WO2015132432A1 - Artificial dental graft - Google Patents

Abstract

The invention relates to an artificial dental graft for fixing to the jaw bone of a user in order to recover the original volume of said bone in a hole in the jaw where bone is missing or the volume has decreased. The artificial graft comprises a body (1) of osteointegratable and non-reabsorbable biomaterial, the size and shape of which match the size and shape of the hole of the jaw of the user, which can be obtained from a 3D image. This ensures a perfect fit of the graft to the jaw of the user.

Description

 DENTAL ARTIFICIAL GRAFT

D E S C R I P C I O N OBJECT OF THE INVENTION

The present invention can be included in the technical field of artificial dental grafts and more specifically it is an osteointegrable graft and not reabsorbed.

BACKGROUND OF THE INVENTION

An important problem that doctors and dentists find when they have to reconstruct or place an implant in areas of the jaws where the remaining bone is not large enough to place such implants.

Generally dental implants attach to the jaw bone. It is essential that this fixation be totally stable so that osseointegration is not lost due to mobility and poor lift. In these cases it is necessary to reconstruct the missing part of the bone and a reconstruction in the vertical direction or in the horizontal direction may be necessary, to have sufficient support for the implant. In other cases it may be necessary to restore part of the jaw to prevent the patient's own teeth from falling out of lack of support.

A generalized solution to these problems is to use an autologous bone, that is, the patient himself, to make a natural graft in the bone of the patient's jaw. You can also use animal bones to achieve this same goal. Autologous bones are usually used because this avoids possible incompatibility problems of the patient with the new bone grafted into his jaw. Other advantages of this type of graft are that it can preserve the matrix, with its bone-inducing properties and undifferentiated cells, and that it conserve vital cells, which are replaced by the host. They also do not induce any immune reaction. Small autogenous grafts can be obtained from the chin, and from the mandibular branch, the largest grafts, from the iliac crest. Generally, for cases of compromised jaws, before rehabilitation with osseointegrated implants, the aim is to recover bone height and volume. For cases of pneumatization of the maxillary sinus, the corticomedular autograft of the iliac crest is the material that is generally used. The biggest drawback of using natural bones to make grafts in patients' mouths is that they end up being reabsorbed. Over time it returns again to the same situation of lack of bone volume that was before the placement of the graft. In cases where the graft is reabsorbed, the implant is left with insufficient fixation.

DESCRIPTION OF THE INVENTION

The present invention describes an artificial dental graft of a biomaterial that is osseointegrated and that allows to restore bones of the oral cavity.

Once installed in its final position, the artificial graft acts as part of the patient's own bone. It is specially designed to be used in cases in which the bone crest of a patient is not large enough in the oral jaws to accommodate endogenous support implants for the placement of dental prostheses.

Artificial grafting is used as a substitute for bone and dental roots respectively to help or complete the repair of skeletal deficiencies that may be due to trauma, tumor pathologies or abnormal development. The graft allows to restore the normal function of the tissue and the dental pieces.

As described above, autologous bone grafts are currently used, that is, bones that are removed from another part of the patient's own body. The artificial graft of the present invention is used in place of said autologous bones to prevent resorption. It is from a non-absorbable biomaterial but that is osseointegrated.

Osseointegration is a direct structural and functional connection between live, ordered bone, and the surface of an implant subjected to functional loading. Through this process the graft is integrated with the alveolar bone, which is the bone that supports the natural tooth portion. For osseointegration to occur, it is necessary that the graft be in direct contact with the bone, so that the process occurs naturally.

The graft of the invention replaces the part of the maxillofacial bone that the patient lacks. In most cases, the graft is used to achieve a larger surface area so that an implant can be placed on the patient. Implant placement requires sufficient support surface to ensure that it will remain fixed in position throughout the patient's life. In cases where the bone in which the implant has to be fixed is too thin or non-existent, the use of the graft of the invention is necessary.

As this artificial graft is not reabsorbed, there is no problem that over time the implant will be loose again but that it will remain fully anchored to the graft, which also osseointegrates forming a compact set with the rest of the jaw bone.

To allow a perfect fit of the artificial graft in the patient's bone Performs a virtual graft design before manufacturing, from a computerized tomography of the patient's oral cavity. This image is taken to have a three-dimensional image of the remaining bone of the jaws and the structures associated with them (such as nerves, blood vessels, mucous membranes, etc.).

To take the image correctly, a simulation of the ideal situation of the teeth of the patient's mouth is made using an invisible x-ray material to represent the gum and opaque materials to represent the patient's teeth. Once this mold is done, the tomography is performed to check what parts of the bone are missing and the exact shape and size of those parts. That is, the exact volumes in which there is a lack of bone tissue in which it is necessary to place the graft are obtained. It is also defined with total accuracy, where the subsequent endogenous implants are to be placed, for optimal occlusal loading with the reference of the simulated teeth in the radiological image.

