An improved cartridge for use in hypodermic syringes is disclosed in which the hollow tubular cartridge body has a first end which has a resilient seal thereon and which engages both the end of the cartridge and a portion of the periphery thereof adjacent the end. The first seal member is also capable of engaging the internal nozzle of the syringe, if one exists, as well as engaging the inner surface of the barrel of the syringe. The opposed end of the cartridge body, which is normally contacted by a plunger to eject the contents, has a second seal member or plug, at least a portion of which is partially received internally of the cartridge and has annular ribs which perform as O-rings and contact the inner surface thereof for sealing purposes. A lip fits over the second end of the cartridge body to achieve a three-way seal at that point and also seals against the inner surface of the barrel of the syringe per se. This second seal member is deformable so that upon actuation of the plunger, the second seal will deform inside the cartridge body to resist back pressure and thereby prevent leakage.

A dental syringe and a method of packaging and dispensing a dental material wherein the package containing the dental material comprises a cartridge containing a bulk supply of dental material, and which cartridge is constructed so as to function as a syringe for effecting the extrusion of the dental material therefrom as may be needed in a dental restorative procedure. The cartridge comprises an elongated tubular barrel having an open end portion and a forward discharging orifice portion through which the material is extruded. A displaceable piston seals the rear end of the barrel to confine the dental material within the barrel, and which cartridge can be readily attached to a handle and associated plunger to complete a syringe assembly. The plunger is also provided with a device for relieving the back pressure imparted to the cartridge piston during an extruding operation to prohibit any unwanted drooling of the material therefrom. The associated plunger may also be adjustably extended to effect total extrusion of the material from the cartridge in predetermined incremental amounts.

A dental capsule that requires a capsule body defining a reservoir that is loaded with predetermined amounts of one or more materials to be mixed, sealed by a removable plug having flexible gripping flange fingers extending laterally relative to the axis of the capsule to facilitate the removal of the plug. Subsequent to the mixing of the materials within the capsule by amalgamation, the capsule is placed in a suitable ejector or syringe whereby the mixed materials can be readily extruded therefrom and directly placed in or about a prepared tooth whereby the flexible gripping flange fingers function as a base for storing the capsule in a vertical position and which flexible fingers are capable of being deflected so as to be pushed through the capsule as the plug is displaced to extrude the mixed material.

A fluid dispensing assembly 10 of the type for dispensing a precise stream of a fluid, such as a liquid and/or gas is disclosed. The fluid dispensing assembly 10 comprises of a fluid dispensing instrument or fluid source means 12, a needle apparatus 14, and is characterized by an adapter 16 for connecting the fluid dispensing instrument 12 to the needle apparatus 14 to establish fluid communication therebetween.

Syringe assembly apparatus and associated methods are provided for use in dispensing viscous materials, such as dental compositions, in a controlled fashion. The preferred embodiment of the syringe assembly of the present invention includes a syringe body of conventional fashion, having a passageway therethrough and a discharge port communicating with the passageway. An adapter member is provided which nests within the syringe body passageway, the adapter member having a bore passing through the length thereof for receiving a viscous material to be dispensed. When the adapter is nested within the passageway of the syringe body, the bore communicates with the discharge port of the syringe body. An important feature of the invention is that the bore has a diameter substantially the same as the diameter of the discharge port at the location where the discharge port communicates with the bore. The assembly of the present invention also includes a plunger member for ejecting viscous material contained within the bore through the discharge port of the syringe body. The present invention is also directed to adapter members for use with conventional syringes.