TRANSGINGIVAL DENTAL IMPLANT AND PROSTHETIC SYSTEM IMPLEMENTING SUCH AN IMPLANT

Abstract

The present invention relates to a transgingival dental implant (1) extending longitudinally (z) along a first smooth section (11) intended to be flush in the oral cavity of a patient at a first end called cervical (114), and along a second section (10) provided with a male thread, extending the first section, said threaded section being intended to be screwed into the jawbone of said patient and defining a second end called apical (108), the implant defining a body of revolution along the longitudinal axis (z) and further comprising an internal housing called connection (115) opening at the first end called cervical (114) and intended to receive the fixing means (20) of a transscrewed dental component, characterized in that the smooth section is provided on its outer circumferential surface with at least one concave portion (111) adjacent to the first end called cervical (114). Figure 1

Description

Title of the invention: TRANSGINGIVAL DENTAL IMPLANT AND PROSTHETIC SYSTEM IMPLEMENTING SUCH AN IMPLANT

[0001] The present invention relates to a transgingival dental implant, as well as a prosthetic system implementing such an implant, said prosthetic system comprising the implant, a prosthetic component of the “pillar” type and a dental prosthesis.

[0002] Oral implantology is a surgical technique that aims to treat a dental pathology, edentulism, by replacing one or more teeth in edentulous patients by placing a dental implant. This technique therefore consists of implanting an artificial root made of biocompatible materials into the bone of the maxilla or mandible.

[0003] The etiological causes of this pathology can be diverse. The consequences of toothlessness depend on its extent depending on whether one or more teeth are missing, and can be diverse. Thus, it can result in a modification of normal physiology, a risk factor for impaired mastication, a deterioration of oral health, a higher prevalence of obesity, an increased risk of cardiovascular diseases and gastrointestinal disorders, an increased risk of chronic inflammation at the gastric level, pancreatic and gastrointestinal cancers, and ulcers, an increased risk of non-insulin-dependent diabetes, a decrease in health-related quality of life, an association between toothlessness and sleep-disordered breathing (such as obstructive sleep apnea). The population affected by toothlessness is very large but it particularly affects the elderly.

[0004] Implantology thus makes it possible to treat single edentulism, i.e. the loss of one tooth, multiple teeth, or the loss of several adjacent or non-adjacent teeth, or total teeth, or the loss of the entire set of teeth. The implant thus serves as a support, either for a crown, or for a partial or total bridge, or for a total removable prosthesis.

[0005] Implantology is a promising alternative to conventional treatments such as tooth-supported bridges or total or partial removable appliances, which can provide a satisfactory response to the dental pathology of edentulism in the short and medium term. Indeed, dental implants give better results and have better long-term performance.

[0006] Thus, for the treated patients, the implant reconstructions showed an improvement in masticatory function, speech function but also a improvement in overall quality of life.

[0007] The fundamental characteristics of an implant system, as well as the various surgical procedures used and the characteristics of the materials used in oral implantology, will now be explained.

[0008] Thus, an implant system is a triptych of components, grouping the implant itself, the prosthetic fittings and finally ancillaries, surgical instruments, necessary for carrying out an implant restoration.

[0009] There are two surgical approaches.

[0010] The approach according to the so-called two-stage surgical technique implies that the implant is buried in the bone and covered by the gum during the time of bone healing. Once this bone healing is complete, during a second surgical stage, the gum is incised above the implant to expose the latter, and a transgingival healing screw is fixed there, thus allowing the gum to heal. In this case, the gum will heal around this healing screw and not around the implant. After gingival healing, this screw is removed and replaced by a prosthetic element on which the crown will be fixed. In this case, we speak of second-intention healing at the gingival level.

[0011] The approach according to the one-stage technique consists of placing an implant of a different design because the latter will have both an endosseous part and a transgingival part. In this configuration, a first intention gingival healing is obtained around the transgingival part of the implant. The crimp, called epithelial attachment, is definitively acquired in this technique. This technique, where the implant is immediately in relation with the oral cavity, therefore does not involve a second stage of surgery.

