This application claims priority to German applications DE 10 2005 027 184.7 filed on Jun. 7, 2005 and DE 10 2005 014 582.5 filed Mar. 24, 2005.
1. Field of the Invention
The invention concerns an implant analog for the production of custom-made prosthetic structures on dental implants using a master cast.
2. Related Art
Implant analogs represent the implant present in the mouth of the patient. If abutments are already mounted on the implant, the implant analogs can also represent the abutments. Likewise, implant analogs can also represent parts of the abutment and of the implant in some implant systems.
Implant analogs used to make master casts for subsequent production of custom-made prosthodontic superstructure in exact agreement with the implants in the jawbones are themselves known. The implant analog is included in the master cast, with the future prosthodontic superstructure being attached to the head of the implant analog and, after the implant superstructure has been produced, transferred to the implant inserted in the mouth of the patient. The anatomic structure of the jaw (morphology) of the patient often does not allow the dental implant to be inserted perpendicularly. In the fabrication of the master cast, this presents substantial difficulties in placing the implant analogs in a manner that ensures simple production and manipulation of the waxup and of the cast structure on the master cast in the event that implants are present that are not inserted perpendicularly. The objective of the invention is to develop the generic implant analog such that the working casts for the implant-based dental work can be produced reliably and easily.
This objective is attained according to the invention with implant analog for custom production of prosthetic superstructures for inserted dental implants, inserted into a master cast directly or indirectly via a model sleeve comprising an implant head equipped with elements to hold and fasten an implant system; a base of said implant analog, having a cross section that tapers over at least part of its length; an implant head having a working surface and a connecting piece; a tenon-like projection on a bottom end surface of said implant head; and an external thread dimensioned to connect with a screw element.
In the implant analog according to the invention, the base of the implant analog which has a head for mounting the dental implant is designed so that its cross-section is tapered over at least part of its length. Due to this form of the base, it is possible to remove the implant analog from the master cast without stress.
Other features of the invention appear from the other claims, the description, and the drawings.
The invention concerns an improved implant analog for production of custom-made prosthetic structures for inserted dental implants.
The anatomic structure of the jaw often does not allow dental implants to be inserted perpendicularly. That results in unavoidable problems in producing prosthetic implants, combined with high expenditures and costs.
The invention eliminates those disadvantages for an implant analog (2). The implant head (5) has a working surface (11) and connecting piece (12) on which the implant reconstructions to be made can be seated and fastened and the bottom end surface (45) of implant analog (2) has a tenon-like projection (36) with an external thread intended for connecting a screw element (39, 54, 58).
The implant analog can be used equally well for single-tooth implants and for implanted bridges.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The invention is explained by means of some embodiments shown in the drawings. Those show:
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
The implant analogs described in the following are selected according to the space available in the impression and are placed in the impression, connected reversibly to the impression post. Subsequently, a casting is made of the impression, giving the master cast. The implant analogs are equally suitable for single-tooth implants and for bridge implants, as well as for telescope crown and bridge work or zirconia-based restorations in the dental laboratory. With the appropriate working surface, they can be used for any implant system.
In implant technology, shaped pieces, preferably made of titanium, are initially used as root replacements. They are generally made up of an implant that is inserted into a previously drilled hole in the jawbone. As a general rule, a spacer or abutment of titanium is fastened to that shaped piece or implant. Subsequently the artificial tooth or superstructure is anchored to that spacer or abutment. An accurate model of the patient's jaw is made so that the artificial tooth or bridge can be fitted exactly to the jaw. First, a negative impression of the jaw is produced with an impression tray filled with impression compound, using system-specific impression posts as carriers. It is removed from the jaw and filled with a casting material that, after hardening, represents an accurate model of the patient's jaw. In place of the implant, an implant analog is inserted into the so-called master cast. The implant analog is placed in the model with its working surface oriented and positioned by exact analogy with the implant in the patient's jaw. Divergences between the implants can now be compensated in a very advantageous manner by the implant analog according to the invention.
As
A head (5), which can be designed in the known manner, corresponding to the particular implant system, sits at the wider end of the base (3). The head (5) forms the working surface, which corresponds to the surface of the implant in the jawbone. The dental technology product is set onto the implant analog in the direction of the arrows.
