Patent Application
20120244498
The disclosure is generally related to the field of bone implants, including dental implants, and, more particularly, to a formable three-dimensional resorbable interface that may be employed with various dental implant devices.
It is becoming more common to replace a missing tooth with a prosthetic tooth that is placed upon and attached to a dental implant. The dental implant serves as the artificial root in that it integrates with the jawbone. Dental implants require bones underneath them for support and to have the implant integrate properly. People who have been edentulous (without teeth) for a prolonged period may not have enough bone left in the necessary locations. Bone grafting may be necessary in cases where there is a lack of adequate maxillary or mandibular bone in terms of front to back depth or thickness, top to bottom height, and left to right width. Sufficient bone is needed in three dimensions to securely integrate with the root-like implant. Improved bone height is particularly important to assure ample anchorage of the implant's root-like shape because it has to support the mechanical stress of chewing, just like a natural tooth. In such cases, bone grafts from the chin, from the pilot holes for the implants or even from the iliac crest of the pelvis have been used.
Bone grafts have various drawbacks including a limited amount of tissue available for grafting, lack of available or appropriate donor sites, and limitations on size and contour to match a defect site. Perforated metal sheets have also been used to correct bone defects prior to dental implantations. A metal mesh, such as titanium mesh, is applied to the bone defect. A disadvantage of the metal mesh is that it is not resorbable and must be removed after bone formation has occurred or a defect has been restored. This adds trauma to the overall procedure. Accordingly, it may be desirable to provide an alternative material that provides increased vascular ingrowth and perfusion and tissue regeneration.
The present disclosure is generally directed to a method of forming a resorbable biomaterial element for guiding bone regeneration in a defined zone as a basis for dental implants. The resorbable biomaterial element may be formed of collagen or bone graft. In one illustrative embodiment, the method involves forming a three-dimensional resorbable product contoured to a bone defect in a mandible or maxilla. The method steps include, providing a resorbable biomaterial element, such as a collagen element or bone graft solid element, texturing at least one surface of the element, wherein the texturing allows the element to be bent and formed into at least one desired and/or predetermined three-dimensional shape. In another method, the steps include determining a shape of the bone defect, selecting a collagen element or bone graft solid element with texturing on at least one surface of the collagen element or bone graft solid element and bending the collagen element or bone graft solid element to form a three-dimensional shape conforming to the shape of the bone defect.
In some embodiments, the collagen element is a sheet, and the texturing step includes forming a plurality of grooves in the collagen sheet in at least one direction, wherein the grooves are formed in at least one surface of the element and are formed to a depth sufficient to allow the sheet to be bent at the grooves. In one embodiment, the plurality of grooves are formed in two or more directions, where at least some of the grooves cross. A first set of substantially horizontal grooves may be formed crossing a second set of substantially vertical grooves, creating a grid pattern.
In other embodiments, a first set of grooves is formed in a first portion of the collagen sheet and a second set of grooves is formed in a second portion of the collagen sheet, and the first and second sets of grooves do not cross or intersect. The first set of grooves may be disposed in a first orientation and the second set of grooves may be disposed in a second orientation, where the first and second orientations are different, and the first portion of the sheet is bent in a first direction and the second portion of the sheet is bent in a second direction.
In still other embodiments, the texturing step may include forming a plurality of indentations in a top surface of the collagen sheet. The surface texturing may also be performed on a collagen element of non-uniform thickness.
The present disclosure is also directed to an implant for guiding bone regeneration for dental procedures. In some embodiments, the implant is a resorbable bone graft solid element in a block or other 3-D form, and the texturing step includes forming a plurality of grooves in the bone graft block in at least one direction, wherein the grooves are formed in at least one surface of the element and are formed to a depth sufficient to allow the sheet to be bent at the grooves.
The present disclosure is also directed to an implant for guiding bone regeneration for dental procedures. In some embodiments, the implant is a resorbable collagen matrix sheet having a plurality of surface contours formed in one or more surfaces of the sheet, the surface contours configured to allow bending of the sheet to conform to a shape of a bone defect in a mandible or maxilla. The plurality of surface contours may include a plurality of grooves extending in at least one direction, wherein the grooves are formed in at least one surface of the sheet and are formed to a depth sufficient to allow the sheet to be bent at the grooves. In some embodiments the grooves are formed such that a 0.3 mm minimum wall thickness is left in each groove. The collagen sheet may have a thickness ranging from about 0.5 mm to about 2.0 mm.
In some embodiments, the plurality of grooves are formed in two or more directions, where at least some of the grooves cross. In one embodiment, a first set of substantially horizontal grooves crosses a second set of substantially vertical grooves, creating a grid pattern. In another embodiment, a first set of grooves is formed in a first portion of the sheet and a second set of grooves is formed in a second portion of the sheet, where the first and second sets of grooves do not cross or intersect. The first set of grooves may be disposed in a first orientation and the second set of grooves may be disposed in a second orientation, the first and second orientations being different, allowing the first portion of the sheet to be bent in a first direction and the second portion of the sheet to be bent in a second direction.
In still other embodiments, the plurality of surface contours includes a plurality of pores through the collagen sheet or a plurality of indentations in a top surface of the collagen sheet.
