Patent ID: 7303392

Claim:
An apparatus for forming a dental clasp from thermoplastic resins including a gun with a barrel and a trigger, the barrel having two ends and a longitudinal internal heating element located therebetween for heating solid thermoplastic resin to a molten state, an opening at the first end of the barrel which accepts a funnel into which is poured solid pellets of thermoplastic resin material and whose second end terminates in a nozzle which delivers molten thermoplastic resin through a tip for use in a silicone putty matrix on to plaster dental mold to make the clasp, the gun also includes a) a removable ratcheting rod with notched pre-cut grooves which moves with piston movement when the gun's trigger is manually squeezed, the grooves of the ratcheting rod that matches grooves in the gun's mechanical linkage thus advancing the rod to expel molten thermoplastic resin when the trigger is squeezed, b) a hollow metal tip that delivers the molten thermoplastic resin to the silicone putty matrix that surrounds a wax replicate of the clasp on the plaster dental mold which has contained inside the wax replicate of the dental clasp; and a separate, solid metal tip that exactly matches the size and dimensions of the hollow metal tip of the nozzle of the gun that is used to indent the silicone putty matrix with an outline of itself that will become a place to engage the tip of the gun so the gun will have a good seal to the putty matrix when squeezed to eject molten resin to form the clasp.