By applying a tapered thread to the straight body, the stress applied to the upper part of the fixture is effectively dispersed. The thread depth decreases upwards, reducing friction on the cortical bone. The depth of the fixture is varied by changing the depth of the body part, and stable implantation is possible like a straight type in a fixture with a long depth. Even with weak bone quality by applying a taper, initial entry is easy even when drilling is weak. More detailed information is below.