A dental implant has a dental implant fixture with a fitting hole at the oral cavity-side end, and an abutment with a fitting portion at one end which is to be fitted, not to be rotatable, in the fitting hole in the dental implant fixture.The dental implant fixture has at a side of the fitting hole opposite to the oral cavity an internal thread with which external threads formed on a cover screw and healing abutment are to be put into engagement. The abutment has a truncated-conical gum piercing portion with a cross section which is larger in area as it goes away from the fitting portion, and a columnar portion which is not circular in cross section and to which a dental prosthesis fixing device is to be attached. The fitting portion has an internal thread smaller in inside diameter than that in the dental implant fixture.
