An assembly for forming an interface part for dental implants with variable height, wherein said assembly comprises: - an interface part having a tubular shape with a central axis (Z) and comprising: a base end for seating said interface part on a dental implant body, a pillar for integrally attaching a prosthesis element to said interface part , said pillar being coaxial with said central axis (Z) and extending from said base end to a free end of said pillar , and an inner conduit coaxial with said central axis (Z) going through said interface part from said free end to said base end forming a passage for a set screw, said inner conduit being provided with an inner rib which forms a seating for the head of the set screw, and - at least one auxiliary part formed for being coupled in a detachable manner to said interface part , such that in a coupled position: said auxiliary part is coupled to said interface part so that it cannot move relatively to said interface part at least in a sense of direction parallel to said central axis (Z); a final segment of said pillar , adjacent to said free end , protrudes through an upper end of said auxiliary part ; said upper end of the auxiliary part forms a peripheral surface outside said pillar , said peripheral surface comprising at least one planar face in a plane (P); and said plane (P) of the planar face intersects with said final segment of the pillar and said central axis (Z); so that said plane (P) defined by said planar face is a cutting plane for cutting said pillar with a cutting tool along said plane (P) at a specific height which is predetermined by the actual dimensions of said auxiliary part , thereby enabling to modify the height of said interface part . - an interface part having a tubular shape with a central axis (Z) and comprising: a base end for seating said interface part on a dental implant body, a pillar for integrally attaching a prosthesis element to said interface part , said pillar being coaxial with said central axis (Z) and extending from said base end to a free end of said pillar , and an inner conduit coaxial with said central axis (Z) going through said interface part from said free end to said base end forming a passage for a set screw, said inner conduit being provided with an inner rib which forms a seating for the head of the set screw, and - at least one auxiliary part formed for being coupled in a detachable manner to said interface part , such that in a coupled position: said auxiliary part is coupled to said interface part so that it cannot move relatively to said interface part at least in a sense of direction parallel to said central axis (Z); a final segment of said pillar , adjacent to said free end , protrudes through an upper end of said auxiliary part ; said upper end of the auxiliary part forms a peripheral surface outside said pillar , said peripheral surface comprising at least one planar face in a plane (P); and said plane (P) of the planar face intersects with said final segment of the pillar and said central axis (Z); so that said plane (P) defined by said planar face is a cutting plane for cutting said pillar with a cutting tool along said plane (P) at a specific height which is predetermined by the actual dimensions of said auxiliary part , thereby enabling to modify the height of said interface part . <EOS>