A dental implant according to the present invention comprises: an elastic fastening leg for performing a function to fasten an abutment to a fixture by elastic bending in the direction of a central axis and the restoring force of elastic legs of the abutment； a non-fastening elastic support leg not involved in direct engagement of the abutment and the fixture； and a first corresponding fastening part formed on an outer circumferential surface of the elastic fastening leg of the abutment, and formed by a fastening protrusion complementarily joined to a first fastening part formed on the inner surface of the shaft hole of the fixture, wherein in the state where the abutment is engaged in the fixture by the complementary engagement of the first fastening part and the first corresponding fastening part, a function to prevent rotation of the abutment against the fixture is performed at a rotational force of less than a predetermined level, while at a rotational force of more than a predetermined level, the elastic fastening leg of the abutment is elastically bent in an inner diameter direction, and the abutment is rotated in a circumferential direction so that the fastening protrusion of the first corresponding fastening part is separated from the fastening groove of the first fastening part, thereby separating the fixture from the abutment.
