DE102007043023A1 - Fastener for absolute removable of dental prosthesis, comprises ceramic component and another ceramic component, and third ceramic component consisting of plastic - Google Patents

Abstract

The fastener comprises a ceramic component and another ceramic component, and a third ceramic component consisting of plastic. The former component and the latter component are detachably connected with each other by the third component. The third component is firmly connected with the latter component. The third component is detachably connected or associated with the former component. An independent claim is also included for a method for production of fastener. The method involves milling a component and another component by a computer assisted Computer aided designingor Computer aided machining.

Description

Field of the invention

The Invention is in the field of dental technology and relates to a Connecting element for an absolutely removable denture and a manufacturing process for the Connecting element.

State of the art

In In dentistry dentures are divided into three categories, namely fixed dentures, which is removable only by destruction, in conditionally removable dentures removable only by the dentist and in necessarily removable dentures, by the patient at any time can be removed without assistance and used again. Absolutely removable dentures can be used as a total or partial denture in the latter case, a natural or artificial residual dentition must be present.

In Partial dentures are used connecting elements, the necessarily removable dentures with the remaining teeth releasably connect. In such For example, fasteners are parentheses, Joints, bars, attachments or telescopic crowns.

The Connecting element telescope crown, which has recently been used more in dentistry is one of two components Double crown, in which a primary crown ("inner telescope") on a corresponding groomed natural or artificial tooth cemented and an open cavity forming secondary crown ("External telescope") with an adhesive and / or frictional Connection to the outside wall the inner crown can be placed. To make a reliable releasable adhesive (on intermolecular forces based) and / or frictional Liability between primary and secondary crown To achieve this, it is necessary that the cavity forming Cavity wall of the secondary crown the surface the primary crown is very precisely adjusted.

primary crowns are hitherto made of metal, metallic alloys or ceramic Made of materials.

For metallic primary crowns Essentially, two different manufacturing processes come about Use, namely a production by Lost Wax process and a production using the computer-aided CAD / CAM process.

At the Lost-wax procedure is first a wax model of the primary crown modeled with wax on a tooth stump model and then using a manually operated milling device parallel-walled pre-milled. From the wax model, a mold is created, which then in a mold is bedded to the primary crown to pour. Finally done a fine machining with rotating instruments in a milling machine. At the computerized CAD / CAM (CAD = Computer Aided Design, CAM = Computer Aided Manufacturing) becomes the primary crown computer controlled by means of a milling device from a blank milled.

For ceramic primary crowns There are essentially four different manufacturing processes Use, namely a production of glass ceramic in the pressing process, oxidic High-performance ceramics in the electrophoretic process, made of oxidic High-performance ceramics using computer-aided CAD / CAM technology and out oxidic high-performance ceramics by means of manual copy milling technology.

at For the production by pressing, the primary crown is first modeled in wax and then in Lost lost wax process by means of pressing technique in glass ceramic implemented. Finally a fine machining with rotating instruments takes place in one Milling device. In the production in the electrophoretic method is first a framework of oxidic ceramic on a tooth stump model by means of electrophoresis in defined strength deposited, which subsequently sintered and infiltrated with Lanthanglas. After removing Lanthanglasüberschüssen takes place a fine machining with rotating instruments in a milling device. When manufactured using computer-aided CAD / CAM technology a computer-controlled milling from a blank by means of a milling device. In the preparation of by means of a manual copy router becomes the primary crown first from a modeling plastic on a tooth stump model by hand modeled and then in a sample and milling into a scaffold converted from oxidic high-performance ceramics. Finally done a fine machining with rotating instruments in a milling device.

secondary crowns are made of production reasons so far only from metallic Materials (noble, base metals, pure metal or metallic alloys) manufactured. In most cases, the secondary crowns are made of high-gold made of metallic alloys.

