Bone Grafting / Bone Augmentation
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 esthetic appearance.
Bone grafting sources can be from the following sources: a patients own bone – taken from another area of the jaw, human bone processed from a tissue bank or a xenograft (animal source). These graft materials are quite effective and very safe. Synthetic materials can also be used to stimulate bone formation. We even use factors from your own blood to accelerate and promote bone formation in graft areas.
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 various areas of 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.
Major bone grafts are typically performed to repair defects of the jaws or areas that have suffered extreme loss of bone structure due to a combination of periodontal disease and tooth loss. Of course, over time more bone volume is lost due to the aging process and atrophy (lack of stimulation within the bone due to tooth loss). These bone defects can often times be repaired and rebuilt to support future implant placement.
Sinus Lift Procedure
The maxillary sinus spaces are located behind the cheeks and above the upper posterior teeth. Sinuses are like empty rooms that have nothing in them. Some of the roots of the natural upper teeth extend up close or into the floor of the maxillary sinuses. When these upper teeth are removed, additional shrinkage of the bone (sinus enlargement) will occur within the sinus areas as healing occurs and the aging process continues. A significant deficiency in the thickness of the jawbone becomes evident, especially when an implant is to be placed. Over time this shrinkage of bone will result in a thin wall of bone separating the floor of 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.
There is a solution called a sinus augmentation or sinus lift graft. The sinus is surgically accessed from the previous tooth position in the mouth. The sinus membrane (which is an internal lining inside the sinus cavity) is then loosened and lifted or pushed upward and a contained space is created. Bone graft material can now be inserted to fill this newly created space for the future implants. After several months of healing, the bone graft transforms or becomes part of the patients jaw and dental implants can be inserted and stabilized in this new sinus bone.
The sinus graft makes it possible for many patients to have dental implants when years ago there was no other option other than wearing loose dentures.
If the remaining bone between the upper jaw ridge and the bottom (floor) of the sinus is deficient, but adequate to initially stabilize the implant well, sinus augmentations and implant placement can sometimes be performed as a single procedure. If not enough bone is available, the sinus augmentation will have to be performed first, then the graft will have to mature for several months, depending upon the type of graft material used. Once the graft has matured, the implants can be placed.