To make a needle of a syringe pierce through a dense bone by rotating the needle of the syringe itself for anesthesia of a mandibular tooth, especially a molar tooth and to inject an anesthetic under a condition where the needle is penetrated as it is and to prevent tissues from intruding by passing a wire through the needle and blocking up the space as the tissues forming the dense bone are clogged in the needle when the needle of the syringe is rotated to make it pierce through the dense bone layer.
A constitution is provided for the purpose wherein a reversible needle of the syringe can be fixed on the apex of a shat which can be inserted and rotated in an engine for dentistry and the wire is passed through the needle of the reversible needle of the syringe and the head is protruded a little from the apex of the needle and the end of the wire on the opposite side is bent, and the wire can be pulled out when the reversible needle of the syringe piercing through the dense done is connected with a cartridge type syringe.
HASEGAWA TAKASHI
KAMITSUJI MAMIKO