Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C8/00—Means to be fixed to the jaw-bone for consolidating natural teeth or for fixing dental prostheses thereon; Dental implants; Implanting tools
  • A61C8/0012—Means to be fixed to the jaw-bone for consolidating natural teeth or for fixing dental prostheses thereon; Dental implants; Implanting tools characterised by the material or composition, e.g. ceramics, surface layer, metal alloy
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C8/00—Means to be fixed to the jaw-bone for consolidating natural teeth or for fixing dental prostheses thereon; Dental implants; Implanting tools
  • A61C8/0018—Means to be fixed to the jaw-bone for consolidating natural teeth or for fixing dental prostheses thereon; Dental implants; Implanting tools characterised by the shape
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C13/00—Dental prostheses; Making same
  • A61C13/20—Methods or devices for soldering, casting, moulding or melting
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C8/00—Means to be fixed to the jaw-bone for consolidating natural teeth or for fixing dental prostheses thereon; Dental implants; Implanting tools
  • A61C8/0018—Means to be fixed to the jaw-bone for consolidating natural teeth or for fixing dental prostheses thereon; Dental implants; Implanting tools characterised by the shape
  • A61C8/0037—Details of the shape
  • A61C2008/0046—Textured surface, e.g. roughness, microstructure
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C8/00—Means to be fixed to the jaw-bone for consolidating natural teeth or for fixing dental prostheses thereon; Dental implants; Implanting tools
  • A61C8/0018—Means to be fixed to the jaw-bone for consolidating natural teeth or for fixing dental prostheses thereon; Dental implants; Implanting tools characterised by the shape
  • A61C8/0022—Self-screwing

