The evolution of dental implants has came a long way since the 1960’s. On occasion implant surgeons will encounter some of the old style dental implants seen on the X-ray. Blade implants (seen at the bottom of the X-ray) look like long blades and are attached to a tooth to stabilize them. The problem long term is that teeth move and eventually cause the implant to fail.
Subperiosteal implants (seen at the top of the X-ray) are large frameworks that set on the bone. In theory the bone is to attach to the entire framework. However, what usually occurs is that only a portion of the framework fuses to the bone. The nonattached portion moves and causes infection and more bone loss.
These old style implants can cause major problems. Requiring removal and significant dental bone grafting. For large defects illiac crest bone grafts are needed.