EP2911609A2

EP2911609A2 - Device for installing in the oral cavity dental prostheses with implant support and apparatus for controlling the correct application of such device

Info

Publication number: EP2911609A2
Application number: EP13779866.6A
Authority: EP
Inventors: Pietro GOBBO
Original assignee: Hospitadella Dentaltechnik Srl
Current assignee: Hospitadella Dentaltechnik Srl
Priority date: 2012-10-24
Filing date: 2013-10-22
Publication date: 2015-09-02
Also published as: WO2014064117A2; WO2014064117A3; ITPD20120313A1

Abstract

A device (10) for installing in the oral cavity dental prostheses with implant support, which comprises: – an abutment (11), constituted by a base portion (12) from which a frustum-shaped portion protrudes which is either coaxial (13) to the base portion (12), or is inclined (113) with respect to it, the abutment (11) having a through hole (14) on the axis (15) of the base portion (12) for a primary screw (16) for fixing to an implant body (17) and an optional second hole (118), on the axis (119) of the optional inclined frustum-shaped portion (113), for a secondary screw (20), – a sealing and grip cap (21), which is shaped complementarily in order to be fitted onto the frustum-shaped portion (13, 113) and be retained thereon with snap-acting fixing means, – a coupling side wall (22) designed to be incorporated in a dental prosthesis (23) and complementarily shaped in order to receive the cap (21) and the underlying frustum-shaped portion (13, 113) of the abutment (11); the coupling side wall (22) is designed to be fixed to the cap (21) and to the frustum-shaped portion (13, 113) by way of at least one selected from among the following means: – snap-acting engagement means, – means for fixing by way of a secondary screw (20), – means for fixing by way of a lateral threaded element (24) and a threaded bushing (25) that is incorporated in the dental prosthesis (23).

Description

DEVICE FOR INSTALLING IN THE ORAL CAVITY DENTAL PROSTHESES WITH IMPLANT SUPPORT AND APPARATUS FOR CONTROLLING THE CORRECT APPLICATION OF SUCH DEVICE

The present invention relates to a device for installing in the oral cavity dental prostheses with implant support, as well as an apparatus for controlling the correct application of such device.

Nowadays it is common in the field of dental surgery to make dental prostheses by inserting, in a mandibular bone or jawbone, an implant, on which a superstructure called an abutment is mounted, on which the actual dental prosthesis is then fixed.

Since practically everyone, sooner or later, suffers from dental problems, the market of the dental industry is continuously expanding and developing.

The improvements, although ongoing, of the industrial manufacture technique of such implant components have not, however, overcome major difficulties of application at the clinical level, not least because of the factors of extreme individuality of the several problems and of the corresponding technical solutions that can be adopted, and in fact highly specialist professionals are needed to make dental prostheses, thus generating a high incidence of the cost of labor, in addition to the fact that the production of the prosthesis comes to depend directly on the operator.

Nowadays there are a plurality of implant systems on the market, and the problem that arises is that of being aware of the existence, and of being able to source and have available, the components and the proper instruments for using each individual system.

Furthermore, such different implant systems differ from each other in details that cannot be perceived by the naked eye, thus creating real difficulties for dental surgeons in managing their work, as well as communication difficulties between the dental surgeon and the patient.

In particular, no systems are known today for directly controlling the configuration of intra-ossal implants for multi-implant prostheses, which make it possible to verify the correct positioning of the abutments directly in the mouth of the patient before mounting the prosthesis.

The aim of the present invention is to provide a device for installing in the oral cavity dental prostheses with implant support, which is capable of overcoming the above mentioned drawbacks of the known art.

Within this aim, an object of the invention is to provide a device that makes it possible to easily mount on implants of conventional type, even if already applied to the patient, any prosthesis according to the most well- known systems of fixing between prosthesis and abutment.

Another object of the invention is to provide a device that makes it possible to easily position a prosthesis independently of the inclination of the implant in the bone of the patient.

