Attachments for removable dental appliances used in implantology

Abstract

Attachments for removable dental appliances used in implantology. The invention relates to improvements to male (1) and female (2) attachments provided with means for ensuring the removable connection of a dental appliance to the implants dedicated to it and for compensating for the divergence that exists between the implants associated with said appliance. Said means consist of: a) a metallic frustoconical module (13) whose angle (A) of its walls with the axis (X) of the cone is at least equal to 5° and whose base is provided with a stump (14) configured to be fixed to the head (11) of the abutment (1); b) a metallic female module (2) consisting of a single cap (21), provided with a frustoconical axial cavity (22) suitable for receiving the frustoconical head (13) of the new abutment (11,13) thus formed; (c) a metallic, elastic ring segment (3), functioning like a clip, between the head (13) and the cap (21). Figure for the abbreviation: Fig. 1

Description

Title of the invention: Attachments for mobile dental appliances used in implantology Technical field

[0001] The present invention relates to improvements made to “male-female” attachments capable of removably connecting a dental appliance to the implants dedicated to them. Prior art concerned

[0002] The attachments concerned by the improvements are of the type consisting of:

[0003] a) a male pillar capable of being secured, by screwing, to an implant either directly or by means of a milled or cast bar; the head of said pillar being of generally cylindrical shape provided, at the top, with a star-shaped axial cylindrical cavity, over its entire height, used for screwing said pillar onto the dedicated implant by means of a star-shaped tightening key;

[0004] b) a female prosthetic device, intended to be secured to a dental appliance, provided with means capable of ensuring the removable connection between the latter and each pillar dedicated to it and of compensating for the divergence which exists between the implants associated with the same appliance; said prosthetic device being constituted by a rigid metal casing intended to be inserted into the structure of the dental appliance and an intermediate cap, made of plastic material, held in said casing, the shape of which is designed to clip onto the head of the pillar and to ensure the removable retention of the appliance and to compensate for the divergence which exists between the associated implants;

[0005] The most commonly used attachments are identical to those known under the brand name “Locator”.

[0006] They are mainly described in patent EP2315554.

[0007] They have the following main disadvantages:

[0008] a) the first linked to the implementation of this by the practitioner who must have:

[0009] - a first set of 3 caps, with different physical characteristics, to attempt to empirically compensate for the divergence that exists between the implants of the same jaw and this up to a maximum of 20° between the axes of the implants concerned (i.e. 10° in relation to the axis of insertion of the device);

[0010] - of a second set of 4 caps, with different physical characteristics, for attempt to empirically compensate for the divergence that exists between the implants in the same jaw, up to a maximum of 40° between the axes of the implants concerned (i.e. 20° in relation to the axis of insertion of the device);

[0011] with the consequence of storing a large number of caps (7 in total) to treat the different clinical cases encountered and the empirical choice of the cap(s) depending on the divergence existing between the implants associated with the same device;

[0012] b) the second linked to the very design of said device and its operation in the mouth which lead to premature wear and deterioration of the caps which have a small thickness and which undergo an irreversible hardening effect due to masticatory pressures which, on a physiological level, exert laterocircular forces on the implants which compromise their stability and degrade osteointegration (loss of bone coils or even loss of the implant itself);

[0013] c) the third linked to the metal case which weakens the resin structure of the dental appliance by tilting lever effect with the consequence of the recurring repair of said appliance;

[0014] d) the fourth linked to the microbial absorption of the plastic caps with the consequence of frequent cleaning of the device.

[0015] All this with the consequences: a frequent return to the practitioner to clean the device, or change the affected caps, or replace the implant, or replace the device, which is not without logistical and financial consequences. Summary of the invention

[0016] The invention proposes improvements consisting of eliminating the aforementioned drawbacks by replacing, by simple substitution, the prosthetic assembly of the “Locator” type with a new assembly directly adaptable to the “Locator” type pillars belonging to existing prostheses or to future restorations.

[0017] Said new assembly comprises:

[0018] a) a metallic truncated cone module whose angle (A) of its walls with the axis (X) of the cone is at least equal to 5°, provided at its base with a stump intended to be secured to the head of the dedicated pillar and whose shape, identically star-shaped, has been designed to fit, by friction, into the axial cylindrical star-shaped cavity of said pillar so as to constitute a single monolithic pillar with a truncated cone head;

[0019] b) a female module consisting of a single metal cap, provided with a frustoconical axial cavity whose dimensional and angular characteristics have been defined to receive, identically, the frustoconical head of the new pillar thus constituted.

[0020] The advantages of such a configuration are described in patent EP2440153 from the same applicants. They concern on the one hand the removable clip connection means between the male (pillar) and female metal (cap) parts of an attachment dental and on the other hand the head of the abutment and the cavity of the cap which are truncated, of identical dimensions, the value of the angle of inclination of the walls of which is determined to compensate for the divergences which exist between the implants associated with the same device in such a way that any pair of heads and caps belonging to the same device are never undercut with respect to the axis of insertion of the latter and this by using only one type of cap. Brief description of the drawings

[0021] The characteristics and advantages of the invention will appear more clearly on reading the following detailed description of at least one preferred embodiment thereof given by way of non-limiting example and represented in the attached drawing.