[0012] Furthermore, dental implants are manufactured from perfectly biocompatible biomaterials. The properties of these biomaterials, combined with a specific surface condition, induce, after insertion of the implant into the jawbone, a natural colonization of newly formed bone on the surface of the implant. This process, called osseointegration and highlighted by Professor Per-Ingvar Brânemark, is defined as the direct structural and functional connection between living bone and the surface of an artificial implant.

[0013] The vast majority of dental implants are manufactured from alloyed titanium such as Grade 5 Ti6A14V or unalloyed titanium such as Grade 4 T60. New ranges of implants machined from sintered zirconia blank have emerged, so that 80% of implants on the market are made of titanium and 20% of zirconia.

[0014] Now regarding the usual junctions between implants and prosthetic abutments, there is a gap between the buried implant and the prosthetic abutment with aligned connection profile. In other words, the diameter of the implant platform, po located in the juxta-crestal zone, is identical to the diameter of the base of the prosthetic pillar. This hiatus is at the origin of a biological space of comparatively greater dimension than that observed around the natural dentition.

[0015] To achieve an aesthetic result from implant-supported restorations, particularly in the anterior sector, it is necessary to preserve the bone level and peri-implant soft tissues in a sustainable manner. The maintenance of the peri-implant bone level is considered a criterion for the success of implants (Roos J., 1997). A circumferential marginal bone loss, with a vertical and horizontal component of approximately 1 to 1.5 mm, seems to be inevitable for juxta-osseous implants when exposed in the oral environment following the connection of an implant abutment (Cardaropoli G., 2006). Considered physiological, it is likely to lead to a recession of the peri-implant soft tissues which makes aesthetic management delicate (Jemt T., 2008).

[0016] This is why the present invention aims to propose a transgingival dental implant benefiting from an optimized design, to improve the biological response of each of the tissues present, faced with the foreign body that the implant represents.

[0017] It is from the understanding of the three strategic zones which are the bone zone, the gingival zone and the prosthetic zone, that the inventors sought to optimize the cervical zone of a transgingival implant.

[0018] The invention relates in particular to a transgingival dental implant extending longitudinally along a first smooth section intended to be flush in the oral cavity of a patient at a first end called the cervical end, and along a second section provided with a male thread, extending the first section, said threaded section being intended to be screwed into the jawbone of said patient and defining a second end called the apical end, the implant defining a body of revolution along the longitudinal axis and further comprising an internal housing called the connection housing opening at the first end called the cervical end and intended to receive the fixing means of a transscrewed dental component, characterized in that the smooth section is provided on its outer circumferential surface with at least one concave portion adjacent to the first end called the cervical end.

[0019] Optional, complementary or substitutive features of the invention are set out below.

[0020] The smooth section is preferably provided on its outer circumferential surface with a concave portion adjacent to the first end called the cervical end, defining on the first smooth section a substantially toric concave portion.

[0021] The substantially toric concave portion is preferably defined by the rotation of a circle around the longitudinal axis, with a radius rl of between 1 and 2 mm.

[0022] The ratio between the diameter DI of the first end called cervical 114, and the minimum diameter D2 of the concave portion is preferably of the order of 3 / 2.

[0023] The diameter DI of the first end called cervical 114 is preferably between 4 and 7 mm, while the minimum diameter D2 of the concave portion is preferably between 3 and 5 mm.

[0024] The concave portion preferably extends along the longitudinal axis over a distance of between 1 and 4 mm.

[0025] The concave portion preferably has an arithmetic mean roughness, noted Ra, less than 0.50 microns, preferably less than 0.20 microns, preferably less than 0.10 microns.

[0026] The smooth section preferably has a portion adjacent on the one hand to the concave portion and adjacent on the other hand to the threaded section, which is intended to be buried in the jaw bone of said patient.

