About Bone Grafting
What is Bone Grafting?
Over a period of time, the jawbone associated with missing teeth atrophies is reabsorbed. This often leaves a condition in which there is poor quality and quantity of bone suitable for placement of dental implants. In these situations, most patients were not candidates for placement of dental implants. However…
With bone grafting, we now have the opportunity to not only replace bone where it is missing, but also the ability to promote new bone growth in that location! This not only gives us the opportunity to place implants of proper length and width, it also gives us a chance to restore functionality and esthetic appearance.
Types of Bone Grafts
Autogenous Bone Grafts:
Autogenous bone grafts, also known as autografts, are made from your own bone, taken from somewhere else in the 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 material is live bone, meaning it contains living cellular elements that enhance bone growth.
However, one downside to the autograft is that it requires a second procedure to harvest bone from elsewhere in the body. Depending on your condition, a second procedure may not be in your best interest.
Allogenic bone, or allograft, is dead bone harvested from a cadaver, then processed using a freeze-dry method to extract the water via a vacuum. Unlike autogenous bone, allogenic bone cannot produce new bone on it’s own. Rather, it serves as a framework or scaffold over which bone from the surrounding bony walls can grow to fill the defect or void.
Xenogenic bone is derived from non-living bone of another species, usually a cow. 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 procedure to harvest your own bone, as with autografts. However, because these options lack autograft’s bone-forming properties, bone regeneration may take longer than with autografts, with a less predictable outcome.
Bone Graft Substitutes
Bone Morphogenetic Proteins:
Bone morphogenetic proteins (BMPs) are proteins naturally produced in the body that promote and regulate bone formation and healing.
Certain bone morphogenetic proteins, or BMPs, have been studied for decades because of their remarkable ability to heal bone and eliminate the need for bone graft harvesting from other parts of the body. Approximately 20 BMPs have been discovered, but only six appear capable of initiating bone growth. Of these, rhBMP-2 has been studied more than any other BMP and is FDA approved for use in certain spinal, tibial (leg) and oral surgeries.
Naturally occurring BMP is found within the bone itself, but only in small amounts. To provide clinically useful and reproducible amounts of isolated, human BMP, it must be manufactured in a special facility.
Scientists isolated the gene for one protein (BMP-2) from bone tissue and used well-established molecular biology techniques to create genetically engineered cells. These cells then produce large quantities of rhBMP-2. A similar process is used to manufacture other proteins, such as insulin. The recombinant form of rhBMP-2 is identical to the natural form in both its chemistry and its ability to grow new bone.
During surgery, rhBMP-2 is soaked onto and binds with an absorbable collagen sponge (ACS) that is designed to resorb, or disappear, over time. As the sponge dissolves, the rhBMP-2 stimulates the cells to produce new bone. The rhBMP-2 also goes away once it has completed its task of initiating the normal bone healing process.
rhBMP-2 may be used to promote bone growth in several areas of the body. In instances of jaw bone resorption, rhBMP-2 may be placed in the section or sections of the jaw bone that need to be built back up in preparation for dental implants.
Synthetic materials also have the advantage of not requiring a second procedure to harvest bone, reducing risk and pain. Each bone grafting option has its own risks and benefits. Dr. Kurtz or Dr. Lee will determine which type of bone graft material is right for you
As a substitute to using real bone, some synthetic materials are available as a safe and proven alternative, including:
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.