COMPARISON OF 3 INSTRUMENTATION TECHNIQUES IN PREPARATION OF SIMULATED CURVED ROOT CANALS

Forty-five acrylic blocks with simulated curved canals were divided in to three groups of 15 blocks each. In group 1 the canals were instrume nted with ultrasonically energized K-files (UEF) using a piezoelectric ultrasonic device. In group 2 the canals were prepared with Profile 0 .04 Taper Series 29 Rotary Instruments (PRI) in conjunction with a low -speed high torque handpiece. In group 3 (control) the canals were han d instrumented (HI) with conventional K-type files using a standard pu sh-pull circumferential technique. The efficiency of these techniques for preparing the simulated canals were compared by measuring the amou nt of transportation of the prepared canals at different levels from t he working length using a double exposure photographic technique. A st atistical analysis was used to indicate any significant difference amo ng groups. The results showed that the use of PRI provided well-centre d and more tapered preparations. Conversely, the use of UEF and HI res ulted in frequent alteration of the original curvature, showing transp ortation at different levels from the working length.