WO2007028787A1

WO2007028787A1 - Ceramic tooth replacement and method for the production thereof

Info

Publication number: WO2007028787A1
Application number: PCT/EP2006/065992
Authority: WO
Inventors: Marcel Schweiger; Harald Bürke; Peter Burtscher; Volker Rheinberger; Josef Schweiger; Marlies Eichberger; Florian Beuer
Original assignee: Ivoclar Vivadent Ag
Priority date: 2005-09-05
Filing date: 2006-09-05
Publication date: 2007-03-15

Abstract

The invention relates to a tooth replacement, particularly a composite crown or composite bridge, comprising two independent components, i.e. an inner frame structure (1) and an outer facing cover (3), which are joined together by means of a connector material (2). Also disclosed is a method for producing said tooth replacement.

Description

Ceramic denture and method for its production

The present application claims the priorities of DE 10 2005 042091 and DE 10 2005 057410.

All documents cited in the present application are incorporated by reference into the present disclosure (= incorporated by reference).

The invention relates to dental prostheses, in particular composite crowns or composite bridges, consisting of two independent components, which are manufactured independently of one another or coordinated with each other and are interconnected by a Konnektormasse, and to a process for its preparation.

From the prior art, e.g. the patent or registration documents DE 198 53 949 C2, DE 199 24 1 16 A1, DE 198 16 546 C1, DE 36 04 059 A1, DE 299 23 370 U1, EP 1 484 030 A2, EP 0 824 897 A2, EP No. 0 599 187 A1, EP 0 904 743 B1, AT 350 713, US Pat. No. 5,775,912, JP 10075964, various possibilities of dental prostheses are known.

In the case of the framework materials used, a distinction is primarily made between metal and all-ceramic:

Ceramic dental prostheses made of metal-ceramic (the so-called metal-ceramic crowns or metal-ceramic bridges) are currently produced in 2 different processing techniques:

1. Laying of feldspar ceramics on a metal framework (eg Vita VMK® 68 / Degudent) In this process technology, a metal framework is first produced by casting in the Lost-Wax process. On a tooth stump model, the framework is modeled in wax, embedded in a casting mold and finally cast. The cast object must then be fitted on the artificial tooth stump. To veneer the framework, feldspar ceramic is applied to a metal framework and fired in several steps to the final shape. The veneering ceramic must be matched to the metal alloy in terms of its physical properties (eg thermal expansion coefficient = CTE, sintering temperature, etc.). On the Metal framework is first applied a covering opaquer layer, on the one hand to produce a good bond between the metal and veneering ceramic, on the other hand, a show through of the dark metal framework to be prevented. The conclusion usually forms a so-called stain and glaze brandy.

2. Production of a metal-ceramic crown in the pressing process In this technique, the anatomical crown shape or a reduced anatomical crown shape with wax is modeled on a metal framework. In the subsequent Lost Wax process, a glass ceramic mass is pressed onto the metal framework by means of a pressing process. After devesting from the investment material form the crown is finished either in painting technique or in reduced form with additional layering technique.

Both production methods show some serious disadvantages. In processes using layered ceramics, it must be applied by hand by the dental technician. This leads to the known high production costs of ceramic veneers. When working with fully anatomical or partially fully anatomical shape, they must also be waxed by hand, which in turn leads to high costs.

In the CAD / CAM range, there is currently only the option of either producing entirely anatomical dental crowns from metal or completely from glass-ceramic. Full metal crowns have clear aesthetic disadvantages as they are not tooth colored. All-ceramic crowns made of glass ceramic are aesthetically excellent, but show low strengths and are therefore unsuitable for many indications.

All-ceramic crowns and bridges are currently manufactured using 9 different machining techniques:

1. Laying feldspar ceramics on a refractory stump (eg Duceralay®). In this process technique, feldspar ceramics are applied to a refractory stump and fired in several steps to the final shape. After the last firing, the refractory stump is removed using a blasting process. 2. Production of a fully anatomical crown / bridge by pressing (eg IPS Empress®, IPS e.max® Press).

Here, the crown or bridge is fully anatomically modeled in wax and then converted in the lost-wax process by means of pressing technique in glass ceramic. By subsequent painting and glazing, the crown is completed.

3. Production of a glass-ceramic framework for crowns and bridges by means of pressing (IPS Empress®, IPS e.max® Press) and subsequent overlaying with veneering ceramic (silicate ceramics). The framework is also modeled in this technique and pressed in the Lost-Wax process. Subsequently, this is overcoated with a suitable veneering ceramic (silicate ceramic).

4. Slip technique in the inceram method (eg Vita Inceram®) A scaffold made of oxidic ceramic (eg AI2O3) is "slipped" onto a stump model, then sintered and then infiltrated with lanthanum glass removed with the sandblaster and completed the supply with a ceramic veneer.

5. Electrophoretic method (eg Wolceram®)

A scaffold of oxidic ceramic (eg AI2O3) is deposited on a stump model by means of electrophoresis in defined strength. The further steps correspond to point 4.