Definitions

• the invention relates to an endo-osseous ceramic implant for medical or veterinary applications. More particularly, the invention relates to such an implant, non-metallic, preferably consisting of a ceramic material.
• the endosseous implants known from the prior art consist of metallic materials, generally based on titanium. These implants of the prior art are subjected to different surface treatments intended to give them a surface state promoting their osseointegration after implantation into the bone tissue. These surface states are obtained either by coating the implant, or a zone thereof, in particular by projection, with a layer of material having a surface texture and physicochemical characteristics favoring cell colonization by the cells. osteoblasts of the surface thus coated. Alternatively, such a surface state can be obtained by machining, said material removal, all or part of the surface of said implant, for example, by machining with the cutting tool, by laser or by abrasion using techniques sandblasting / shot blasting.
• the surface texture is highly dependent on the nature of the process and the material-process pair.
• the optimization of surface condition conditions involves experimental designs and clinical trials aimed, for example, at correlating characteristic parameters of the surface thus obtained with the speed of osseointegration of the implant. comprising such a surface.
• the invention proposes an endo-osseous implant, in particular for implantation in a periodontal tissue that is remarkable in that:
• a surface texture designates the shape of a pattern in relief on a so-called SL surface according to ISO 25178, that is to say, relief patterns whose order of magnitude lies in the roughness and waviness parameters of any macroscopically shaped surface, virtually reduced to a flat surface, by filtering according to ISO 16610.
• a surface condition qualifies such a surface by a quantity according to ISO 25178.
• analogue is understood here in the sense that the surface texture of the implant reproduces a network of substantially homothetic geometric patterns, the geometry and dimensions of these patterns being comparable to those of the texture patterns of the recipient tissue, without to be identical stricto sensu to this one.
• the implant which is the subject of the invention not only reproduces the surface state of the implantation tissue but has texture patterns whose shape and dimension are adapted to the recipient tissue, which favors the cellular colonization of said surface. of the implant.
• the invention also relates to a method of manufacturing such an implant, which method comprises the steps of:
• the method which is the subject of the invention takes advantage of the very large shrinkage observed during the sintering of the ceramic and makes it possible to engrave a much larger size pattern in the mold than it will be on the sintered implant, thus opening the possibility of using engraving technologies that would not be accessible at the scale of the patterns present on the implant.
• the mold may advantageously consist of a metallic material which has a ductile response to the removal of material, thus allowing the use of etching techniques which would not be usable on the ceramic implant itself.
• the invention can be implemented according to advantageous embodiments, described below, which can be considered individually or in any technically operative combination.
• the method which is the subject of the invention further comprises the steps of:
• the surface texture reproduced on the implant is as close as possible to that of the recipient tissue.
• the implant which is the subject of the invention, the latter comprises a surface capable of being implanted in a cellular alveolar tissue, said surface comprising a texture consisting of alveolar geometry patterns whose average width is between ⁇ and 15 ⁇ .
• said cells are colonized by the bone cells of the tissue after implantation and this surface relief provides mechanical attachment of the implant in the alveolar bone by osseointegration.
• each cell of the implantation surface cooperating with the receiving tissue constitutes a closed microvolume without direct communication. with neighboring texture patterns.
• the surface texture of the implant is not an easy way allowing bacteria, following the surface of the implant, to penetrate deeply into the recipient tissue.
• Each of these closed microvolumes individually constitutes a potential anchoring of the implant in the recipient tissue.
• the surface state Sz of the texture of the surface capable of being implanted in the alveolar bone tissue is between 1 ⁇ and 3 ⁇ .
• This surface state value which corresponds approximately to the depth of the cells of the texture, is optimal for cell colonization in this type of tissue and osseointegration of the implant therein.
• the combination width and depth of cell is thus adapted to the mechanical characteristics of the receiving fabric so as to perform the mechanical anchoring function.
• the surface capable of being implanted in the alveolar bone tissue comprises a texture reproducing the surface texture of a tissue similar to that of the implantation.
• the surface texture is the closest to that of the texture of the tissue in which the implant which is the subject of the invention is implanted.
• the implant which is the subject of the invention, the latter comprises a surface capable of being implanted in a cortical bone and the texture of this surface consists of patterns of cellular geometry whose width is between 1 , 5 ⁇ and 5 ⁇ .
• this surface relief ensures a strong mechanical attachment of the implant in the cortical bone after osteointegration, and therefore the mechanical stability of it.
• the surface state Sz of the texture of the surface capable of being implanted in the cortical bone tissue is between 0.1 ⁇ and 0.5 ⁇ .
• the thickness of the osseointegration layer in the cortical bone harder, is lower than in the alveolar bone, vascularized and more plastic. This reduced thickness makes it possible to better distribute the incompatibilities of elastic deformation between the ceramic implant, whose elastic modulus is significantly higher than that of the bone tissue, and the cortical bone, while ensuring mechanical anchoring thereof in the bone.
• the surface capable of being implanted in a cortical bone tissue comprises a texture reproducing the surface texture of a tissue similar to this implantation tissue.
• the capacity of osseointegration is optimal.
• the implant which is the subject of the invention comprises a surface capable of being implanted in a soft connective tissue, in particular a gingival tissue, said surface comprising a texture reproducing the surface texture of a fabric similar to that of implantation tissue.
• This surface texture promotes the regeneration of soft connective tissue on the implant and thus the sealing of bone implantation of said implant.
• the implant according to the invention extends in a longitudinal direction comprises a longitudinal succession of surfaces having different surface textures reproducing textures similar to those of the fabrics with which they are in contact during in vivo implantation of said implant.
• This embodiment allows optimal anchoring of the implant over its entire length of tissue implantation.
• the implant object of the invention comprises a cylindrical body and the implantable surface in the alveolar bone is a thread comprising a cutting edge extending parallel to the axis of the cylinder so that said thread is self-tapping in the alveolar bone tissue.
• the cutting of the bone tissue by the cutting edge during the introduction of the implant into said tissue promotes, by an effect of compaction, the intimate contact of this fabric with the thread flanks, advantageously for sealing the implantation and osseointegration of the implant surface.
• the implant object of the invention comprises a substantially cylindrical body and the implantable surface in the cortical bone comprises a conical thread having at least one thread.
• This conical thread provides primary mechanical anchoring of the implant in the hard cortical bone.
• the conicity of the threading of the implantable surface in the cortical bone is between 0.02 and 0.1. This low taper makes it possible to ensure radial retention of the implant throughout its implantation length in the cortical bone.
