Dental prosthesis production device and dental prosthesis

Abstract

The invention relates to a dental prosthesis production device and method of manufacturing a dental prosthesis in which the dental prosthesis has an implant (40) and an abutment (10) which has a shape that is compatible with the implant (40) and on or to which abutment a dental structure (28) that is made of a dental material, in particular ceramic and/or plastic, and produced with the aid of a CAM process using rapid prototyping or compression molding technology can be secured. The abutment is mounted on the implant (40) via a releasable connection, in particular a screw connection (44), having an anti-rotation mechanism (50), and an anti-rotation device (groove 22) is formed between the abutment (10) and the dental structure (28). A selection device (66) is provided for abutments, said selection device allowing a selection of the abutment (10) for producing the dental prosthesis, optionally after reducing the abutment height to a specified value in a patient-specific manner, and a machining tool, in particular a milling cutter, or a CAM device is provided for shortening the abutment (10).

Claims

1. A method for production of a dental prosthesis using a production device, comprising: providing an implant (40), an abutment (10) having a shape that is compatible with the implant (40) and having a cylindrical section, and a dental structure (28) which can be attached to the cylindrical section of the abutment, wherein the dental structure is made of a dental material, and providing a machining tool or CAM device, wherein the abutment is mounted on the implant (40) via a releasable connection, having an anti-rotation mechanism (50), and an anti-rotation device (22) being configured between the abutment (10) and the dental structure (28), wherein the anti-rotation device forms at least one flute or groove (22) at the cylindrical section of the abutment (10), the at least one flute or groove, in cross-sectional view, curved concavely, the at least one flute or groove extends across at least a part of the height of the cylindrical section to a distal end of the abutment, both the top of the cylindrical section of the abutment and the at least one flute or groove coming to end at a rounded edge on the distal end, shortening the cylindrical section of the abutment with the machining tool or CAM device such that the at least one flute or groove is/are maintained with the rounded edge and a concave curve after shortening, wherein the shape of the cylindrical section is configured such that the radius of the cylindrical section remains unchanged when the cylindrical section is shortened.

2. The method according to claim 1, wherein a selection device in connection with the machining tool or CAM device is provided for selecting the abutment (10) for fitting with the dental structure, and wherein the machining tool or CAM device shapes an end radius of the abutment automatically.

3. The method according to claim 2, wherein the machining tool or CAM device provides a predefined number of heights of the cylindrical section of the abutment (10), and the height suitable for the dental structure (28) can be selected by the selection device.

4. The method according to claim 2, wherein the selection device selects the abutment for theft dental prosthesis to match a diameter and type of the implant (40) and a diameter and type of the dental structure (28), and wherein machining tool or CAM device supplies shape data which relate to a patient-specific height of the selected abutment (10).

5. The method according to claim 1, comprising reducing in height the abutment (10) to a medium height or a minimum height.

6. The method according to claim 1, comprising finishing the dental structure (28) by calculating the data of the dental structure (28) to be produced based on outer geometry required by the dental structure and on data of the abutment (10) dimensions and forwarding the data to the CAM device.

7. The method according to claim 1, comprising determining a desired shape of the dental prosthesis based on an extraoral or intraoral 3D scan with the aid of a scanbody, by supplying the scanning result to the CAM device which, based on the shape of neighboring teeth of the desired dental prosthesis, forms a virtual shape of the restorations to be produced and which divides the virtual shape virtually into an implant (40), an abutment (10) and a dental structure (28).

8. The method according to claim 2, wherein, in the cylindrical section of the abutment (10), the at least one flute or groove (22) extends from the end radius of the abutment (10), across at least 70% of the height of the cylindrical section of the abutment.

9. The method according to claim 1, wherein the abutment comprises a collar (14) and wherein the at least one flute (22) or groove tapers towards the collar (14) of the abutment (10).

10. The method according to claim 1, wherein the abutment (10) is fabricated of a ceramic, plastic or metal material, and wherein after shortening the abutment (10), exposing the abutment to a jet of a granular sub stance.

11. The method according to claim 1, wherein the abutment (10) comprises a single-colored or two-colored coating comprising TiN or an anodization of TiN for the production of an aesthetic abutment surface, wherein both the single-colored or two-colored coating and aesthetic abutment surface comprises brighter shades which are similar to tooth color.

12. The method according to claim 1, wherein the dental material comprises one or more of ceramic and plastic, wherein the releasable connection comprises a screw connection (44), wherein the machining tool comprises a milling cutter.