6. Production of a fully anatomical crown and bridge using the glass ceramic CAD / CAM process (Cerec® inLab with Vita Mark® or ProCAD®) Using CAD / CAM technology, a fully anatomical crown or bridge is milled out of a glass ceramic block and then painted and glazed ,

7. Fabrication of a framework structure made of glass ceramic in the CAD / CAM process and subsequent overlaying with veneering ceramic (IPS e.max® CAD) A glass ceramic framework made with CAD / CAM technology is then covered with veneering ceramic. This veneering ceramic is applied in powder-liquid technique by brush on the skeleton and sintered in a dental ceramic furnace. After working with rotating instruments, a stain and glaze mass fire is made, which completes the work. 8. Production of a basic framework made of high-performance oxide ceramic with subsequent veneering (eg Cercon® from Degudent, 3M ESPE Lava®, KaVo Everest® ZS, Ivoclar Vivadent E.maxZirCAD®, etc.) Using CAD / CAM technology or copy milling technology, a Scaffolding made of high-performance ceramics, which is then completed by veneering, as described in point 7.

9. Production of a framework made of the high-performance ceramic zirconium dioxide (ZrCh) and subsequent overpressing of this framework with glass ceramic in the Lost

Wax process (eg Cercon® Ceram Express from Degudent or IPS e.max® ZirPress from Ivoclar)

In this technique, a framework structure of ZrCh is produced by CAD / CAM or copy milling. Subsequently, this framework is grown to fully anatomical shape and over-pressed in the lost-wax process with a special, on ZrO≥ tuned press ceramic. The crown or bridge can then be completed either by further layering of cutting / transpamasse or by painting technique.

All these production methods show some serious disadvantages. In all processes in which layered ceramic is used, it must be applied by hand by the dental technician. This leads to the known high production costs of ceramic veneers. If the compression technique is used, the anatomical forms must also be waxed by hand, which in turn leads to high costs.

The production of fully anatomical crowns made of glass ceramic in the CAD / CAM process is inexpensive. However, this technique makes sense only in glass-ceramics, since fully-anatomical dental prostheses made of oxide ceramics give aesthetically extremely unsatisfactory results (too opaque framework). However, since glass-ceramics have low, material-specific characteristics, their field of application is very limited, d. H. These can not be used in areas with high chewing forces, otherwise a failure of the restorations is to be expected.

Prefabricated elements for the production of dental prostheses are known from DE 103 48 369 and from DE 103 48 370. These prefabricated elements are made on the substructure with the help of a connecting material (preferably plastic) applied and aligned by the technician in the articulator and then fixed by supplying energy. Since this alignment requires a certain mobility of the superstructure on the substructure, a certain margin is required between substructure and superstructure. An adjustment in the articulator by the technician is necessary because it is prefabricated elements that are not individually made for the individual patient. This has the disadvantage that the dental technician has to invest working hours in the alignment of such elements. Furthermore, the substructure has a uniform layer thickness, with the result that the superstructure has no uniform layer thickness. The result is tensions in the superstructure, especially when using ceramic materials for the superstructure, which can lead to cracks and fractures of this superstructure. In addition, the elements mentioned are applicable only in the premolar and molar area.

The document DE 199 44 130 A1 describes a method for the automatic production of dental prostheses using a standardized block of material. According to a variant of this method, an existing scaffolding, which is produced by milling, provided with a veneer, which is made of a block, is fitted on the framework of ceramic, plastic or metal and on the framework adhesive, by sintering or by diffusion processes is attached. A ceramic connector mass is not mentioned.

From the document DE 36 04 059 A1 it is known that in a ceramic composite crown the outer shell used is made of refractory substance whose inner surface is coated with a low-melting substance, which combines with the low-melting mineral Unterbaumasse.

In the method for treating the attachment surfaces of a milled tooth restoration according to DE 197 27 264 A1, a glass powder is fired as a glass intermediate layer.

The specifications EP 1062916 A2 and US 5,092,022 A describe a dental prosthesis which is composed of milled individual parts. Ceramic Konnektormassen are not mentioned in these documents.

The object of the present invention was therefore dentures, in particular composite crowns or composite bridges, consisting of at least two independent components, which no longer have the disadvantages of the cited prior art, as well as to provide methods for its production. A particular aspect of the task according to the invention was to produce ceramic dental prostheses, in particular ceramic composite crowns and composite bridges, anatomically shaped by means of CAD / CAM methods for each individual patient and to specify a method for the production thereof, and the composite crowns and composite bridges thereby have strength values which are well above that previously produced in the CAD / CAM method, anatomically shaped, glass-ceramic prosthesis and at the same time have the aesthetic advantages of glass-ceramic dentures.

This object is achieved by the prosthesis set out below and the method described below.

In the context of the present invention, all quantities are, unless stated otherwise, to be understood as weight data.

In the context of the present invention, the term "room temperature" means a temperature of 20 ° C + 2 ° C.

