Syringe with piston assembly

A syringe assembly for containing and dispensing a fluid material comprising:

• a syringe body having at least one barrel, said barrel having an open upper end and a lower end in communication with an outlet opening for accommodating and dispensing said fluid material;
• a piston assembly movably positioned within said barrel, movable to dispense said material through said outlet opening;
• and
• an activatable plunger in contact with said piston assembly to effect dispensing movement of said piston assembly;
• said piston assembly including an outer piston in sealed engagement with said barrel and an inner piston in sealed engagement with said outer piston, said inner piston being movable within said outer piston with and against the bias of a spring to maintain said inner piston in contact with said fluid material in said barrel upon thermal expansion and contraction of said fluid material.