WO2023007334A1 - Dental implant - Google Patents

Abstract

A dental implant (1) comprising a head (3) as well as an anchoring body (2), characterised in that: -the anchoring body (2) comprises a shaft (23) comprising an apical portion (21) and a cervical portion (22) and extending along an axis; -the anchoring body (2) comprises a helical thread (24) projecting radially relative to the shaft (23); -at the apical portion (21), the ratio R is greater than approximately 2.5, with R=df/da, with df being the external diameter of the helical thread (24) and da being the external diameter of the shaft (23) in the same transverse section perpendicular to the axis.

Description

Dental implant

The invention relates to the technical field of dental implants, and in particular dental implants comprising a head as well as an anchoring body intended to be screwed into the bone of the jaw.

In the context of the present description, an interval which is described by the expression “between […] and […]” includes the terminals. For example, the interval "between 1 and 2" includes the two values "1" and "2" as well as all the values being both strictly greater than 1 and strictly less than 2.

In the context of the present description, the term “approximately” preceding a numerical value means that the value can be modified by plus or minus 10%. In the particular case of a numerical value being an interval limit, the term “approximately” means that the lower limit can be reduced by 10% or the upper limit can be increased by 10%. It is also possible to delete the term “approximately” preceding a numerical value.

In the context of this application, the diameter of an element can be "fixed" (same diameter along the element) or "variable" (variable diameter along the element). When an embodiment deals with a "diameter" without further specification, for example "diameter less than Di", it can be transformed into "fixed diameter less than Di" or "variable diameter always less than Di".

Nowadays, a majority of practitioners routinely practice implant treatments, which in particular make it possible to avoid the use of dentures or to sacrifice healthy teeth.

In general, a dental implant can completely replace a missing tooth. Inserted into the jawbone, it acts as an artificial root and allows the attachment of a dental prosthesis.

In practice, the placement of dental implants can be offered to patients from whom one or more teeth have been extracted beforehand. Dental implants allow both a good aesthetic rendering and to find adapted chewing capacities.

The placement of a dental implant is carried out after a medical examination and in particular the realization of a dental X-ray scanned in three dimensions (3D). This step confirms that the clinical situation is suitable for the placement of the dental implant.

A dental implant is usually used to support a dental prosthesis (sometimes also called a "crown"), by anchoring it into a patient's jaw bone.

Bone density is an important element that determines the success of the installation and in particular the primary stability (stability of the implant at the end of the installation), as well as the long-term osseointegration of the implant.

For example, it is preferable to plan an implant placement relatively soon after tooth extraction, because over time the bone density decreases, which has an impact on the possibility for the patient to be implanted.

A dental implant usually consists of a threaded anchor body and an abutment. The placement of the implant involves prior drilling of the jaw bone to create a housing. The threaded anchor body is then screwed into the housing to secure the implant to the jaw bone. A dental prosthesis is then attached to the protruding abutment of the implant, typically 3 to 6 months later.

In practice, the preparation of the jaw bone and the fixation of the implant are complex operations, making the intervention of the practitioner relatively demanding in terms of meticulousness, especially in the case of multiple implant placement. The duration of the intervention is a source of discomfort for both the patient and the practitioner, so there is a need for solutions to reduce this intervention time.

More specifically, there is a need to have dental implants that can improve the comfort of the patient and the practitioner during installation, primary stability, as well as long-term osseointegration.

Generally, the dental implants known from the prior art are formed by a threaded anchor body, the depth of the thread can vary but is often relatively low. Additionally, some implants have a slightly conical shape, with a smaller diameter at the apical ("deep" end) and larger as one moves away from the apical part and approaches. therefore from the cervical part ("shallower" part).

In patent US5533898 (Mena), an implant is described having oblique or straight engagement structures. The reliefs of the implant are discontinuous, which limits the contact surface, and therefore the primary and longer-term stability. In addition, the structure of the implant is very irregular, which complicates its placement in terms of risk and installation time. Finally, when the engagement structures are straight, it is difficult to design a pose without completely destroying the jaw bone first.

In application WO2011027338 (Golz, BASAD-MEDICAL), an implant is described having discontinuous fins arranged in a helical manner. The fins are discontinuous and therefore the anchorage is limited. Moreover, given the small contact surface, it is obvious that the bone is likely to be fragmented during placement by the action of the fins, and therefore that the primary stability is compromised. Moreover, these abrasions are completely unpredictable.

In application EP0922439 (Faraci, L.S.S. LIFE SUPPORT SYSTEMS S.P.A), a spiral implant is described having recessed apical parts. The implant section has a structure resembling a boat propeller, so it is discontinuous. Here again, the structure of the implant makes its insertion problematic, and potentially very traumatic for the jawbone.

In application WO2010146383 (Mullen, ULIVEENTERPRISES LIMITED) a spiral implant is described. The apical part of this implant is not self-drilling, therefore the insertion of the implant will require numerous successive drillings and traumatisms of the jaw before insertion.

In application US2013115572A1 (Reed, BERNHARD KRETEN), a spiral implant is described having turns curved upwards.