[0027] The adjacent portion is preferably cylindrical or truncated cone-shaped.

[0028] The adjacent portion preferably extends longitudinally over a length of between 1 and 4 mm.

[0029] The adjacent portion preferably has an arithmetic mean roughness, noted Ra, less than 0.50 microns, preferably less than 0.20 microns, preferably less than 0.10 microns.

[0030] The invention also relates to a prosthetic system comprising a transgingival dental implant in accordance with one of the embodiments of the invention, as well as a transscrewed dental component of the abutment type, and a dental prosthesis.

[0031] Other advantages and particularities of the invention will appear on reading the detailed description of implementations and embodiments which are in no way limiting, and the following appended drawings:

[0032] [Fig.l] This figure represents a schematic exploded view of a prosthetic system according to an embodiment of the invention.

[0033] [Fig.2] This figure represents a detailed schematic view along a sagittal section of an assembled prosthetic system conforming to an embodiment of the invention.

[0034] [Fig.3] This figure represents a detailed schematic view of an assembled prosthetic system conforming to an embodiment of the invention.

[0035] [Fig.4] This figure represents a schematic view along a sagittal section of a prosthetic system in accordance with an embodiment of the invention, and implanted in the jaw of a patient.

[0036] In relation to figures 1 and 2, the prosthetic system according to the invention comprises a transgingival dental implant 1, as well as a transscrewed dental component 2 of the abutment type, and a dental prosthesis 3.

[0037] The transgingival dental implant extends longitudinally along a z axis and comprises a first smooth section 11 intended to be flush in the oral cavity of a patient at a first end called cervical 114 of the implant.

[0038] The implant also comprises a second section 10 provided with a male thread, extending the first section, said threaded section being intended to be screwed into the jaw bone of said patient and defining a second end called the apical end 108 of the implant.

[0039] The implant defines a body of revolution along the longitudinal axis z and may further comprise a so-called connection appendage 113 extending the first so-called cervical end 114, as well as an internal so-called connection housing 115 opening at the level of the first so-called cervical end 114.

[0040] The so-called connection appendage 113 makes it possible to reinforce the connection between the implant and a screw-retained dental component 2, such as an abutment, at the level of the part of the prosthetic system which emerges in the patient's oral cavity. Once the implant is installed in the patient's jaw, the abutment is screwed into the implant and the dental prosthesis 3 is fixed (generally by gluing) to the abutment. The prosthetic system is thus obtained.

[0041] The housing 115 is intended to receive the fixing means 20, such as a screw, of a transscrewed dental component 2, such as an abutment.

[0042] According to the principle of the invention, the smooth section is provided on its outer circumferential surface with at least one concave portion 111 adjacent to the first end called cervical 114.

[0043] The profile of the present implant, not buried, is therefore characterized by a diameter DI of the first end called cervical 114, preferably between 4 and 7 mm, located in the supra-gingival zone, wider than the minimum diameter D2 of the concave portion, preferably between 3 and 5 mm, located in the underlying juxta-gingival zone.

[0044] Towards the second end called apical 108 of the implant, the concave portion ends when the smooth section reaches a diameter D3 substantially close to DI.

[0045] The ratio of diameters D2 / D1 is of the order of 2 / 3. The three diameters D1, D2 and D3 are successively connected to each other by tangential rays. The curved zones thus formed limit trauma when screwing the implant and promote coronal repositioning of the gingival tissues.

[0046] Gingival tissue is a defense and barrier element by protecting the underlying bone and creating a separation between the internal and external environments. A certain distance between the superficial part of the gum and the alveolar bone is necessary to obtain this protection. We can thus speak of peri-implant biological space (Berglundh and Lindhe, 1996). As around a natural tooth, Any disturbance of this space causes bone lysis which thus restores sufficient thickness to the gum tissue to ensure this protection.

[0047] The concave portion, located in the underlying juxta-gingival zone, thus makes it possible to reinforce the role of seal around the implant of the marginal gum.