Unless stated otherwise, the reactions or process steps given are carried out at normal pressure (atmospheric pressure).

In the context of the present invention, the term "composite" means physical and / or chemical mixtures or compounds of polymers, copolymers or mixtures of polymers or copolymers with at least 10% by weight of one or more inorganic substances may be preferred, pigments, fillers and / or glass fibers of various

Length and diameter.

The term (meth) acrylic is intended in the context of the present invention both

Methacryl and acrylic or mixtures of both.

In the context of the present invention, the term connective mass means a solid and / or liquid mass which connects two independent components with one another. The terms veneer or veneer are used synonymously in the context of the present invention.

The acronyms CAD and CAM are understood within the scope of this invention, as used e.g. in Römpp Chemie Lexikon, 9th edition, Bandi, 1989, pages 541 and 565 are shown. In addition, since the terminology CAD / CAM is known in the field of motor technology, further or more precise embodiments are well known to the person skilled in the art

Unless otherwise indicated, all percentages in the description are percentages by weight and compositions add up to 100% each.

The dental prosthesis according to the present invention is produced from at least two individual components, preferably by a computer-aided method, particularly preferably by a CAD / CAM method. The at least two individual components are connected to one another in a joining step, preferably by means of a connector mass. The inner framework structure preferably consists of

(I) metal, preferably titanium or gold, particularly preferably titanium or

(II) dental alloy, in particular a non-noble metal alloy (NEM alloy) and / or a noble metal alloy (EM alloy) or

(III) oxide ceramic, in particular Al 2 O 3, with Y 2 O 3, CeO 2, CaO and / or MgO stabilized tetragonal ZrO 2 and / or a mixture of Al 2 O 3 and stabilized ZrO 2 ceramic or glass-infiltrated oxide ceramic or

(IV) glass ceramic, in particular lithium disilicate, feldspar, leucite, SiIi katkeramik and / or apatite or a mixture of two or more of these components.

In particular, the inner framework structure consists of a metal framework and / or of a high-strength framework ceramic, in particular of a metal framework and / or an oxide ceramic. Most preferred is a ZrO2 framework.

The outer veneer or veneer is preferably made

(A) glass ceramic, in particular lithium disilicate, feldspar, leucite, silicate ceramic and / or apatite-containing ceramic or

(B) glass ceramic and glass, in particular lithium disilicate, feldspar, leucite, silicate ceramic, apatite and / or silicate glass or

(C) plastic, in particular acrylic and / or filled composite or a mixture of two or more of these components. Preferably, the outer veneer is made of a silicate

Veneering ceramic material, in particular feldspar, leucite, silicate ceramic, apatite and / or silicate glass ground. Most preferred is a lithium disilicate glass-ceramic.

The composite of framework and veneering is preferably carried out by means of a

Connector mass consisting preferably made

(I) glass or glass ceramic, or (ii) adhesive cement or

(iii) primer and bonding, or

(iv) mixtures of two or more of these components, preferably of a low-melting glass ceramic (i) or a low-melting glass (i) in a sintering process. The term low melting means that glass or glass ceramic (i) a

Have melting point or melting range below the melting point or melting range of the inner framework structure and / or the outer

Verblendhülle lies.

In a preferred embodiment of ii) and iii) the connector mass is liquid at room temperature or at least viscous or by a slight supply of heat, i. at most 50 ° C, to liquefy. This simplifies the processing.

In the prior art, the temperature difference in the sintering between the sintering temperature and the softening temperature or the

Deformation temperature of the veneering ceramic in the minimum 50 ° C amount. However, this number only applies to two different ceramics, not points ii and iii. For ii and iii, there is no effective melting, just a change in consistency

(Viscosity).

According to the invention, a sinterable material is preferably used as Konnektormasse. For the purposes of the invention, sintering means a process which proceeds under certain temperature, pressure and atmospheric conditions and which brings about the transition of a collection of independent grains into a dense, mechanically strong structure whose properties correspond to those of a continuous phase.

Preferably, according to the invention, connector compounds are used which can be sintered under normal pressure. In particular, according to the invention Konnektormasse be used, which at normal pressure has a sintering temperature very close to the deformation temperature of the burn-stable lithium disilicate veneer. The temperature difference should preferably be greater than 50 ° C. Preferably, the Konnektormasse be sintered at 850 ° C. It is very particularly preferred for the connector material to crystallize during the sintering process, ie the sintering temperature is oriented at the temperature of the crystallization of the connector glass and the formation of a glass ceramic. As a result, an increase in the mechanical strength of the connector glass can be achieved, for. B. of less than 100 MPa in a connector glass ceramic having a strength above 300 MPa. In a variant of the present invention, the use of a glass ceramic, z. As the lithium metasilicate glass ceramic as Konnektormasse possible, which undergoes the same crystal transformation as the veneering ceramic.

