Bone Grafting Materials
Types of Bone Grafts
Autogenous Bone Grafts:
An autogenous bone graft involves harvesting bone from elsewhere in our body. The primary advantage of employing an autogenous bone graft is that the graft material is alive. Autogenous bone grafts contain living cellular elements that enhance graft survival and promote new bone growth. Should an autogenous bone graft be indicated, Dr. Novack’s choice whenever possible is to harvest bone from an intraoral site (chin or the back of the lower jaw). This approach eliminates the need to involve a secondary surgical site elsewhere in your body. Dr. Novack employs a precision bone harvesting approach (Piezosurgery®) to procure bone from inside the mouth (intraoral). The benefits of this approach include no scarring or changes in facial appearance, reduced pain, convenience and faster covalence. Only when bone loss is extreme would other bone harvest sites be considered.
The obvious downside to an autogenous bone graft is the requirement for a secondary harvest site. Dr. Novack will advise whether an autogenous graft represents the best approach to manage your specific situation.
Allogenic or allograft bone is derived from a human donor. You will be reassured to know that the graft materials Dr. Novack employs do not merely meet, but exceed Health and Welfare Canada safety standards by an order of 106 (1,000,000) times. Graft material is selected only from those individuals who were both young and healthy. Once procured, allogenic bone undergoes rigorous processing involving freeze-drying, vacuum water extraction, fat removal (lipid denaturation), to name just a few of the many processes employed to ensure that the final end product is free of any bacteria, viral contaminants and absolutely safe. Unlike autogenous bone, allogenic bone cannot produce new bone on its own. Rather, it serves as a scaffold or matrix over and into which your own bone can grow to fill the defect or void.
Xenogenic bone is derived from another species, usually cow or pig. Similar to allogenic bone, xenogenic bone undergoes rigorous processing to reduce the potential for immune rejection and contamination. Both allogenic and xenogenic bone serve as a framework for new bone from the surrounding area to grow and fill in the defect or void. Although xenogenic bone is similar to human – allogenic bone, the exact architecture of non-human bone is different (species specificity).
Xenogenic bone tends to be extremely difficult for our body to resorb and thus remains in place for extended periods of time (years). Wherever possible, Dr. Novack’s choice is to employ (human) allogenic donor bone because of the exact structural architecture match and improved speed of replacement with your own living vital bone.
The advantage of using allogenic or xenogenic bone is that these approaches do not require a secondary site to harvest one’s own bone, as compared with an autograft. Both these options however lack an autograft’s robust bone-forming properties. As such, bone regeneration typically takes longer than when an autograft is employed. Finally, the results in specific instances may be less predictable when allogenic or xenogenic bone graft material is used.
Synthetic Bone Graft Substitutes
Many synthetic graft products have over the years been brought to market as an alternative to employing real bone. Dr. Novack has a passion for bone grafting procedures, especially the reconstruction of advanced periodontal and implant sites. He has been asked by various companies on an ongoing basis to evaluate the effectiveness of various bone graft materials. Based upon the most current research, synthetic bone graft products are effective primarily as volume expanders when incorporated into conventional bone grafts. Unfortunately, the research has determined that the results achieved with entirely synthetic bone graft products to recreate living – vital bone has been variable to poor as compared with autogenous or allogenic bone.
Bone Promoting Proteins – Biologic Mediators
The latest advances in bone graft technologies involve the incorporation of bone promoting proteins into a variety of bone graft materials to direct and thereafter accelerate the growth of new bone. The following represents materials Dr. Novack employs to improve the potential for new bone formation and maximize our patients’ treatment outcomes.
- Platelet Derived Growth Factors – are synthetically produced proteins that occur naturally in our blood (platelets) that promote healing including the regulation of new bone formation.
- Enamel Matrix Derivative – represents a biologic based product that has been shown to promote the re-growth of hard (bone) and soft (gum) tissues lost due to gum disease.
- Bone Morphogenetic Proteins (BMPs) – are very powerful proteins that promote and regulate bone formation and healing.
A significant advantage of employing bone promoting proteins is that in many instances, their use can eliminate the need for a second surgical procedure to procure your own bone (autograft). From a patient’s perspective, this translates into a significant reduction in surgical risk and post operative pain.
The use of recombinant DNA proteins has to be weighed against the cost of such products. In addition, due to the power of Bone Morphogenetic Proteins (BMP’s), at times these proteins can exert effects systemically well beyond the localized site where new bone growth is required. Each bone graft option has its own benefits and risks. Dr. Novack will be glad to discuss which bone graft material would be best to manage your situation.