Bone grafting is a procedure which involves the replacement of missing bone with bone from another part of the patient's body, bone from a donor or a substitute material.  This surgical procedure is often necessary for patients undergoing dental restorations such as bridge work and dental implants.  When a patient's jawbone has either receded or become damaged, it will not provide sufficient support for implants.  It is in such cases that bone grafting is necessary in order to provide a stable foundation for restorative work.

Factors That Can Affect Jawbone Volume

The stability and volume of the patient's jawbone can be affected by a number of factors.  The most common of such factors include:

• Periodontal disease -- Periodontal disease can cause permanent damage to tissue and bone.  When this disease affects the jawbone, it can ultimately lead to the loosening and loss of teeth as the support structures become progressively less stable.
• Dental injuries and infections -- Trauma to the jawbone caused by physical injuries or oral infections can cause the jawbone to deteriorate and recede.
• Tooth extractions -- Tooth extractions typically lead to the loss of 40 to 60 percent of the surrounding bone over the three years following the extraction procedure. 

Why Bone Grafting May Be Necessary

• Stabilization -- In order for restorative dental procedures such as implants to be successful, they require the jawbone to provide a stable foundation.  Bone grafting can correct damage and deterioration by increasing jawbone volume and by filling in any voids.
• Preservation -- Bone grafting can be employed to preserve the structure and integrity of the jawbone following potentially damaging procedures, such as tooth extractions.  Jawbone preservation through the use of bone grafting may also be necessary when a patient suffers from periodontal disease.

The Bone Grafting Procedure

Prior to carrying out a bone grafting procedure, a patient will undergo an oral examination.  During the examination, the dental professional will determine the condition of the patient's teeth and gums.  If there are any problems present, such as periodontal disease, they will have to be dealt with before any bone grafting can occur.  Panoramic x-rays are commonly used by dentists to determine the precise condition and volume of the jawbone.  In some cases, a CAT scan may also be recommended.

Once the assessment phase is complete, the dentist will determine which type of bone grafting will be the most suitable in the circumstances.  The different types of bone grafts include:

• Autogenous bone grafts -- This type of bone graft uses bone from the patient's own body (often from another part of the jaw) to repair the damaged or deteriorated areas of the jawbone.  Since the harvested bone comes from the patient's own body, this method provides the most predictable and successful results and is therefore generally the preferred method.
• Allograft bone grafts -- These grafts use either synthetic bone or human bone taken from cadavers.  Bone can be donated in the event of a donor's death, just as organs can be donated.  Prior to use, donated bone undergoes numerous tests to ensure that it is safe for grafting.
• Xenografts -- These grafts use cow bone which has been processed and sterilized to ensure that it is biocompatible.

When the human, cow or synthetic bone is added to the affected area it will fuse with the existing bone.  While the entire process can take several months, bone grafting provides greater bone mass and therefore greater support for dental implants. 

During the procedure, the affected area will be numbed with local anaesthetic and a small incision will be necessary in order to secure the new bone into place.  The bone may then be covered with a synthetic membrane which will provide protection from bacteria while also promoting bone growth.  Post-operative medications will be prescribed in order to prevent infection and to help manage swelling and discomfort.