In applications DE202011104513U1 on behalf of Biomed Est. Vaduz, LI, WO2010021478 on behalf of MEGAGEN IMPLANT CO., LTD., WO2015115692 on behalf of MEGAGEN IMPLANT CO., LTD. and WO2016016236 in the name of ERIC ROMPEN IMPLANTOLOGY, there are disclosed implants presented as being dental implants, and having central elements having large diameters.

All of these solutions are imperfect. For example, osseointegration takes place on the outer wall of the implant, at the ends of the threads; it is therefore only a vertical osseointegration.

The invention relates to a dental implant 1 comprising a head 3 as well as an anchor body 2, characterized in that:

the anchor body 2 comprises a shaft 23 comprising an apical part 21 and a cervical part 22 and extending along an axis;

-the anchor body 2 comprises a helical thread 24 projecting radially with respect to the shaft 23;

-at the apical part 21, the ratio R is greater than approximately 2.5, with R=df/da, with df the external diameter of the helical thread 24 and da the external diameter of the shaft 23 in the same section transverse perpendicular to said axis.

In the context of the present description, the term "apical part of the shaft 23" refers to the deep part corresponding to 50% of the length of the shaft 23. The term "cervical part of the shaft 23" refers to the part corresponding to 50% of the length of shaft 23 and being the outermost. The intermediate part of the shaft 23 is called the intermediate part corresponding to 50% of the length of the shaft 23. For example, if the shaft 23 of the implant 1 measures 16 millimeters, the part corresponding to 8 millimeters the deepest part of the shaft 23 is the apical part of the shaft 23, the part corresponding to the shallowest 8 millimeters of the shaft 23 is the cervical part of the shaft 23, and the part corresponding to the intermediate 8 millimeters (4 millimeters belonging to the cervical part and millimeters belonging to the apical part) is the intermediate part of the shaft 23. The lengths of each of these parts are presented in .

The apical and cervical portions of the shaft 23 are intended to be implanted in the jaw bone of the patient, and therefore the intermediate portion of the shaft 23 is also intended to be implanted in the jaw bone of the patient .

Surprisingly, it has been demonstrated that the implant according to the invention, thanks to its structure, has ease of installation (rapid insertion, self-drilling implant), improved primary stability and improved long-term biological osseointegration, thanks in particular to less trauma during installation.

Indeed, the implant according to the invention has a certain number of advantages.

First of all, its structure allows less erosion of the bone during insertion. Indeed the insertion can, in most cases, be provided directly after the use of the first pointer drill with a diameter of between approximately 0.5 and approximately 3 millimeters, preferably approximately 2 millimeters, and without the use of drills with diameters successive as is the case so far.

In certain other situations corresponding to other clinical realities, it will be necessary to tap/format before implantation. The tapping/formatting is carried out by means of a forming tap specially designed for the subsequent use of the implant according to the invention.

Concretely, the forming tap has the same structure as the anchoring body of the implant according to the invention which will be implanted subsequently, but has surface barbs. Thus, the bone is machined in order to create a structure which corresponds perfectly to the implant according to the invention which will be inserted, thus an intimate contact between bone and thread of the implant according to the invention will be created.

Then, its insertion is very suitable for situations in which the removal of the natural tooth took place shortly before implantation, in particular for single-rooted teeth (teeth with only one root), the patient still having of a little involute bone volume. It turns out that with the development of dental care, this category of patient has become very predominant (about 80% of patients who are candidates for implantation).

In the case of multi-rooted teeth (teeth with several roots), the situation is different, insofar as the bone tends to colonize the cavities of the roots. In the latter case, an implant placement can be planned later.

Then, the implant object of the invention gives rise to the direct placement of the temporary dental prosthesis after the surgical placement of the implant according to the invention, which is very appreciated by the patients.

Next, the implant according to the invention has the particularity of being able to be implanted in almost all clinical situations. Indeed, the slightest bone erosion that it causes during insertion makes it possible to have the best possible clinical situation. In addition, if it were necessary to remove this implant, little damage and bone loss would be caused.

Then, the implant allows, in addition to a vertical osseointegration, also a multiple horizontal osseointegration (due to the multiplicity of the number of revolutions of the thread) because of its structure. This is truly advantageous, the implant will eventually be composed of bone and the material of the implant (for example a titanium alloy) in proportions very suitable for good solidity and durability. It will present different areas that have been heavily colonized by bone due to the depth of the thread and the multiplicity of revolutions of said thread.

Very concretely, compared to conventional implants, at the level of the anchor body 2, the ratio "volume available for osseointegration / volume of material of the implant" will be greatly increased.

Then, because of its structure, the implant according to the invention allows a very improved primary stability. The patient can, at the end of the installation appointment, have an aesthetic temporary dental prosthesis, and benefit from a diet which must remain adapted, called "flexible".

Then, the implant according to the invention is particularly indicated for carrying out a recovery after failure of the placement of a first implant. In this case, the external diameter of the helical thread 24 must be greater than the diameter of the cavity left by the previous implantation attempt. In this case, the placement of the implant according to the invention can be carried out concomitantly with the placement of a bone biomaterial.

