Once a tooth is extracted from the jaw, it will shrink in volume over time. If the tooth has been extracted and left for many years, then excessive shrinkage will have occurred. This results in inadequate bone volume to support a proper sized implant to support a tooth.
Bone grafting may be required if there is not enough bone to support the implant. The bone surrounding the implant should be at least 2mm thickness in volume to be able to properly support the implant, and not worry about thin bone receding.
The bone grafting procedure requires two separate surgical sites: the donor site and the recipient site. The recipient site is the area where the implant will need the bone. The donor site is typically the lower mandible or the upper maxillary tuberosity, or even bone shaved from the outer surface.
Once the bone has been grafted, the surgical sites are closed up and allowed to heal. Bone grafting can take up to six months for the new bone to fuse and bond to the original bone. If the dental implant is placed into the new bone earlier than six months, it will fracture away from the original bone resulting in failure. Some surgeons allow nine months for the new bone to completely interlock and bond with the original bone.
Is there pain involved in bone grafting? During the procedure you will not feel a thing, as you are anaesthetised. However afterwards for 3-4 days there will discomfort swelling and even bruising at both the donor and recipient site.
The advantage of bone grafting is that it allows you to place dental implant in a site which does not have adequate bone to support a dental implant without damaging surrounding nerves and sinuses. The disadvantage is that it takes a very long time for the new bone graft to bond and heal with the original bone. There are ways to get around having inadequate bone. You can place long implants in the zygoma (upper cheek bone) or place the All on 4 technique and have implants cantilevered to the back of the mouth.
It should be made clear that each case is different and that you should consult with your dentist regarding your case.