Abstract
It must be remembered that any dental implant has the possibility to fail, because the implant is one of the artificial materials in dentistry. However, it is well-known that the treatment for the unsuccessful implants are not easy, because the excision of the implant from the jaw bone is sometimes very difficult and the postoperative bone resorption is often so severe that the implant can't be installed and that the conventional removable prosthesis can not be applied.
In this article we completely reported that the four implant failure patients were treated satisfactorily by the application of the removable prostheses with tapered telescopic crowns (Konuskronen) after excision of the unsuccessful implants, and then we discussed the interface between the implant and bone tissue, the excision method and postoperative bone resorption, the reconstruction with removable prosthesis and the indication for the implant therapy from the view of pathology, oral surgery, and prostihodontics.
The results obtained are below;
1. After the excision of the implants: If the patient had partial edentulism, the removable prosthesis with tapered telescopic crowns (Konuskronen) was very beneficial.
2. The soft tissue was unfavorable for the interface between the endosseous implant and the bone tissue.
3. According to the failure implant: The excision method should be selected to remove the implant simply and to minimize the postoperative bone resorption.
4. The degree of the bone resorption after excision: The screw-type endosseous implant and the pin-shaped endodontic-endosseous implant were slight in degree, but the plate-type endosseous implant, the blade-vent endosseous implant, and the periosteal implant were prominent in degree.
In conclusion at the present time we feel that the screw-type endosseous implant with direct bone anchoring might be most favorable.
