Endosseous implant

An endosseous implant suitable for application to a human or animal bone, said implant having a surface made from titanium or a titanium alloy, said surface having a smooth or rough texture, wherein said surface has a layer formed thereon of at least one pharmaceutically acceptable organic compound or an ester, an amide or a salt thereof, corresponding to the general formula (I):

• A-[P(O)(OH)2]p (I),
• wherein A means A1, and
• A1 is a residue of a linear, branched or cyclic, saturated or unsaturated, hydrocarbon residue with n carbon atoms, wherein n is a number from 1 to 70, whereby said residue is not interrupted or is interrupted by one or more oxygen and/or nitrogen atoms, wherein each residue A1 carries p phosphonic acid groups, and
• when n is 1 and p is 2:
• A is —CH2—, or
• when n is 1:
• p is 3 or 4, or
• when n is 2 to 10:
• p is 2, provided each phosphonic acid group or phosphonic acid ester group is bound to a different carbon atom within the same molecule;
• or
• when n is 2 to 10:
• p is 3, 4, 5 or 6;
• or
• when n is 11 to 70:
• p is 2, 3, 4, 5 or 6;
• or A means A2 and
• A2 is a residue of an amino acid or of a sequence of amino acids respectively of a protein or of a polypeptide;
• or a residue of a specific drug molecule, wherein each residue A2 carries p phosphonic acid groups, and
• p is 1 to 6 when A2 is a residue of an amino acid or of a sequence of amino acids respectively of a protein or of a polypeptide;
• or
• p is 1 or 3-6 when A2 is a residue of a specific drug molecule originally not bearing any phosphonate group, optionally falling under the definition given for A1.