Furthermore, the implant according to the invention is particularly indicated for carrying out an attempt after a bone graft with the use of biomaterials. In this very particular context, placement of the implant according to the invention will be recommended approximately two months after the graft, and the possibility of making a temporary fixed dental prosthesis will be evaluated for the premolar and molar sectors. In some cases, it will be possible not to provide a temporary dental prosthesis if this is correct from an aesthetic point of view, so as not to mechanically stress the implant according to the invention for a certain period of time.

Then, the implant according to the invention is "one-piece", that is to say that all the parts (apart from the dental prosthesis) are in a single continuous block of material. This allows faster placement, and in particular avoids the second stage of the realization of a patient-dependent implant head.

Indeed, the implant according to the invention has a universal head (part to accommodate the temporary and permanent dental prostheses) which can be composed of an abutment, a fillet as well as an upper part of the head. The abutment serves as abutment against the bone during implantation, and the fillet and the upper part of the head serve as mechanical support for the dental prosthesis.

In the context of this description, the term "head" or "head of the implant 1" is used to refer to the part of the implant intended to remain extra-osseous after placement, and of which at least a part serves to fix the dental prosthesis.

The lower part of the head (thickness of about 3 millimeters), and in particular the abutment and the fillet, is transgingival, while the upper part of the head is extragingival.

Concretely, the head can be of two different sizes depending on the clinical situation. The two types of head can be used to screw in the complete implant when the implant is in one piece, using the same tool, in this case a 2.5 mm hexagonal key.

The invention thus relates to a dental implant 1 comprising a head 3 as well as an anchor body 2, characterized in that:

the anchor body 2 comprises a shaft 23 comprising an apical part 21 and a cervical part 22 and extending along an axis;

-the anchor body 2 comprises a helical thread 24 projecting radially with respect to the shaft 23;

-at the apical part 21, the ratio R is greater than approximately 2.5, with R=df/da, with df the external diameter of the helical thread 24 and da the external diameter of the shaft 23 in the same section transverse perpendicular to said axis.

In one embodiment, said head 3 is intended for fixing a dental prosthesis 7.

In one embodiment, said anchor body 2 is intended to be housed in the bone.

In one embodiment, said head 3 is intended for fixing a dental prosthesis 7, and said anchor body 2 is intended to be housed in the bone.

In one embodiment, said head 3 is made up of an abutment 4, a fillet 5 and an upper part of said head 3.

In one embodiment, said head 3 is of height H, and comprises a hexagonal well allowing both the manipulation of the implant 1 and its face. Thus, this hexagonal well allows the gripping and the introduction of the implant 1 thanks to a short or long conveyor, then the use of the torque wrench.

In a preferred embodiment, the distance between the parallel edges of the hexagonal well is approximately 2.5 millimeters and the height H of the head 3 is approximately 6 millimeters.

In a preferred embodiment, the distance between the parallel edges of the hexagonal well is approximately 2.5 millimeters and the height H of the head 3 is approximately 7 millimeters.

In one embodiment, said head 3 is composed of an abutment 4, a fillet 5 and an upper part of said head, starting from the most apical part of head 3.

In one embodiment, the diameter of the head 3 at the level of the stop 4 is between about 4 and about 7 millimeters. In a preferred embodiment, the diameter of the head 3 at the level of the stop 4 is approximately 5 millimeters. In a preferred embodiment, the diameter of the head 3 at the level of the stop 4 is approximately 6 millimeters. It has been observed that for the support on the bone of the stop 4 to be effective without too much bulk, these dimensions are ideal.

In one embodiment, the thickness of the abutment 4 is between about 0.2 and about 0.7 millimeters, preferably about 0.5 millimeters. This ideal thickness takes into account mechanical, clinical and aesthetic criteria.

In one embodiment, the diameter of the head 3 at the level of the fillet 5 is between about 4 and about 5 millimeters. In a preferred embodiment, the diameter of the head 3 at the fillet 5 is approximately 4.5 millimeters. It has been observed that these dimensions are ideal in particular for properly fixing the dental prosthesis.

In one embodiment, the thickness of fillet 5 is between about 0.75 and about 1.5 millimeters, preferably about 1 millimeter. It has been observed that these dimensions are ideal in particular for properly fixing the dental prosthesis 7.

In one embodiment, the height H of the head 3 is approximately 7 millimeters, the diameter of the head 3 at the level of the abutment 4 is approximately 5 millimeters, the thickness of the abutment 4 is approximately 0.5 millimeters, the diameter of the head 3 at the level of the fillet 5 is approximately 4.5 millimeters, and the thickness of the fillet is approximately 1 millimeter.

In one embodiment, the height H of the head 3 is approximately 7 millimeters, the diameter of the head 3 at the level of the abutment 4 is approximately 6 millimeters, the thickness of the abutment 4 is approximately 0.5 millimeters, the diameter of the head 3 at the level of the fillet 5 is approximately 4.5 millimeters, and the thickness of the fillet is approximately 1 millimeter.