13. The method according to claim 1, wherein the cylinder is shortened to a height selected from large, medium and small.

14. The method according to claim 1, wherein the abutment can be reduced to a height selected from two to three different lengths.

15. The method according to claim 1, wherein the at least one flute or groove (22) extends at least 80% of the height of a total area of the cylindrical section.

16. The method according to claim 10, wherein the metal material comprises titanium or a titanium alloy.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages, details and features may be taken from the following description of several exemplary embodiments of the invention in conjunction with the drawings, in which:

(2) FIG. 1 shows a perspective schematic representation of an inventive dental prosthesis;

(3) FIG. 2 shows the embodiment according to FIG. 1, however, in a sectional view;

(4) FIG. 3 shows a modified embodiment of an inventive dental prosthesis according to FIG. 1;

(5) FIG. 4 shows the embodiment according to FIG. 3 in a sectional view;

(6) FIG. 5 shows a further modified embodiment of the inventive dental prosthesis in a perspective view;

(7) FIG. 6 shows the embodiment according to FIG. 5 in a sectional view;

(8) FIG. 7 shows a view of a further embodiment of an inventive dental prosthesis in a side view;

(9) FIG. 8 shows the embodiment according to FIG. 7 in a top view;

(10) FIG. 9 shows the embodiment according to FIGS. 7 and 8 in a sectional view;

(11) FIG. 10 shows a schematic representation of an inventive dental prosthesis production device illustrating the part relevant for the invention; and

(12) FIG. 11 shows a schematic representation of an inventive dental prosthesis production device illustrating the part relevant for the invention, however, in a modified embodiment.

DETAILED DESCRIPTION

(13) In FIG. 1 an abutment 10 is illustrated as part of a dental prosthesis which can be connected to an implant for the production of a dental structure (see FIG. 2).

(14) The abutment 10 comprises an implant connection 12 which is able to be supported in a torque-proof manner on an implant. The anti-rotation mechanism realized in this respect can be configured, for instance, with a hexagonal outer shape or a hexagonal inner shape.

(15) A collar 14 is formed above the implant connection 12 which collar merges into the implant connection 12 across a relatively large radius (see FIG. 2). The collar 14 tapers off in a relatively pointed manner and its top ends in an internal radius 16 which is even considerably smaller than the radius of the implant connection 12.

(16) Subsequent to the collar 14 and starting from it, a tubing section 18 or upper part of the abutment extends. The tubing section 18 comprises a central recess 20 which is suitable for receiving an implant screw (see FIG. 8). Towards its upper end, the tubing section 18 comprises a slightly conical shape; the cone angle is, for instance, 3°.

(17) For providing an anti-rotation device between the implant on the one hand and the dental structure on the other hand the abutment 10 comprises a plurality of grooves 22 which are evenly distributed around the periphery and which extend in an open manner towards the top and vertically across a chamfer in a closed manner towards the bottom.

(18) It can be seen from FIG. 2 how a dental structure 28 can be connected to the tubing section 18. As is schematically suggested in FIG. 2, an adhesive gap 30 extends between the dental structure 28 on the one hand and the collar 14 and the tubing section 18 on the other hand. The dental structure 28 comprises flanges which face inwards and which are intended to extend into the grooves 22 of the tubing section 18 in order to ensure that no rotation occurs.

(19) It can also be seen from FIG. 2 that the implant can basically be provided with several lengths. The three different lengths presented herein only differ in the height of the tubing section 18, while the shape of the implant does not exhibit any difference apart from that.

(20) All the shapes “L”, “M” and “S” have in common that they end in an end radius 32. In this way, notch effects with respect to the dental structure 28 are prevented.

(21) Now, the inventive selection device (FIG. 10) selects the appropriate shape depending on the size and shape of the dental structure 28. Additionally, if necessary, it is possible to perform a fine adjustment by determining the exact desired height of the tubing section 18 by means of the CAD/CAM device (FIG. 10).

(22) The height adjustment and the selection are also performed depending on the type of the tooth: While anterior teeth are rather slim and tall, molars comprise dental material in the approximal or buccal/lingual direction.

(23) The shear forces introduced by the masticatory forces are correspondingly larger with molars, but due to the larger wall thickness in the area surrounding the tubing section 18 molars are also more stable such that a higher surface pressure in the tubing section 18 is possible. In the exemplary embodiment illustrated, the depth of the grooves 22 amounts to approximately half of the wall thickness of the tubing section 18, and it is to be understood that, if necessary, the selection device can also select an abutment for anterior teeth, which has a slightly smaller wall thickness, for instance 0.5 mm instead of 0.6 mm. In this way, the wall thickness of the dental structure can even be increased slightly.

