About Bone Grafting
Autogenous Bone Grafts:
Autogenous bone grafts, also known as autografts, is bone taken from somewhere else in a patient’s body. The bone is typically harvested from the chin, jaw, lower leg bone, hip, or the skull. Autogenous bone grafts are advantageous in that the graft contains cellular elements and growth factors that can enhance bone growth.
Autografts do requires a second procedure to harvest bone from elsewhere in the body. This second surgical site can prolong recovery and can be susceptible to infections. Some patients may not be candidates for autogenous bone graft because of their physical condition or amount of available bone.
Allogenic mineralized bone, or allograft, is bone from a human donor. the process is similar to receipt of donated organs, but has many significant difference. Prior to the obtaining of this bone, donors are screened for infectious disease. The bone is then obtained and undergoes a process to remove the protein components of the original donor. The bone is then prepared into particles, blocks or strips. The prepared bone undergoes freeze-drying and is then sterilized. There is not process like rejection of organs that occurs with allografts and anti-rejection medications are not needed. In the forty or more years that allografts have been prepared in this manner, there have been no reported cases of infections disease transmission for donor to recipient. Allografts are frequently used in orthopedic surgery and other reconsturctive surgeries.
Unlike autogenous bone, allogenic bone dose not contain cellular elements and growth factors. Allografts serves as a framework or scaffold over which bone from the surrounding bony walls can grow to fill the defect or void. This type of graft is indicated for small defects and in patients that are not candidates for autogenous bone grafts. Allografts are occasionally combined with autografts.
Bone Morphogenetic Proteins:
Bone morphogenetic proteins (BMPs) are proteins naturally produced in the body that promote and regulate bone formation and healing. These proteins have the ability to quickly and predictably induce bone growth on their own and do not require a second surgical site to obtain.
Xenogenic bone is derived from non-living bone of another species, usually a cow (bovine). The bone is processed at very high temperatures to avoid the potential for immune rejection and contamination. Like allogenic grafts, xenogenic grafts serve as a framework for bone from the surrounding area to grow and fill the void.
Both allogenic and xenogenic bone grafting are advantageous in that they do not require a second surgical site to harvest a patients own bone (autograft). Like allografts, xenografts lack some of the bone-forming properties of auto grafts. Bone regeneration may take longer than with autografts, with a less predictable results.
Bone Graft Substitutes
As a substitute to using real bone, many synthetic materials are available as an alternative. These man made products the resemble the composition of bone. These products have the advantage of not requiring a second site to harvest bone, reducing risk and pain. These grafts are less predictable and may have a longer bone regeneration phase.
Demineralized Bone Matrix (DBM)/Demineralized Freeze-Dried Bone Allograft (DFDBA):
This product is processed allograft bone, containing collagen, proteins, and growth factors that are extracted from the allograft bone. It is available in the form of powder, putty, chips, or as a gel that can be injected through a syringe.
Graft composites consist of other bone graft materials and growth factors to achieve the benefits of a variety of substances. Some combinations may include: collagen/ceramic composite, which closely resembles the composition of natural bone, DBM combined with bone marrow cells, which aid in the growth of new bone, or a collagen/ceramic/autograft composite.