In one embodiment, the dental implant 1 is characterized in that the ratio R is greater than about 3.

In one embodiment, the dental implant 1 is characterized in that the ratio R is greater than about 3.5.

In one embodiment, the dental implant 1 is characterized in that the ratio R is greater than about 4.

In one embodiment, the outer diameter of the helical thread 24 is between about 2 and about 6 millimeters. In one embodiment, the outer diameter of the helical thread 24 is between about 3 and about 5 millimeters. In one embodiment, the outer diameter of the helical thread 24 is less than about 5 millimeters. In one embodiment, the outer diameter of the helical thread 24 is fixed. In one embodiment, the outer diameter of the helical thread 24 is variable. In one embodiment, the outer diameter of the helical thread 24 is between about 3.6 and about 4.2 millimeters. In one embodiment, the outer diameter of the helical thread 24 is approximately 4 millimeters. In one embodiment, the outer diameter of the helical thread 24 is approximately 4.2 millimeters. Generally, helical diameters of about 4.0 or about 4.2 millimeters are preferred. They allow adequate anchorage while remaining easily implantable and sufficiently aesthetic.

In one embodiment, the outer diameter of shaft 23 is between about 0.5 and about 1.5 millimeters. In one embodiment, the outer diameter of shaft 23 is between about 0.7 and about 1.3 millimeters. In one embodiment, the outer diameter of shaft 23 is between about 0.8 and about 1.2 millimeters. In one embodiment, the outer diameter of shaft 23 is between about 0.9 and about 1.1 millimeters. In one embodiment, the outer diameter of shaft 23 is less than about 1.2 millimeters. In one embodiment, the outer diameter of shaft 23 is less than about 1 millimeter. In one embodiment, the outer diameter of shaft 23 is less than about 0.8 millimeters. In one embodiment, the outside diameter of shaft 23 is about 1 millimeter. When the diameter of the shaft 23 is less than a given value, it is also possible in the context of the present description for the shaft 23 to be completely absent. In the latter case, the ratio R=df/da is equal to plus infinity. Such an embodiment is given in , in this embodiment, the outer diameter of the shaft 23 is 0 millimeters. This embodiment is advantageous because it makes it possible to further reduce the invasiveness of the implantation. In one embodiment, the diameter is the same all along the shaft 23, we then speak of "fixed diameter" along the shaft 23, this can be advantageous because the invasiveness due to the shaft 23 remains stable along said shaft 23. In one embodiment, the diameter of shaft 23 is variable, and increases from the apical end towards the other end of shaft 23.

Finally, in an embodiment that is also advantageous in terms of invasiveness, the external diameter of the shaft 23 is variable along said shaft 23, but is always less than approximately 1.2 millimeters, preferably less than approximately 1.0 millimeter, preferably less than about 1.0 millimeter, preferably less than about 0.8 millimeter, preferably less than about 0.6 millimeter, preferably less than about 0.4 millimeter. In other words, the maximum outer diameter of shaft 23 is less than about 1.2 millimeters, preferably less than about 1.0 millimeters, preferably less than about 1.0 millimeters, preferably less than about 0. 8 millimeters, preferably less than about 0.6 millimeters, preferably less than about 0.4 millimeters.

The external diameters of the shaft and the helical thread, and in particular the df/da ratio, are crucial.

Indeed, they allow, in some cases, an insertion of the implant immediately after the use of the pointer drill (diameter of about 2 millimeters).

In addition, they make it possible to create true multiple horizontal osseointegration. The volume available for osseointegration, which corresponds to the volume of colonizing bone, is considerable in the context of the implant according to the invention. This volume is calculated as "total volume bounded by anchor body 2 - volume of anchor body 2".

In one embodiment, the volume available for osseointegration is between about 100 and about 200 square millimeters.

In one embodiment, the volume available for osseointegration is between about 110 and about 190 square millimeters.

This available volume will be used in particular for the multiple horizontal osseointegration of implant 1.

Ultimately, the implant will consist of the material of implant 1 (for example a titanium alloy) and bone, in optimized proportions.

In addition, implant 1 allows for renewed osseointegration over time. Indeed, the structure of the anchoring body 2 of the implant 1 allows better mechanical stress on the bone, in particular in compression. Osteogenesis is thus mechanically stimulated, in particular between revolutions of the thread of implant 1, by compression.

In one embodiment, the dental implant 1 is characterized in that the helical thread 24 extends continuously over at least two revolutions around said shaft 23.

Indeed, in order for the anchoring to be effective, it is preferable to provide at least two revolutions around the shaft 23.

In one embodiment, the dental implant 1 is characterized in that the helical thread 24 extends continuously over at least three revolutions around said shaft 23.

In one embodiment, the dental implant 1 is characterized in that the helical thread 24 has a decreasing thickness starting from the central part towards the peripheral part.