A further important object of the invention is to provide a device which with a reduced number of components can offer technical characteristics that are not inferior to conventional implant technologies, and in fact brings together, in the same reduced number of components, the best peculiarities of the conventional systems.

Another object of the invention is to provide an apparatus for controlling the correct application of a device according to the invention.

Another object of the invention is to provide a device for installing in the oral cavity dental prostheses with implant support, as well as an apparatus for controlling the correct application of such device, which can both be made using conventional technologies.

This aim and these and other objects which will become better evident hereinafter are achieved by a device for installing in the oral cavity dental prostheses with implant support, which comprises:

- an abutment, constituted by a base portion from which a frustum- shaped portion protrudes which is either coaxial to said base portion or is inclined with respect to it, said abutment having a through hole on the axis of said base portion for a primary screw for fixing to an implant body and an optional second hole, on the axis of said optional inclined frustum-shaped portion, for a secondary screw,

- a sealing and grip cap, which is shaped complementarily in order to be fitted onto said frustum-shaped portion and be retained thereon with snap-acting fixing means,

- a coupling side wall designed to be incorporated in a dental prosthesis and complementarily shaped in order to receive said cap and the underlying frustum-shaped portion of said abutment;

the coupling side wall is designed to be fixed to said cap and to said frustum-shaped portion by way of at least one selected from among the following means:

- snap-acting engagement means;

- means for fixing by way of a secondary screw;

- means for fixing by way of a lateral threaded element and a threaded bushing that is incorporated in the dental prosthesis.

Further characteristics and advantages of the invention will become better apparent from the description of two preferred, but not exclusive, embodiments of the device according to the invention, illustrated by way of non-limiting example in the accompanying drawings wherein:

- Figure 1 is an exploded perspective view of a device according to the invention in a first embodiment thereof;

- Figure 2 is an exploded perspective view of a device according to the invention in a second embodiment thereof;

- Figures 3 and 4 show a first detail of the invention in the first embodiment thereof;

- Figures 5 and 6 show a first detail of the invention in a second embodiment thereof;

- Figures 7, 8 and 9 each show a variation of the first detail in the second embodiment thereof; - Figure 10 is a perspective view of a second detail of the invention;

- Figure 11 is a view from below of the second detail of Figure 10;

- Figure 12 is a sectional side view of the second detail of Figures 10 and 11 ;

- Figure 13 is a perspective view of a third detail of the device according to the invention;

- Figure 14 is a sectional side view of the third detail of Figure 13;

- Figure 15 is a sectional side view of the third detail of Figures 13 and 14;

- Figure 16 is a side view of a device according to the invention, in the first embodiment thereof, assembled;

- Figure 17 is a sectional side view of the assembled device as in Figure 16;

- Figure 18 is a side view of a device according to the invention, assembled, in the second embodiment;

- Figure 19 is a first sectional view of the device according to the invention, as in Figure 18;

- Figure 20 is an additional sectional view, taken along the line XX- XX in Figure 18;

- Figure 21 shows an apparatus for optimizing the use of a device according to the invention;

- Figure 22 is a sectional side view taken along the line XXII-XXII in Figure 21 ;

- Figure 23 is a detail of Figure 22;

- Figure 24 is an exploded perspective view of the apparatus in Figure

21 ;

- Figure 25 is a sectional side view of a portion of an apparatus according to the invention, in the functional configuration for mounting a device according to the invention in the first embodiment thereof; - Figure 26 is a sectional side view of a portion of an apparatus according to the invention, in the functional configuration for mounting a device according to the invention in the second embodiment thereof.

With reference to the figures, a device for installing in the oral cavity dental prostheses with implant support according to the invention is generally designated with the reference numeral 10.

The device 10 comprises an abutment 11 , constituted by a base portion 12 from which extends a frustum- shaped portion, which can be either coaxial with respect to the base portion 12, and the frustum-shaped portion indicated with 13 in Figure 1 , or inclined with respect to the base portion 112, and the frustum-shaped portion indicated with 113 in Figure 2.

