Comparison of removal times of Thermafil plastic obturators using ProFile rotary instruments at different rotational speeds in moderately curved canals

The purpose of this study was to compare the time required for removal of small Thermafil plastic carriers in moderately curved MB roots of mandibular molars using the ProFile rotary system at 300 and 1,500 rpm. MB roots of 40 mandibular molars were instrumented and obturated with size 30 Thermafil plastic obturators. Teeth were divided into two groups. In group 1, sizes 55 to 25 ProFile 0.04-taper instruments were used in a crown-down manner at 300 rpm. In group 2, size 25 ProFile 0.04-taper instruments were used at 1,500 rpm. Time of carrier removal and the number of instrument separations were recorded. The Student's t test demonstrated a significant difference between groups: 4 minutes 12 seconds for group 1 and 1 minute 28 seconds for group 2 (p < 0.001). However, a trend for greater separation of instruments was found with the higher rpm group.