One of the most frequently applied grafting procedures is the sinus “lift” bone graft.
As one gets older the sinuses grow larger in volume and literally take away valuable jaw bone as the yellow arrows show on the x-ray below. This happens to almost every one.
If teeth are lost in this area it makes it difficult if not impossible to place dental implants in that area. To solve this problem, a bone grafting method was developed to literally raise the bottom of the sinus and allow bone to fill in where it naturally occurred before the sinuses expanded allowing space for implants and better yet—teeth! You can see the comparison between the before and after x-rays below.
This technique has been successfully used for over two decades now and is considered a highly predictable method of bone grafting. The grafting material used is a combination of your own bone, donor bone (freeze dried, demineralized, and with the DNA of the cells removed so that the risk of disease is eliminated), and synthetic bone materials. The newly formed bone tissue will take approximately 4 to 9 months to mature and in extreme cases over a year.
Implants can sometimes be placed at the same time as the sinus bone grafting in one combined procedure, if enough bone below the sinus is available to stabilize the implant well. If not enough bone is available, the sinus bone graft is performed first, then the new bone matures for several months and then the implants are placed.
With respect to the bone graft material used, there are several choices. All materials can be categorized into five different categories:
- Autograft, or autogenous bone graft;
- Allograft, or allogenic bone graft;
- Xenograft, or xenogenic bone graft; and
- Alloplast, or alloplastic bone graft
The Autograft is considered the ‘Gold Standard’. It is your own bone taken from a donor site and placed somewhere else in the body, into the recipient site. The best success rates in bone grafting occur with this method since the living tissues with their bone cells intact are present. There is no immune reaction and the microscopic architecture is perfectly matched.
The only disadvantage of the autograft is that it has to be harvested from another site in your body, which usually means more post-operative discomfort and a more complicated surgery, overall. For most grafting purposes needed with dental implants, we can use bone from another part of the jaws (i.e., chin or back portions of jaw where the wisdom teeth were) as an acceptable donor site. This allows us to stay inside the mouth. Sometimes, however, when there is not enough bone available in the mouth, bone is taken from elsewhere in the body (usually from the top of your hip bone).
The Allograft is defined as a bone graft between two individuals of the same species (i.e., humans) but of non-identical genetic composition. The source is cadaver bone that undergoes many different chemical treatment sequences to render it neutral to immune reactions and to avoid transmission of disease. These treatments may include irradiation, freeze-drying, acid washing and other chemical treatments. Between the prescreening of donors and the processing of the bone the chance of cross-infection is nearly non-existent.
The Xenograft is defined as a tissue graft between two different species (i.e. bone of cow origin). This bone has a similar microscopic structure as human bone which encourages bone growth.
The Alloplast is synthetically derived bone graft material not coming from animal or human origin. This usually includes hydroxyapatite.
Dr. Radomski makes the decision with respect to the type of bone graft material, based on your individual needs and the latest research in this field.