MODULAR APPARATUS FOR INSTALLATION OF MULTIPLE DENTAL PROSTHESES

Abstract

A modular apparatus for installation of multiple dental prostheses being adapted to connect and join various cylindrical stumps protruding from the maxillary or mandibular bone of a patient.

Claims

1. Modular apparatus for installation of multiple dental prostheses formed of a plurality of implants inserted in the patient's maxillary or mandibular bone and of a corresponding number of cylindrical stumps associated with the implants in order to protrude from the bone, the apparatus comprising: a joint comprising a ring adapted to be slidingly and revolvingly inserted outside a stump, and provided in an external circumference with a radial fork formed of two rounded branches in symmetrically opposite position, defining an intermediate compartment that extends perimetrally for an arch greater than a semi-circumference and ends at a base with a tapered edge adapted to reduce its section; wherein the fork has an opening and the opening of the fork has a width lower than the maximum distance between the two branches in the fork; and a rod comprising a cylindrical element adapted to be helically coupled, in correspondence with each of its ends and by means of a threaded stem, with a ball adapted to be exactly inserted, rotating freely, into the intermediate compartment of the fork that belongs to one of the joints.

2. The apparatus of claim 1, wherein said cylindrical element of the rod comprises a short tube with a circular section that is internally provided, at approximately half of its length, with a vertical partition that separates two identical cylindrical ducts, provided with internal threaded walls, and wherein each of said threaded stems is associated to the ball, being helically coupled inside one of said cylindrical ducts of the short tube.

3. The apparatus of claim 1, wherein the fork of each joint has a thickness that is substantially double than the thickness of the adjacent ring, in such manner that a vertical shoulder with rounded profile is created between the fork and the ring.

4. The apparatus of claim 1, wherein the rod is made in a long version that comprises: two specimens of the short tube; two specimens of the threaded stem provided with ball, each of them being adapted to be helically coupled with one of the cylindrical ducts provided in an adjacent specimen of the short tubeone specimen of a pin formed of a central cylindrical body with substantially the same diameter as the short tube and provided at each end with a threaded axial pin having the same diameter as the threaded stem; wherein each of said threaded pins is adapted to be helically coupled with one of the cylindrical ductsthe one that is not occupied by the threaded stemof one of said short tubes when the pin is disposed in intermediate position between the two specimens of the short tube.

5. The apparatus of claim 1, wherein said cylindrical element of the rod comprises a short tube with circular section that is provided, at one of its ends and for approximately half of its length, with a cylindrical duct with threaded walls and, at the other end, with the threaded stem adapted to be helically coupled with a threaded cylindrical duct obtained inside a nozzle associated with a small ball.

6. The apparatus of claim 5, wherein the rod is made in a long version that comprises: two specimens of the short tube with threaded stem; two specimens of the small ball provided with nozzle internally provided with the cylindrical duct that is adapted to be helically coupled with the threaded stem; one specimen of a pin formed of a central cylindrical body with substantially the same diameter as the short tube and provided at each end with a threaded axial pin having the same diameter as the threaded stem; wherein each of said threaded pins is adapted to be helically coupled with the cylindrical ducts of two specimens of said short tube between which the pin is disposed.

Description

[0046] For explanatory reasons, the description of the invention continues with reference to the attached drawings, which only have an illustrative, not limiting value, wherein:

[0047] FIG. 1 is a diagrammatic view that shows the bearing structure of a multiple prosthesis obtained with the modular apparatus of the invention;

[0048] FIG. 2 is an axonometric view of a possible solution according to which the apparatus of the invention is used to connect three stumps of a multiple dental prosthesis;

[0049] FIG. 3 is an exploded axonometric view of the cooperation of some elements of the apparatus according to the present invention;

[0050] FIGS. 4 and 5 are respectively an exploded side view and an exploded top view of some elements of the apparatus according to the present invention;

[0051] FIG. 6 is a side view of an element of the apparatus according to the present invention;

[0052] FIGS. 7A, 7B and 7C are respectively an axonometric view, a top view and a side view of an additional element of the apparatus according to the present invention, expressly adapted to cooperate with the element shown in FIG. 6;

[0053] FIG. 8 is an alternative embodiment of the element shown in FIG. 6;

[0054] FIGS. 9A and 9B are a side view and an axonometric view of an alternative embodiment of another element of the apparatus according to the present invention.

[0055] With reference to FIG. 1, the modular apparatus of the invention is used to connect and join the stumps (M) of a typical multiple dental prosthesis that normally protrude from implants (IM) screwed into the mandibular or maxillary bone (OS) of the patient.

[0056] As mentioned above, the apparatus of the invention is composed of two main cooperating elements, or modules, which are adapted to be used, from time to time, in a number of specimens that corresponds to the number of stumps (M) to be connected; it being also provided that both elements have a completely metal structure.

[0057] The first element, or module, of the apparatus of the invention is a a joint (G) basically consisting in a ring (1) adapted to be slidingly and revolvingly inserted outside a typical stump (M) of a dental prosthesis, as expressly shown in FIG. 2.

