ABSTRACT

The aim of this study is to compare efficacies of four different types of techniques including balanced force (roane), crown down pressureless, step-back and conventional techniques in vitro.

Mesial canal of 35 mandibular teeth possessing 20- 40 degrees of curvature angle were separated into 5 groups in a manner each group including 14 canals. Horizontal cross-sections were obtained from the polyester embedded species 2 , 5 and 8 millimetres above the apex. Dentin removal was evaluated with regards to central ratio, rounding ratio, wall thickness and post-preparational canal shape. According to our findings most dentin removal was obtained by conventional technique and least dentin removal was observed in step-back tecnique utilizing Ni-Ti K type file. Central ratio was greatest in crown down presureless technique utilizing rotating Ni-Ti K type file and step-back technique utilizing Ni-Ti K type file while least in conventional technique. Most rounded canal shape was obtained by crown down technique and most irregular canal shape was observed in conventional technique. Least wall thinning was achieved utilizing Ni-Ti K type file in both crown down presureless techniques and step back techniques. Most wall thinning was obtained by conventional technique and step-back technique.