In one embodiment, the dental implant 1 is characterized in that the helical thread 24 has a decreasing thickness starting from the central part, with a thickness of between approximately 0.5 and approximately 1 millimeters, towards the peripheral part, with a thickness of between about 0.2 to about 0.4 millimeters.

In a particularly preferred embodiment, the dental implant 1 is characterized in that the helical thread 24 has a decreasing thickness starting from the central part, with a thickness of approximately 0.7 millimeters, towards the peripheral part, with a thickness of about 0.3 millimeters.

In a preferred embodiment, said helical thread 24 has a thickness between approximately 0.3 and approximately 1.2 millimeters, and preferably between approximately 0.5 and approximately 0.9 millimeters.

In one embodiment, the dental implant 1 is characterized in that the ratio R is greater than approximately 2.5, and preferably greater than approximately 3, over at least the length of the shaft 23 corresponding to the apical part 21.

In one embodiment, the dental implant 1 is characterized in that the ratio R is greater than approximately 2.5, and preferably greater than approximately 3, over the entire length of the shaft 23.

In one embodiment, the dental implant 1 is characterized in that the ratio R is greater than about 2.5, and preferably greater than about 3, over all revolutions of the helical thread 24 except for the revolution the most apical. This embodiment is preferred, it makes it possible to obtain an implant with improved insertion capabilities, because in particular the diameter of the helical thread 24 corresponding to the most apical revolution can be reduced. This will facilitate the insertion of the implant 1.

It should be noted that apical anchorage is particularly important. Indeed, by leverage, this is the area creating the most stability.

In one embodiment, the dental implant 1 is characterized in that the ratio R is greater than approximately 2.5, and preferably greater than approximately 3, over the entire height of the shaft 23.

In the context of the present description, the term "average R ratio" means the average of the R ratios present along a portion of the shaft 23 or of the entire shaft 23. For example, if the apical part 21 of the shaft 23 is 8 millimeters long, with 4 millimeters having an R ratio of 3, and 4 millimeters having an R ratio of 4, then the average R ratio at the apical portion will be 3.5.

In one embodiment, at the apical portion 21, the average R ratio is greater than about 2.5, and preferably greater than about 3.

In one embodiment, at the apical portion 21, the average R ratio is greater than about 4.

In one embodiment, at the level of the anchor body 2, the average ratio R is greater than approximately 2.5, and preferably greater than approximately 3.

In one embodiment, at anchor body 2, the average R ratio is greater than about 4.

In one embodiment, at the level of the anchor body 2, the ratio R is as disclosed within the present description over approximately ten tenths (10/10) of the length of said anchor body 2.

In one embodiment, at anchor body 2, the ratio R is as disclosed herein over more than nine tenths (9/10) of the length of said anchor body 2. This means that if the anchor body measures 10 units, then the ratio R is as presented in the various embodiments of this description over 9 units.

In one embodiment, at anchor body 2, the ratio R is as disclosed herein over more than eight tenths (8/10) of the length of said anchor body 2. This means that if the anchor body measures 10 units, then the ratio R is as presented in the various embodiments of this description over 8 units.

In one embodiment, at anchor body 2, the ratio R is as disclosed herein over more than seven tenths (7/10) of the length of said anchor body 2. This means that if the anchor body measures 10 units, then the ratio R is as presented in the various embodiments of this description over 7 units.

In one embodiment, at anchor body 2, the ratio R is as disclosed herein over more than six tenths (6/10) of the length of said anchor body 2. This means that if the anchor body measures 10 units, then the ratio R is as presented in the various embodiments of this description over 6 units.

In one embodiment, at anchor body 2, the ratio R is as disclosed herein over more than five tenths (5/10) of the length of said anchor body 2. This means that if the anchor body measures 10 units, then the ratio R is as presented in the various embodiments of this description over 5 units.

In one embodiment, at the level of the anchor body 2, the ratio R is as disclosed within the present description over less than nine tenths (9/10) of the length of said anchor body 2. This means that if the anchor body measures 10 units, then the ratio R is as presented in the various embodiments of this description on less than 9 units.

In one embodiment, at the level of the anchor body 2, the ratio R is as disclosed within the present description over less than eight tenths (8/10) of the length of said anchor body 2. This means that if the anchor body measures 10 units, then the ratio R is as presented in the various embodiments of this description on less than 8 units.

In one embodiment, at the level of the anchor body 2, the ratio R is as disclosed within the present description over less than seven tenths (7/10) of the length of said anchor body 2. This means that if the anchor body measures 10 units, then the ratio R is as presented in the various embodiments of this description on less than 7 units.

In one embodiment, at the level of the anchor body 2, the ratio R is as disclosed within the present description over less than six tenths (6/10) of the length of said anchor body 2. This means that if the anchor body measures 10 units, then the ratio R is as presented in the various embodiments of this description on less than 6 units.

In one embodiment, at the level of the anchor body 2, the ratio R is as disclosed within the present description over less than five tenths (5/10) of the length of said anchor body 2. This means that if the anchor body measures 10 units, then the ratio R is as presented in the various embodiments of this description on less than 5 units.

