If a tooth is lost, the jaw bone can atrophy, leaving a level of basal bone. When a patient gets a dental implant, it may be necessary to perform a bone graft to rebuild the jaw.
Bond grafts for dental implants can often be performed in an office setting. Processed bone from cows is typically used. It prevents the surrounding tissues from collapsing and is gradually resorbed and replaced with the patient’s natural bone.
When a tooth is lost, the remaining alveolar bone is resorbed unless it is replaced immediately with another tooth, an implant, or a ridge preservation graft (socket graft). This fills the space left by the missing tooth and allows natural bone to fill the space. Cow bone in a granular form is usually used and secured with a pledget of collagen and dissolvable sutures. An implant can be placed three to six months after a ridge preservation graft.
In some cases, bovine bone cannot provide enough bulk to replace the missing bone in the jaw. In that case, the patient’s own bone needs to be used. In an autogenous graft, a block of bone is taken from the lower jaw where the third molars used to be in a region called the mandibular ramus, or from the chin. A block approximately one square centimeter is transferred to the area with missing bone, secured with screws, and overlaid with particulate bovine bone and a collagen membrane. It generally takes four months for the graft to fuse to the jawbone so that an implant can be placed. After the graft has matured, it can house an implant in live bone that will support the tissue and will be aesthetically pleasing and easy to clean.
The maxilla, or upper jaw, has different requirements because of the presence of the maxillary sinus. If a tooth is lost in the upper jaw, there may be very little bone left between the oral cavity and the sinus. A subantral graft, or sinus lift procedure, can be performed in which a small window is made in the sinus above the roots of the teeth in the upper jaw. It takes six to nine months for the bone to consolidate. Depending on the amount of bone present, it may or may not be possible to place an implant immediately after the graft is performed.