Overview of Bone Grafting
Over a period of time, the jawbone associated with missing teeth atrophies or 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 are not candidates for placement of dental implants.
Today, we have the ability to grow bone where needed. 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.
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. 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 and protect the bone graft and encourage bone regeneration. This is called guided bone regeneration or guided tissue regeneration.
Here are a few resources to learn about the broad capabilities of bone grafting techniques:
Causes of Bone Loss
When an adult tooth is removed and not replaced, jawbone deterioration may occur. Natural teeth are embedded in the jawbone, and stimulate the jawbone through activities such as chewing and biting. When teeth are missing, the alveolar bone, or the portion of the jawbone that anchors the teeth in the mouth, no longer receives the necessary stimulation, and begins to break down, or resorb. The body no longer uses or "needs" the jawbone, so it deteriorates and goes away.
The rate the bone deteriorates, as well as the amount of bone loss that occurs, varies greatly among individuals. In general, most loss occurs within the first eighteen months following the extraction, and continues throughout life.
Periodontal diseases are ongoing infections of the gums that gradually destroy the support of your natural teeth. While there are many diseases which affect the tooth-supporting structures, plaque-induced inflammatory lesions make up the majority of periodontal issues. Periodontitis is affected by bacteria that adhere to the tooth’s surface, along with an overly aggressive immune response to these bacteria. If gingivitis progresses into periodontitis, the supporting gum tissue and bone that holds teeth in place deteriorates. The progressive loss of this bone can lead to loosening and subsequent loss of teeth.
Dentures and Bridges
Unanchored dentures are placed on top of the gum line, and therefore do not provide any direct stimulation to the underlying alveolar bone. Over time, the lack of stimulation causes the bone to resorb and deteriorate. Because this type of denture relies on the bone to hold them in place, people often experience loosening of their dentures and problems eating and speaking. Eventually, bone loss may become so severe that dentures cannot be held in place even with strong adhesives, and a new set may be required. Proper denture care, repair, and refitting are essential to maintaining oral health.
With bridgework, the teeth on either side of the appliance provide sufficient stimulation to the bone, but the portion of the bridge that spans the gap where the teeth are missing receives no direct stimulation. Bone loss can occur in this area.
When a tooth is knocked out or broken to the extent that no biting surface is left below the gum line, bone stimulation stops, which results in jaw bone loss. Some common forms of tooth and jaw trauma include: teeth knocked out from injury or accident, jaw fractures, or teeth with a history of trauma that may die and lead to bone loss years after the initial trauma.
A bone grafting procedure would be necessary to reverse the effects of bone deterioration, restoring function and promoting new bone growth in traumatized areas.
Altered Developmental Conditions
Some conditions or syndromes known as birth defects are characterized by missing portions of the teeth or jaw bone. Dr. Serra may be able to perform a bone graft procedure to restore bone function and growth where it may be absent.
When molars are removed from the upper jaw, air pressure from the air cavity in the maxilla (maxillary sinus), causes resorption of the bone that formerly helped the teeth in place. As a result, the sinuses become enlarged, a condition called hyperneumatized sinus.
This condition usually develops over several years, and may result in insufficient bone from the placement of dental implants. Dr. Serra can perform a procedure called a “sinus lift” that can treat enlarged sinuses.
Socket Preservation Bone Graft
Preserving Your Jawbone After Tooth Extraction
Removal of teeth is sometimes necessary because of pain, infection, bone loss or fracture of the tooth. The bone that holds the tooth in place (the socket) is often damaged by disease and/or infection resulting in deformity of the jaw after the tooth is extracted. In addition, when teeth are extracted, the surrounding bone and gums can shrink and recede very quickly after the extraction resulting in unsightly defects and collapse of the lips, and cheeks.
These jaw defects can create major problems in performing restorative dentistry whether your treatment involves dental implants, bridges or dentures. Jaw deformities from tooth removal can be prevented and repaired by a procedure called socket preservation. Socket preservation can greatly improve your smile’s appearance and increase your chances for successful dental implants for years to come.
Several techniques can be used to preserve the bone and minimize bone loss after an extraction. In one common method, the tooth is removed and the socket is filled with bone or bone substitute. It is then covered with gum, artificial membrane, or tissue stimulating proteins to encourage your body’s natural ability to repair the socket. With this method, the socket heals eliminating shrinkage and collapse of surrounding gum and facial tissues. The newly formed bone in the socket also provides a foundation for an implant to replace the tooth. If your dentist has recommended tooth removal, be sure to ask if socket preservation is necessary. This is particularly important if you are planning on removing a front tooth and replacing it with a dental implant.
Ridge Augmentation Bone Graft
The alveolar ridge of the jaw is the bone that surrounds the roots of teeth. When a tooth is removed, an empty socket is left in the alveolar ridge bone. Usually this empty socket will heal on its own, filling with bone and tissue. Sometimes when a tooth is removed, the bone surrounding the socket breaks, and is unable to heal on its own. The previous height and width of the socket will continue to deteriorate. This process is called bone atrophy.
We now have the ability to graft and grow bone where needed. This not only gives us the opportunity to place implants of proper length and width, it also gives us a chance to restore function and the aesthetic appearance.
Sinus Augmentation Bone Graft
The maxillary sinuses are behind your cheeks and on top of the upper teeth. These sinuses are empty, air-filled spaces. Some of the roots of the natural upper teeth extend up into the maxillary sinuses. When these upper teeth are removed, there is often just a thin wall of bone separating the maxillary sinus and the mouth. Dental implants need bone to hold them in place. When the sinus wall is very thin, it is impossible to place dental implants in this bone.
The key to a successful and long-lasting dental implant is the quality and quantity of jawbone to which the implant will be attached. If bone loss has occurred due to injury or periodontal disease, a sinus augmentation can raise the sinus floor and allow for new bone formation. A sinus lift is one of the most common bone grafting procedures for patients with bone loss in the upper jaw. The procedure seeks to grow bone in the floor of the maxillary sinus above the bony ridge of the gum line that anchors the teeth in the upper jaw. By strengthening and growing bone in this location, dental implants can be placed and secured in the new bone growth.
Indications for a Sinus Augmentation Bone Graft
Missing one or more teeth in the back of your upper jaw
Missing a significant amount of bone in the back of your upper jaw
You wish to replace your back teeth with one or more dental implants