CAP FOR DENTAL PROSTHESIS

Abstract

The invention relates to a cap for removable dental prosthesis, a removable prosthesis and a process for the production of a removable prosthesis; the cap for removable dental prosthesis is suitable to be anchored by one or more implants which consist of an artificial root (1) and an abutment (4), said cap (6) being adapted to be received in the prosthesis (8) to be fit on said abutment (4) for defining a stable but removable constraint which allows the detachment of the prosthesis from the abutment; the cap is provided with a threaded outer surface (68).

Claims

1. Cap for removable dental prosthesis suitable to be anchored by one or more implants which consist of an artificial root (1) and an abutment (4), said cap (6) being adapted to be received in the prosthesis (8) to be fit on said abutment (4) for defining a stable but removable constraint which allows the detachment of the prosthesis from the abutment; cap characterized in that it is provided with a threaded outer surface (68).

2. Cap according to claim 1, characterized in that it is provided with an inner frusto-conical cavity (64) adapted to receive a corresponding frusto-conical portion (46) presented by the abutment (4) with which the cap (6) is intended to couple.

3. Cap according to claim 1, characterized in that is provided with an internal seat (61) complementarily shaped with respect to a tool used to unscrew and screw the same cap (6) from/into the prosthesis (8) to which it is associated.

4. Cap according to claim 3, characterized in that said inner seat (61) has polygonal shape in plan.

5. Removable prosthesis of the type which can be anchored to one or more implants which consist of an artificial root (1) and an abutment (4), comprising at least one cap (6) which can be reversibly fitted on said abutment (4), characterized in that said cap (6) has a threaded outer surface (68) adapted to engage a correspondingly threaded seat (86) of said prosthesis (8).

6. Prosthesis according to claim 5, characterized in that the cap (6) is provided with an internal frusto-conical cavity (64) adapted to receive a corresponding frusto-conical portion (46) presented from the abutment (4) with which the cap (6) is intended to couple.

7. Prosthesis according to claim 5, characterized in that the cap (6) is provided with an internal seat (61) complementarily shaped with respect to a tool used to unscrew and screw the same cap (6) from/into the prosthesis (8) to which it is associated.

8. Process for the production of a removable prosthesis of the type which can be anchored by one or more implants which consist of an artificial root (1) and an abutment (4), comprising a step of insertion into said prosthesis (8) of at least a cap (6) fixable to said abutment (4), characterized in that said cap (6) has a threaded outer surface (68), the insertion of said cap (6) determining the formation of a correspondingly threaded seat (86) in said prosthesis (8).

9. Process according to claim 8, characterized in that the cap (6) is provided with an internal frusto-conical cavity (64) adapted to receive a corresponding frusto-conical portion (46) presented from the abutment (4) with which the cap (6) is intended to couple.

10. Process according to claim 8, characterized in that the cap (6) is provided with an internal seat (61) complementarily shaped with respect to a tool used to unscrew and screw the same cap (6) from/into the prosthesis (8) to which it is associated.

Description

[0011] These and other advantages and features of the present invention will be best understood by anyone skilled in the art from the following description and with the help of the attached drawings given as a practical exemplification of the invention, but not to be considered in a limitative sense, wherein:

[0012] FIGS. 1A, 1B, 1C, 1D, 1E, 1F, 1G 1H, 1I, 1J, 1K, 1L, 1M, 1N schematically represent a known process for the production of a prosthesis of the type called overdenture O-ring;

[0013] FIG. 2 is a schematic side view with parts removed of a possible example of embodiment of a cap according to the invention, represented together with an abutment fixed to the artificial root of the corresponding dental implant and in which the prosthesis and the gingiva of patient are represented in a schematic way;

[0014] FIGS. 3, 4 are schematic side views of an abutment, which in FIG. 3 is associated with a cap represented in transparency, while FIG. 4 is represented without the cap;

[0015] FIG. 5 is a plan view from below of the cap of FIGS. 2, 3;

[0016] FIG. 6 is a view according to a longitudinal section of the cap of FIGS. 2, 3, 5;

[0017] FIGS. 7, 8 represent schematically some steps of a method for manufacturing a prosthesis according to the invention; and

[0018] FIG. 9 shows partially a prosthesis according to the invention, in which is visible the threaded seat that is formed in it.

[0019] With reference to the drawings of FIGS. 2-9, a cap (6) in accordance with the present invention is used for making a removable prosthesis (8) anchored by means of two dental implants, each comprising an artificial root (1) and an abutment (4). The artificial root (1) is implanted in the mandible or maxilla (M) in a known manner and therefore not described.

