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.
Do I Have Enough Bone?
After tooth extraction, if the walls of the socket are very thick, they will usually fill naturally with bone in two to three months. However, when the walls of your socket are very thin (such as in your upper and lower front teeth), this type of healing will not be as predictable. In these situations, a bone graft is often placed at the time of tooth extraction to help your body fill in the empty socket with bone. This step will maintain the width and volume of bone you will need for implant placement several months later.
1. Inadequate Bone
2. Graft Material Placed
3. Implants Placed
There may be inadequate bone for implant placement if your tooth was removed many years ago and your bony ridge is extremely thin. In this case, a bone graft can be placed next to the thin bone and allowed to heal for up to six months. After the graft has fused to your pre-existing bone, the ridge will be re-entered and the implant placed. Bone grafting is usually a relatively comfortable office procedure. Many different bone-grafting materials are available, including your own bone.
1. Inadequate Bone
2. Graft Material and Implant Placed
You may also need bone grafting if the sinus cavities in your upper jaw are very large, or very low, and extend into the tooth-bearing areas. This often occurs when teeth in the back of a person’s upper jaw have been removed many years before, and the amount of bone available for implant placement is limited. A “sinus grafting procedure” is then required. Most often, it is performed in the office with local anesthesia and perhaps sedation. During this procedure, the membrane that lines the sinus will be located and elevated. Bone will then be added to restore the bone height and ensure that dental implants of an adequate length can be placed. This procedure often can be performed at the time of implant placement.
Types of Bone Grafts
Autografts, also known as autogenous bone grafts are typically harvested from your own chin, upper or lower jaw, leg bone or hip. Autografts 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.
Allograft, or allogenic bone 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 an 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.
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.
DFDBA can act as a bone graft substitute to using real bone. Many synthetic materials are available as safe and proven alternatives.
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. Park & Dr. Lindquist will determine which type of bone graft material best suited to your particular needs.