PROPERTIES OF HAND-HELD SPREADERS AFTER SIMULATED USE

Root canal spreaders are available in a wide variety of diameters, len gths, and tapers, Proposed ANSI/ADA ADA Specification no, 71 standardi zes certain properties of these instruments; however, none of these te sting procedures subjects the instruments to conditions of clinical us age, Diameters (D3 and Die) and taper of 40 D11T root canal spreaders from each of three companies [Endeco (EN), HuFriedy (HF), and Premier (PR)] were measured, Permanent angular deformation of the instrument t ip was measured by a bend test apparatus for four conditions: (group A ) as-supplied control, (group B) spreader sterilized in an autoclave f or 10 cycles, (group C) spreader inserted 50 times at a rate of 200 mm /min into plastic blocks with a canal curvature of 30 degrees, and (gr oup D) spreader sterilized for 10 cycles and then inserted in blocks a s described. All instruments passed the bend test in proposed specific ations under all conditions, The EN spreader was more susceptible to p ermanent deformation than HF or PR. There were no statistical differen ces among the control and the three simulated clinical conditions.