, the procedure used so far is merely extended by the times for hardening of the placeholder. The dentist or dental technician uses the provided with the curable placeholder transfer post or model analog as usual. The curable placeholder must, of course, if it has been connected to the object at the factory, no longer be pushed on, but may rest against the object inside. The placeholder thus essentially encloses the object.

Further Advantages will become apparent from the following description and the accompanying drawings. As well can The above-mentioned and still further features according to the invention in each case be used individually or in any combination with each other. The mentioned embodiments are not exhaustive to understand and have exemplary character. Showing:

1 Implants with an attached transfer post in the jaw before the impression;

2 the situation 1 after the impression;

3 the impression off 2 after transfer to a plaster model with placeholders placed on the model analogs;

4 the finished plaster model; and

5 a placeholder.

1 shows in the jaw 9 Screwed conventional implants. The dentist has so-called transfer posts 11 by means of a in the upper region of the transfer post 11 accessible fixing screw 12 screwed to the implants. A previously individually made impression tray made of plastic 7 was first put on trial to check if the fixing screws 12 through the in the impression tray 7 introduced recesses 71 fit. In the 1 bottom side of the impression tray 7 is then filled with impression material, for example silicone, and placed under pressure on the patient's jaw 9 pressed.

2 shows the situation after the impression. Between impression spoons 7 and gums 6 is now the cured impression material 51 made of silicone. The second implant 10 from the right shows the still before the impression on the transfer post 11 placed placeholder 3 , next to the transfer post 11 a free space 4 creates, in the no impression material 51 has penetrated. After hardening of the impression material 51 can the placeholder 3 forming sleeve are now pulled out, so that then the free space 4 poured out 53 can be. This may be a different material than the impression material 51 his or the same material. It is crucial that when curing the impression material 51 no tension on the transfer post 11 could be transferred. At the latest with the removal of the placeholder 3 is the transfer post 11 because of the surrounding free space 4 completely tension-free. The implant on the right shows the condition with silicon 53 filled open space 4 , Removing excess impression material on fixation screws 12 and placeholders 3 in the area of the recesses 71 of the spoon 7 occurs before setting or hardening of the impression material 51 ,

Now the dentist can fix the screw 12 to solve. The impression, consisting of spoon 7 , Impression material 51 , hardened filling 53 of the open space 4 and included transfer post 11 can now from the gums 6 and implant 10 be lifted off.

3 already shows the casting 2 , where the underside of the transfer posts 11 with model analogues 21 by means of the fixing screw 12 have been firmly connected. Thereafter, in the usual way, a gingival mask 61 made of silicone to the impression material 51 . 53 modeled. After that come placeholders again 3 for use; However, these will be the model analogues this time 21 ie those components that are in the model of the implant 10 replace, attached. As known from the prior art, then the negative mold thus formed with gypsum 52 or other application-suitable materials, e.g. As plastic or epoxy resin, poured out, during curing, the inevitable shrinkages because of the placeholder 3 and the space created by them 4 not on the model analogues 21 be transmitted. Then the placeholders 3 pulled out again and thereby resulting comparatively small and uniform space 4 poured out, for example by plastic 54 ,

The example shown here with several model analogues, preferably also first removes certain wildcards and the freed up space can be poured while others Placeholder first remain on the object. These are only after curing of the Removed spout. This will cause the negative mold to slip difficult because all objects are never exposed at the same time. Because The placeholders always cause a certain fixation.

4 shows the in plastic 54 cast model analogue 21 in the finished model. These were again the fixing screws 12 solved, leaving the impression tray 7 with impression material 51 . 53 and transfer posts embedded therein 11 could be removed. The dental technician can now the implant posts (not shown) on the model Analog 21 touch down and start building the tooth.

5 shows a placeholder according to the invention 3 made of a soft elastic material, eg. Silicone. The essentially cylindrical spout 3 is hollow inside and has several inwardly directed lamellae 31 on, which taper inward, The spout 3 therefore centers itself when pushed onto a suitable object. notches 32 are provided on the outer wall of the spout as anti-rotation. Preferably, these lie along the slats, so that the thicker wall thickness of the spout can be used in the region of the slats for the notches. The wall thickness W can therefore remain low, which leads to reduced residual stresses and wherein the spout can be easily bedded. Similarly, outward-facing slats or other raised shapes such as rounding for rotation security are possible.

The lambs 31 , as well as the notches extend in the longitudinal direction of the spout, so that it can be manufactured as a continuous strand, in particular by extrusion.

Claims (19)

