CANAL WALL PLANNING BY ENGINE-DRIVEN NICKEL-TITANIUM INSTRUMENTS, COMPARED WITH STAINLESS-STEEL HAND INSTRUMENTATION

Twenty-two mesial roots of extracted human mandibular molars were divi ded into two groups based on root curvature and length, The mesiolingu al canals were instrumented using either Flexofiles in a step-back ant icurvature filing method, or they were instrumented with engine-driven 0.02 taper nickel-titanium files, Ground sections were prepared at 1- , 2.5-, and 5-mm levels from the working length, The mesiobuccal canal was used as an uninstrumented control for predentin character, Digiti zing software was used to calculate the instrumented portion as a perc entage of the total canal perimeter. The results indicated no signific ant difference in overall canal wall planing between the two groups an d no significant difference at each of the three levels.