Abstract: An improved injection syringe device for use especially by dental surgeons is disclosed. The needle assembly tip of said improved injection syringe device has a male threaded portion which can fit into the internally threaded portion of a hollow sleeve integrally connected at the bottom on a housing forming the syringe. The top of the needle assembly is thus guided and protected before passing through the orifice without touching the edges of the sleeve by screwing said needle assembly into said sleeve. Upon completion of the placement of said needle assembly into said sleeve, a plug between the housing and the sleeve is pierced; thus, permitting fluid contained within said housing to be injected through said needle assembly.