(24) According to the invention it is particularly favorable that the selection device automatically selects a suitable abutment based on the result that has already been determined, that is to say the dental prosthesis to be produced, and that it adjusts this abutment optionally in a patient-specific manner, reduces its height or adjusts the rest of it.

(25) It is to be understood that the shape of the abutment is compatible with that of the implant, as can be seen from FIG. 8.

(26) When selecting the abutment, the selection device selects an abutment whose height is the same or larger than a target height such that sufficient material is always provided for the machining process which may be required.

(27) According to the invention it is important in this connection that the end radius 32 is attached or kept quasi automatically during machining or milling.

(28) In this connection, the dental prosthesis production device also produces at least the inner structure of the dental structure 28 in a suitable manner and adapted to the result of the selection by the selection device and apart from that also adapted to the shape of each abutment 10 used for the production of the dental prosthesis.

(29) As the outer shape of the dental structure 28 can already be determined based on a detection of the oral situation of the patient by means of a 3D scan, it is also possible and particularly favorable if the scanning result forms a virtual shape of the restoration to be produced based on the shape of neighboring teeth of the dental prosthesis to be produced and at the same time performs the division of this shape into implant, abutment and dental structure.

(30) In this connection, it is preferable if the production device refers to an abutment library which has available a certain number of sizes of the abutment depending on the type of the dental prosthesis, wherein then, depending on the size, the production device takes into account the forces to be absorbed and the selection device selects the abutment also based on this.

(31) It is to be understood that, in this connection, the height level of the occlusal surface of the dental structure is preferably taken into consideration that is to say that the abutment is shortened to such an extent or is selected in a shorter form by the selection device that sufficient dental material, such as ceramic material, is available between the upper end of the abutment and the occlusal surface.

(32) Preferably, the groove 22 or the plurality of grooves 22 extends across a significant part of the height of the tubing section 18 of the abutment 10.

(33) In a plurality of grooves 22 the surfaces which are available for the transmission of torques are larger than if only one groove is realized (FIG. 3 and FIG. 4) such that in this case partially covering the height of the tubing section 18 is sufficient, as can be seen from FIG. 2. Even with the smallest height or greatest reduction according to “S” a part of the height of the groove 22 is still available for the anti-rotation device.

(34) In contrast, FIG. 3 illustrates an embodiment of an abutment 10 with only one groove 22. As can be seen from FIG. 4, it extends to the collar 14 such that sufficient torque-active surface is still available even if the tubing section 18 has been shortened as greatly as possible.

(35) Preferably, the flute (groove 22) comprises one end radius or one chamfer, respectively, in order to prevent abrupt changes in stiffness of the abutment.

(36) The wall thickness of the tubing section can be constant from the collar 14 to the end radius 32, or can decrease slightly, for instance by 10% to 15%, wherein it is to be understood that the internal diameter of the tubing section 18 is constant across the height as in the recess 20 an implant screw with its head must be received.

(37) In a way known per se the abutment 10 comprises an internal taper 34 in the area of the collar or slightly above, and the head of the implant screw is in contact with the internal taper.

(38) In contrast, FIG. 5 illustrates an embodiment which is modified even further. In this solution the anti-rotation device is realized by means of a groove 22 in the area of the collar 14, while the tubing section 18 is free of grooves or flutes (grooves 22).

(39) Even if only two grooves 22 or flutes 18 are to be seen in FIG. 5 and FIG. 6 in the area of the collar 14, it is to be understood that a plurality of corresponding grooves is preferably provided to maximize the surfaces suitable for transferring torques.

(40) In FIG. 7 an abutment is shown slightly enlarged in a position screwed into the implant. The area between the collar 14 and the upper end of the implant 40 is smoothed in a way known per se with dental cement for providing a suitable emergence profile; due to the small height of the collar 14 an adaptation to the requirements of the patient is possible to a large extent.

(41) In this respect, the transition towards the dental structure 28 is important which is in connection with the abutment 10 by means of the adhesive gap 30.

(42) It is to be understood that any desired suitable biocompatible adhesive or dental cement can be used as a filling material for the adhesive gap 30.

(43) It can be seen from FIG. 8 how an implant screw 42 can be inserted into the recess 20. The screw head is, for instance, provided with an inbus structure which has been modified towards a TORX structure and the screw head 44 fills the recess 20 radially almost completely.

