The best time to preserve bone is right after the tooth is removed/extracted through a procedure called socket preservation. Socket preservation is also the cheapest and very effective at preserving the bone that is present. About 40% (forty) percent of bone is lost within the first six months through a process called resorption if the socket is not filled with a bone graft.
Think about backfilling a hole after you dig out and uproot a tree or plant in your garden. Basically, we backfill the extraction site with the following alternatives: autograft, your bone; allograft, sterilized human bone; or alloplast, synthetic bone. By filling up the extraction site, we can preserve up to 95 (ninety-five) percent of the bone following tooth removal.
Once a tooth is removed, the body will continue to remove bone over time by a process called resorption. It has been shown that 40 (forty)percent of your bone is lost within 6 months if no measures were taken to maintain bone volume at the extraction site.
Unfortunately, when bone is lost, implants does not have have an adequate amount of support to properly function under normal biting forces. Luckily, there are techniques to increase the amount of native bone in the sinus if careful elevation of the membrane is performed through a procedure called crestal, through the socket, or lateral, through the side, sinus lifts.