In one embodiment, the ratio R is as disclosed within the present description on at least the 10% of said most apical shaft 23.

In one embodiment, the ratio R is as disclosed within the present description on at least the 20% of said most apical shaft 23.

In one embodiment, the ratio R is as disclosed within the present description on at least the 30% of said most apical shaft 23.

In one embodiment, the ratio R is as disclosed within the present description on at least the 40% of said most apical shaft 23.

In one embodiment, the ratio R is as disclosed within the present description on at least the 50% of said most apical shaft 23.

In a particularly preferred embodiment, at the level of the apical part of the shaft 23, that is to say the deep part corresponding to 50% of the length of the shaft 23, the average ratio R is called Ra , and at the level of the cervical part of the shaft 23, that is to say the shallower part corresponding to 50% of the length of the shaft 23, the average ratio is called Rc, and Ra is greater than RC. This embodiment is preferred because it allows better hold of the implant and less decay.

In one embodiment, Ra/Rc is greater than about 1.1.

In one embodiment, Ra/Rc is greater than about 1.2.

In one embodiment, Ra/Rc is greater than about 1.3.

In one embodiment, Ra/Rc is greater than about 1.4.

In one embodiment, Ra/Rc is greater than about 1.5.

In one embodiment, Ra/Rc is greater than about 1.6.

In one embodiment, Ra/Rc is greater than about 1.7.

In one embodiment, Ra/Rc is greater than about 1.8.

In one embodiment, the ratio R is as disclosed within the present description over at least the length of the intermediate part Lpi of the shaft 23.

In one embodiment, the ratio R is as disclosed within the present description over at least 30% of the length of the intermediate part Lpi of the shaft 23.

In one embodiment, the ratio R is as disclosed within the present description over at least 40% of the length of the intermediate part Lpi of the shaft 23.

In one embodiment, the ratio R is as disclosed within the present description over at least 50% of the length of the intermediate part Lpi of the shaft 23.

In one embodiment, the ratio R is as disclosed within the present description over at least 60% of the length of the intermediate part Lpi of the shaft 23.

In one embodiment, the ratio R is as disclosed within the present description over at least 70% of the length of the intermediate part Lpi of the shaft 23.

In one embodiment, the ratio R is as disclosed within the present description over at least 80% of the length of the intermediate part Lpi of the shaft 23.

In one embodiment, the ratio R is as disclosed within the present description over at least 90% of the length of the intermediate part Lpi of the shaft 23.

In one embodiment, the dental implant 1 is characterized in that the apical end of the helical thread 24 is self-drilling.

In one embodiment, the dental implant 1 is characterized in that the apical part of the helical thread 24 comprises a leading edge 25 forming an angle of between approximately 20 and approximately 40 degrees with respect to said axis, and preferably comprised between about 25 and about 35 degrees relative to said axis. In a particularly preferred manner, the apical part of the helical thread 24 comprises a leading edge 25 forming an angle of approximately 30 degrees with respect to said axis.

It should be noted that the angle of attack is very important in the context of insertion, because it makes it possible to obtain an apical end of the implant which is self-drilling. It has been observed that the ideal angle is around 30 degrees. The presence of an angle of approximately 30 degrees accentuates to the maximum the self-drilling mechanical force of the implant.

In one embodiment, the dental implant 1 is characterized in that the shaft 23 has a length of between about 10 and about 18 millimeters, preferably between about 12 and about 16 millimeters. In one embodiment, the length of shaft 23 is approximately 12 millimeters. In one embodiment, the length of shaft 23 is approximately 14 millimeters. In one embodiment, the length of shaft 23 is approximately 16 millimeters.

The choice of shaft length 23 will depend on the clinical situation. The longest length compatible with the clinical situation will be chosen, for obvious reasons of stability. Generally, the lengths used will be: 12 millimeters, 14 millimeters or 16 millimeters.

In one embodiment, the dental implant 1 is characterized in that said shaft 23 has a diameter da of between about 0.8 and about 1.5 millimeters, and preferably of between about 0.8 and about 1.2 millimeters. In a particularly preferred embodiment, the diameter da is about 1 millimeter. In a particularly preferred embodiment, the diameter da is approximately 1 millimeter over the entire length of said shaft. In a particularly preferred embodiment, the diameter da is approximately 1 millimeter over the entire length of said shaft, including at the level of the apical end of said shaft. The advantage of having an apical end with the presence of the tree is that it allows better centering during insertion of the implant.

The diameter of the tree must be as small as possible, while preserving its robustness. It has been observed that a thickness of 1 millimeter is ideal.

In one embodiment, the dental implant 1 is characterized in that the helical thread 24 has a pitch of between about 1 and about 4 millimeters. Preferably, the helical thread 24 has a pitch of between about 2 and about 3 millimeters. In one embodiment, said pitch is about 2.5 millimeters.

The helical pitch must be compatible with rapid placement (pitch as large as possible), optimal safety (zero risk of implant breakage during placement; pitch as small as possible), as well as less abrasion during the pose. In this context, a pitch of between about 1 and about 4 millimeters is particularly suitable, and a pitch of about 2.5 millimeters is ideal.

