If large defects are encountered, which prevents the placement of dental implants, an actual block of bone can be removed from the chin or back behind the lower teeth and transplanted to the area in need.

These "blocks" of bone are held in place using small titanium screws to allow for healing. They will often be covered with a thin collagen membrane.

These grafts typically require four to six months to heal and form new bone identical to the shape of the transplanted block. Implants can then be placed securely in this bone. It will usually take another three to four months for the bone to remodel around the implants.