DE102022000954A1 - ADHESIVE BASE, DENTURES AND THEIR COMBINATION - Google Patents

Abstract

According to the invention, a rotation protection between an adhesive base (1) and a denture (10) is designed in such a way that active surfaces (7, 13) of the adhesive base (1) or the denture (10) which are in positive engagement with one another are on the outer sides of the adhesive base (1 ) or the denture (10) are formed.

Description

The invention relates to an adhesive base for a denture with an outer surface which is rotationally symmetrical about a central axis for bonding to a form-fitting inner surface of a denture and with rotation protection of the adhesive base relative to the denture by positive locking between mutually engaging active surfaces of the adhesive base and the denture and on a denture with an inner surface that is rotationally symmetrical about a central axis for bonding to a form-fitting outer surface of an adhesive base and with a rotation protection of the denture relative to the adhesive base by positive locking between mutually engaging active surfaces of the denture and the adhesive base, and a combination of such an adhesive base with such Dentures.

With two-part implant systems, the denture must be connected to the implant using a screw connection. This requires an intermediate structure (abutment) that connects the implant anchored in the bone to the actual tooth replacement.

Adhesive bases form a subclass of abutments in that their connection geometry to the tooth replacement is standardized and stored in the respective dental CAD/CAM systems. This means that the dental technician can design the appropriate dentures, CNC them and then connect them to the adhesive base. This fundamentally enables the efficient digital production of implant-supported dentures. In principle, it would be possible to produce dentures without a model.

However, today's adhesive bases and corresponding digitally manufactured superstructures have a high degree of clearance and freedom of rotation, which makes it difficult to connect the two components precisely, as is required clinically. The main problem currently is the inadequate indexing against rotations, which leads to significant inaccuracies in fit and loss of quality in both the occlusal area and the approximal area. Due to the lack of control options when working without a model, it is currently not possible to eliminate this error, meaning that clinical adjustments are often necessary in the patient's mouth or the denture cannot be inserted. On the one hand, this costs time and therefore money, it also reduces the surface quality due to the necessary rework and weakens the microstructure, especially in the case of all-ceramic dentures.

• • Fertigungsschwierigkeiten für CAD/CAM-Systeme durch nicht CAD/CAM-gerechte Geometrie des Rotationsschutzes
  • ◯ Rotationsschutz im Zahnersatz muss mit aufwendigen Fräs-/Schleifstrategien unter Einsatz der Spitze des Schleifkörpers gefertigt werden, was einen hohen Verschleiß der Werkzeuge und Passungenauigkeiten des Zahnersatzes nach sich zieht.
  • ◯ Bei einigen Systemen entstehen durch die ungünstige Geometrie und Lage des Rotationsschutzes systembedingte Hohlräume, die zu einer Vergrößerung der Klebefuge führen.
• • Reduktion der Materialschichtstärke am Ort des Rotationsschutzes und somit höheres Frakturrisiko
• • Freiheitsgrade in der Rotation, die ein modelfreies Arbeiten quasi unmöglich machen.

Today's adhesive bases have vertical rotation protection, the effective surfaces of which are aligned parallel to the central axis of the components and which are often too angular. This has the following disadvantages:

• • Manufacturing difficulties for CAD/CAM systems due to non-CAD/CAM-compliant geometry of the rotation protection
  • ◯ Rotation protection in dentures must be manufactured using complex milling/grinding strategies using the tip of the grinding wheel, which results in a high level of wear on the tools and inaccuracies in the fit of the dentures.
  • ◯ In some systems, the unfavorable geometry and position of the rotation protection creates system-related cavities, which lead to an enlargement of the adhesive joint.
• • Reduction of the material layer thickness at the location of the rotation protection and thus higher risk of fracture
• • Degrees of freedom in rotation that make model-free work virtually impossible.

There is currently no solution to the problem. All previous approaches have an imprecise fit and rotation lock. One approach to solving these difficulties in CAD/CAM production was through prefabricated material blocks tailored to the adhesive base. However, these also have a high degree of clearance and rotation.

