General Bone Grafting
Over a period of time, the jawbone associated with missing teeth atrophies (dissolves). This leaves insufficient bone for implant placement without bone grafting.
Today, we have the ability to place and grow bone to place implants of proper length and width, and restore the function and appearance new teeth.
Major Bone Grafting
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 the patients own bone is taken from the jaw or hip. Sinus bone grafts are performed to replace bone in the posterior upper jaw. 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.
Major bone grafts are performed to repair defects of the jaws that occur from resorption, traumatic injuries, tumor surgery, or congenital defects. Large defects are repaired using the patients own bone which is harvested from the hip. This procedure is routinely performed in the operating room of the ambulatory surgery center and does not require overnight stay in a hospital.
Sinus Lift Procedure
The maxillary sinuses are empty cavities behind your cheeks and on top of the upper teeth. Some of the roots of the upper teeth extend up into the maxillary sinuses. When these upper teeth are removed, there is often just a thin wall of bone that forms the floor of the maxillary sinus. 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 thin bone without first adding bone to the sinus cavity. This is called a Sinus Lift Bone Graft. The surgeon enters the sinus cavity from the side of the upper jaw, elevates the membrane upward and donor bone is inserted into the floor of the sinus. Keep in mind that the floor of the sinus is the roof of the upper jaw. After several months of healing, the bone becomes part of the patients jaw and dental implants can be inserted and stabilized in this new sinus bone.
The sinus graft now makes it possible for many patients to have dental implants. Years ago there was no option other than wearing loose dentures.
With enough bone at the bottom of the sinus to stabilize the implant, sinus grafting and implant placement can be performed at the same time.
In severe cases of bone loss, the ridge has been reabsorbed and a bone graft is placed to increase ridge height and/or width. This is a technique used to restore the lost bone dimension when the jaw ridge gets too thin to place conventional implants. After the bone graft has solidified in a few months, implants are placed.
Minor Bone Grafting
Upon removal of a tooth the jawbone begins to dissolve. This leaves an irregular ridge for implant placement. The implant must be completely encased in bone. Often there is enough bone to securely place the implant, but it leaves the top and side of the implant exposed. A minor bone graft is used at the time of implant placement to reconstruct this bone. Various materials and techniques are used for this, but essentially it involves lifting the gum back, placing the implant, adding bone to the side of the implant and then protecting the bone from dissolving. Usually the gum is completely closed over the top of the implant. However in some cases the metal abutment can be left exposed without the need for secondary surgery depending upon the materials that were used. Two advances in bone grafting technology are PRP (Platelet Rich Plasma) and BMP (Bone Morphogenic Protein).