What is Bone Grafting?
Over a period of time, the jaw bone associated with missing teeth atrophies and is reabsorbed. This often leaves a condition in which there is poor quality and quantity of bone suitable for the placement of dental implants. In these situations, most patients are not candidates for the placement of dental implants.
With bone grafting we now have the opportunity to not only replace bone where it is missing, but we also have 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 aesthetic 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 your own live bone, meaning it contains living cellular elements that enhances bone growth, also eliminating the risk of your body rejecting the graft material since it comes from you.
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 recommended.
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 have the advantage of not requiring 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 and have a less predictable outcome.
Major & Minor Bone Grafting
Missing teeth over a period of time can cause your jaw bone to atrophy, or resorb. This often results in poor quality and quantity of bone suitable for the placement of dental implants as well as long term shifting of remaining teeth and changes to facial structure. Most patients, in these situations, are not candidates for dental implants.
Fortunately, today we have the ability to grow bone where it is needed. This not only gives us the opportunity to place implants of proper length and width, but it also gives us a chance to restore functionality and aesthetic appearance.
Major Bone Grafting
Bone grafting can repair implant sites with inadequate bone structure due to previous extractions, gum disease, or injuries. The bone is either obtained from a tissue bank or your own bone is taken from the jaw, hip or tibia (below the knee). Sinus bone grafts are also performed to replace bone in the posterior upper jaw. In addition, special membranes may be utilized that dissolve under the gum to protect the bone graft, as well as encourage bone regeneration. This is called guided bone regeneration, or guided tissue regeneration.
Major bone grafts are typically performed to repair defects of the jaws. These defects may arise as a result of traumatic injuries, tumor surgery, or congenital defects. Large defects are repaired using the patient’s own bone. This bone is harvested from a number of different areas depending on the size needed. The skull (cranium), hip (iliac crest), and lateral knee (tibia), are common donor sites. These procedures are routinely performed in an operating room and require a hospital stay.
Minor Bone Grafting
Usually referred to as “socket preservation”, the simplest form of bone reconstruction involves filling up a fresh extraction socket with bone granules and, when necessary, covering the graft with a protective sheet called a membrane. Some membranes will disintegrate by themselves over time and some will require removal at some point.
Bone Graft Substitutes
As a substitute to using real bone many synthetic materials are available as safe and proven alternatives, including:
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.
Bone Morphogenetic Proteins
Bone morphogenetic proteins (BMPs) are proteins naturally produced in the body that promote and regulate bone formation and healing.
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. Hershkin will determine which type of bone graft material best suited to your particular needs.
How Do You Prepare for Bone Grafting?
Bone grafting can be performed either awake or asleep depending on the extent of the planned surgery as well as patient preference. If you are having IV anesthesia the patient must fast (no food/drink/water) for 6 hours prior to surgery. After the surgery you will eat softer foods for a period of time so stocking your kitchen with soft foods such as soups, pudding, yogurt, eggs, fish, soft pasta and of course ice cream is advisable.
Why is Bone Grafting performed?
Bone grafting is performed in order to regenerate or reconstruct areas of the jaws that have lost bone, whether it is from trauma, pathology or age related. Most often, bone grafting is performed prior to or at the same time as dental implant placement.
What Can You Expect During a Bone Grafting?
Bone grafting is accomplished by exposing the area of deficient bone and placing bone graft material to replace the missing volume of bone. Membranes or mesh of varying materials may be placed over the grafted bone to help stabilize the bone as well as to exclude the overlying soft tissue from the healing bone. Once the bone has matured over several months it can be used for a dental implant.
What is the followup and recovery like for Bone Grafting?
Depending upon the size of the defect that requires reconstruction, that usually causes only mild to moderate postoperative pain and swelling. In most cases chewing in the area of the new implant(s) will be altered for a period of time postoperatively to ensure proper healing. Normal yet careful oral hygiene should be maintained, especially on the teeth adjacent to the surgical site.
What are the potential risks for Bone Grafting?
General surgical risks are pain, infection, swelling and bleeding. With bone grafting there is also
the risk of the graft failing to be converted into living bone, either partially or completely.
Are there related treatments to Bone Grafting?
Bone grafting is most often performed prior to or at the same time as dental implant placement.