Dental implants act as artificial tooth roots and are placed in the jawbone. To ensure sufficient anchoring for the prosthesis, the implants must be placed above sufficient bone volume. When the bone volume is too low, it can be surgically increased by a bone graft.
The bone volume available to place the implants is assessed using three-dimensional imaging techniques that quantify the height and thickness of bone available in the area to be implanted. These images also provide the opportunity to verify that there are no surgical obstacles in this area. The most classic examinations for an analysis of the bone volume of the jaws are the scanner and the Cone Beam (3-dimensional panoramic X-ray).
HOW DOES THE BONE TRANSPLANT WORK?
There are different types of bone grafts. Depending on the type of transplant performed, the procedure is done in the clinic, under local or general anesthesia. In all cases, the operation is performed under very strict aseptic conditions in the operating room. There are generally three types of bone grafts:
- Autogenous Bone Grafts
Autogenous bone grafts, also known as autografts, are made from your own bone, taken from somewhere else in the body. The bone is typically harvested from the chin, jaw, lower leg bone, hip, or the skull. Autogenous bone grafts are advantageous in that the graft material is your own live bone, meaning it contains living cellular elements that enhances bone growth, also eliminating the risk of your body rejecting the graft material since it comes from you.
However, one downside to the autograft is that it requires a second procedure to harvest bone from elsewhere in the body. Depending on your condition, a second procedure may not be recommended.
- Allogenic Bone
Allogenic bone, or allograft, is dead bone harvested from a cadaver, then processed using a freeze-dry method to extract the water via a vacuum. Unlike autogenous bone, allogenic bone cannot produce new bone on it’s own. Rather, it serves as a framework, or scaffold, over which bone from the surrounding bony walls can grow to fill the defect or void.
- Xenogenic Bone
Xenogenic bone is derived from non-living bone of another species, usually a cow. The bone is processed at very high temperatures to avoid the potential for immune rejection and contamination. Like allogenic grafts, xenogenic grafts serve as a framework for bone from the surrounding area to grow and fill the void.
Both allogenic and xenogenic bone grafting have an advantage of not requiring a second procedure to harvest your own bone, as with autografts. However, because these options lack autograft’s bone-forming properties, bone regeneration may take longer than with autografts, and have a less predictable outcome.
WHAT ARE THE FOLLOW-UP OF THE INTERVENTION?
The consequences of a bone graft depend on the nature and extent of the graft. Like any surgical procedure, pre-implant bone grafts are followed by a period of healing, during which pain, swelling, and in very rare cases a complication may appear.