Particularly suitable are those Konnektormassen whose crystallization temperatures correspond to those of lithium disilicate. Examples of systems which are particularly preferred according to the invention are, on the one hand, the lithium silicate systems already mentioned above which are preferably used as the veneering material and, on the other hand, the ZrO 2 -containing glasses and glass ceramics which are preferably used as the framework material. Both systems show crystallization at a temperature around 850 ° C. This also corresponds to the crystallization transformation temperature of the metasilicate or the crystallization temperature of lithium disilicate.

The sintering can additionally be improved by exerting a pressure on the connector mass during the sintering process itself. However, this must be done so that the pressure z. B. is generated by a weight that acts exactly in the "insertion direction" of scaffolding and veneer and a

Changing the fit of the restoration part is excluded. This additional pressure can increase the strength of the connection itself and minimize the presence of bubbles and voids in the connector layer.

Which combination of materials the specialist selects exactly from the respective indication and is readily apparent to the skilled person, since he knows the advantages and disadvantages of the various materials. For example, glass-ceramics as inner framework structures are only released for certain indications. Examples include bridge scaffolds that can be used in the frontal area, as well as single-tooth restorations.

The different components are now explained in more detail:

(I) Metal:

All metals can be used in the context of the present invention. Titanium, silver and gold are preferably used, the use of titanium being particularly preferred.

(II) Dental alloy:

Here are both precious metal alloys (EM alloys) such as high-gold cast or Aufbrennlegierungen, z. B. Degudent U, as well as precious metal reduced alloys in question. In the field of non-precious metal alloys (NEM alloys) CoCrMo alloys such. For example, use Remanium 2000. It is also possible to use a titanium-aluminum alloy

(III) Oxide Ceramics: The material used for this purpose is aluminum oxide (Al 2 O 3, eg Procera) and yttria-stabilized zirconia Y-TZP, especially 3 mol% Y 2 O 3 stabilized ZrO 2 3Y-TZP (eg Ivoclar IPS e.max® ZirCAD, KaVo Everest® ZS, Degudent Cercon®, 3M ESPE Lava® or Vita Inceram® YZ).

(IV) Glass Ceramics:

Lithium disilicate, feldspar, leucite, silicate ceramics and / or apatite, eg lithium disilicate IPS e.max® CAD and Press, feldspar ceramics (eg IPS InLine®, IPS Classic, Vita Omega® 900, Vita® VM 13, Vita Mark ® Il Blocs, Wieland Reflex®, Degudent Duceragold®, Degudent Duceram® Kiss), leucite (eg IPS Empress® Esthetic, IPS Empress® CAD) or fluorapatite glass-ceramic (eg Ivoclar IPS d ^' Sign®, IPS e. max® Ceram, IPS e.max® ZirPress). Particularly preferred are solid glass ceramics of the lithium disilicate type such as IPS e.max® CAD and Press.

(i) glass or glass ceramic:

Here, silicate glasses and / or glass ceramics with adapted sintering temperature and thermal expansion coefficient can be used, such as IPS e.max® glaze, IPS e.max® Ceram, IPS d.SIGN®, IPS Empress® Esthetic Veneer. It is also possible to use mixtures of silicate glasses and glass ceramics.

(ii) adhesive cement:

Light-curing cements (Variolink® Veneer) or dual-curing cements (Variolink® II) are conceivable. All cements have in common that they contain 15-50% methacrylate monomer and 50-85% filler. Since the curing of the cement takes place extraorally, a hot-curing cement is also suitable in which the light-curing initiator system is replaced by a thermosetting initiator.

(iii) primer and bonding:

Silicate ceramic surfaces are treated with a silane primer (Monobond®S) to ensure an optimal bond between ceramic and adhesive cement. On metal or zirconium a metal / zirconia primer is conceivable. Instead of the cement, unfilled bonding (Heliobond®) is possible for very narrow joints (<20 μm).

(A) Glass-ceramic: Lithium disilicate, feldspar, leucite, silicate ceramic and / or apatite, eg lithium disilicate IPS e.max® CAD and Press, feldspar ceramic (eg IPS InLine®, IPS Classic, Vita Omega® 900, Vita VM ® 13, Vita Mark® II Blocs, Wieland Reflex®, Degudent Duceragold®, Degudent Duceram® Kiss), leucite (eg IPS Empress® Esthetic, IPS Empress® CAD) or fluorapatite glass ceramic (eg Ivoclar IPS d ^' Sign ®, IPS e.max® Ceram, IPS e.max® ZirPress)

Milling blocks from the material group (A) can be used for the veneering of metal frameworks.

Milling blocks from material group (A) can be used for the veneering of frameworks made of high-performance oxide ceramics. Preference is given to existing CAD / CAM blocks of the following silicate ceramic compositions: Ivoclar IPS e.max® CAD, Ivoclar IPS e.max® ZirPress, Ivoclar IPS e.max® Press, Ivoclar Empress® E2, Ivoclar ProCAD®, Vita Mark® II, Vita Triluxe®.