The implant can be made of any biocompatible and suitable material.

Preferably, the dental implant is made of titanium or a titanium alloy, but an alternative to titanium, to make the dental implant, consists in choosing zirconia, an alloy of these two elements, or any other biocompatible material.

A titanium alloy is preferred.

Preferably, a titanium alloy of the TiAl6Nb7 type is used.

In a preferred embodiment, the surface of the anchor body 2 (intended to be implanted in the bone) is treated to create surface microporosities (the ideal thickness is approximately 80 microns), and/or undergoes anodic oxidation (the ideal thickness is about 180 to 200 nanometers).

In a preferred embodiment, the surface of the anchor body 2 (intended to be implanted in the bone) is treated to create surface microporosities (the ideal thickness is approximately 80 microns), and undergoes oxidation anodic (the ideal thickness is about 180 to 200 nanometers).

The anodic oxidation has the effect of giving the surface of the anchoring body 2 (intended to be implanted in the bone) a pink color, which allows a good aesthetic rendering (color compatible with that of the gum). Obtaining such a color is due to the fact that the thickness of the passivation layer increases from 2 nanometers to 200 nanometers by means of said anodic oxidation.

Regarding the head 3 of the implant 1 (extra-osseous), it is preferably smooth (absence of porosity; polished-mirror). Preferably, it has no porosity. On the other hand, it is preferably treated by means of the anodic oxidation described previously.

In one embodiment, the entire surface of the implant 1 is treated by anodic oxidation.

In one embodiment, the entire surface of the implant according to the invention has an oxidation layer of between about 100 and about 250 nanometers.

In one embodiment, the entire surface of the implant according to the invention has an oxidation layer of between about 150 and about 250 nanometers.

In one embodiment, the entire surface of the implant according to the invention has an oxidation layer of between about 170 and about 210 nanometers.

In one embodiment, the entire surface of the implant according to the invention has an oxidation layer of between about 180 and about 200 nanometers.

In one embodiment, the ratio R is greater than about 3.

In one embodiment, the helical thread 24 extends continuously over at least two revolutions around said shaft 23.

In one embodiment, the helical thread 24 has a decreasing thickness starting from the central part towards the peripheral part.

In one embodiment, the helical thread 24 has a thickness of between about 0.3 and about 1.2 millimeters.

In one embodiment, the ratio R is greater than 3 over at least half the height of the shaft 23 starting from the apical end 21.

In one embodiment, the apical portion of the helical thread 24 has a leading edge 25 forming an angle between approximately 20 and approximately 40 degrees with respect to said axis.

In one embodiment, shaft 23 has a length of between about 10 and about 18 millimeters.

In one embodiment, the shaft 23 has a diameter da of between about 0.8 and about 1.5 millimeters.

In one embodiment, the helical thread 24 has a pitch between about 2 and about 3 millimeters.

Finally, in a particularly preferred embodiment, the implant 1. This is of considerable interest and in particular facilitates the placement of the implant. In the context of such an embodiment, it is necessary to validate the alignment of the prosthetic axes and the jaw before installation.

The invention also relates to a method of manufacturing a dental implant according to the invention.

In one embodiment, said method comprises a step of three-dimensional printing of said implant. In this embodiment, the dental implant is therefore manufactured by three-dimensional printing. This is particularly advantageous, since it makes it possible to obtain an implant having improved robustness. Moreover, for example in the particular case in which no shaft 23 is present (see ), three-dimensional printing is particularly indicated.

In one embodiment, said method includes a milling step. In this embodiment, the dental implant is therefore manufactured by milling a metal part. Such a manufacturing method is particularly advantageous in terms of cost.

Those skilled in the art will understand that each of the characteristics of the following variants can be combined independently with the characteristics above, without however constituting an intermediate generalization.

Other characteristics and advantages of the invention will emerge clearly from the description given of it below, by way of indication and in no way limiting, with reference to the appended figures, in which:

is a perspective view of an exemplary embodiment of an implant according to the invention, in addition to the internal part, is visible in this figure the female screwing recess 31, the implant head 3 composed of the abutment 4, of the fillet 5 as well as of the upper part of the head. The implant 1 shown is in one piece. The diameter is fixed along the shaft 23.

is a side view of implant 1 of the .

is a cross-sectional view of the implant 1 of the at the level of the thread.

is a cross-sectional view of the implant 1 including the bonding glue 6 allowing the installation of a dental prosthesis 7. This view is theoretical, the jaw (in which the implant is in practice fixed before laying the glue and dental prosthesis) is not shown.

is a side view of an exemplary embodiment of an implant according to the invention, in addition to the internal part, is visible in this figure the female screwing recess 31, the implant head 3 composed of the abutment 4, of the fillet 5 as well as of the upper part of the head. The implant 1 shown is in one piece. No tree 23 is present, the ratio R=df/da is therefore equal to plus infinity.

is a side view of an exemplary embodiment of an implant according to the invention, on which is visible the length of the shaft 23 named La, the length of the apical part of the shaft 23 named Lpa, the length of the cervical part of the shaft 23 named Lpc, as well as the length of the intermediate part of the shaft 23 named Lpi. All Lpc, Lpi, Lpa and La designations are shown in the figure below the corresponding lengths. The length La corresponds to the part to be implanted.