• the at least one thread of the conical thread is interrupted on each turn. This arrangement prevents bacteria, depending on the surface of the net, from penetrating deeply into the tissue implantation.
• the interrupting surface of the net comprises a cutting edge.
• the part of the implant implantable in the cortical bone is self-tapping, taking advantage of the very hard ceramic nature of the implant.
• FIG. 1 shows in perspective and front, an implant body, according to an exemplary embodiment of the invention and two views of detail surface textures of such an implant;
• FIG. 2 shows in perspective from the front and in section an implant according to an exemplary embodiment of the invention in mandibular implantation
• FIG. 3 is a front and in greatly enlarged section of the contact between the textured surface of an implant according to an exemplary embodiment of the invention, and a bone bone recipient;
• FIG. 4 shows in a front view and in perspective an embodiment of a healing ring adaptable to an implant object of the invention
• - Figure 5 is a bottom view and in perspective of an embodiment of a false abutment adaptable to an implant object of the invention
• FIG. 6 is a logic diagram describing the sequence of steps according to one embodiment of the method which is the subject of the invention.
• an implant (100) object of the invention comprises a substantially cylindrical body, the surface in contact with the recipient tissues comprises three sections longitudinal.
• a first section (1 10) intended to be implanted in the alveolar bone comprises a thread with wide pitch. This thread is interrupted on each turn and each interruption of this thread defines a cutting edge (1 15).
• a second section (120) for implanting in the cortex includes a conical microfilet (121) which is also interrupted on each turn, each interruption constituting a cutting edge (125).
• Finally a third section (130) is intended to be implanted in the gingiva.
• the surface of the first section (1 10) comprises a surface texture (detail Z 2 ) consisting of cells (142) with a closed contour whose width l 2 is between 8 m and 15 ⁇ .
• the contours of the cells (142) are the relief points protruding from the surface (1 10) of the implant, the inside of the cells (142) being recessed.
• the depth of the cells is between 1 ⁇ and 3 ⁇ , so that the surface state Sz of this surface (1 10) is substantially between these values.
• the surface of the second section (120) comprises a surface texture
• the implant (100) is made of ceramic, preferably of zirconium dioxide (ZrO 2 ), commonly called zirconia, and more particularly of tetragonal zirconia (ZrO 2 / Y 2 O 3) stabilized with yttrium oxide. latest composition offering optimum resistance to bending and cracking.
• zirconium dioxide commonly called zirconia
• tetragonal zirconia ZrO 2 / Y 2 O 3
• the conical microfiletage of the portion (120) of the implant (100) implanted in the cortex (220) has a taper between 0.02 and 0.1, which is an angle at the apex of the cone of between 1.15 ° and 6 °.
• the taper is defined by the ratio (D-d) / L, that is to say the variation of the diameter measured at the top of the nets on a length L determined.
• the osteointegration is carried out by the colonization of the cells (340) of the surface of the implant by the cells of the recipient tissue (310).
• Each cell thus colonized (340 ') being of closed contour, constitutes, as an individual, a mechanical anchoring of the implant.
• the implant which is the subject of the invention comprises an internal thread (240) and a fixation interface (250) able to receive various supra structures, such as a pillar, a stump or a healing ring.
• these supra structures are also made of a sintered ceramic material, preferably of tetragonal yttrium zirconia.
• These supra structures may advantageously comprise surface textures similar to the surface texture of the recipient tissue in which they are implanted.
• a healing ring (400) adaptable as supra structure to the implant body (100) comprises a thread (440) adapted to be screwed into the internal thread (240) of the implant body and a bearing surface (450) adapted to center and abut on the attachment interface (250) of said implant body (100).
• This healing ring is made of a sintered ceramic material and made according to the method of the invention. It comprises a healing surface (430) which is in contact with the gingiva after the installation of this ring on the implant body (100) implanted in the bone tissue.
• this healing surface has a surface texture similar to that of the gingival tissue, similar to the texture of the outer surface of the upper portion (130) of the implant body. This surface texture promotes the cicatrisation of the gingiva on said healing surface (430), allowing the subsequent disassembly of this ring without bleeding.
• the false stump (500) allows the installation of a crown. It has a bottom surface (530) which is housed in the gum. This surface is of the same shape as the healing surface of (430) of the healing ring (400).
• the surface (530) of the abutment has a surface texture similar to the texture of the gingival tissue.
• the invention also relates to a method for manufacturing the body (100) or a supra structure (400, 500) of an endosseous implant consisting of zirconia.
• the method comprises a first step (610) of acquiring a representation, hereinafter referred to as an image, of the desired surface texture, in particular an image of the texture of a tissue similar to the recipient tissue. It is not necessarily the image of the recipient tissue but that of a tissue similar to this one.
• This image may be a simple photograph (601), it may also consist of a digital file from a three-dimensional survey of the fabric texture by any method known to those skilled in the art.
• a scale factor is applied to this image.
• This scaling or scaling factor is a function of the shrinkage of the ceramic during sintering.
• the homothety can be two-dimensional, for example in the case of a photograph, or three-dimensional, in the case of a topographic survey of the surface.
• the shrinkage factor of the ceramic during sintering can reach 50% depending on the nature of the ceramic used and its porosity tau in the green state.
• the surface delimited by the contour of a cell is 2 to 2.5 times larger than the surface on the initial image (601), and in the case of an image three-dimensional, the volume of a cell is 3 to 3.5 times larger than its initial volume.
• the application of the scaling factor can be performed by a digital image processing (601) when it is in the form of a data file, it can also be performed analogically, for example by an enlargement of the photographic image (601).
• this homothetic image is etched on a wall of the mold cavity used for the realization of the implant by injection.
• This mold is preferably made of steel and the etching can be performed by conventional photoengraving techniques or by micromachining techniques including laser.
• the mold thus etched is used for the injection (640) of a ceramic paste in order to produce a green implant, which is sintered, during a sintering step (650) in order to confer its properties final.
• the pressure injection of the ceramic paste into the mold ensures the faithful reproduction of the shape of the impression including surface textures.
• the minimum size of the surface patterns that can be reproduced is a function of the grain size of the ceramic. Yttriated zirconia is particularly favorable for this point of life because its grain size is less than 0.5 ⁇ . In addition to its other advantageous properties, known from the prior art, this material therefore offers the possibility of reproducing the finest surface textures such as those of the cortical bone to ensure optimum osteointegration of the implant.

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• Health & Medical Sciences (AREA)
• Epidemiology (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Orthopedic Medicine & Surgery (AREA)
• Dentistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Ceramic Engineering (AREA)
• Engineering & Computer Science (AREA)
• Dental Prosthetics (AREA)
• Prostheses (AREA)

Applications Claiming Priority (4)

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• 2010
  • 2010-11-29 EP EP10790632A patent/EP2519182A1/de not_active Withdrawn
  • 2010-11-29 US US13/512,410 patent/US20130011811A1/en not_active Abandoned
  • 2010-11-29 WO PCT/EP2010/068431 patent/WO2011064369A1/fr active Application Filing

Non-Patent Citations (1)

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