[0048] Thus, it would allow the inflammatory infiltrate to be located in a limited exposure zone less than or equal to 90° relative to the peripheral hard and soft tissues instead of a direct exposure surface less than or equal to 180° with the conventional system. The diffusion trajectory would be modified by the protruding diameter D3 of the implant. This modification of the inflammation diffusion trajectory would result in the preservation of the bone crest and low horizontal lysis. In addition, with a conventional system, the biological space is established vertically and horizontally accompanied by vertical and horizontal bone resorption whereas with the integration of a concave portion on the transgigival implant, the biological space is established mainly horizontally and very little vertically, which explains limited bone lysis.Finally, the concave portion 111 allows more volume for the connective tissue around the cervical portion of the implant. This helps create a thick mucosal O-ring that acts as a barrier against external aggressions.

[0049] According to one embodiment, the smooth section may comprise one or more recesses on its circumferential surface.

[0050] According to a preferred embodiment, the smooth section is provided on its outer circumferential surface with a concave portion 111 adjacent to the first so-called cervical end 114, defining on the first smooth section 11 a substantially toric concave portion.

[0051] Advantageously, the substantially toric concave portion is defined by the rotation of a circle around the longitudinal axis (z), with a radius rl of between 1 and 2 mm.

[0052] According to a variant, the substantially toric concave portion is defined by the rotation of an ellipse around the longitudinal axis (z)

[0053] Preferably, the concave portion 111 extends along the longitudinal axis (z) over a distance of between 1 and 4 mm.

[0054] Also preferably, the concave portion 111 has an arithmetic mean roughness, noted Ra, less than 0.50 microns, preferably less than 0.20 microns, preferably less than 0.10 microns.

[0055] Advantageously, the smooth section 11 has a portion 116 adjacent to the threaded section 10, intended to be buried in the jaw bone of said patient.

[0056] Preferably, the adjacent portion 116 is cylindrical or frustoconical in shape, and extends over a length of between 1 and 4 mm.

[0057] Also preferably, the adjacent portion 116 has an arithmetic mean roughness, noted Ra, less than 0.50 microns, preferably in- less than 0.20 microns, preferably less than 0.10 microns.

[0058] This portion 116 promotes the establishment of remote osteogenesis and therefore corticalization. New bone formation, secondary (biological) stability, will occur from the adjacent bone surface, resulting in the formation of woven bone. The newly formed woven bone will then mature and remodel. The organization first becomes lamellar and then Haversian with permanent remodeling. As remodeling and maturation progress, the bone becomes increasingly mechanically resistant.

[0059] In summary and in relation to Figures 2 and 3, the implant according to the invention is provided with a smooth section 11 having a concave portion just below its first end flush with the oral cavity. This concave portion extends over the entire depth of the gingival tissues ZG.

[0060] The profile of the present implant, not buried, is characterized by a diameter DI of the first end called cervical 114, located in the supra-gingival zone, wider than the minimum diameter D2 of the concave portion, located in the underlying juxta-gingival zone.

[0061] The combination of a non-buried implant design and this concave portion moves the prosthetic connection away from the bone area.

[0062] As a result, the cratering of the bone and the depth of the sulcus S are limited, due to the phenomenon of horizontal and vertical bone lysis. A minimal sulcus S is necessarily synonymous with greater stability over time of the marginal gingiva both in its architecture (biological distance) and in its microbiology.

[0063] According to preferential characteristics, the smooth section has a very low roughness over a contact depth ZL in the direction of the apex, first with the gingival tissues ZG then with the bone zone ZO and in particular with the crestal bone Oc.

[0064] The anchoring of the implant is further ensured by means of a threaded section 10 having a preferably higher roughness over a contact depth ZR in the direction of the apex, with the bone zone ZO and in particular with the spongy bone Os.