For metallic secondary crowns Essentially, two different manufacturing processes come about Use, namely a production in the Lost Wax process and a production by electroplating.

at the production of secondary crowns in the lost wax procedure, the secondary crown is completed on the finished primary crown modeled from wax or a modeling plastic, embedded in a mold and cast with the metallic material. The casting object becomes subsequently on the primary crown beware, whereby by the frictional engagement between primary and secondary crown a defined adhesion of the secondary crown is achieved. In the production of secondary crowns by electroplating is the finished primary crown by special procedures first made electrically conductive. The thus prepared primary crown is placed in an electrolytic bath, on the anode fine gold located and connected to the cathode. After applying an electric Strom's fine gold is deposited on the primary crown, where the thickness of the metal layer depends on the treatment duration and the current intensity. A defined adhesion of the secondary crown on the primary crown is achieved by the intermolecular forces in the boundary layer region (adhesion).

For high quality Telescopic crowns will be the primary crown usually made of a ceramic material (eg zirconium dioxide) and the secondary crown Galvanized from 99.9% fine gold. In this case is an example of titanium or a metallic alloy existing tertiary construction for reinforcement the secondary crown required the with the secondary crown is glued.

As shown above, the secondary crowns are so far exclusively from made of metallic materials. As has been shown, however can the metallic materials used here, for example due to interactions between different metals, in unwanted Way to incompatibility reactions in patients, leading to allergic symptoms. Should avoided such incompatibility reactions it is necessary to use biocompatible metals such as gold alloys, for the secondary crowns use, but this leads to very high production costs for the telescopic crowns leads and can not be realized by every patient.

As already described above, require secondary crowns from fine gold (not gold alloys) to obtain a sufficient Stability one reinforcing Tertiary structure, which often leads to oversizing the telescopic crown leads and for the Patients may cause an unpleasant foreign body sensation.

to Preparation of the denture is on the secondary crown, for example made of glass ceramic existing veneer, which is a natural Tooth as possible to be faithfully reproduced. Secondary crowns made of metallic materials However, they have the disadvantage that they are affected by the veneer reflect incident light in a manner which differs significantly from the light reflection of a natural tooth. this leads to often too aesthetic unsatisfactory results and is in terms of as possible low visual difference between natural and artificial tooth undesirable.

Farther the holding function is based on the lost-wax process Secondary crowns on a frictional Connection to the primary crowns, which is reduced by abrasion over time and lost completely can go. Equally it is possible even with galvanically produced secondary crowns a decline in the Determine holding effect. A satisfactory solution to this problem exists often only in a new production of the telescope crown, but what high production costs caused.

Summary of the invention

Object of the invention

In contrast there is the object of the present invention is a connecting element for an unconditionally removable denture, and a method for its production available too to avoid the above problems can. Thus, relatively inexpensive materials are used for the fasteners can be through the incompatibility reactions can be avoided and that too aesthetically lead to a satisfactory result. In addition, the connecting elements with comparatively low Manufacturing costs can be manufactured. Problems due to a decreasing holding action between the components of the connecting elements should be simple, reliable and cost-effective can be corrected.

Solution of the task

These and further objects are according to the proposal of the invention a connection element for a removable denture, as well as a method of manufacture solved such a connecting element with the features of the independent claims. advantageous Embodiments of the invention are indicated by the features of the subclaims.

According to the invention, a releasable connection element for a necessarily removable dental prosthesis is shown which comprises a first component consisting of a ceramic material and a second component consisting of a ceramic material which can be released (ie from the patient) removable) interconnected or are connectable.

In the connecting element according to the invention is for this purpose between the first ceramic component and the second ceramic component is a third made of plastic Part arranged. To detachable Compound of the first component and the second component the third component with the second component is fixed (in particular cohesively) connected and not firmly connected to the first component, but solvable (Removable from the patient) adhesive (on intermolecular forces the two interfaces based) connected or connectable. In addition, the third component optionally additionally releasably frictionally connected with the first component be or in a releasable frictional connection to be brought.