[0020] The cap (6) is intended to be inserted into the prosthesis (8) for be fitted on the abutment (4) and it is adapted to define a stable but removable constraint which permits the detachment of the prosthesis from the abutments (4) when necessary. The cap (6) of the invention is provided with a threaded outer surface (68). This allows replacement of the cuff (6) in case of damage or for other requirements. The removal of the cap (6) from the prosthesis (8) is achievable thanks to an internal seat (61) of the cap, complementarily shaped with respect to a tool used to unscrew and tighten the same cap (6) from/into the prosthesis (8) to which it is associated. In the example shown in FIG. 5 and FIG. 6 said inner housing (61) has a hexagonal shape in plan to allow the insertion of a correspondingly shaped key. Obviously there are other possible conformations of the tool used, as well as the size and conformation of the cap (6).

[0021] The cap (6) is further provided with an internal cavity (64) adapted to receive a corresponding frusto-conical frustum portion (46) presented from the abutment (4) with which the cuff (6) is intended to couple. This allows to properly attach the cap (6) to the abutment (4) ensuring a remarkable stability of the prosthesis (8).

[0022] As shown in FIG. 6, the aforementioned housing (61) is above the cavity (64) for coupling with the abutment (4).

[0023] The present invention also relates to a prosthesis provided with the cap (6) abovementioned. In particular, the prosthesis (8) is characterized by the fact of being provided with at least a cap (6) which can be fixed to the abutment (4) and which has a threaded outer surface (68) which is engaged in a correspondingly threaded seat (86) formed on the prosthesis (8). The prosthesis (8) is therefore provided with a female thread (87) in which the male screw (68) of the cap (6) can be screwed.

[0024] In practice, as described in the attached drawings, the cap (6) is constituted by a single body provided with a threaded outer surface (68) and an internal seat (61) shaped complementarily with respect to a tool used to unscrew and tighten the same cap (6) from/into the prosthesis (8) to which it is associated.

[0025] A prosthesis (8) according to the invention is therefore provided with a female thread (87) in which is screwed the male thread (68) of the cap (6).

[0026] The process for the construction of a removable prosthesis (8) according to the present invention is of the type usable for the formation of a conventional prosthesis, being essentially similar to the procedure described in FIGS. 1A-1N. The process of the invention (of whom two operating phases are schematically shown in FIGS. 7-8) is characterized in that it includes a step of inserting, in the base of the prosthesis (8), at least one cap (6) fixable to the abutment (4) and having a threaded outer surface (68), the insertion of said cap (6) determining the formation of a seat (86) correspondingly threaded into the prosthesis (8). In the drawings of FIGS. 7-8, the references 7 and 10 mark a spoon and a dam which correspond, respectively, to the spoon 107 and the dam 110 of the FIGS. 1A-N drawings.

[0027] More particularly, the process of the invention has the first steps that are similar to the procedure already described with reference to FIGS. 1A-1F. After these steps, a cap (6) is fitted on each abutment (4) as shown in FIG. 3. Then, in the seats (86) so formed in the base of the prosthesis (8) is entered the acrylic resin and acrylic resin is put on each cap (6).

[0028] In practice, during the substantial embedding of the caps (6) in the prosthesis body (8), the threaded surface (68) determines the formation of a corresponding female thread (87) on the walls of the seat (86) which receives the same cap (6).

[0029] In a final step, after the polymerization of the resin, the procedure is similar to that described with reference to FIG. 1N.

[0030] The present invention therefore allows to provide a dental prosthesis in which the connection between cap (6) and intra-bone implant (1) is particularly effective, in particular when the union between the abutment (4) and cap (6) is of conometric type, guaranteeing the possibility of detachment of the cap (6) from the prosthesis (8) thanks to the screw connection between these two elements.

[0031] In the present description reference is made to at least one cap (6) but it is noted that the inventive concept is extended to a number of caps that can be equal to two, as expected generally in the most widespread form of embodiment of the dental prosthesis (8) anchored to two dental implants, or greater than two whereas the number of usable dental implants for anchoring the prosthesis is greater than two.

[0032] For realizing the invention can be used the materials normally used to make the dental prosthesis, implants and anchoring caps of the prosthesis to the implants. The invention is not limited to those described and illustrated, but can be widely modified with regard to the nature and arrangement of the materials used, without departure from the inventive teaching as disclosed and claimed.