Method for creating a model of a patient's dentition, wherein impressions and / or outpourings are made of a form to be molded, comprising the following steps: a.) Selecting an object ( 2 ) on the shape to be formed ( 1 ); b.) Providing the object with a placeholder ( 3 ), which is such that in the subsequent impression or spout a free space ( 4 ), which is essentially free of impression material ( 51 ) or pouring material ( 52 ), wherein the placeholder is surrounded by impression material or pouring material. c.) application of the impression material ( 51 ) or pouring material ( 52 ) on the form; d.) hardening of the impression material ( 51 ) or pouring material ( 52 ) and subsequent e.) stiffening of the free space ( 4 ) and thereby fixation of the object with respect to the cured impression material or pouring material; and f.) removing the impression material ( 51 ) or pouring material ( 52 ) together with the stiffened space and preferably the object of the shape to be molded. Method for creating a model of a patient's dentition for making implants ( 10 ) attachable dentures, with a first impression, in which the patient dentition the form to be molded ( 1 ) and a transfer post ( 11 ) as an object ( 2 ) provided on one in the bone ( 9 ) of the patient's denture fixed implant ( 10 ) is releasably secured, comprising the following steps: a.) selecting a transfer post ( 11 ) on the patient dentition to be formed; b.) Providing the transfer post with a wildcard ( 3 ), which is such that during the subsequent impression a free space ( 4 ), which is essentially free of impression material ( 51 ), wherein the placeholder is surrounded by impression material; c.) application of the impression material ( 51 ) on the patient's dentition; d.) hardening of the impression material and then e.) stiffening of the free space ( 4 ) and thereby fixing the transfer post with respect to the cured impression material; and f.) removing the impression material ( 51 ) together with the stiffened free space and the transfer post of the patient dentition to be molded. Method according to one of the preceding claims, wherein the impression material ( 52 ) using a spoon, in particular an individual spoon ( 7 ) is brought to the patient's dentition and during the implementation of steps c) -f) is continuously connected to the spoon, with the following step: - application of the impression material ( 51 ) on the spoon ( 7 ). Method according to one of the preceding claims, wherein the spoon is designed so that step e) is feasible and between step e) and f) of the transfer post ( 11 ) can be released from the implant, with the following step between step e) and f): - release of the transfer post ( 11 ) from the implant ( 10 ). Method according to one of the preceding claims, wherein the transfer post at its upper end a fastening means, in particular a fixing screw ( 12 ) for releasable attachment to the implant, comprising the following step: - making an individual tray ( 7 ) and introducing recesses ( 51 ) in the same for the transfer post ( 11 ) and / or fastening means ( 12 ). Method for creating a model of a patient's dentition for making implants ( 10 ) attachable dentures, with a second impression, in which the previously molded from the patient denture negative form the form to be molded ( 1 ) and a model analogue ( 20 ) as an object ( 2 ) is provided, which on one in the negative form ( 9 ) fixed transfer posts ( 11 ) is detachably attached, with the following steps: a.) selecting a model analogue ( 20 ) on the negative mold to be formed; b.) Providing the model analog ( 20 ) with a placeholder ( 3 ), which is such that during the subsequent pouring a free space ( 4 ), which is substantially free of spout material ( 52 ), wherein the placeholder is surrounded by pouring material; c.) Application of the pouring material ( 52 ) in the negative form; d.) hardening of the spout material and subsequent e.) stiffening of the free space ( 4 ) and thereby fixation of the model analog ( 20 ) with respect to the cured spout material; and f.) removal of the spout material ( 52 ) together with the stiffened free space and the model analogue ( 20 ) of the negative form to be formed. The method of claim 6, wherein the transfer post at its upper end a fastening means, in particular a fixing screw ( 12 ) for releasable fastening with the model analog ( 21 ), with the following step between step e) and f): - release of the transfer post ( 11 ) of the model analog ( 20 ). Method for creating a model of a patient's dentition for making implants ( 10 ) attachable dentures, comprising a first impression according to one of the preceding claims 1-5 and a subsequent second impression according to one of the preceding claims 6-7, Method according to one of the preceding claims, wherein as wildcard ( 3 ) a modeled wax layer is used, which in particular is rotationally symmetrical, wherein the step d) for stiffening the free space comprises the following steps: d1) melting out the wildcard ( 3 ) from the spout material ( 52 ); d2) completing the freed up space ( 4 ) with a pouring mass ( 6 ); and then d3) stiffening the pouring mass ( 6 ). Method according to one of the preceding claims, wherein as a placeholder an elastic sleeve, in particular a rotationally symmetrical Sleeve, used becomes. Method according to one of the preceding claims, wherein the elastic sleeve is configured such that they are pushed onto the object in step b) can. Method according to one of the preceding claims, wherein the step e) for stiffening the free space comprises the following steps: d1) pulling out the wildcard ( 3 ) from the impression material or pouring material; d2) completing the freed up space ( 4 ) with a pouring mass ( 6 ); and then d3) stiffening the pouring mass ( 6 ). Method according to one of the preceding claims, wherein the wildcard ( 3 ) is soft in the ground state and can harden activatable. Method according to one of the preceding claims, wherein the step e) for stiffening the free space ( 4 ) comprises the following steps: d1) activating the wildcard ( 3 ) in the impression material or pouring material; d3) stiffening the wildcard ( 3 ) in the impression material or pouring material Method according to one of the preceding claims, wherein in steps a) and b) the object ( 2 ) with the placeholder ( 3 ) before it comes in contact with the form to be molded. Placeholder, in particular for carrying out the Method according to one of the preceding claims. A plat holder according to one of the preceding claims, wherein the placeholder - like that elastic is that it is pulled out of a potting compound can; - out Materials consists of the potting compound no chemical compound received; - tubular is; - self-centering is such that when you put on an object of the placeholder centered on an object, especially by itself inwardly extending lamellae; - On its outer lateral surface a Anti-rotation, especially in the longitudinal direction extending recesses or bulges; and or - Essentially rotationally symmetrical is. Platinum holder according to one of the preceding claims, wherein the wildcard ( 3 ) soft in the ground state is hardened after activation. Object, namely Primary structure in particular transfer posts, Model analog or scaffolding for dental crowns with a placeholder according to one of the preceding claims.