Figure 1 shows a first embodiment of the device 10 according to the invention, while Figure 2 shows a second embodiment of the device according to the invention, designated therein with the reference numeral 110, where the reference numeral 111 designates the abutment in this second embodiment.

The abutment 11 has, as can be seen in Figure 4, a through hole 14, on the axis 15 of the base portion 12, for a primary screw 16 for fixing to an implant body 17, the latter being understood as being of conventional type, for example a screw implant, and indicated by way of example by a dotted line in Figures 16 and 17.

In the second embodiment of the device 110, the frustum-shaped portion 113 of the abutment 111 has, in addition to the first through hole 114 on the axis 115 of the base 112, for a primary screw 116, a second hole 118, on the axis 119 of said inclined frustum- shaped portion 113, for a secondary screw 120.

The device 10 and 110 comprises a sealing and grip cap 21 and 121, which is shaped complementarily in order to be fitted onto the frustum- shaped portion 13 and 113, and be retained thereon with snap-acting fixing means, which are better described hereinbelow. The device 10 and 110 also comprises a coupling side wall 22 and 122 which is designed to be incorporated in a dental prosthesis 23 and 123, see Figures 16 to 20, and complementarily shaped in order to receive the cap 21 and 121 together with the underlying frustum-shaped portion 13 and 113 of the abutment 11.

The coupling side wall 22 and 122 is designed to be fixed to the cap 21 and 121 and to the frustum-shaped portion 13 and 113 by way of at least one selected from among the following means:

- snap-acting engagement means, better described hereinbelow, - means for fixing by way of a secondary screw 20 and 120,

- means for fixing by way of a lateral threaded element 24 and a threaded bushing 25 that is incorporated in the dental prosthesis 23 and 123, described in more detail below.

In particular, the abutment 11 according to the invention is preferably made of pure titanium or an alloy thereof, for example Ti6A14V, which is capable of conferring a degree of hardness of 5 according to the ASTMA B 265 standard.

The base portion 12 can have a height comprised between 1 millimeter and 6 millimeters.

On the face 26 of the base portion 12 that is directed toward the implant body 17 there is a seat 27 for mating with the head of the implant body 17.

The seat 27 can be made so as to allow the use of the device 10 and 110 according to the invention on implant bodies 17 and 117 which are of conventional type and are already on the market.

The segment for transition from the base portion 12 to the frustum- shaped portion 13 has a frustum-shaped surface 27 the generatrix of which defines an angle 28 substantially of 30° with a plane 29 that is perpendicular to the axis 15 of the base portion 12; similarly, in the second embodiment of the device 110, the segment for transition from the base portion 112 to the frustum-shaped portion 113 has a frustum- shaped surface 127 the generatrix of which defines an angle 128 substantially of 30° with a plane 129 that is perpendicular to the axis 119 of the second hole 118.

The angle 28 and 128 is understood to be comprised in a range between 1° and 35°, and preferably takes a value of 30°.

The generatrix of the frustum- shaped portion 13 and 113 defines an angle 30 and 130 with a line that is parallel to the axis 15 and 119, the value of which is 6°.

The angle 30 and 130 is understood to be comprised in a range between 4° and 6°, and preferably takes a value of 6°.

The device 110 has the frustum-shaped portion 113 inclined, with respect to the axis 115 of the base 112, at an angle 131 that can be selected from among a predefined number of different angles, for example 20° as in Figure 7, 30° as in Figure 8, and 40° as in Figure 9.

The frustum-shaped portion 13 and 113 has a circular perimetric groove 32 and 132 that is designed to receive by snap-acting engagement corresponding grip protrusions 33 that are defined so as to protrude from the inner surface of the cap 21 , such protrusions being clearly visible in Figures 11 and 12.

The sealing and grip cap 21 and 121, of which one cap 21 is shown in

Figures 10 to 12, the cap 121 being understood to be identical, is made of plastic material, for example of nylon.

