Endosseous osseointegrated implants have become an integral part of the treatment scheme for the prosthetic reconstruction and rehabilitation of masticatory function following scientific studies of the reactions between implant and soft and hard tissues. Furthermore, implants offer good chances for prosthetic rehabilitation in the insufficient bone site, if the extremely atrophic jaw is to be reconstructed by grafting procedures with avascular and vascular grafts, by guided bone regeneration, by distraction osteogenesis, by bone substitutes and in the future by osteoinductive proteins in order to prepare the conditions for implant insertion. Those reconstruction procedures combined with implants become often necessary, if complicated hard and soft tissue defects of the skull have to be reconstructed to create the prerequisites for the stabilisation of epitheses or to insert implant-supported devices.