PURPOSE: A replaceable drill for expanding a bored hole is provided to adjust the depth of a bored hole when a lower bone of maxillary sinus is drilled during the operation of implants. CONSTITUTION: A replaceable drill for expanding a bored hole comprises an edge(210) and a shank part(220). The edge comprises an upper edge(212). The upper edge is coupled at the upper end of the edge support part(211) by an edge combining unit(230). The shank part is arranged at the lower end of the edge part.