• - Im CAD/CAM-Verfahren nicht exakt zu fertigen
• - Eckige Gestaltung ist nicht keramikgerecht
• - Ausdünnung und Schwächung des Materials über dem Rotationsschutz
• - Daraus resultierende hohe Rotationsfreiheit und mangelnde Passung der gefertigten Kronen auf der Klebebasis.

In summary, it can be said that the connection geometries (for dentures) of currently existing adhesive bases are inadequately designed:

• - Cannot be manufactured exactly using the CAD/CAM process
• - Angular design is not suitable for ceramics
• - Thinning and weakening of the material above the rotation protection
• - The resulting high freedom of rotation and lack of fit of the manufactured crowns on the adhesive base.

The invention is based on the object of providing an adhesive base, a denture and a combination of an adhesive base and dentures that are tailored to the special requirements of CAD/CAM production.

According to the invention, this object is achieved with regard to an adhesive base of the type mentioned in that the active surface of the adhesive base is formed on an outwardly projecting shoulder of the adhesive base which apically delimits the outer surface.

With regard to a denture of the type mentioned at the outset, the invention provides that the active surface of the denture is formed on an apical/cervical end surface of the denture that extends between the inner surface of the denture and its outer tooth surface.

Conventionally, the active surfaces provided for mutual positive engagement extend vertically, i.e. in the direction of the central axis on the outer surface of the adhesive base or the inner surface of the denture, which in particular leads to a weakening of the material of the adhesive base and / or the denture. In contrast, in the invention the active surfaces extend horizontally, i.e. transversely to the central axis on areas of the outer sides of the adhesive base and the denture. The entire adhesive base and the dentures can therefore be easily manufactured using CAD/CAM-based production. This simplifies production using CAD/CAM systems, expands the applicability on various systems and makes production independent of prefabricated blanks with a hole geometry. The advantage that with the horizontal rotation protection according to the invention there is no weakening of the material of the adhesive base and/or the denture also applies to manually manufactured or processed components as well as subtractively or additively manufactured components. This geometry also enables a reduction in the diameter of the adhesive base (e.g. when supplying implants with a so-called platform switch).

Preferably, the effective surface of the rotation protection on the adhesive base is convex in relation to its shoulder and the effective surface of the rotation protection on the denture is concave in relation to its apical end surface. In particular, the shoulder of the adhesive base is designed to run around its outer surface in a ring shape and in particular forms an annular surface whose surface normal is directed coronally parallel to the central axis. For this purpose, the apical end surface of the denture is designed to be congruently annular with apically directed surface normals parallel to the central axis. The convex effective surface of the rotation protection of the adhesive base rises from the annular surface of the shoulder rising and falling again in the circumferential direction, while the concave effective surface of the denture in its annular end surface deepens in the circumferential direction and rises again towards the annular surface. When the adhesive base is connected to the dentures, the two annular surfaces and the corresponding active surfaces lie against each other in a form-fitting manner.

The effective surfaces of the rotation protection on the adhesive base and on the dentures each advantageously have the shape of the lateral surface of a circular cylinder segment, the cylinder axes of which preferably intersect the central axes of the adhesive base or the dentures. The circular cylindrical concave active surface of the denture can be easily produced with the aid of a milling cutter or grinding wheel of the CAD/CAM system in a shape congruent to the radius of this milling cutter or grinding body in the denture material.

The geometry of the horizontal rotation protection according to the invention can vary in its shape, angulation, size and position as well as its number of active surfaces. The materials of the adhesive base and the dentures can also vary. The invention can be applied to all two-part implants and can also be transferred to the abutment geometry of one-piece implants.

• 1 eine perspektivische Ansicht einer Klebebasis
• 2a und 2b jeweils eine schematische Teilansicht einer Klebebasis und einer damit verbundenen Zahnkrone.

The invention is explained below by way of example with reference to the drawing. Show it:

• 1 a perspective view of an adhesive base
• 2a and 2 B each a schematic partial view of an adhesive base and a dental crown connected to it.

An in 1 The illustrated embodiment of an adhesive base 1 has an outer surface 2 which is rotationally symmetrical about a central axis (not shown) and which tapers in a frustoconical shape from its apical axial end 3 to its coronal axial end 4. The outer surface 2 is delimited at its apical end 3 by an outwardly projecting shoulder 5, which forms an annular free surface 6, the surface normal of which is directed coronally parallel to the central axis.