(B) Glass ceramic and glass: Specifically, the glasses and glass ceramics from the Ivoclar Vivadent patents (applications) should be mentioned:

^■ * Alkali silicate glass (EP 0 885 606 A2) ^■ * Translucent apatite glass ceramic (EP 0 885 855 A2) ^■ * Leucithated phosphosilicate glass ceramic (EP 0 690 030 B1)

^■ * Alkali-zinc-silicate glass-ceramics and glasses (EP 0695726 A1) ^■ * Tiefsinterndes potassium-zinc-silicate glass (EP 0001 170 261 A1)) ^■ * ^• Tiefsintemde apatite glass ceramic (EP 0001167311 A1) ^■ * ^• ZrO ₂ -containing glass ceramic (EP 0 690 031 A1) ^■ * Sinterable lithium disilicate glass ceramic (EP 0000827941 A1)

-> Apatite glass ceramic based on silicate oxyapatites (EP 1 584 607

A1) -> Translucent and radio-opaque glass ceramics (EP 1 514 850 A1)

The dental glass ceramic may contain SiO 2, Al 2 O 3 and P 2 O 5 as main components. As additional components z. B. Na2θ, K2O, B2O3, U2O, ZrO2, CeO2, O2, ZnO, CaO, La2θ3, Tb ₄ Oz or fluoride are used. Preference is given to alkali metal oxides, in particular Na 2 O or K 2 O, into consideration.

In addition to main crystal phases of leucite, apatite and / or lithium disilicate, it is also possible for further secondary crystal phases to be present in the dental glass ceramic. For such secondary crystal phases, starting from the composition of the starting glasses, such as lithium phosphate or monazite or xenotime into consideration.

The mixed crystal ceramics described are also compatible with other dental glass ceramics, e.g. Leucite dental glass ceramics or leucite apatite dental glass ceramics. Thus, further applications of the dental glass ceramic according to the invention open up for the production of sintered glass ceramics with leucite and / or leucite-apatite glass-ceramic systems.

The further glasses are preferably selected from the group of opal glasses, alkali silicate glasses and / or low-temperature sintering potassium-zinc-silicate glasses and the other glass ceramics, preferably selected from the group of the deep-sintered apatite glass ceramics, the translucent apatite glass ceramics, the sinterable lithium silicate ceramics , the ZrO 2 -SiO 2 glass-ceramics and / or the leucite-containing phosphosilicate glass ceramics. The xenotime-type glass-ceramics can be mixed with other glasses and / or glass-ceramics. In this case, the xenotime glass-ceramic forms the main component in, for example, an inorganic composite. The glass-ceramics can be combined with a variety of other glass-ceramics to achieve the adjustment of certain optical, mechanical or thermal properties. Examples of such glasses or glass ceramics can be found, for example, in DE 43 14 817 A1, DE 44 23 793 A1, DE 44 23 794 A1, DE 44 28 839 A1, DE 196 47 739 A1, DE 197 25 552 A1 and DE 100 31 431.A1 Such glasses and glass-ceramics are preferably derived from silicates, borates or phosphates or aluminate-silicate systems. Preferred glass ceramics are derived from the following material systems: SiO 2 -Al 2 O 3 -K 2 O with cubic or tetragonal leucite crystals, SiO 2 -B 2 O 3 -Na 2 O, alkali silicates, alkali-zinc silicates, silico-phosphate systems and / or the SiO 2 -ZrO 2 G system. In the mixture of such glasses and / or glass ceramics with xenotime glass ceramics, the thermal expansion coefficient of the resulting mixed glass ceramics in a range of 7 to 20 ^* 10 ^{~ 6} K " ¹ , measured in the range of 100 to 400 ⁰ C, can be adjusted.

In addition, the dental glass ceramic may contain one or more coloring or fluorescent metal oxides. For this purpose, preferably metals from subgroups 1 to 8 with the rare earth elements of the Periodic Table of the Elements into consideration.

(C) plastic:

Commercially available, light-curing composite, such as Artemis®, Tetric® EvoCeram, Heliomolar®.

In the context of the present invention, e.g. Acrylic blocks can be used. These are preferably made of preferably non-crosslinked polymethyl methacrylate (PMMA).

Composite materials which can be used according to the invention are preferably composed of polymerized (and usually crosslinked) monomers which contain both inorganic and organic particulate or fibrous fillers.

The material group (C) can be used both as a short-term but also as a long-term temporary, since plastic materials in terms of appearance but also in terms of strength and Plaqueanlagerung the ceramic materials

(Glass ceramic or ceramic) are inferior. For a lasting supply Accordingly, such combinations are less preferred in the context of the present invention.