For a releasable adhesive connection between the third component and the first component It requires that the opposite surfaces of the third component and the first component in the context of certain inaccuracies (generally less than 1 ° deviation) parallel to each other. In addition, a (thin) gap ("micro-gap") between the each other opposite surfaces the third constituent and the first constituent are present the filled with saliva can be.

With the connecting element according to the invention is it thus possible for the first time that the two are detachable from each other Components of a detachable Connecting element can be made of ceramic material, which advantageously a relatively inexpensive production of the connecting element allows is, with the incompatibility reactions of the patient can be avoided.

As ceramic materials advantageously bioinert high performance ceramics (industrial ceramics) are used in the connecting element according to the invention, which are able to withstand high mechanical loads (tensile and compressive stresses, bending moments, etc.). This is particularly advantageous for high-performance oxide ceramics, for example zirconium dioxide (ZrO ₂ ) or aluminum oxide (Al ₂ O ₃ ).

In a particularly advantageous in terms of manufacturing technology embodiment of the connecting element according to the invention, the first component and the second component of a same ceramic material, such as zirconia (ZrO ₂ ), made.

at a particularly advantageous in terms of production engineering, further embodiment of the connecting element according to the invention the third component of a dimensionally stable and stable hardening Plastic (polymer), which flows before its polymerization is capable of forming. this makes possible an exact adaptation of the surface of the third constituent to the surface of the first constituent in particular by means of a so-called FGP procedure (FGP = Functionally Generated Path).

at the releasable connecting element according to the invention it can be, for example, a bridge, a bed load or a Telescope crown (parallel or cone crown) act. Especially advantageous is the connecting element according to the invention is a Telescopic crown, wherein, for example, the first component of the connecting element an inner telescope and its second component an external telescope the telescope crown are. In conventional Way forms the outer telescope in this case an open cavity in which the inner telescope at least partially receivable or received.

In In the latter case, it is particularly advantageous if the third Component with the external telescope is firmly connected and the cavity opening of an undercut held by the cavity bounding wall of the outer telescope is formed. This may cause the third component to slip out from the cavity of the outer telescope be effectively avoided in a technically simple manner.

In the connecting element according to the invention It is advantageous if the outdoor telescope by means of a copy router is made. Alternatively, it may be advantageous if the outer telescope by means of a computer-aided CAD / CAM milling process is made.

The Invention further extends to a necessarily removable (In particular partial) denture, which with a as described above Connecting element is provided. In such a necessarily removable Denture can be the first ingredient with a natural or artificial tooth of a patient, while the second component with a dental prosthesis forming veneer can be firmly connected.

Moreover, the invention extends to a method for producing such a connecting element, which comprises the following steps:
Production of the first ceramic component by means of a milling method, wherein the first ceramic component advantageously by means of a copy router or by means of a computer-aided CAD / CAM milling process.

manufacturing the second ceramic component provided with an open cavity by means of a milling process, wherein the second ceramic component advantageously by means of a Copy router or using a computer-aided CAD / CAM milling process milled becomes.

arrange a third component made of plastic between the first component and the second component, such that the third best portion is firmly attached to the second component and with the first component is not firmly connected, but solvable adhesively connected or connectable. This is advantageously done in such a way that made of a hardenable Plastic third ingredient on the second ingredient applied and thus firmly connected. Then be the first connection element and the second connection element the hardening of the third component (joined) and the third component cured in the assembled state.

at an advantageous embodiment of the method according to the invention will be on the surface of the first component, before assembling the first and second Component (before curing the plastic), a spacer serving as a spacer, after curing of the third component is removed again. About the thickness of the top layer, which after removing them to a corresponding gap between the both in an adhesive releasable Connection leads to bringing components can, in an advantageous manner targeted the strength of the adhesive Holds between the third component and the first component be set.

embodiment

The Invention will now be explained in more detail with reference to an embodiment, wherein Reference to the attached Figures taken.

