The present invention relates to a one-piece dental implant in which a fixture and an abutment are formed into one body to integrate a portion to be placed within a bone, a gum-fitting portion, and a prosthesis-mounting portion, and more particularly, to a one-piece dental implant in which the length of the prosthesis-mounting portion can be extended. The one-piece dental implant according to the present invention comprises said portion which is to be placed within a bone and which is threaded, said gum-fitting portion, said prosthesis-mounting portion, and a prosthesis extension portion. The prosthesis extension portion is attachably/detachably coupled to the prosthesis-mounting portion so as to extend the length of the prosthesis-mounting portion. In addition, the prosthesis extension portion of the dental implant preferably includes a main body and a bolt. The main body is disposed on the prosthesis-mounting portion so as to extend the length of the prosthesis-mounting portion. The bolt is inserted into the main body and threaded into the prosthesis-mounting portion so as to tighten the main body onto the prosthesis-mounting portion. According to the present invention, the one-piece dental implant has the prosthesis extension portion to extend the length of the prosthesis-mounting portion. In this case, the length of the prosthesis extension portion can vary to obtain a variety of lengthwise extensions of the prosthesis-mounting portion. When the prosthesis-mounting portion is prepared with a predetermined length, the prosthesis extension portion is mounted on the prosthesis-mounting portion in consideration of the inserted length of the dental implant, thereby preventing the inconveniences of cutting the prosthesis-mounting portion during dental implant surgery.La présente invention concerne un implant dentaire monobloc dans lequel une fixation et une butée sont formées dans un corps pour intégrer une partie à placer dans un os, une partie d'ajustement de genciv
