Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Reexamination Certificate
2001-10-09
2004-10-26
Yao, Sam Chuan (Department: 1733)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
C156S245000, C156S296000, C264S109000, C623S023610, C623S023630, C435S372000
Reexamination Certificate
active
06808585
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to an osteogenic osteoimplant made up of, at least in part, elongate bone-derived elements intended for use in the repair, replacement and/or augmentation of various portions of animal or human skeletal systems. More particularly, this invention relates to an implant made up of a mass of elongate bone-derived elements optionally in combination with bone powder. The elongate bone-derived elements and/or bone powder may be nondemineralized bone, partially or fully demineralized bone or any combination of the foregoing. An implant of the invention herein is especially suitable for use in periodontal applications, e.g., guided bone regeneration; plastic and reconstructive surgery, e.g., where the contour of the bone must be modified; and filling of cranial defects; though other skeletal applications are also envisioned.
The use of pulverized exogenous bone growth material, e.g., derived from demineralized allogenic or xenogenic bone, in the surgical repair or reconstruction of defective or diseased bone is known. See, in this regard, the disclosures of U.S. Pat. Nos. 4,394,370, 4,440,750, 4,472,840, 4,485,097, 4,678,470, and 4,743,259; Bolander et al., “The Use of Demineralized Bone Matrix in the Repair of Segmental Defects”,
The Journal of Bone and Joint Surgery
, Vol. 68-A, No. 8, pp. 1264-1273; Glowacki et al, “Demineralized Bone Implants”,
Symposium on Horizons in Plastic Surgery
, Vol. 12, No. 2; pp. 233-241 (1985); Gepstein et al., “Bridging Large Defects in Bone by Demineralized Bone Matrix in the Form of a Powder”,
The Journal of Bone and Joint Surgery
, Vol. 69-A, No. 7, pp. 984-991 (1987); Mellonig, “Decalcified Freeze-Dried Bone Allograft as an Implant Material In Human Periodontal Defects”,
The International Journal of periodontics and Restorative Dentistry
, pp. 41-45 (June, 1984); Kaban et al., “Treatment of Jaw Defects with Demineralized Bone Implants”,
Journal of Oral and Maxillofacial Surgery
, pp.623-626 (Jun. 6, 1989); and, Todescan et al., “A Small Animal Model for Investigating Endosseous Dental Implants: Effect of Graft Materials on Healing of Endosseous, Porous-Surfaced Implants Placed in a Fresh Extraction Socket”,
The International Journal of Oral & Maxillofacial Implants
Vol. 2, No. 4, pp. 217-223 (1987).
More recently, processed bone has been developed into new shapes for use in new surgical applications, or as new materials for implants that were historically made of non-biologically derived materials.
U.S. Pat. No. 4,678,470 describes a non-layered osteoimplanting material produced from bone by a process which includes tanning with glutaraldehyde. The bone may be pulverized, used as a large block or machined into a precise shape. The tanning stabilizes the material and also renders it non-antigenic but negatively impacts the osteoinductivity of the product. The bone material may also be demineralized.
U.S. Pat. No. 5,464,439 describes a continuous sheet of completely or partially demineralized natural bone having sufficient flexibility to conform to the implant site.
U.S. Pat. No. 5,556,430 describes the use of a continuous sheet of demineralized bone or partially demineralized bone, however, the sheet must be sufficiently flexible, therefore sacrificing strength, in order to conform to the skeletal site to which it is applied.
U.S. Pat. No. 5,507,813 describes a surgically implantable sheet formed from elongate bone-derived elements, optionally demineralized, containing biocompatible ingredients, adhesives, filler, plasticizers, etc.
U.S. Pat. No. 4,932,973 describes an artificial organic bone matrix with holes or perforations extending into the organic bone material. These holes or perforations are indicated to be centers of cartilage and bone induction following implantation of the bone matrix.
U.S. Pat. No. 4,394,370 describes a one-piece sponge-like osteoimplant material fabricated from filly demineralized bone powder or micro particulate bone, and reconstituted collagen. The sponge-like graft is optionally cross-linked with glutaraldehyde.
Another one-piece porous implant is described in U.S. Pat. No. 5,683,459. The implant is made up of a biodegradable polymeric macrostructure, which is structured as an interconnecting open cell meshwork, and a biodegradable polymeric microstructure composed of chemotactic ground substances such as hyaluronic acid.
U.S. Pat. No. 5,899,939 describes an osteoimplant fabricated from a number of layers possessing compression strength characteristics approximating those of natural bone.
However, the prior art demineralized bone products have proven to be unsatisfactory for applications requiring a thin osteogenic material capable of displaying a variety of properties. In one embodiment of the invention herein, the material is thin and conforming, i.e., able to be shaped closely to the exterior of bony surfaces, thereby minimizing stress on the overlying soft tissues. In a different embodiment of the invention herein, the material is form holding, i.e., able to maintain its three-dimensional architecture even after rehydration and deformation prior to or during implantation. Moreover, prior art products have been limited as to the size and shape of the finished product by the size and type of starting material used to form the product. In every embodiment of the invention herein the size of the implant is limited only by the total amount of starting material available and not by the size and type of starting material. Thus, a thin osteogenic material capable of displaying a variety of properties would be highly desirable.
SUMMARY OF THE INVENTION
Therefore, it is an object of the invention to provide an osteogenic osteoimplant having a void volume of not greater than about 32% prepared by providing, at least in part, elongate bone-derived elements in a coherent mass and mechanically shaping the mass.
It is a further object of the invention to provide an osteogenic osteoimplant made up of, at least in part, elongate bone-derived elements which is capable of being three-dimensionally shaped prior to implantation to provide for, say, the specific architecture of an implant site.
It is a further object of the invention to provide an osteogenic osteoimplant consisting of a laminate formed at least in part from the osteoimplant of the invention herein.
It is a further object of the invention to provide an osteogenic osteoimplant made up of fully demineralized bone elements that is membrane like yet capable of holding its shape and volume despite pressure from overlying gingival tissue, i.e., shape retaining.
It is yet a further object of the invention to provide a highly flexible, highly conformable, osteogenic osteoimplant by adding a bio-compatible fluid carrier to the fully demineralized bone-derived elements, the carrier remaining in the implant even after dehydration.
It is yet a further object of the invention to provide an osteogenic osteoimplant wherein one surface is less penetrable by cells.
It is yet a further object of the invention to provide an osteogenic osteoimplant which can be tailored to have varied permeability and handling characteristics.
It is yet a further object of the invention to provide an osteogenic osteoimplant in which at least one surface can be treated to produce a visible pattern.
It is yet a further object of the invention to provide an osteogenic osteoimplant whose size is limited only by the amount of starting materials available.
In keeping with these and related objects of this invention, there is provided an osteogenic osteoimplant in the form of a flexible sheet having not greater than about 37% void volume comprising a coherent mass of bone-derived particles. This is in contrast to the shaped materials prepared in accordance with U.S. Pat. No. 5,507,813 that have a void volume of at least about 37% and the load-bearing materials prepared in accordance with U.S. patent application Ser. No. 09/256,447 filed Feb. 23, 1997 which have a wet compressive strength of at least about 3 MPa.
Although not wishing to be bound by theory,
Boyce Todd M.
Kaes David
Scarborough Nelson L.
Dilworth & Barrese LLP
Osteotech Inc.
Yao Sam Chuan
LandOfFree
Osteogenic implants derived from bone does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Osteogenic implants derived from bone, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Osteogenic implants derived from bone will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3300860