Brief description of the figures

1 illustrates in a schematic sectional view a method step for producing a telescopic crown;

2 illustrates in a schematic sectional view of a further method step for producing the telescopic crown;

3 illustrates in a schematic sectional view of a further method step for producing the telescopic crown;

4 illustrates in a schematic sectional view of a further method step for producing the telescopic crown;

5 illustrates in a schematic sectional view of the placement of the secondary crown on the primary crown of the telescopic crown;

6 shows in a schematic sectional view of the finished telescopic crown.

Detailed description of the figures

In the 1 to 6 is an embodiment of the inventive method for producing an embodiment of the form of a telescopic crown 1 illustrated inventive connecting element.

Be first 1 wherein, in a schematic sectional view, a method step for producing the telescopic crown 1 is illustrated. In 1 is a primary crown in longitudinal section 2 (or primary framework) of the telescopic crown to be produced 1 shown.

The primary crown 2 consists of bioinert, oxidic advanced ceramics, such as zirconia (ZrO ₂ ) or alumina (Al ₂ O ₃ ), and is milled using a manually operated copy router or alternatively by computer-aided CAD / CAM technology in the desired form of a blank made of this material.

In 1 is the primary crown 2 shown in a vertical position, wherein the primary crown 2 forms a cavity not shown in detail, which has a lower cavity edge 4 is accessible. To prepare a dental prosthesis, the primary crown 2 firmly connected with a natural or artificial tooth of a patient, for which purpose the primary crown is slipped over the correspondingly prepared tooth and cemented, for example.

On a part of the surface of the primary crown 2 subsequently becomes a wax layer manually 16 applied with a minimum thickness of 0.2 mm. The wax layer 16 serves as a spacer for the secondary crown to be produced. Instead of wax, any other suitable as a spacer Ma material can be used, for example, a plastic film, the deep drawing process on the primary crown 2 is applied. In the case of the production of the primary crown 2 Using CAD / CAM technology, the spacer can be displayed digitally.

The on the surface of the primary crown 2 applied wax layer 16 ends about 1 mm above the lower cavity edge 4 , where the wax layer 16 a substantially perpendicular to the surface of the primary crown 2 lying stepped edge forms. The wax layer 16 forms in this way a so-called negative stage 3 , which in forming an undercut 10 in the forming material leads.

In 2 is another process step for the production of the telescopic crown 1 illustrated. This is a form 5 for the produced secondary crown (or secondary framework) made of a plastic on the surface of the partially with a wax layer 16 provided primary crown 2 modeled. As a plastic, for example, a micro-hybrid or Feinstpartikel composite can be used, for example, a mixture of urethane dimethacrylate and ethylene glycol dimethacrylate, which is marketed under the trade name "Synfonie" by the company 3M-Espe commercially. Likewise possible is the use of an autopolymer, for example a mixture of methyl methacrylate, ethyl methacrylate and N, N-dimethyl-p-toluidine, which is marketed under the trade name "Pattern Resign" by the company GC.

Subsequently, the shape 5 for the secondary crown to be produced from the primary crown 1 removed, serving as a placeholder wax layer 2 for example, removed by melting, and the shape 5 clamped in a manually operated copy router.

In 3 is the already finished secondary crown 6 shown, which is made from a blank, which in the copy router using a holding arms 8th provided fixing device 7 is clamped. Any other suitable method of attachment of the blank in the copy router is possible. For example, the blank in the fixing device 7 be glued. The blank or the secondary crown made therefrom 6 consists of bioinert, oxidic high-performance ceramics, for example zirconium dioxide (ZrO ₂ ) or aluminum oxide (Al ₂ O ₃ ).

In the copy router is by means of a suitable for the production of undercuts undercut router 9 the secondary crown 6 according to the previously prepared form 5 Milled, making one of a cavity wall 14 the secondary crown 6 shaped cavity 13 is trained. Through the undercut cutter 9 Can the by the negative stage 3 the wax layer 16 given undercut 10 be implemented.