The cap 21 is substantially shaped complementarily with respect to the frustum-shaped portion 13 and 113 of the abutment 11 and 111, and when it is fitted onto the corresponding frustum- shaped portion 13 or 113 the grip protrusions 33 are inserted in the groove 32 and 132 thus stabilizing the position of the cap with respect to the frustum-shaped portion.

The cap 21, as with 121, also has an outer lateral raised portion 34 for the first locking of the coupling side wall 22 and 122, thanks to the lateral hole 35 defined on the latter for the use of a lateral threaded element 24 with a threaded bushing 25 that is incorporated in the dental prosthesis 23, described in more detail below.

The cap 21 has at least one centering raised portion, for example the centering raised portion 36 shaped like a circular arc in Figure 10, which protrudes in the direction of assembly of the side wall on the cap, and is designed to arrange itself in a corresponding complementarily shaped seat 37 defined inside the side wall 22.

In an equivalent variation of embodiment of the invention, not shown for the sake of simplicity, the cap has three centering raised portions, which are substantially cylindrical and adapted to arrange themselves in three complementarily shaped seats defined inside the side wall.

The sheath 21 can be made so as to have a different degree of hardness, according to the degree of friction and retention that is required of it between the abutment 11 and the side wall 22.

Advantageously for an operator, the cap 21 can be provided in different colors according to the degree of hardness.

The cap 21, and 121, has, at its lower edge 40, a step 41 that is adapted to define, with the frustum-shaped surface 27 of the base portion 12 of the abutment 11, a hollow 43 and 143, as in Figures 17 and 20, that is designed for engagement with a complementarily shaped inner annular raised portion 42 which is defined inside the side wall 22.

The coupling side wall 22 is substantially shaped complementarily with respect to the cap 21, and has perimetric protrusions 38, or perimetric grooves 39, for gripping the prostheses with which it is intended to be used.

Differently, but understood to be equivalent for the invention, the inner shape of the coupling side wall can be provided directly in the dental prosthesis, with CAD-CAM systems.

The coupling side wall 22 can be made of titanium, or a gold alloy, or of steel, or of rigid plastic material.

The primary screw 16 and 116 can vary in length and diameter according to the implant body 17 or 117 for which it is destined; extending axially from its head, which has an inner cavity contoured for its screwing with corresponding instruments that are understood to be conventional, is the threaded seat for the secondary screw 20, which can be used to screw to the primary screw 16 in the first embodiment 10 of the device, in which the frustum-shaped portion 13 is coaxial to the base 12.

The snap-acting engagement means for the connection of the coupling side wall 22 and 122 with the cap 21 and 121 are thus comprised of the hollow 43 and 143, as in Figures 17 and 20, and of the complementarily shaped inner annular raised portion 42 which is defined inside the coupling side wall 22.

Alternatively, or simultaneously with the means of engagement by snap action described above, the coupling side wall, 22 and 122, and the abutment, 11 and 111, can be connected with means for fixing by way of a secondary screw 20 and 120, for a standard fixing with a screw introduced from an open hole on the chewing surface.

Also as an alternative, or simultaneously with the means of engagement by snap action described above, the coupling side wall, 22 and 122, and the abutment, 11 and 111, can be connected by way of a lateral threaded element 24, a grub screw or a micro-screw, and a threaded bushing 25 that is incorporated in the dental prosthesis 23 and 123, as in Figures 17 and 20.

In this last solution, the lateral threaded element 24, screwed, pushes against the outer protrusion 34 of the cap 21, firmly locking the side wall 22 to the frustum- shaped portion 13 of the abutment 11.

Such range of technical solutions for fixing the side wall to the abutment makes numerous fixing options, both permanent and temporary, available to the operator without such operator having to expend time and money in deciding which components to source, such components to be selected from the innumerable components available on the market, but unlikely to be compatible if from different makers.

