Grafting for Dental Implants
Over a period of time, the jawbone associated with missing teeth, atrophies or dissolves away to some degree. If an area of jawbone does not have a tooth in it, it is not stimulated, and then the bone where the tooth was extracted from diminishes in several dimensions, namely height, width and density. This leaves a poor quality and quantity of bone in which to place a dental implant. This situation, many times, can be remedied with the placement of donor bone, most often taken either from a bovine (cow) source or less often the patient's own bone is used (autogenous) and it is taken from behind the last molar or from the chin. Implants then can be placed to restore functionality and esthetic appearance.
Ridge preservation is a type of bone grafting that helps to preserve bone at the time of extraction. It helps to maintain the bony ridge and helps prevent the atrophy that occurs after a tooth if removed. Bone grafting material is placed into the empty tooth socket from where the tooth was just removed. A membrane is placed over the graft and both the bone graft and the overlying membrane are held in place and prevented from being displaced by sutures. This procedure minimizes bone loss that occurs after a tooth extraction. Ridge preservation may prevent more extensive bone grafting later and foster a denser bone in which a future implant will be placed.
Many people who have lost teeth in the molar area of the upper jaw do not have enough bone height for implants to be placed. However the sinus floor can be lifted or raised to create greater vertical height of bone in the back portion of the upper jaw so that dental implants can be placed. The sinus lift makes it possible for a patient who has worn a denture for many years, or just gone without teeth, to now have teeth. This procedure was not available many years ago.
A sinus lift is done when there is inadequate bone in the upper jaw, or the sinuses unduly hollow out the upper jaw, and dental implants cannot be placed. There are several reasons for this:
- Many people who have lost teeth in their upper jaw—particularly the back teeth, or molars—do not have enough bone for implants to be placed.
- Bone may have been lost because of gum disease, failure of root canal-treated teeth, or abscessed teeth.
- Once teeth are gone, the bone that surrounded those roots begins to be resorbed (absorbed back into the body). If teeth have been missing for a long time, there often is not enough bone left to place implants.
Rather than grind down healthy teeth to support a fixed bridge or wear a partial denture that affects speech or eating, people prefer dental implants. Sinus lifts consequently have become common during the last 15 years.
Because specialized instrumentation now is readily available, sinus lift surgery now is a much more conservative procedure.
Nasal Floor Lift
For patients who are missing upper front teeth and are experiencing atrophy (dissolving away) of bone, a nasal floor lift can be performed through the gum tissue to create vertical height of bone in which to place dental implants.
Bone can also be placed to repair larger defects of the jaws that can result from trauma, infection, tumor removal, or congenital defects.