The inner contour, that is the contour of the cavity wall 14 of the cavity 13 the secondary crown 6 corresponds after completion of the outer contour of the primary crown 2 with applied wax layer 16 , Would the secondary crown 6 now on the primary crown 2 are placed, so there is one of the wax layer 16 corresponding cavity between the primary and secondary crown.

Subsequently, the secondary crown 6 dyed in a conventional dyeing process to give it a color that corresponds to a natural tooth color. For this purpose commercially available classic Vitafarben can be used. The staining is followed by conventional sintering of the high performance oxide ceramics of the secondary crown 6 in a sintering furnace.

Thereupon will be on the surface 16 the secondary crown 6 a delusion 15 in a conventional manner, for example by over-pressing, applied. At the lingual (tongue-facing) and palatal (palate-facing) areas of the secondary crown 6 For reasons of stability, no veneering takes place, so that the secondary crown 6 in this area consists only of oxidic high-performance ceramics.

As in 4 is illustrated, after completion of the secondary crown 6 by means of a brush 12 (or for example a spatula) a layer of a polymerizable by polymerization plastic 11 on the cavity wall 14 of the cavity 13 the secondary crown 6 applied, which up to the undercuts 10 enough. In the plastic 11 For example, it is a mixture of acrylic resin, glass powder and silicon dioxide which further contains urethane dimethacrylate, aliphatic and aromatic dimethacrylate and carboxyl methacrylate. (Such a plastic is marketed by the company Bredent as so-called "FGP plastic" in the trade.)

Plastic 11 is sufficiently moldable or flowable to polymerize on the cavity wall prior to its polymerization 14 of the cavity 13 the secondary crown 6 to be able to be applied. By polymerization, the plastic cures and is dimensionally stable after curing.

Before applying the plastic 11 become the parts of the cavity wall 14 of the cavity 13 the secondary crown 6 , which with the plastic 11 Come in contact, conditioned to ei ne reliable cohesive (ie non-detachable or non-removable) connection between the plastic 11 and the cavity wall 14 to ensure. For this purpose, the known "Rotatec" method can be used, in which a silane layer on the surface of the secondary crown 2 is applied, which ensures a chemical bond to the plastic. Here are melted by a special blasting process in the surface to be coated due to a high impact energy particles, resulting in a silicization of Oberflä leads. An additional applied liquid causes a silanization of the surface, whereby the silane layer is produced.

The surface of the primary crown 2 will be in the places where they are in contact with the plastic 11 passes, covered with a thin cover layer not shown in the figures, which during curing of the plastic 11 serves as a spacer. The cover layer consists of a material suitable for its function as a spacer, for example Vaseline, wax and the like.

In the case of a partial denture without bridge construction, the secondary crown 6 connected by means of an adhesive bond with a metal-free framework construction, for example, oxide high performance ceramics, which carries the teeth to be replaced.

Then, see 5 , becomes the secondary crown 6 even before curing the plastic 11 on the provided with a topcoat primary crown 2 put on, with the primary crown 2 in the cavity 13 the secondary crown 6 is recorded. In this case, the surface of the primary crown provided with a cover layer arrives 2 in gapless contact with the plastic 11 , After curing the plastic 11 have the upper surfaces of the plastic 11 and the primary crown 2 a very precise parallel course, whereby after removal of the cover layer and the resulting micro gap between plastic 11 and primary crown 2 in the desired manner a releasably adhesive hold between primary and secondary crown is realized. Due to the thickness of the cover layer and the resulting gap width of the micro-gap between the surfaces of plastic 11 and primary crown 2 it is possible to influence the strength of the adhesive bond between the primary and secondary crown.

In the connecting element produced in this way 1 can the secondary crown 6 in a simple way from a patient himself from the primary crown 2 be lifted off. Slipping out of the plastic 11 from the cavity 13 the secondary crown 6 gets through the undercut 10 effectively prevented.