[0022] [Fig-1] represents, in longitudinal section, the assembly according to the invention. Description of the embodiments

[0023] With reference to this drawing, the device according to the invention generally comprises:

[0024] a) a male pillar (1) capable of being secured, by screwing, to an implant either directly or by means of a milled or cast bar; the head (11) of said pillar (1) being of generally cylindrical shape provided, at the top, with a star-shaped axial cylindrical cavity (12), over its entire height, used for screwing said pillar onto the dedicated implant by means of a star-shaped tightening key;

[0025] b) a female prosthetic device, intended to be secured to a dental appliance, provided with means capable of ensuring the removable connection between the latter and each pillar (1) associated with it and of compensating for the divergence which exists between the implants associated with the same appliance.

[0026] The improvements according to the invention are essentially characterized in that means, totally substitutable, in the mouth or in any new restoration, for those described above known under the brand name "Locator", adaptable to each head (11) of the "Locator" type abutment, capable of ensuring the removable connection between the device concerned and each dedicated head (11) and of compensating for the divergence which exists between the implants associated with said device, are constituted:

[0027] a) a metallic truncated cone module (13), the angle (A) of its walls with the axis (X) of the cone is at least equal to 5°, provided at its base with a stump (14) intended to be secured to the head (11) of the dedicated pillar (1) and whose shape, identically star-shaped, has been designed to fit, by friction, into the axial cylindrical star-shaped cavity (12) of said pillar so as to constitute a single monolithic pillar with a truncated cone head (1, 13);

[0028] b) a female module (2) consisting of a single metal cap (21), provided with a truncated axial cavity (22) whose dimensional characteristics and angular were defined to receive, identically, the truncated head (13) of the new pillar (1,13) thus formed.

[0029] These two modules (13) and (2) cooperate in combination with the pillar (1) to achieve the result obtained.

[0030] According to other particular features of the invention:

[0031] - the removable connection between the truncated head (13) and the truncated cavity (22), is produced by means of a metallic annular segment (3), split in order to make it elastic, which is housed simultaneously and partially in opposite annular grooves (15) and (23) arranged respectively on said truncated head (13) of the pillar and in the truncated cavity (22) of the cap (21);

[0032] - the connection between the star stump (14) and the star cavity (12) is secured by the supply of suitable glue.

[0033] These two parts are also mechanically inseparable thanks to the disparallelism of the cylindrical cavities whose axes are parallel to the axes of the associated implants.

[0034] According to the preferred embodiment of the invention, the angle (A) is equal to 15°.

[0035] The lower stem (16) of the abutment (1) is threaded to be screwed into the implant.

[0036] The assembly according to the invention is capable of remedying all the problems of divergence between implants and wear of the removable connection between the device and the anchors with the addition of biomechanical protection of the implants.

[0037] Of course, a person skilled in the art will be able to carry out the invention as described and represented by applying and adapting known means without it being necessary to describe or represent them.

[0038] It may also provide other variants without departing from the scope of the invention as determined by the content of the claims.

Claims

[Claim 1] Claims Attachments for mobile dental appliances used in implantology and each consisting of: a) a male pillar (1) capable of being secured, by screwing, to an implant either directly or by means of a milled or cast bar; the head (11) of said pillar (1) being provided, at the top, with a star-shaped axial cylindrical cavity (12), over its entire height, used for screwing said pillar onto the dedicated implant by means of a star-shaped tightening key; b) a female prosthetic device which is intended to be secured to a dental appliance and which is provided with means capable of ensuring the removable connection between said appliance and each pillar (1) associated with it and of compensating for the divergence which exists between the implants associated with said appliance; characterized in that the means capable of ensuring the removable connection between the device concerned and each head (11) and of compensating for the divergence which exists between the implants associated with said device, are each constituted, in cooperation: a) a metallic truncated cone module (13) whose angle (A) of its walls with the axis (X) of the cone is at least equal to 5° so as to compensate for the divergence which exists between the implants and whose base is provided with a stump (14) intended to be secured to the head (11) of the dedicated male pillar (1) thanks to its star-shaped shape which has been designed to fit, by friction, into the axial cylindrical star-shaped cavity (12) of said pillar so as to constitute a single pillar (11, 13) with a truncated cone head (13); b) a female metal module (2) consisting of a cap (21) which is provided with a frustoconical axial cavity (22) whose dimensional and angular characteristics have been defined to receive, identically, the frustoconical head (13) of the new pillar (11, 13) thus constituted; c) a metallic annular segment (3), split to make it elastic, functioning in the manner of a clip, capable of ensuring the removable connection between the device concerned and each pillar (11, 13), which is housed simultaneously and partially in opposite annular grooves (15) and (23) arranged respectively on the head truncated cone (13) of the pillar (11,13) and in the truncated cone cavity (22) of the cap (21).

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