(44) It can be seen from FIG. 9 that the screw head 44 of the implant screw 42 contacts the internal taper 34 of the abutment, via the taper support thereof, in order to provide for the screw connection 46. Screws comprising a vertical to flat shoulder also come into question for this purpose, and it is therefore also apparent that an anti-rotation mechanism 50 is realized between the implant 40 and the abutment 10, for instance in the form of hexagonal surfaces which fit one another.

(45) It is to be understood that, in practice, the implant 40 is provided with an external thread known per se even if this is not shown in the Figures.

(46) As can be seen from FIG. 8, in the area of the internal radius 16 an undercut 48 is formed which serves to receive adhesive which drains off. Furthermore, in this embodiment it is provided to compress the surface of the abutment after the shortening process which has been performed optionally, for instance by exposing it to a jet of a granular substance.

(47) In a further modified embodiment it is provided instead to provide the abutment with a single- or two-colored coating.

(48) FIG. 10 illustrates the schematic configuration of a dental prosthesis production device 62.

(49) Initially, the oral situation of the patient, in particular the neighboring teeth of the dental prosthesis to be produced, is scanned by means of a scanning device 60. In this way, the scan data are present in the dental prosthesis production device 62. Based on this, the dental prosthesis production device 62 develops a dental prosthesis in a way known per se, for instance as a virtual hybrid between both the neighboring teeth or in any other suitable manner corresponding to the position of the dental prosthesis in the mouth of the patient.

(50) Thus, the dental prosthesis production device 62 defines the outer shape of the dental structure 28, also including the height level for the provision of a suitable occlusal surface (or incisal surface) with respect to the antagonist of the dental prosthesis.

(51) Thus, apart from the height level and position, the outer shape of the dental structure is also determined, also including the dimensions of the dental structure in the approximal and lingual/buccal direction. Based on this and based on the data comprised in a library 64 of abutments (and optionally implants) a selection device 66 selects a suitable abutment. The abutment 10 is selected such that its height fits the virtual internal space of the dental prosthesis, that is to say such that sufficient ceramic dental material is available for the support at the tubing section 18. Furthermore, the wall thickness of the dental structure is taken into consideration as a marginal condition in the selection process, for instance >1 mm with anterior teeth and >2 mm with molars and pre-molars.

(52) It is to be understood that these values can be adapted to the requirements to a large extent.

(53) The selection device 66 is part of a CAD station and determines the suitable abutment based on this, which can optionally be shortened in order to optimize it. A CAM device 68 serves this purpose and performs the shaping step which comes up in this respect and which in particular also shapes the end radius 32 of the abutment automatically.

(54) Furthermore, the selection device 66 also transmits shape data 72 for providing the internal shape of the dental structure 28 which is produced by the CAM device 68.

(55) It is to be understood that a separate milling cutter can be realized instead for processing the abutment 10.

(56) Preferably, in a test step it is further checked at the same time if the inner surface of the dental structure 28 fits the respective abutment 10 to be processed. This can be done either by adaptation—without adhesive—or by means of a scan for which the scanning device 60 can be used again.

(57) In this connection, it is checked as part of a test step if the fit is appropriate or sufficient in order to ensure the desired height level on the one hand but also torque-proof mounting on the other hand.

(58) If necessary, finishing is carried out in a finishing step again by means of the CAM device 28.

(59) From FIG. 11 a further embodiment of the dental prosthesis production device 62 is apparent. Again, scan data is initially provided which has been produced by the 3D scanning device 60. Based on this and using shape data from a library 64, the selection device 66 does not only determine the shape of the abutment 10 but also the outer shape of the dental suprastructure 28. This data which fits one another, also with regard to the height of the tubing section 18 in case of the abutment 10, is supplied to the corresponding production devices, and the height of the abutment 10 is shortened to “L”, “M” or “S”, if necessary. The associated radius is rounded off at the same time. The internal structure of the dental structure 28 is determined such that it matches the radius and produced by means of CAD/CAM, and, of course, at the same time also the outer structure.

(60) As a result, the finished parts are available for providing the dental prosthesis. The dental prosthesis is now assembled in a step 74, wherein the dental structure 28 is adhesively bonded onto the abutment 10.

(61) In a test step and optionally in a finishing step 70 the result is reviewed and finishing is carried out, if necessary, for instance by removing occlusal defects at the occlusal plane of the produced molar of the dental structure 28.