The inventive connecting element and the corresponding manufacturing process thus enable the first time Production of the two detachable components of the connecting element from a particular same ceramic material. By the Use of biocompatible ceramics can cause incompatibility reactions be avoided in the patient. The exclusive use of tooth colored Materials with transparent and translucent optical properties guaranteed one in the highest Dimensions satisfied posing aesthetic Appearance. Connected with comparatively low material costs can be the connecting element according to the invention Produce inexpensively by a technically relatively simple manufacturing process. A possibly decreasing frictive / adhesive holding effect between the components of the connecting element can be in a simple manner economical remedy. To achieve this, it is only necessary that a dentist with rotating instruments made the plastic out of the secondary crown removed and then the primary crown cemented in the patient's mouth, for example, with liquid Vaseline insulated. Subsequently he fills Dentist the secondary crown with new plastic, the denture re-integrates and leaves the Cure plastic.

1

connecting element

2

primary crown

3

negative level

4

lower cavity edge

5

shape for secondary crown

6

secondary crown

7

fixing

8th

holding arm

9

Undercut Router

10

undercut

11

plastic

12

brush

13

cavity

14

cavity wall

15

facing

16

wax layer

17

Surface of the secondary crown

Claims (14)

Connecting element ( 1 ) for necessarily removable denture, which comprises a first ceramic component ( 2 ) and a second ceramic component ( 6 ), as well as the first component ( 2 ) and the second component ( 6 ) releasably interconnecting, plastic, third component ( 11 ), wherein for the detachable connection of the first constituent ( 2 ) and the second component ( 6 ) the third component ( 11 ) with the second component ( 6 ) and is releasably adhesively connected or connectable to the first component. Connecting element ( 1 ) according to claim 1, wherein the first constituent ( 2 ) and the second component ( 6 ) are made of a same ceramic material. Connecting element ( 1 ) according to one of claims 1 to 2, in which the first component ( 2 ) and the second component ( 6 ) consist of oxidic high performance ceramics, such as zirconia and alumina exist. Connecting element ( 1 ) according to one of claims 1 to 3, in which the third component ( 11 ) consists of a dimensionally stable and thermosetting plastic. Connecting element ( 1 ) according to one of claims 1 to 4, which is a telescopic crown, the first component being an inner telescope ( 2 ) and the second component is an external telescope ( 6 ) of the telescopic crown, the outer telescope ( 6 ) an open cavity ( 13 ), in which the inner telescope is at least partially receivable or received. Connecting element ( 1 ) according to claim 5, in which the third component ( 11 ) with the external telescope ( 6 ) is firmly connected and to the cavity opening of an undercut ( 10 ) is limited. Connecting element ( 1 ) according to one of claims 5 to 6, in which the outer telescope ( 6 ) is made by means of a copy router. Connecting element ( 1 ) according to one of claims 5 to 6, in which the outer telescope ( 6 ) is produced by means of a computer-aided CAD / CAM milling process. Removable denture with a connecting element ( 1 ) according to one of claims 1 to 8. A method of manufacturing a connector according to claim 1, comprising the steps of: preparing the first ceramic component ( 2 ) by means of a milling method, producing the second ceramic component provided with an open cavity ( 6 ) by means of a milling method, arranging the third component made of plastic ( 11 ) between the first component and the second component such that the third component ( 11 ) with the second component ( 6 ) is firmly connected and releasably adhesively connected or connectable to the first component. The method of claim 10, wherein the first Component and the second component are each milled using a copy router. The method of claim 11, wherein the first Component and the second component in each case by means of a computer-aided CAD / CAM milling process milled become. A method according to any one of claims 10 to 12, wherein on the surface of the second component before the solid compound with the third component a conditioning layer is applied. Method according to one of Claims 10 to 13, in which before curing of the third component, on the surface of the first component at least partially serving as a spacer cover layer is applied, the first component and the second component for hardening of the third component be, and after curing the third component, the topcoat is removed.