The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
The present invention will now be described with reference to the attached figures that are included to describe and explain illustrative examples of the present invention. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.
In general, in one aspect, the present disclosure is directed to various embodiments of a resorbable biomaterial interface or element for guiding bone regeneration to reconstruct or augment anatomical defects in preparation for various dental, oral, maxillofacial, and craniofacial procedures. Such procedures include the reconstruction or augmentation of a portion of the anterior and posterior maxilla or the anterior and posterior mandible, and in reconstruction of a palatal graft. In particular, the disclosure is directed to resorbable biomaterial elements designed for procedures involving dental implants. As will be readily apparent to those skilled in the art upon a complete reading of the present application, the resorbable biomaterial elements described herein may be used with a variety of different surgical procedures performed to install dental implants. Thus, neither the type of dental implant used nor the type of surgical procedure performed should be considered a limitation of the present invention. The resorbable nature of the resorbable biomaterial material reduces the trauma to the surgical site upon follow-up procedures when in preparation for placement of a dental implant. Examples of resorbable biomaterials are collagen and bone graft solids.
The resorbable biomaterial element is adapted to be securely positioned in a patient's jawbone (mandible or maxilla). The resorbable biomaterial element can be used in dental procedures to reconstruct or augment a portion of the anterior and posterior maxilla or mandible. It may also be used in reconstruction or a palatal graft, covering of a lateral window created during a Caldwell-Luc sinus lift procedure. An example of a dental procedure in which the formed resorbable biomaterial element may be used is a socket repair procedure with a 4-walled socket defect.
The resorbable biomaterial element is implanted in a non-hydrated state that maintains its semi-rigid construction. The element is cut to match the defect size and formed by hand to match the patient's anatomy. Surgical anchors are used to secure the element to the bone. The resorbable biomaterial element may take the form of a scaffold, sinus floor drape, ridge cover, socket liner, pallet shield, or bridge over a bony defect.
Resorbable biomaterial may be provided as a sheet or a three-dimensional form. Surface texturing is performed on the resorbable biomaterial sheet or element to create unique surface features designed to give versatility to the mechanical properties of the material. The resorbable biomaterial sheet or three-dimensional form may be scored to create grooves or channels. The grooves or channels may create a surface feature of ribs and valleys forming a grid along an otherwise flat surface. The ribs provide sheet strength and thickness, while still maintaining some flexibility through the thinner areas. Textures such as micro-grooves may be formed for channeling of fluid flow. Another surface texture is made up of tiny protruding hooked spines, simulating Velcro®. This type of surface texture would provide initial fixation of a resorbable biomaterial sheet to the host tissue. Micro-pores or holes may also be formed in the resorbable biomaterial sheet to preclude some cells while allowing the diffusion or infiltration of other cells. This has the benefit of increasing the potential for vascular ingrowth and perfusion by exposing the graft material to the natural healing environment.
The grooves or channels may extend in multiple directions to provide flexibility in multiple directions allowing the sheet to be contoured to the patient's anatomy and bone defect. The grooves or channels may be formed parallel or perpendicular to each other, in a converging or diverging orientation, or any other pattern that provides flexibility to the sheet or three-dimensional form. The grooves or channels may be formed on one side of the sheet. In other embodiments, grooves or channels are scored into both sides of a resorbable biomaterial sheet. Scoring on both sides provides increased flexibility and allows the sheet to be formed into at least one desired and/or predetermined three-dimensional shape.
Various combinations of surface texturing may be used to achieve a particular function. Examples of functions provided by surface texturing include, but are not limited to, controlled permeability, targeted flexibility, localized porosity, increased strength, added fixation, guided release of therapeutic agents, and cell occlusion. The various surface texturing effects can be created through the use of laser technology, similar to laser etching, 3-D printing, engraving, stamping, molding, or sintering technologies.
An alternative to adding surface textures to a resorbable biomaterial sheet or element is utilizing a mesh, sponge or other porous form of resorbable biomaterial which has a repeated or random pattern on the surface. Increasing the porosity of the material or decreasing the density may provide an alternative to the surface texturing.
The resorbable biomaterial may be in a three-dimensional form such as a block or wedge.
An embodiment of collagen sheet 40 with grooves 42, 44, 46 arranged to allow the sheet 40 to be formed into a three-dimensional shape that confirms to the anterior maxilla is shown in
The grooves or channels provide flexibility without compromising surface coverage and exposing the graft material to movement and contact with surrounding soft tissue.
The collagen sheet 40 illustrated in
Another embodiment of formed collagen sheet 50, shown in
Another surface treatment of the collagen sheet that allows for forming the sheet into a three-dimensional shape to conform to a bone defect is perforation. The collagen sheet 12 is perforated to create pores 22 which increases the vascular ingrowth and perfusion through the sheet. See
The collagen is resorbable and provides a structure to guide bone regeneration in a defined zone or region based on its semi-rigid shape. The resorbable nature of the collagen material reduces the trauma to the surgical site upon follow-up procedures when in preparation for placement of a dental implant. In another embodiment, a block form bone graft is covered by a collagen sheet that is scored and formed to contour to the bone defect.
Those skilled in the art will recognize that the present invention may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departure in form and detail may be made without departing from the scope and spirit of the present invention as described in the appended claims.