The invention also relates to an apparatus for controlling the correct application of such device, which is generally designated in Figures 21 to 24 with the reference numeral 45.

Such apparatus 45 comprises a bar 46 for supporting a plurality of articulated arms 47, 48 and 49, which can be moved parallel to a single plane 50, shown in Figure 22.

Each arm 47, 48 and 49 bears, at the free end, a through hole 51, 52 and 53 for a positioning pin 54, 55 and 56 that is adapted to support, fixed at the tip, an abutment 11 or 111 , as in Figures 25 and 26, to be positioned on an implant body.

The abutment 11 or 111 is supported by the positioning pin 54, 55 and 56 with the cooperation of a transfer element 57, 58 and 59, shaped complementarily with respect to the frustum-shaped portion 13 and 113 of the abutment 11 and 111.

The transfer element is locked between the positioning pin 54, 55 and 56 and the supported abutment 111, as in Figure 26, or between the positioning pin and a primary screw 16 which is associated with the abutment 11, as in Figure 25.

Figure 21 shows three articulated arms, but it should be understood that such arms can be two in number upwards, up to a preferable maximum of six.

For this reason the support bar 46 has six holes 60, 61 , 62, 63, 64 and 65 for fixing a corresponding pin 66, 67 and 68 with axis perpendicular to the plane 50.

Each pin can be fixed to the support bar 46 for example by way of an axial screw 69.

The articulated arms 47, 48 and 49 are shown by way of example as being composed of two portions, respectively 47a, 47b, 48a, 48b, 49a and 49b, but it should be understood that they can also be constituted by three or more mutually pivoted portions.

The first portion, for example 47a, of each articulated arm has a first bush 70 for rotation and sliding with respect to the respective pin 66, 67, 68.

The first portion, for example 47a, and the second portion, for example 47b, are mutually pivoted by way of an intermediate bush 71 which is fixed, for example with an axial screw 72, to the first portion 47a and is coupled rotatably to a complementarily shaped annular portion 73 of the second portion 47b.

The through holes 51 , 52 and 53 for the positioning pins 54, 55 and 56 are flared with a total angle 74 of approximately 12° from both mouths of the hole.

The through holes 51 , 52 and 53, thus shaped, enable an easier but no less precise insertion of the positioning pins, as well as a gauged tolerance in their use for positioning the supported abutments.

The positioning pins 54, 55 and 56 have a shank 75 with a threaded end 76, the latter being shaped so as to screw directly into the second hole 118 of an abutment 111, as in Figure 26, or into the head of a primary screw 16, as in Figure 25.

The transfer element 57, 58 and 59 also has a threaded axial hole 77 that is such as to allow the passage, by screwing, of the threaded end 76 of the positioning pin, in order to then accommodate without play the shank 75 of the pin, so as to be locked stably and precisely between the shoulder 78 at the base of the shank and the head of the primary screw 16 or of the frustum-shaped portion 113 of the abutment 111.

Use of the apparatus 45 according to the invention is the following.

For a correct mounting of an abutment 11 or 111 on a predefined implant body 17 or 117 in the oral cavity of a patient, the abutments are temporarily mounted on the respective implant bodies, the positioning pins 54, 55 and 56 are each fixed to an abutment with transfer elements 57, 58 and 59 interposed, and subsequently the pins are inserted into the through holes 51 , 52 and 53 of the articulated arms.

If the positioning pin does not slide inside the corresponding through hole, the abutment associated with the positioning pin is rotated until the pin is not free to slide in its corresponding through hole.

When the support bar 46 can freely perform a translational movement parallel to the positioning pins, then it means that all the abutments are positioned correctly and that it is possible to stabilize the locking thereof to the respective implant bodies, by way of screwing the primary screws.

In order to join the prostheses 23 or 123 with the abutment 11 or 111 directly in the oral cavity, the side wall 22 or 122 is positioned on the cap 21 or 121, with the snap upon the insertion of the inner annular raised portion

42 into the corresponding hollow 43 between the cap and the base portion

12 or 112 confirming its correct positioning.

