COMPARISON OF CROSS-SECTION CHANGES AND CLEANING OF CURVED CANALS PREPARED BY DIFFERENT SYSTEMS

Abstract

Aim: to evaluate the changes in the canal cross sectional area by using cone beam computed tomography (CBCT) and the cleaning ability of root canals by using stereo microscope and scanning electron microscope. Materials and methods: a total of 40 extracted mandibular first molar teeth were collected. The curvature of each mesio-buccal canal in each root was determined according to Schneider’s technique by using cone beam computed tomography and Roots with angles of curvature ranging from 25-45o were selected. The samples were classified into four groups (10 each) according to the preparatory system used in the preparation. Evaluation of change in cross sectional area was done by using Cone beam computed tomography and Evaluation the cleaning ability of root canals was done by using stereo microscope and scanning electron microscope. Results: One-shape and Revo-S Ni-Ti rotary systems produced more changes in the canal cross sectional area at all canal levels than Liberator Ni-Ti rotary system and K-file hand instruments. Regarding smear layer scores, all the tested systems were unable to produce dentin surface free from smear layer: Revo-S and Liberator Ni-Ti rotary systems produced less amount of smear layer than One-shape Ni-Ti rotary system and K-file hand instruments at the apical region. Conclusions: The change in the canal cross sectional area is directly proportional to the amount of debris removal from the canal space with the four tested systems