[0058] Moreover, as shown in FIGS. 7A, 7B and 7C, the ring (1) is provided, in a section of its external circumference, with a radial fork (10) formed of two rounded branches (10a, 10b) in symmetrically opposite position, defining an intermediate compartment (V) that perimetrally extends for an arc higher than a semi-circumference; it being provided that the opening (10c) of the fork (10) has a width lower than the maximum distance (x) internally measured in the fork (10) between the two branches (10a, 10b).

[0059] A tapered edge (10d) is provided at the base of the compartment (V) in order to reduce the section of the compartment (V) in such point.

[0060] As shown in FIG. 8C, the thickness (S1) of the two branches (10a, 10b) of the fork (10) is substantially double than the thickness (S2) of the bearing ring (1), so that a vertical shoulder (11) with rounded profile is generated between the radial fork (10) and the ring (1).

[0061] The second element, or module, of the apparatus according to the present invention consists in an extensible rod (A) that is formed of some cooperating elements that, being mutually connected by means of helical coupling, provide the entire rod (A) with a variable length that can be selectively chosen according to the specific user needs.

[0062] As mentioned above, the specific function of the rod (A) is to connect and join two consecutive stumps (M) of a multiple prosthesis, taking advantage of the cooperation of two specimens of joint (G) that is are suitably installed on the stumps (M).

[0063] With reference to FIGS. 4 and 5, each rod (A) is composed of a short tube with circular section (2) that is internally provided, at approximately half of its length, with a vertical partition (20a) adapted to separate two identical cylindrical ducts (20b, 20c) provided with internal threaded walls.

[0064] The other elements that are used to complete the rod (A) consist in two specimens of a threaded stem (3) ending with a ball (30) at one side, as expressly shown in FIG. 6.

[0065] The diameter of each threaded stem (3) corresponds to the section of the ducts (20b, 20c) of the short tube (2), whereas each ball (30) is configured like an enlarged head with respect to the stem (3).

[0066] In fact, the two threaded stems (3) are adapted to penetrate progressively, by means of helical coupling, inside the threaded cylindrical ducts (20b, 20c) of the short tube (2) in such manner that the balls (30) protrude from the two ends of the short tube (2).

[0067] Moreover, it must be noted that each ball (30) is adapted to be exactly inserted, with freedom of rotation in all directions, inside the compartment (V) of the fork (10) of a joint (G), obtaining a typical spherical joint coupling, in which the threaded bearing stem (3) of each ball (30) basically occupies the opening (10d) of the fork (10).

[0068] It must be noted that the tapered edge (10d) provided at the base of each fork (10) is used to prevent the ball (30) from coming out of the fork (10) because of simple gravity.

[0069] In the foreground FIG. 2 shows a first embodiment of the rod in its short version (A), which is formed of one specimen of the short tube (2) and of two specimens of the threaded stem (3) and is expressly adapted to be used to connect two stumps (M, M) disposed at a close distance.

[0070] FIG. 2 also shows the cooperation between the rod (A), the two stumps (M, M) between which the same is position and the two specimens of joint (G) inserted on the stumps (M, M).

[0071] Firstly, a specimen of the joint (G) is inserted into each of said is stumps (M, M), then the two balls (30) provided at the ends of the rod (A) are inserted from up down into the forks (10) belonging to the two joints (G).

[0072] Evidently, if the stump is the last one of the series, as in the case of the stump (M) shown at the far right end of FIG. 2, a single specimen of the joint (G) is to be inserted into it.

[0073] If, on the contrary, the stump occupies an intermediate position between two other stumps, as in the case of the stump (M) shown in the center of FIG. 2, two specimens of the joint (G) are to be inserted into it.

[0074] In such a situation, the two specimens of the joint (G) are adapted to be exactly interfaced one onto the other, mutually penetrating and originating a prismatic coupling that reduces the vertical volume.

[0075] More precisely, the first of the joints (G) is inserted into the stump (M) in such a position that the shoulder (11) is faced upwards, whereas the second joint (G) is inserted in the stump (M) in overturned position, i.e. with the shoulder (11) faced downwards.

[0076] Therefore, after bringing into mutual contact the rings (1) of the two joints (G, G), the shoulder (11) of the joint (G) in upper position is stopped against the external border of the ring (1) of the joint (G) in lower position, whereas the shoulder (11) of the joint (G) in lower position is stopped against the external border of the ring (1) of the joint (G) in upper position.

[0077] The additional consequence of the above is that the two interfaced joints (G) form a perfectly compact body, without undercut either in lower or upper position, because the total thickness of the two overlapped rings (1) is equal to the thickness of the corresponding forks (10).

[0078] FIG. 2in combination with FIGS. 3 and 4shows the configuration of the rod in its long version (A), which is adapted to be installed between two stumps positioned at a considerable distance.

[0079] A similar long version of the rod (A) is composed of the following five cooperating elements: [0080] two specimens of the short tube (2) [0081] two specimens of the threaded stem (3) with ball (30) [0082] one specimen of a pin (4) adapted to helically connect the two specimens of the short tube (2).

