German Society of Dental Medicine. At that time, the scientific status of implantology was described and therapeutic guidelines were established. In recent years, this was the basis for negotiations and decisions in the most diverse institutions, and ultimately for the recognition of this specialty in terms of health policy. From a scientific and practical point of view, the stormy further development of implantology in recent years had led to the demand for a consensus conference. This consensus conference was to be organized to draw up a statement on the present state of the art. On the occasion of the 12th Scientific Meeting in Hamburg, April 21 to 23, 1989, during the members' meeting of the Implantology working group within the German Society of Dental Medicine, the convocation of such a conference was resolved. It took place on October 18, 1989, in Mainz and led to the present statement. (The leading speaker is specified for each individual section.) In the following, implants are considered to be artificial abutments that are implanted into the jaw bones (endosseous implants). They serve to support crowns and fixed prostheses or to stabilize a prosthesis.