[0065] The anchoring of the smooth section 11 in the crestal bone Oc by means of the adjacent portion 116 makes it possible to protect the gingival attachment zone GA consisting of the peri-implant connective tissue T covered by the juxta-implant epithelium E. The gingival attachment zone GA located between the marginal gingiva GM and the alveolar mucosa MA is in fact a particularly sensitive zone.

[0066] Preferably, the length ZR of the threaded section 10 is of the order of twice the length ZL of the smooth section 11, the implant being buried over the entire depth corresponding to the gingival zone ZG and the bone zone ZO.

[0067] Concerning the dimensions, the implants can have, in compliance with the ZR / ZL ratio of the order of 2, the following dimensions: Length ZR of the threaded section Length ZL of the smooth section 6 mm 3 mm 7.5 mm 3.5 mm 8.5 mm 4.5 mm 10 mm 5 mm 11.5 mm 5.5 mm

[0068] The embodiments described below being in no way limiting, it will be possible in particular to consider variants of the invention comprising only a selection of described characteristics, isolated from the other described characteristics (even if this selection is isolated within a sentence comprising these other characteristics), if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art. This selection comprises at least one characteristic, preferably functional without structural details, or with only a part of the structural details if this part only is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art.

[0069] Note that the various features, forms, variants and embodiments of the invention may be combined with each other in various combinations, provided that they are not incompatible or mutually exclusive.

Claims

Claims

1. Transgingival dental implant (1) extending longitudinally (z) along a first smooth section (11) intended to be flush in the oral cavity of a patient at a first end called cervical (114), and along a second section (10) provided with a male thread, extending the first section, said threaded section being intended to be screwed into the jawbone of said patient and defining a second end called apical (108), the implant defining a body of revolution along the longitudinal axis (z) and further comprising an internal housing called connection (115) opening at the first end called cervical (114) and intended to receive the fixing means (20) of a transscrewed dental component, characterized in that the smooth section is provided: - on its outer circumferential surface with at least one concave portion (111) adjacent to the first end called cervical (114) and substantially toric,the diameter DI of the first end called cervical, being wider than the minimum diameter D2 of the concave portion, - of a portion (116) adjacent on the one hand to the concave portion (111) and adjacent on the other hand to the threaded section (10), said adjacent portion admitting a diameter D3 substantially close to Dl, and being intended to be buried in the jaw bone of said patient.,

2. Transgingival dental implant according to the preceding claim, characterized in that the substantially toric concave portion is defined by the rotation of a circle around the longitudinal axis (z), of radius rl between 1 and 2 mm.

3. Transgingival dental implant according to any one of the preceding claims, characterized in that the ratio between the diameter D1 of the first end called cervical 114, and the minimum diameter D2 of the concave portion is of the order of 3 / 2.

4. Transgingival dental implant according to any one of the preceding claims, characterized in that the diameter D1 of the first end called cervical 114 is between 4 and 7 mm, while the minimum diameter D2 of the concave portion is between 3 and 5 mm.

5. Transgingival dental implant according to any one of the preceding claims, characterized in that the concave portion (111) extends along the longitudinal axis (z) over a distance of between 1 and 4 mm.

6. Transgingival dental implant according to any one of the preceding claims, characterized in that the concave portion (111) has an arithmetic mean roughness, noted Ra, less than 0.50 microns, preferably less than 0.20 microns, preferably less than 0.10 microns.

7. Transgingival dental implant according to claim 1, characterized in that the adjacent portion (116) is cylindrical or frustoconical in shape.

8. Transgingival dental implant according to claim 1 or 7, characterized in that the adjacent portion (116) extends longitudinally over a length of between 1 and 4 mm.

9. Transgingival dental implant according to one of claims 1, 7 to 8, characterized in that the adjacent portion (116) has an arithmetic mean roughness, noted Ra, less than 0.50 microns, preferably less than 0.20 microns, preferably less than 0.10 microns.

10. Prosthetic system comprising a transgingival dental implant according to any one of claims 1 to 9, as well as a transscrewed dental component (2) of the abutment type, and a dental prosthesis (3).

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