The conicity of the base (3) varies depending on the size, length, and shape of the implant analog (2). In the example embodiment, the cone angle is only a few degrees, and is in the range of about 15°. Because of their conicity, the implant analogs can also be used for implants that have not been inserted perpendicularly into the jawbone. In that case, the angulation of the implant analog is equal to the relative angulation of the implants and allows the bridge to be removed from the master cast in one piece and optionally together with the implant analogs. It is advantageous to use the implant analogs (2) so that they can be removed from the master cast (1) and reinserted into it it. In particular, it is possible, in this way, to produce a model for implant-supported bridges using wax so that the modeled wax bridge, together with the conical implant analog (2), can be removed from the master cast (1) without strain and without stress. Furthermore, every individual implant analog (2) can be removed from the master cast without problem. That prevents distortion of the modulation on removal of the framework, so that no tedious soldering or laser-welding necessitated by distortion or new production are required, as is the case with the usual designs. To be able to arrange the implant analog in the master cast (1) better, a sleeve (6) can optionally be used (
So that it is possible to check that the base (3) of the implant analog (2) is sitting securely in the sleeve (6, 14, 34, 50, 38), the sleeve or the implant analog (2) has, in the region visible after casting of the model, a defined transition region to the implant analog (2), preferably a step or a bevel (8) which extends radially past the wider end of the base (3). The implant analog (2) is inserted into the sleeve (6) so far that the implant analog (2) fits, preferably precisely, with this bevel (8) on the end (9) of the sleeve. The sleeve (6, 14, 34, 50, 38) can be produced of metal or similarly stable material. As the region in which the bevel (8) of the implant analog (2) fits closely to the end (9) of the sleeve (6, 14, 34, 50, 58) can be exposed by a removable papilla, a visual check of the satisfactory seating of the implant analog (2) in the sleeve (6, 14, 34, 50, 38) at any time is assured. The head has a centrally projecting connecting piece (12).
A compensating sleeve, described by FIGS. 5 to 7, is used for implants inserted extremely non-perpendicularly. Even standard model implants can be used when these sleeves are used. The compensating sleeve is used if the angle is large, more than about 25°, for instance. The angled implant analogs are selected appropriately by the dental technician.
The compensating sleeve (13) according to
The compensating sleeve (13) according to
The conic inner wall (17) of the base (14) is provided with retention elements (18), which project into the sleeve (13) and can have any suitable form. These retention elements assure interlocking with the plastic, resin, or impression compound put into the sleeve later.
The radially projecting edge (15) acts as a stop if the sleeve (13) is inserted into sleeve (19) according to
A bar 26 projecting inward and running in the axial direction is provided on the conical inner wall (25) of the outer sleeve (19). Its shape is matched to that of the slot (16) of the sleeve (13). If the sleeve (13) is inserted into the outer sleeve (19), then the bar 26 engages with the slot (16), so that the two sleeves (13, 19) fit together so that they cannot rotate.
The outer sleeve (19) is designed open at its narrower end (
In production of the master cast (1) the outer sleeve (19) is first placed on the inner sleeve (13) and the pin (30) is inserted into the opening (29′) of the bar (28) of the outer sleeve (19). Then that unit is clamped in a dental surveyor with which the compensating sleeve (13) and the outer sleeve (19) are fixed in the selected direction on the implant analog already inserted into the impression. The height of the pin (30) is adjusted accurately by sliding it. Then the inner or compensating sleeve (13) is filled with a liquid plastic or resin. In this process, the end of the pin (30) with the profiling 31 is included in the casting. After the model is produced, a silicone molding which serves to make a removable papilla is made over the jaw region of the implant. Thus, the edge (15) of the compensating sleeve (13) is exposed on the plaster model, so that the seating of the compensating sleeve (13) in the outer sleeve (19) can be checked properly.
Because of the use of the outer sleeve (19), the compensating or inner sleeve (13) with the implant analog can be removed from the master cast (1) and replaced exactly. If this removability is not needed, the compensating sleeve (19) can also be cast and anchored directly in the master cast (1).
FIGS. 8 to 13 show other embodiments of implant analogs (2), each of which have different cross-sectional shapes.
The implant analog (2) according to
The oval shape of the base (3) or of the holding cone further makes it possible for this implant analog (2) to be cast directly into the master cast without further protection against rotation.
