Bone regeneration is a natural process in which bone is formed and lost through re-absorption by the body. It occurs over a lifetime, but the level of formation and re-absorption changes as a person ages. Bone regeneration is also called remodeling and occurs at the cellular level. When the process becomes unbalanced, bone mass decreases and bones may become brittle.
Bone grafting and guided bone regeneration represent two processes that may reverse bone loss and promote new bone growth. These procedures are commonly used in dental surgery to encourage bone growth lost through gum disease, also known as periodontal disease, injury, or surgery to remove tumors or other growths. Bone that has degraded can reform and grow to increase bone mass.
Grafting is a form of regeneration that creates a link between existing bone and grafted material. Over time, the new bone overtakes and replaces the bone that was surgically implanted. Bone mass might be completely restored through this process for some patients, while others may see partial restoration.
Donor cadavers are one source of bone used for bone regeneration through grafting. Bone may also be taken from the patient undergoing the procedure, with the hip or chin being the most common sites. Other regeneration materials include bone mineral from animals and synthetic materials that must be removed once new bone forms, usually several months later.
Bone minerals commonly come from pigs, and appear similar to human minerals under a microscope. The minerals are purified to lessen the chance of infection or rejection. These materials stimulate cells and blood vessels to create new bone to replace lost mass.
In guided bone regeneration, a natural or synthetic membrane is placed in the area where bone loss is evident. The membrane prevents scar tissue from developing as new bone begins to grow. Natural membranes contain collagen that the body reabsorbs, usually within four months. The synthetic form must be removed in a subsequent surgery, and is commonly used on patients who are allergic to collagen or pork products.
When dental procedures are needed, the tooth is removed and the cavity cleaned of any infected tissue. Bone membrane or bone mineral is placed into the dental cavity before the tooth is reinserted. If a cavity exists from an extraction, bone regeneration materials are placed in the cavity, which is stitched to keep it in place.
Most bone regeneration procedures are done under local or general anesthetic. In dental surgery, pain and swelling are common side effects of the operation. The degree of discomfort depends on how much grafting or other work was done in the mouth. Patients are commonly advised to avoid pressure on the surgery site for at least six weeks to allow cultivation of new bone.