[0083] In particular, the pin (4) is formed of a central cylindrical body (40) substantially having the same diameter as the short tube (2) and of two identical threaded pins (41) that axially diverge from opposite sides from the central body (40) and are adapted to be exactly inserted and helically coupled with said cylindrical ducts (20b, 20c) provided in each specimen of the short tube (2).

[0084] The installation of the long version of the rod (A) provides for screwing the two threaded pins (41) of the pin (4), specifically one into the first cylindrical duct (20b) of the short tube (2) positioned on the right-hand side and one into the second cylindrical duct (20c) of the cylindrical ducts of the short tube (2) positioned on the left-hand side.

[0085] Now it is simply necessary to provide for the helical coupling of the two specimens of the threaded stem (3) in correspondence of the two cylindrical ducts (20b, 20c) that are still free of the two specimens of the short tube (2), in such manner to generate, also at the two ends of the long version of the rod (A), the pair of balls (30) adapted to cooperate, as illustrated above, with a corresponding pair of joints (2) inserted in correspondence of the two stumps (M) between which the rod (A) is installed. also at the two ends of the long version of the rod (A).

[0086] Such a detailed description provides a better understanding of the logic principle that allows for adjusting the elements (G, A) of the apparatus of the invention.

[0087] As mentioned above, the installer of a multiple prosthesis can choose the position of each joint (G) with respect to the stump (M), by making the ring (1) provided in the joint (G) slide vertically along the stump (M).

[0088] Moreover, the installer can choose the correct angular position of the fork (10) that belongs to the same joint (G), by using the free rotation of the ring (1) of the joint with respect to the stump (M).

[0089] After correctly choosing the height of each joint (G) and the angular position of the fork (10), the installer can stabilize the position of the joint (G) with a welding line applied between the joint (G) and the surface of the stump (M).

[0090] An additional operation is the adjustment of the length and inclination of the various rods (A) adapted to be disposed between the corresponding pairs of stumps (M), it being evident that such a double adjusting is necessary to adjust each rod to the specific distance between the two stumps (M), to the difference in height between the two joints (G) inserted on the stumps (M), and to the vertical misalignment of the stumps (M).

[0091] The length of the short version of the rod (A) can be adjusted by adjusting the depth of the helical coupling of the two specimens of the threaded stem (3) provided with ball (30) inside the two ducts (20b, 20c) of a short tube (2) in intermediate position between them.

[0092] On the other hand, the length of the long version of the rod (A) can be adjusted by adjusting the depth of the coupling of the threaded pins (41) of the connection pin (4) in the two ducts (20b, 20c) of the two specimens of the short tube (2) between which the pin is positioned.

[0093] In such a case, an additional adjustment of the length of the long version of the rod (A) is also related with the higher or lower depth given to the helical coupling between the two specimens of the threaded stem (3) with ball (30) in the cylindrical ducts (20c, 20b) that are free and belong to the two specimens of the short tube (2).

[0094] Finally, the inclination of each rod (A) between two adjacent stumps (M) can be easily adjusted by means of the spherical joint coupling established between each ball (30) provided at the ends of the rod (A) and the fork (10) of the joint (G) inserted into the stump (M).

[0095] Also in this case, after giving the correct inclination to each rod (A), the installer of the prosthesis will stabilize such a position by applying a welding point between the ball (30) and each of the branches (10a, 10b) of the fork (10) of the joint (G).

[0096] Suitable welding points must be also applied in correspondence of all helical couplings in each rod (A), after defining the correct position of the apparatus of the invention inside the patient's mouth.

[0097] With reference to FIGS. 8, 9A and 9B, it must be noted that, while still falling within the scope of the present invention, the rod (A) can have a different embodiment, which is completely equivalent from the functional viewpoint to the one described with reference to the preceding figures.

[0098] While still providing for the helical coupling of the various elements of each rod (A) in order to allow for the easy adjustment of the total length of the rod (A), a different configuration can be given to the two ending balls (30) and the adjacent short tube (2).

[0099] As shown in FIG. 8, in such a case, the ball (30) is associated with a nozzle (31) that is internally provided with a cylindrical duct (32) with threaded walls (32).

[0100] As shown in FIGS. 9A and 9B, the short tube (2) is provided on one side with one of the cylindrical ducts (20c) with threaded internal walls and on the other side with a threaded stem (3) adapted to be helically coupled with said cylindrical duct (32) provided in the nozzle (31) associated with the ball (30).

[0101] A similar coupling between the short tube (2) and the nozzle (31) of a ball (30) allows for assembling the structure of a rod (A) only at one end.

[0102] Evidently, a second ball (30) must be mounted at the opposite end of the rod (A) in order to complete the structure of the rod (A).

[0103] In order to do that, after coupling another specimen of the ball (30) provided with nozzle (31) with another specimen of the short tube (20) provided with threaded stem (3), the operator must simply install a specimen of the pin (4) shown in FIGS. 3, 4 and 5 between the two short tubes (20).