By arranging a spacer disk of soft sealant plastic, of conventional type and not shown, at the base of the abutment and around the side wall, contact is prevented between the fixing materials and the gingival tissues, thus protecting the latter, and it is possible to test the dental prosthesis 23 or 123 in order to verify its correct operation, and it can be bonded to the side wall by using specific acrylic adhesives.

The retention of the prostheses occurs thanks to the mechanical friction between the inside of the side wall and the plastic cap fitted onto the frustum-shaped portion of the abutment.

If it is desired to stably fix the prostheses it is sufficient to remove the plastic cap and substitute it with adhesive cements.

If on the other hand a fixed, screwed prosthesis is desired, the operator can, after the side wall has been correctly locked to the prosthesis, fix the prosthesis by way of the lateral threaded element, or by way of adopting the secondary screw.

In practice it has been found that the invention fully achieves the intended aim and objects. In particular, with the invention a device is provided that makes it possible to easily mount on implants of conventional type, even if already applied to the patient, any prosthesis according to the most well-known systems of fixing between prosthesis and abutment.

Furthermore, with the invention a device is provided that makes it possible to easily position a prosthesis independently of the inclination of the implant in the bone of the patient.

Furthermore, with the invention a device is provided which with a reduced number of components can offer technical characteristics that are not inferior to conventional implant technologies, and in fact brings together, in the same reduced number of components, the best peculiarities of the conventional systems.

Moreover, with the invention an apparatus is provided for controlling the correct application of a device according to the invention, which solves the problems of parallelism error between implants with multi-implant prostheses, such apparatus making it possible to use a single work protocol both for providing fixed prostheses, and for providing prostheses that can move, as well as being adaptable to all conventional types of implant bodies.

Last but not least, with the invention a device is provided for installing in the oral cavity dental prostheses with implant support, as well as an apparatus for controlling the correct application of such device, which can both be made using conventional technologies.

The invention, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

In practice the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art. The disclosures in Italian Patent Application No. PD2012A000313 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, such reference signs have been inserted for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A device (10, 110) for installing in the oral cavity dental prostheses with implant support, characterized in that it comprises:

- an abutment (11, 111), constituted by a base portion (12, 112) from which a frustum-shaped portion protrudes which is either coaxial (13) to said base portion (12) or is inclined (113) with respect to it, said abutment (11, 111) having a through hole (14, 114) on the axis (15, 115) of said base portion (12, 112) for a primary screw (16) for fixing to an implant body (17) and an optional second hole (118), on the axis (119) of said optional inclined frustum-shaped portion (113), for a secondary screw (120),

- a sealing and grip cap (21, 121), which is shaped complementarily in order to be fitted onto said frustum-shaped portion (13, 113) and be retained thereon with snap-acting fixing means,

- a coupling side wall (22, 122) designed to be incorporated in a dental prosthesis (23) and complementarily shaped in order to receive said cap (21, 121) and the underlying frustum-shaped portion (13, 113) of said abutment (11, 111),

said coupling side wall (22, 122) being designed to be fixed to said cap (21, 121) and to said frustum-shaped portion (13, 113) by way of at least one selected from among the following means:

- snap-acting engagement means,

- means for fixing by way of a secondary screw (20, 120),

- means for fixing by way of a lateral threaded element (24) and a threaded bushing (25) that is incorporated in the dental prosthesis (23).

2. The device according to claim 1, characterized in that on the face

(26) of the base portion (12) that is directed toward an implant body (17) there is a seat (27) for mating with the head of the implant body (17).

3. The device according to the preceding claims, characterized in that the segment for transition from the base portion (12, 112) to the frustum- shaped portion (13, 113) has a frustum- shaped surface (27, 127) the generatrix of which defines an angle (28, 128) substantially of 30° either with a plane (29) that is perpendicular to the axis (15) of said base portion (12) or with a plane (129) that is perpendicular to the axis (119) of the second hole (118), said angle (28, 128) being comprised in an interval between 1° and 35° and preferably assuming the value of 30°.