The graft is modeled based on the shape and size calculated in the previous step and is manufactured using that exact data. The grafts and all the necessary attachments for implantation in the patient's oral cavity are superficially treated and sterilized before performing the implant surgery on the patient.

The implant surface design is based on a porous trabecula that can be combined with a plasma rich in growth factors and / or with bone morphogenetic proteins that favor and accelerate your own bone growth. This is osseointegration and occurs in the postimplantar phases, that is, after having placed the graft. The artificial graft comprises through holes intended to receive means for joining the bone of the patient's jaw. Preferably the connecting elements are threaded elements. In an embodiment of the invention, in the occlusal face of the graft (that is, in the face that is furthest from the bone and is intended to be in contact with future implants), properly spaced, thread steps where the pillar implants are subsequently housed which are intended to support subsequent prostheses.

The graft thread steps are primarily intended to serve as a surgical guide in the placement of implants. Threaded stops are placed in the threaded passage housings that act as a limit for the surgical bits. The secondary and main purpose of the graft threads is to serve as a mechanical stabilization for future endogenous implants, as well as to ensure, through a morse cone at the base, a biological seal that prevents bacterial colonization in compromised areas such as the implant-graft interface /bone.

Subsequently, either after the necessary osseointegration time or by immediate loading, on the implant head, for example threaded elements such as traspitelials, hollow or solid pillars can be connected, for the placement of manufacturing prostheses by conventional systems .

The most prominent applications of the graft of the invention are described below. A possible application is in patients who have long worn mucosoported prostheses (they are the prostheses that are supported on the alveolar process, in contact with the gum that is a fibromucosal tissue, such as the typical "dentures" (full dentures of resin)) and that have an extreme bone resorption, even with a few millimeters of remaining bone, and with risk of mandibular fracture and exposure of the dental nerve. In these cases the artificial graft of the invention acts as reinforcement throughout the jaw and allows the fixation of the implantomucosoported prosthesis.

The artificial graft can also be used to level the dentogingival line, increasing bone support (i.e., increasing bone surface) in patients who have gingival asymmetries. The graft can be combined with gingivectomies or osteotomies if necessary. It is also used in recreations of the alveolar bone support. In these cases, the grafts are placed in the jaws of patients with acute and chronic periodontitis as dental support and to promote the regeneration of periodontal tissues. The artificial graft is placed in the bone areas of the patient's jaw where part of the bone has been lost or is too thin. As it is not reabsorbable, once it joins the bone it no longer moves or becomes thinner or lost. In addition, the proposed artificial graft osseointegrates and behaves as part of said bone to which it has been fixed.

It can also be used to perform large bone restructuring of the two jaws, placing one or more complementary grafts for the total recovery of the original support bone in complex maxillofacial surgeries.

In programmed dental extractions it can be used as a pseudorant graft when the graft is manufactured from a 3D model with the shape and size of the original. In these cases, an induced mechanical primary stabilization is used while preserving periodontal tissues. Since the graft described is of a biomaterial that promotes cell adhesion, it can be combined with growth proteins that favor angiogenesis to consolidate the original periodontal fibers attached to the graft. The result is an artificial implant with all the biomechanical and functional characteristics of the original tooth.

The graft can also be used in palatoplasties (plastic surgery of the palate) as a definitive palatal obturator in patients who have cleft lip-alveolus-palatine. This graft allows to operate early, reducing the surgical stages, with excellent aesthetic results. It does not slow the growth and normal development of the maxilla and prevents maxillary collapse and a satisfactory occlusion can be obtained. That is, with the conventional method only They make soft tissue grafts as obturation of the palatal fissure in several surgeries usually, while with the graft of the invention artificial bone support for the palatal mucosa is being placed in the palatal fissure in a single surgical act.

Other applications are as soft tissue support such as nose, cheekbones, chin, etc. in maxillofacial surgery for facial bone reconstruction; in cases of perforations or disappearance of the external bone table due to cysts or root infections; or as a support for interdental papillae in cases where there are no bones in those areas; to gain vertical bone inside the maxillary sinuses by raising the floor with "open pit" type surgeries (in which the surgeon has direct access to the superior intersinusal cortex).

Thus, it can be used as bone reconstruction in all the intraoral areas of a patient that are destroyed or where there has been a physiological reabsorption of the bone due to pathologies, trauma or edentulism (lack of dental pieces).