EXAMPLES

Example 1: Clinical diagram

The purpose of this example is to illustrate treatment using the implant according to the invention.

During the first visit, a three-dimensional (3D) scanned dental x-ray is performed to assess the overall situation and to assess the available bone volume in real dimensions,

Then, a drilling of 1 millimeter in diameter and about 7 millimeters deep is made at the place where the implant must be inserted in the prosthetic axis.

Then, an implant analog (metal rod 1 millimeter in diameter and of the same length as the shaft of the implant to be implanted, topped with a head identical to that of the implant to be implanted) is placed in this hole. During this step, the choice of the size of the head to be used is made by the practitioner according to the clinic and the size of the environment of the tooth to be replaced.

Then, a three-dimensional (3D) digitized dental X-ray is made on the site corresponding to the presence of said implant analog, in order to verify that the prosthetic axis (materialized by the metal rod) is well aligned with the axis of the jaw and that a bone volume will allow the introduction of a 4.2 mm diameter implant.

Then an impression is taken with the analog. In addition, an impression of the opposing jaw is made as well as a bite registration.

If the clinical situation corresponds to the implantation of a single dental prosthesis (1 implant corresponds to 1 tooth to be replaced), then a dental technician is asked to make a temporary dental prosthesis as well as a transparent resin guide which will transform into a surgical guide suitable for a 2 mm diameter drill.

Then, a splaying drilling can be carried out allowing to pass from a diameter of 2 millimeters to a diameter of 4 millimeters on a few millimeters of depth, for example 2 millimeters of depth.

Then, the implantation can be carried out by screwing the implant, or in some cases with the use of the forming tap (the forming tap has the same structure as the anchoring body of the implant to be implanted, but has surface barbs).

The implantation takes about 12 minutes. Tightening is at least 30N.cm.

Then, the temporary dental prosthesis can be directly put in place.

Then, the final dental prosthesis is placed after healing to obtain perfect aesthetics. This placement is performed approximately 1.5 months after implantation.

If the clinical situation corresponds to the implantation of multiple crowns (x implants corresponds to y teeth to be replaced, with x < y), the implant according to the invention can also be used, and an appropriate clinical protocol will be considered.

Example 2: Aptitude for osseointegration of the implant according to the invention

Implant according to the selected invention:

- shaft diameter: 1 mm;

- shaft length: 16 millimeters;

- outer diameter of helical thread: 4.2 millimeters;

- thickness of the helical thread decreasing starting from the central part, from 0.7 millimeters to 0.3 millimeters;

- outer diameter of the shaft: 1 millimeter.

The volume available for osseointegration is calculated as: "total volume bounded by the anchor body - volume of the anchor body".

In the case of the selected implant, the total volume bounded by the anchor body is approximately 220 square millimeters, the volume of the anchor body is approximately 40 square millimeters, thus the volume available for osseointegration is about 180 square millimeters.

Thus, the volume available for horizontal osseointegration is considerable. This breaks with the existing prior art, and in particular the aforementioned documents.

Claims (10)

Dental implant (1) comprising a head (3) as well as an anchoring body (2), characterized in that:
the anchor body (2) comprises a shaft (23) comprising an apical part (21) and a cervical part (22) and extending along an axis;
-the anchor body (2) comprises a helical thread (24) projecting radially with respect to the shaft (23);
- at the apical part (21), the ratio R is greater than approximately 2.5, with R=df/da, with df the external diameter of the helical thread (24) and da the external diameter of the shaft ( 23) in the same cross section perpendicular to said axis. A dental implant (1) according to claim 1, wherein the ratio R is greater than about 3. A dental implant (1) according to claim 1 or 2, wherein the helical thread (24) extends continuously over at least two revolutions around said shaft (23). Dental implant (1) according to any one of the preceding claims, in which the helical thread (24) has a decreasing thickness starting from the central part towards the peripheral part. A dental implant (1) according to claim 4, wherein the helical thread (24) has a thickness of between about 0.3 and about 1.2 millimeters. A dental implant (1) according to any preceding claim, wherein the ratio R is greater than about 3 over at least half the height of the shaft (23) from the apical end (21). A dental implant (1) according to any preceding claim, wherein the apical portion of the helical thread (24) has a leading edge (25) forming an angle of between about 20 and about 40 degrees relative to said axis. A dental implant (1) according to any preceding claim, wherein the shaft (23) has a length of between about 10 and about 18 millimeters. Dental implant (1) according to any one of the preceding claims, in which the said shaft (23) has a diameter da of between about 0.8 and about 1.5 millimeters. A dental implant (1) according to any preceding claim, wherein the helical thread (24) has a pitch of between about 2 and about 3 millimeters.

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