A wholly disposable dental type syringe arranged in a packaged-for-sale form and rearrangeable to its disposition for operation, comprising in combination:
- a hollow transparent cylindrical body capable of encasing a dental anesthetic cartridge and formed at its interior with ribs extending substantially the entire length of the hollow interior of the cylindrical body to prevent said cartridge from being removed therefrom, which hollow cylindrical body has one end open and the other end closed and is formed integrally with ears at said open end;
- an injection needle which has two points at its opposite ends and is mounted in the closed end of said cylindrical body with one of said points projecting into the interior of said cylindrical body so that when the dental anesthetic cartridge is encased in the interior of the cylindrical body, the projecting point is introduced into said cartridge to contact the dental anesthetic;
- a hollow piston removably attached to the closed end of the hollow cylindrical body, which hollow piston has one end open and the other end closed and is formed at its open end with curved arms forming an open ring having a clearance between the free ends of the arms substantially equal to the outside diameter of said cylindrical body, the free ends of the curved arms being slightly concave to embrace said cylindrical body;
- a harpoon-like device mounted in the closed end of said hollow piston and projecting therefrom;
- and
- protecting means removably attached to said hollow piston and covering said harpoon-like device, said protecting means comprising a frustoconical component of annual cross-section, the internal diameter of the smaller end of said component being slightly less than the external diameter of said hollow piston and the external diameter of said smaller end being less than the diameter of the open end of said cylindrical body, the external diameter of the larger end of said component being greater than the external diameter of said open end of the hollow cylindrical body, and the conicity of said frustoconical component being such that said component can be inserted into said open end of the hollow cylindrical body by a distance that is at least equal to the difference between the length of the interior of the hollow cylindrical body and the length of the dental anesthetic cartridge, said frustoconical component and said hollow piston being rearrangeable into said disposition for operation by introducing said frustonical component through the open end of the cylindrical body encasing the dental anesthetic cartridge until said one point of the needle is in contact with the dental anesthetic, and introducing said hollow piston into said cylindrical body through said frustoconical component.