Bone disappears or atrophies once you lose your teeth. The bone can be taken from another site in your mouth or some times from your hipbone. Other sources can also be the source of bone. This bone graft acts as a scaffold for your own bone to grow across, regenerate and calcify. A large percent of the time, a membrane is used to guide the graft to grow to the new bone in the proper way.
Many different membranes are available to achieve the desired result.
A bone graft may or may not be done at the same time the implant is placed, depending on the individual situation. If it is determined that they need to be performed at separate visits, the length of time between them is normally 6 to 8 months, again depending on what type of bone the graft will be placed in. Bone expansion can sometimes be used if the area of bone is too narrow to house an implant and may sometimes be used as an alternative or in conjunction with a bone graft. Using a series of instruments can expand the bone in the prospective implant site outwards. The implant is inserted and since bone is flexible, it immediately conforms itself around the implant snugly.