Endosseous implant

PROBLEM TO BE SOLVED: To provide an endosseous implant having a modified surface for fixation of an artificial tooth in dentistry and of a hearing aid to replace or reinforce a bone with damage or disease in orthopedic surgery.SOLUTION: An endosseous implant applicable to human or animal bones has a surface made of a selected metal, a selected metal alloy, or a ceramic. Each of the metals and the metal alloys is selected from chromium, niobium, tantalum, vanadium, zirconium, aluminum, cobalt, nickel, and stainless steel or an alloy thereof. The surface has a smooth or rough texture. The surface is treated with at least one pharmaceutically allowable organic compound having at least one phosphonic acid group or a derivative thereof, which is preferably a pharmaceutically allowable salt thereof, an ester, or an amide.