In the example embodiment, the small exposed end (35) of the base (3) is larger than in the embodiment shown in
The implant analog (2) according to
The implant analog (2) according to
The implant analog (2) is inserted into an outer sleeve (38) and is fastened in that outer sleeve (38) by a screw (39) that is screwed onto the projection (38). The outer sleeve (38) has a seat part (42) for the base (3) of the implant analog (2) and has a conical seat (40), with the base (3) of the implant analog fitting tightly to its internal wall. The internal wall of the seat (40) is provided with a corresponding flat in the region of the anti-rotation element (4).
A sleeve part (43) having a cylindrical inner wall (46) connects to the seat part (42) and accepts the screw (39). The transition between the seat (40) and the cylindrical inner wall (46) forms an internal shoulder surface (45) that supports the screw (39) when the implant analog (2) is mounted. The implant analog (2) is screwed into the seat (40) until its collar (8), which is made circular, fits tightly against the end surface (44) of the seat part (42). The diameter of the bevel (8) is the same as the outside diameter of the seat part (42).
The sleeve part (43), which has the same outside diameter as the seat part (42), keeps the casting material away from the screw (39) during production of the master cast (1). The screw (39) can be turned easily with a screwdriver through the open end of the sleeve part (43). The screw (39) has a screw slot (47) for that purpose. The implant analog (2) can be clamped in the outer sleeve (38) with the screw (39), so that it cannot be separated accidentally. Retentions, such as bars, ribs or the like can be provided on the cylindrical outside (41) of the outer sleeve (38) as anti-rotation means and/or as anchoring means (not shown). It is possible to make at least the sleeve part (43) oval, elliptical, or angular in its cross section so that no special anti-rotation means is required.
As shown in
The outer sleeve (49) is designed in one piece, corresponding to the embodiment of
There is a shoulder surface (53) directed radially inward at the transition from the cylindrical inner wall (46) of the sleeve part (51) to the conical inner wall (50′) of the seat part (50). Differing from the previous embodiment, it projects radially inward over the inner wall (50′). This produces a thin annular wall (59). The annular wall (59) bounds an opening (60) through which the tenon-like projection (36) of the base (3) projects, with the outer thread in the inner space of the cylindrical sleeve part (51).
A screw (54) with internal thread is inserted into the inner space of the sleeve part (51) and screwed onto the projection (36) to hold the implant analog (2) to the outer sleeve (49). In this way the base (3) of the implant analog (2) is drawn into the inner cone of the seat part (50) until the bevel (8) or the collar lies tightly against the end surface (56) of the seat part (50).
Instead of the projection (36) with the external thread (37), a hole with an internal thread can be provided in the base (3) of the implant analog (2), into which an ordinary screw can be screwed to fasten the implant analog (2) in the cylindrical part of the outer sleeve (49).
In the example shown, the working surface or head (5) of the implant analog (2) has a hexagonal connecting piece (12). Other polygonal shapes such as triangular, quadrangular, or octagonal connecting pieces can also be provided instead of this hexagonal connecting piece (12). Alternatively, connecting pieces can also be provided in the form of an internal cone, internal cones combined with an internal polygon, a bayonet connection, Torx designs or combinations of those in the working surface or in the head of the implant analog (2). The choice is guided solely by the particular implant desired.
Instead of the screw connections described, it is also possible to fasten the implant analog (2) into the outer sleeve with other fastening means, for example, with a notch or clip connection, with a bayonet connection, with a bolt, a split pin, and the like.
The base (3) of the implant analog (2) can also be designed in a star or kidney shape or have some other configuration, instead of the conical, oval, elliptical or angular cross-sectional shapes. In any case, the base (3) must be tapered in the direction of insertion.
The implant analogs described (2 or 13) can also be used with extremely oblique position of the inserted implants as well as to produce implant reconstructions for single-tooth implants and for implant-supported bridges. Quite different implant analogs (2) can be inserted into the seating sleeves (6, 19, 38, 49), each of them lying with its base (3) tightly against the inner wall of the seats of the seating sleeves. The implant analogs according to the invention are usable in all the usual dental implant systems. However, the implant analogs are also suitable for scanning implant reconstructions for virtual models.
As various modifications could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.
Number | Date | Country | Kind |
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DE/102005014582.5 | Mar 2005 | DE | national |
DE/102005027184.7 | Jun 2005 | DE | national |