A further embodiment allows the artificial graft to be used as a housing for the slow and controlled release of drugs in the oral cavity. In this embodiment the graft has at least one hollow cavity in which the drug is housed and a communication hole with the outside

The most prominent advantages of the present invention are:

-Allows the placement of implants, and therefore of fixed prostheses, in all cases despite the fact that the patient is partially or totally edentulous.

-It allows to completely regularize the patient's missing bone support regardless of the causes for which it has disappeared (in a biological, pathological or traumatic way). -Eliminates the problem of the critical dimensional relationship between tooth / root and its disproportion in traumatic occlusal loads very common in traditional traditional metal endogenous implants. -Disappearance of bone resorption around the implant by lateral loads because the graft has biomechanical characteristics similar to cortical bone.

-It allows to reimplant not only the dental roots but all the bone tissue surrounding them, obtaining an optimal gingival architecture from all points of view (biological, functional and aesthetic).

-It allows to recover dental stability in cases of periodontal implant, even in those teeth with extreme mobility in which the only possible treatment with traditional methods would be exodontia.

-Eliminates the risk of injuring the mandibular nerve and invading the maxillary sinuses and the risk of perforating the corticals since the juxtaosseous graft itself guides and stops the surgical burr.

DESCRIPTION OF THE DRAWINGS

To complement the description that is being made and in order to help a better understanding of the characteristics of the invention, according to a preferred example of practical implementation thereof, a set of drawings is attached as an integral part of said description. where, for illustrative and non-limiting purposes, the following has been represented:

Figure 1.- Shows a perspective view of the graft in which the different parts of the graft body are observed.

Figure 2 - Shows a view in which the means of union of the body are observed to the jaw of a user.

Figure 3.- Shows a view in which a graft with support projections is observed.

Figure 4.- Shows a view in which another example graft with support projections is observed.

PREFERRED EMBODIMENT OF THE INVENTION

Examples of embodiments of the present invention are described below with the aid of Figures 1 to 4.

The described artificial dental graft is intended to be fixed to the jaw bone of a user. The objective is to be able to recover the original volume of said bone in a hollow of the jaw in which bone is missing or its volume has decreased.

This artificial graft comprises an osteointegrable and non-absorbable biomaterial body (1) that has a shape and size coinciding with the shape and size of the user's jaw hollow obtainable from a 3D image.

In some users it may be necessary to use more than one graft to completely recover the jaw bone. Each graft is in the corresponding jaw hole for which it is designed.

Figure 1 shows the body parts (1) of the implant. As can be seen, said body (1) comprises a lingual / palatal face (2) intended to be oriented towards the lingual / palatal area, a vestibular face (3) opposite the lingual / palatal face (2), a basal face (5 ) intended to be in contact with the jaw bone and an occlusal face (6) opposite to said basal face (5). In addition, the artificial graft comprises a plurality of microperforations (4) that cross the lingual / palatal face (2) and the anterior face (3) and that are configured to favor osseointegration in the jaw bone. As the biomaterial has osteoconductive characteristics, these multiple microperforations (4), induce the bone to grow through them, integrating the graft over time with the bone mass as a whole.

The occlusal face (6) of the body (1) is perforated with through holes (7) that also cross the basal face (5). These holes are intended for the placement and fixation of endogenous implants.

In order to allow the primary fixation of the artificial graft to the patient's jaw bone, the graft additionally comprises joining means (9) that are configured to fix the body (1) to the jaw bone. Preferably these joining means (9) are screws as shown in Figure 2.

The graft can also comprise depth limiters that have a hollow cylindrical configuration with a stop at its end. These limiters are arranged inside the holes (7) and are configured to limit the depth of said holes (7).

When an implant is to be placed to the graft user, the doctor has already marked the trajectory of the screw for the implant thanks to the depth limiters that allow limiting the depth of the bone drill used by the doctor for placement depending on the kind of endogenous implant planned for placement in each case.

The body (1) comprises on its occlusal face (6) support projections (8). Likewise, the artificial graft can additionally comprise a dental implant attached to the body (1) through the support projections (8).

Preferably the biomaterial with which the artificial graft of the The invention is a material comprising hydroxyapatite that is the main inorganic component of bones and is also present in dentin and tooth enamel. Synthetic hydroxyapatite has a great chemical physical similarity to bone tissue and behaves like an osteoconductive structure that allows it to be invaded by connective tissue from the surrounding bone to later ossify, maintaining its original characteristics. In a first embodiment of the present invention, the artificial dental graft is used as a juxta or supraosseous graft prepared for the accommodation of an endogenous dental implant.

