A method for implementing vascular anastomosis in the attachment of a graft vessel to a target vessel such as a coronary artery, and subsequently creating a passageway between the vessels in order to establish fluid flow communication therebetween. The base includes a first casing and a ferromagnetic unit fastened to the first casing. The second terminal includes a second contact beam having a width smaller than that of a first contact beam of the first terminal. When there is an instruction by the user for output of the additional information, a display signal is generated by using the program signal and the additional signal read from the memories, while only the program signal is read from the memory for generation of the display signal in other cases. The form has a curved surface previously formed at a corner along a tooth trace of a tooth flank.