For the production of aesthetic restorations, the substrate, that is to say the inner framework structure, must not show through the outer veneer, therefore, in the context of the present invention, an opaque can be applied to the framework (except with glass ceramics). For this purpose, in particular, the adhesive cements are suitable because they can bring into the dental restoration by the fillers covering and / or fluorescent properties. Furthermore, the usual for this purpose

Ceramic materials and / or covering lacquers are used, but are less preferred in the context of the present invention. Translucent apatite glass-ceramic (EP 0 885 855 A2)

^■ * Leucithated phosphosilicate glass-ceramic (EP 0 690 030 B1) ^■ * Alkali-zinc-silicate glass-ceramics and glasses (EP 0 695 726 A1)

^■ * Deep-sintering apatite glass-ceramic (EP 0001 16731 1 A1) ^■ * ^• ZrO ₂ -containing glass ceramic (EP 0 690 031 A1) ^■ * Sinterable lithium disilicate glass ceramic (EP 0000827941 A1) ^■ ^ Apatite glass ceramic based on silicate oxyapatites (EP 1 584 607 A1)

The dental prosthesis according to the invention, such as ceramic composite crowns or composite ceramic bridges, is preferably divided into two separate steps, which are both carried out in a preferred embodiment by means of a computer-aided method, in particular by CAD / CAM method and both components by means of a Konnektormasse, preferably that described above Konnektormasse, zusammenfügt, preferably by a sintering fire.

The invention is applicable both in the anterior region and in the posterior region. The invention is intended both for ground tooth stumps and for implant abutments.

In the first step, a framework in anatomically reduced form is preferably produced by means of a computer-assisted method, in particular by means of CAD / CAM technology. If the inner framework structure consists of metal or of a dental alloy, however, this component can also be produced in an alternative embodiment by means of a casting process, preferably by centrifugal casting. If the inner framework structure consists of glass ceramic (IV), the inner framework structure can also be produced by hot pressing. The pressing technique for the processing of glass-ceramics is a common method for many years, which generates the necessary cavities using the lost wax technique, in which then the ceramic is pressed under pressure and elevated temperatures. The pressing on metallic or ceramic frameworks per se is also already known, so that in the context of the present invention, accordingly, a combination of materials or processing techniques is possible. Examples of these techniques are described, inter alia, in DE 44 23 794 C1, EP 1 396 237 A1, EP 0 781 530 or US Pat. No. 6,413,660.

For example, the inner skeleton structure may be milled from a metal blank consisting of the metal (I) or the dental alloy (II). It is likewise possible to mill or grind the inner framework structure from an oxide-ceramic blank. Milling or grinding can be done in green, flake or hipped condition.

The shape of the frameworks should be designed such that the outer surface has a cone angle alpha, cone angle alpha / 2 (4), which indicates the deviation of the framework conicity to the crown frame axis and bridge frame axis of> = 0 ° to the crown frame axis or bridge frame axis. In the edge area, the framework can be extended to the preparation margin, as well as a shortened framework is possible with a correspondingly wide groove. In bridge constructions, the shape must be made in the area of the intermediate member so that from basal in the direction of chewing surface also a cone angle alpha of> = 0 ° to the bridge frame axis must be present. The connectors must also meet this requirement, with a rounded design on the connector bottom to eliminate stress spikes from edges. In the case of bridges, the connectors and bridge members may be designed with both a fillet and a fillet to fit the veneer to be fitted later, the fluted construction resulting in higher overall strengths of the all-ceramic composite bridges. The frameworks of crowns and bridges are anatomically reduced Design, that is, the frameworks have a three-dimensional geometry, which is reduced by the wall thickness of the veneer against the fully anatomical outer shape of the restoration.

In the area of the crown edge, a glass-ceramic shoulder can be formed by the outer veneer envelope.

It is preferred if the inner framework structure is manufactured in a hocker-supporting, anatomically reduced form.

Accordingly, in the case of the ceramic tooth replacement as ceramic composite bridge in the region of the connectors, the framework on the side facing the tongue (lingual) and on the side facing the cheek (buccal) preferably have a groove which forms the termination for the glass-ceramic veneer in this area ,

Accordingly, in the ceramic denture as a ceramic composite bridge in the region of the intermediate member, the framework on the side facing the tongue (lingual) and on the side facing the cheek (buccal) preferably has a groove, which forms the conclusion for the glass-ceramic veneer in this area ,

In the second step, the corresponding veneer (= the outer veneer) is made.

This is preferably done in a computer-aided method, in particular in the CAD / CAM method, wherein a glass ceramic material which is suitable in the material-specific characteristic values (eg thermal expansion coefficient = CTE or sintering temperature) is milled.

The inner contour of the veneer corresponds to the outer contour of the metal framework, wherein for the joining of the two components, a joint gap on the inside of the veneer may be present, but also a gapless fit is also possible.

The outer shape of the veneer corresponds to the shape of the fully anatomical crown. If the outer veneer sheath is produced from a glass-ceramic block by means of CAD / CAM methods, it is also possible for large inner framework structures to produce the outer veneer in several parts. This is particularly advantageous when large (long-span) restorations must be produced and not sufficiently large glass ceramic blanks are available. It is inventively preferred if the outer veneer is made in a computer-aided process, in particular a CAD / CAM process, tailored to the outer shape of the inner framework structure or tuned.