4. The device according to the preceding claims, characterized in that said generatrix of the frustum-shaped portion (13, 113) defines an angle (30, 130) with a line that is parallel to the axis (15) of the base portion (12) or with the axis (119) of the second hole (118) the value of which is 6°, said angle (30, 130) being comprised in an interval between 4° and 6°, with the preferred value of 6°.

5. The device according to the preceding claims, characterized in that said frustum- shaped portion (13, 113) has a circular perimetric groove (32, 132) that is designed to receive by snap-acting engagement corresponding grip protrusions (33) defined so as to protrude from the inner surface of said sealing and grip cap (21).

6. The device according to the preceding claims, characterized in that said sealing and grip cap (21, 121) is made of plastic material.

7. The device according to the preceding claims, characterized in that said cap (21, 121) has an outer lateral raised portion (34) for the first locking of the coupling side wall (22, 122), thanks to the lateral hole (35) defined on the latter for the use of a lateral threaded element (24) with a threaded bushing (25) incorporated in a dental prosthesis (23).

8. The device according to the preceding claims, characterized in that said cap (21) has a centering raised portion (36), which protrudes in the direction of assembly of the side wall on the cap and is designed to arrange itself in a corresponding complementarily shaped seat (37) defined inside the side wall (22).

9. The device according to the preceding claims, characterized in that said cap (21) has, at its lower edge (40), a step (41) that is adapted to define, with the frustum-shaped surface (27) of the base (12) of the abutment (11), a hollow (43, 143) that is designed for engagement with a complementarily shaped inner annular raised portion (42) defined inside said side wall (22).

10. The device according to the preceding claims, characterized in that said snap-acting engagement means for the connection of the coupling side wall (22, 122) to said cap (21, 121) are constituted by said hollow (43, 143) and by the complementarily shaped inner annular raised portion (42) defined inside said side wall (22).

11. An apparatus (45) for controlling the correct application of a device for installing in the oral cavity dental prostheses with implant support according to the preceding claims, characterized in that it comprises - a bar (46) for supporting a plurality of articulated arms (47, 48, 49), which can be moved parallel to a single plane (50), each arm bearing, at the free end, a through hole (51, 52, 53) for a positioning pin (54, 55, 56) that is adapted to support, fixed at the tip, an abutment (11, 111) to be positioned on an implant body, said abutment (11, 111) being supported by said positioning pin with the cooperation of a transfer element (57, 58, 59) that is shaped complementarily with respect to said frustum-shaped portion (13, 113) of said abutment, said transfer element (57, 58, 59) being locked between said positioning pin and said abutment, or between said positioning pin and a primary screw associated with said abutment.

12. The apparatus according to claim 11 , characterized in that said articulated arms (47, 48, 49) are composed of at least two mutually pivoted portions (47a, 47b, 48a, 48b, 49a, 49b).

13. The apparatus according to claims 11 and 12, characterized in that said through holes (51, 52, 53) for the positioning pins (54, 55, 56) are flared with a total angle (74) of approximately 12° from both mouths of said hole.

14. The apparatus according to claims 11 , 12 and 13, characterized in that said positioning pins (54, 55, 56) have a shank (75) with a threaded end (76), the latter being shaped so as to screw directly into the second hole (118) of an abutment (111) or into the head of a primary screw (16).

15. The apparatus according to claims 11 to 14, characterized in that said transfer element (57, 58, 59) also has a threaded axial hole (77) that is such as to allow the passage, by screwing, of the threaded end (76) of the positioning pin, in order to accommodate without play the shank (75) of said pin, so as to be locked stably and precisely between the shoulder (78) at the base of the shank and the head of the primary screw (16) or of the frustum-shaped portion (113) of the abutment (111).