Source of Support: None, Conflict of Interest: None
To compare the ability of three techniques (with two different instruments) of preparing root canal to provide a property shaped canal silicon models and crosssection methods were used. The canals of 180 permanent molars having root canal curvature greater than 300 were prepared with SB, BF and PSB using Ni- Ti/FF and divided into six groups of 30 each. 15 samples from each group were filled with silicon impression material (Viny1 Polysiloxane). The teeth were dissolved and the remaining models were evaluated and photographed. 15 samples from each group were studied after making cross sections at 1 mm, 3 mm and 5 mm intervals after leaving 1mm from the tip of the root. On statistical analysis it was observed that the difference in frequencies of SB, BF and PSB using Ni-Ti/FF was significant with the value of P<0.05, however when SB and PSB was compared the result was not significant in quality of five criteria and shapes of preparations.