In the third step, the joining of the two parts takes place by means of a connector ground, preferably by the connector ground described above. This is preferably a lower-melting connector compound. This Konnektormasse is given in a thin-flowing consistency on the inner surface of the veneer and then placed on the framework structure with a slight pressure. This step is done on the stumps of the master model. Then the assembled parts are lifted off, the excess of the connector mass is removed and then the restoration is burned in the conventional ceramic oven (eg Ivoclar P300, Ivoclar P500, Vita Vacumat® 40, Dekema Austromat® 3001) and the occlusion is then ground in after sintering together and the restoration completed in a glaze firing.

A second possibility for joining scaffolds made of oxidic high-performance ceramics as an inner framework structure and outer veneer shell is that the CAD / CAM block of silicate ceramic composition for the outer veneer shell is not completely crystallized. During the crystallization, the structure of the ceramic is rebuilt, so form, for example, acicular lithium disilicates. This causes the volume to decrease by a minimal percentage in the crystallization process (eg, IPS e.max® CAD blanks shrink by approximately 0.5% in the crystallization process). The construction of the outer veneer in this case must be such that the veneer made in the pre-crystallized stage fits snugly on the framework. The crystallization firing is now carried out in a fire together with the assembly by the Konnektormasse, so that the outer veneer very precisely adapts to the framework (in the case of IPS e.max® CAD firing takes place at about 850 ° C). Another effect of this method is the pressing effect of the veneer on the Konnektormasse, so that the extremely minimal space between the frame and veneer is filled optimally and without bubbles

It is preferred if the bonding of the outer veneer shell to the inner framework structure by means of the bonding compound takes place together with a crystallization firing of the outer veneer shell in a single sintering process in the ceramic furnace. Another type of attachment of dental restorations on tooth stumps is the cementation, for example, adhesive cements (ii) can be used based on polymerizable monomers. Also usable systems are the bonding systems of a primer and an adhesive, wherein the primer of the adhesion mediation of at least one system (tooth stump, restoration or restoration part) with the other is used. Specific examples of the pretreatment of the individual parts are:

> Precious metal:

Sandblasting and priming with S compounds silicating and silanizing (Monobond® S, Ivoclar Vivadent AG)> non-precious metal:

Sandblasting and metal primer (Metal / Zirconia Primer, Ivoclar Vivadent AG); Silicate (Rocatec®, 3M ESPE) and silanize

> Glass-ceramic: Silanization (Monobond® S)> Oxide Ceramics:

Silicating and silanizing; ZrC ^: also primer possible

Of course, the above-mentioned connectors are only real connection points if the inner framework structure and the outer veneer shell were not made in one piece; otherwise they are only imaginary connection points.

According to the invention, the connector mass can be preferred, in particular as a low-melting, thin-flowing ceramic composition, a) opaque properties, b) have translucent and transparent properties.

It may have either independently or in combination with a) or b) c) fluorescent properties.

For the joining of metal framework with veneer the Konnektormasse must have an opaque color, in order to avoid a shine through the metal framework.

For joining scaffolds made of oxidic high-performance ceramics with the veneer, the connector mass should have translucent and transparent properties in order to ensure the good optical properties of all-ceramic restorations. This can be achieved, for example, with IPS e.max Ceram or IPS e.max Zirliner from Ivoclar. The layer thickness of the connector mass is according to the invention in the range between 0.005 and 0.2 mm, preferably between 0.01 and 0.1 mm.

An additional increase in strength is achieved in that the inner framework structure is made in anatomically reduced form, so that the outer veneer has a uniform layer thickness and thus no internal stresses in the ceramic occur. This construction form is possible in that the geometry of the inner framework and the outer veneer are calculated by CAD to each other, so that both structures fit each other in an ideal manner without play.

In a preferred embodiment, the outer veneer is produced in a computer-aided process, in particular a CAD / CAM process, from a silicate ceramic, which is present in a pre-crystallized stage and which shrinks by a defined value in a subsequent crystallization process.

In a preferred embodiment, a Konnektormasse of a lower melting, low-viscosity ceramic composition is used, which connects the inner framework structure and the outer veneer in a sintering process in the ceramic furnace together.

Within the scope of the present invention, it is particularly preferred if, in particular in the case of composite bridges, both the inner framework structure and the outer veneer shell are each manufactured from one piece by means of CAD / CAM methods.

The various embodiments of the present invention, e.g. those of the various dependent claims can be combined with each other in any manner.

The invention is explained below with reference to six figures, which are to be regarded only as examples, but do not limit the invention.

Figure 1: Side section through ceramic composite crown

Figure 2: Side section through ceramic composite crown with ceramic

shoulder Figure 3: section through ceramic composite bridge in the longitudinal direction (sagittal

Direction)

FIG. 4: cross section through ceramic composite bridge in the region of FIG

Connectors Figure 5: Cross section through ceramic composite bridge in the region of

bridge link

FIG. 6: cross-section through ceramic composite crown in the posterior region with hock-supporting, anatomically reduced framework geometry

FIGS. 1 and 2 show a ceramic composite crown consisting of a framework 1 produced in the CAD / CAM process and a glass-ceramic veneer 3 produced in the CAD / CAM process, which are sintered together in the ceramic furnace by a low-melting connector compound 2. The angle alpha / 2 4 is> = 0 °. The layer thickness d of the connector mass 2 should be between 0.01 and 0.1 mm.

