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Abstract
To evaluate the efficacy of revo - S and reciproc R40 NiTi files in preparation of oval root canals using cone beam computed Tomography (CBCT). Forty extracted single rooted premolars were divided into 2 groups (n = 20). group 1 (R - S) were prepared with revo - S up to size #40 / .06. group 2 (R40) were prepared to the same size with a single file R40. Pre - and post-instrumentation CBCT scanning was done. Calculated parameters were: increase ({u1EB0}) in canal volume and surface area. Transportation, centering ability, and untouched canal areas were tested at 3, 6, 9 mms axial sections. Statistical analyses were made using Mann-Whitney U and Friedman{u2019}s test (P {u2264} 0.05). Significant increase in {u1EB0} volume (P = .000 and P = .003 for R - S and R40 respectively) and {uF044} surface area (P = 0.048 and P = 0.038 for R - S and R40 respectively) was found for both instrumentation kinematics with no significant differences between them. Canals{u2019} transportation and decreased centering ratio were detected in both groups at all tested levels with insignificant smaller values in the M - D direction. Exception was found at 9mm level where a significantly highest transportation was found in R - S group P = 0.022