On this annular surface 6 rises an active surface 7 of a rotation protection based on positive connection with an active surface formed on a denture. The active surface 7 has the shape of the lateral surface of a circular cylinder segment 8, the cylinder axis (not shown) of which intersects the central axis of the outer surface 2, which is rotationally symmetrical with respect to this central axis. The angle at which the lateral surface appears when viewed from the cylinder axis is at most 180°.

2 shows schematically the outline of the outer tooth surface 9 of a denture 10, which is connected to the adhesive base 1. The denture 10 has an inner surface 11 which is rotationally symmetrical about a central axis (not shown). is positively engaged with the outer surface 2 of the adhesive base 1 and is glued to it. An annular apical end surface 12 of the denture 10 extends orthogonally to the central axis between the inner surface 11 and the outer tooth surface 9 of the denture 10. A recess is formed in the annular end surface 12, which has an active surface 13 for positive engagement with the active surface 7 on the circular surface 6 of the adhesive base 1 forms. This positive engagement protects the adhesive base 1 and the dentures 10 from mutual rotation. The areas of the annular surfaces 6 and 12 adjoining the active surfaces 7 and 13 also lie against one another in a form-fitting manner.

While in 2a the two active surfaces 7 and 13 are designed to be identical in the shape of corresponding lateral surfaces of a circular cylinder segment, is shown in 2 B the concave active surface 13 of the denture 10 is designed to be flatter in its transition areas to the circular surface 6, deviating from the strict cylindrical shell shape of the active surface 7 of the adhesive base 1. In this case, the positive connection between the two active surfaces 7 and 13 required for rotation security takes place in the non-flattened area.

List of reference symbols

1

Adhesive base

2

external surface

3

apical end

4

coronal end

5

shoulder

6

circular surface

7

Effective area

8th

Circular cylinder segment

9

external tooth surface

10

dentures

11

Inner surface

12

apical annular end surface

13

Effective area

Claims (10)

Adhesive base (1) for a denture (10) with an outer surface (2) which is rotationally symmetrical about a central axis for bonding to a form-fitting inner surface (11) of a denture (10) and with protection against rotation of the adhesive base (1) relative to the denture (10) by positive locking between mutually engaging active surfaces (7, 13) of the adhesive base (1) and the denture (10), characterized in that the active surface (7) of the adhesive base (1) faces outwards on an apical boundary of the outer surface (2). projecting shoulder (5) of the adhesive base (1) is formed. Adhesive base after Claim 1 , characterized in that the active surface (7) is convex in relation to the shoulder (5). Adhesive base after Claim 1 or 2 , characterized in that the shoulder (5) is designed to surround the outer surface (2) in a ring shape. Adhesive base according to one of the Claims 1 until 3 , characterized in that the active surface (7) of the adhesive base (1) has the shape of the lateral surface of a circular cylinder segment. Adhesive base after Claim 4 , characterized in that the cylinder axis of the circular cylinder segment intersects the central axis of the rotationally symmetrical outer surface (2). Dentures (10) with an inner surface (11) which is rotationally symmetrical about a central axis for bonding to a form-fitting outer surface (2) of an adhesive base (1) and with a rotation protection of the dentures (10) relative to the adhesive base (1) through positive engagement between one another standing active surfaces (7, 13) of the dentures (10) and the adhesive base (1), characterized in that the active surface (13) of the dentures (10) is located between the inner surface (11) of the dentures (10) and its outer Tooth surface (9) extending apical end surface (12) of the denture (10) is formed. Dentures after Claim 6 , characterized in that the active surface (13) is concave in relation to the end surface (12). Dentures after Claim 6 or 7 , characterized in that the end surface (12) is circular. Dentures according to one of the Claims 6 until 8th , characterized in that the active surface (13) of the denture (10) has the shape of the lateral surface of a circular cylinder segment, the cylinder axis of which in particular intersects the central axis of the rotationally symmetrical inner surface (11). Combination of an adhesive base (1) according to one of the Claims 1 until 5 with a denture (10) according to one of the Claims 6 until 9 , whose effect surfaces (7, 13) engage with each other in a form-fitting manner.

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