According to FIG. 2, it is also possible in the region of the crown edge for the glass-ceramic veneer to form a shoulder 5.

FIGS. 3, 4 and 5 show a composite ceramic bridge which likewise comprises a framework 1 produced in the CAD / CAM process and a glass-ceramic veneer 3 produced in the CAD / CAM process, which are sintered in a conventional sintering firing process by the bonding compound 2 dental technical ceramic furnace are interconnected.

The cone angle alpha / 2 4 is, as with the composite crown, at the composite bridge> = 0 °.

In the area of the "connectors" 6, the framework 1 forms on the side facing the tongue (lingual) and on the side facing the cheek (buccally) a groove 8 which forms the termination for the glass-ceramic veneer in this area The bridge framework also forms a lingual lingual and buccal border in the area of the pontic 7, as well as a border for the alveolar ridge (basal) 9 also bounded by the framework material which rests here against the ridge 1 0 basic veneer.

Corresponding to FIG. 6, the anatomically reduced geometry of the framework structure 1 produced in the CAD / CAM method is recognizable, so that the glass-ceramic veneer 3 produced in the CAD / CAM method has a uniform layer thickness having. This hump-assisting framework geometry 11 causes an increase in the strength of the veneer 3.

Claims

claims

1. Dental prosthesis, in particular composite crown or composite bridge, consisting of two components

- the inner framework structure (1) and

- The outer veneer (3), which are interconnected by a Konnektormasse (2).

2. Dental prosthesis according to claim 1, characterized in that the inner framework structure (1) of

(I) metal, preferably titanium or gold, particularly preferably titanium or

(II) Dental alloy, in particular a non-noble metal alloy (NEM alloy) and / or a noble metal alloy (EM alloy) or (IM) oxide ceramic, in particular Al2O3, with Y2O3, CeO2, CaO and / or MgO stabilized tetragonal ZrO2 and / or a mixture from Al 2 O 3 and stabilized ZrO 2 ceramic or glass-infiltrated oxide ceramic or (IV) glass ceramic, in particular lithium disilicate, feldspar, leucite, SiIi katkeramik and / or apatite or a mixture of two or more of these components.

3. Dental prosthesis according to claim 1, characterized in that the

Konnektormasse (2) from (i) glass or glass ceramic or

(ii) adhesive cement or

(iii) primer and bonding or a mixture of two or more of these components.

4. Dental prosthesis according to claim 1, characterized in that the outer veneer (3)

(A) glass ceramic, in particular lithium disilicate, feldspar, leucite, silicate ceramic and / or apatite-containing glass ceramic or

(C) plastic, in particular acrylic and / or filled composite or a mixture of two or more of these components.

5. A dental prosthesis according to claim 1, characterized in that the inner framework structure (1) of non-noble metal alloy (NEM alloy) and / or a noble metal alloy (EM alloy) or titanium, the Konnektormasse (2) of a low-melting glass ceramic and / or a low-melting glass and the outer veneer (3) consists of a feldspar ceramic, silicate ceramic and / or a glass ceramic.

6. A dental prosthesis according to claim 1, characterized in that the inner framework structure (1) of a high-performance oxidic ceramic, in particular Al2O3, with Y2O3, Ceθ2, CaO and / or MgO stabilized tetragonal Zrθ2 and / or a mixture of Al2O3 and stabilized Zrθ2- ceramic , the Konnektormasse (2) consists of a low-melting glass ceramic and / or a low-melting glass and the outer Verblendhülle (3) of a Feldspatkeramik, silicate ceramic and / or a glass ceramic.

7. A dental prosthesis according to claim 1, characterized in that the inner framework structure (1) and / or the outer veneer shell (3), in particular that the inner framework structure (1) and the outer veneer shell (3), in a computer-aided process, in particular a CAD / CAM processes are made.

8. Dental prosthesis according to claim 1, characterized in that the inner framework structure (1) and / or the outer veneer shell (3) are each made of at least one piece.

9. Process for the preparation of a denture by at least two components

an inner framework structure (1) and

- An outer facing shell (3) by a Konnektormasse (2) are interconnected.

10. The method according to claim 9, characterized in that the components (1) and / or (3), preferably (1) and (3) by a computer-aided method, in particular a CAD / CAM method, are produced.

1 1. A method according to claim 9, characterized in that the outer Verblendhülle (3) of a silicate ceramic or glass ceramic (in particular lithium disilicate, feldspar, leucite, silicate ceramic and / or apatite,) in a computer-aided process accurately on the outer shape of the inner framework structure (1) is produced.