Figure 2 shows a biomaterial bone crest graft with the purpose of recovering the total volume of the jaw bone of the patient disappeared due to various causes, both vertically and horizontally. The holes (7) are intended to receive endogenous implants of the same biomaterial as the graft body (1) or traditional titanium implants. The implants connect the body (1) of the graft with the user's remaining bone.

It also includes the joining means (9), which are in this case titanium or non-self-tapping screws of between 3 and 6 mm flat head for primary graft stability. They allow the body (1) of the graft to be attached to the remaining cortex in the vestibular / lingual / palatine areas.

The depth limiters in this case are made of titanium and have a different height depending on the implant that is to be arranged later attached to the graft. They allow to limit the pre-designed depth virtually of access of the surgical drill to the remaining bone, facilitating the surgeon the correct instrumentation, avoiding damaging important tissues (nerves, vessels, cortical, teeth, etc.). In a second embodiment, which can be seen in Figure 3, the artificial dental graft is used as a juxta or supraosseous monoblock crest graft with built-in supports or stumps (8) that are configured for the conventional cementation of a fixed prosthesis .

This second embodiment also includes a body (1) intended to recover part of the missing bone from a user's jaw. In this case, the body (1) comprises the projections or stumps (8) described above which are the supports for the placement of a future prosthesis. The joining means (9) are as described for the first embodiment.

Additionally, it includes screwed or friction pins, made of titanium or of the body's own biomatenal (1), which are transoseos and allow the vestibular / lingual / palatine face to be connected for greater stability and load distribution.

In a third embodiment, the graft is used as a periodontal graft. In this case, the body (1) is a vestibular and lingual / palatal anatomical lamina of vertical bone support recovery of the dental socket. It is used in periodontal teeth with micro perforations at the level of the bone papillae on both sides to accommodate the titanium microvarillas. An autologous fibrin clot is arranged between the graft and the dental root, as a scaffold for cell regeneration.

In this third example there are also the same joining means (9) as in the first and second example, and additionally it comprises friction titanium microvarillas for the connection / fixation of the bone papillae of the graft.

In a fourth embodiment, the graft is used as a bone papilla graft as a support for mucous papilla. In this case the body (1) has a rounded pyramidal configuration. Furthermore, in this embodiment, the body (1) comprises additional micro perforations that are intended to accommodate impacted titanium rods as fixation to the interdental bone. remainder.

In a fifth embodiment, the graft is used as an intersinusal graft in "open sky" surgeries. In this case, the graft has an elongated and flat configuration and is supported by the maxillary sinus bone and under the sinus membrane as a vertical bone augmentation for the support of threaded implants. The joining means (9) are also flat head titanium screws. The exact mold or shape of the graft is achieved by making a virtual simulation of the patient's bone in its optimal or ideal state at an early age. Thus the amount of graft necessary in its ideality, still in virtual phase, is obtained. Subsequently, using specialized software, machining / milling strategies are calculated on a precision machine with 5 continuous axes on a virgin biomaterial block. In this way the physical artificial graft object of virtual design is achieved.

Claims

1.- Artificial dental graft intended to be attached to the jaw bone of a user to recover the original volume of said bone in a gap in the jaw in which bone is missing or its volume has decreased, and is characterized in that it comprises a body (1) made of osseointegrable and non-resorbable biomaterial that has a shape and size that matches the shape and size of the user's jaw hole obtainable from a 3D image. 2 - Artificial dental graft according to claim 1 characterized in that the body (1) comprises a lingual/palatal face (2) intended to be oriented towards the lingual/palatal area, a vestibular face (3) opposite to the lingual/palatal face (2), a basal face (5) intended to be in contact with the jaw bone and an occlusal face (6) opposite said basal face (5). 3. - Artificial dental graft according to claim 2 characterized in that the body (1) comprises a plurality of microperforations (4) that cross the lingual/palatal face (2) and the anterior face (3) and that are configured to favor its osseointegration in the jaw bone. 4. - Artificial dental graft according to claim 2 characterized in that the body (1) comprises a plurality of through holes (7) on the upper face (6). 5.- Artificial dental graft according to claim 1 characterized in that it additionally comprises connecting means (9) that are configured to fix the body (1) to the jaw bone. 6.- Artificial dental graft according to claim 4 characterized in that it additionally comprises depth limiters that have a hollow cylindrical configuration with a stop at its end and are arranged inside the holes (7) configured to limit the depth of said holes (7). 7.- Artificial dental graft according to claim 1 characterized in that the body (1) comprises on its occlusal face (6) support projections (8) intended for the cementation of a conventional fixed prosthesis. 8.- Artificial dental graft according to claim 6 characterized in that it additionally comprises a dental implant attached to the body (1) through the support projections (8).