[Comparison of canal transportation after preparation by 3 different rotary systems]

ABSTRACT

Cleaning and shaping has been recognized as one of the most important steps of root canal treatment. Various Ni-Ti rotary systems have been introduced for reduction of complications and facilitating the root canal shaping process. The purpose of this study was to determine the amount of transportation by using the three rotary systems, Profile, Flex master and Race. This ex-vivo randomized controlled trial was carried out on mesial mandibular root canals [type 3 Weine] with mild curvature [15-35°]. The roots were randomly divided into three groups of 20 canals each. The roots were sectioned horizontally at 3mm, 6mm from the apex and then, reassembled before instrumentation according to the manufacture's guidelines. Photographs were taken from the cross sections before and after instrumentation. Image analyses were performed by Photoshop software, version 8. The ability to preserve canal shape centrally as well as the direction of transportation was determined next. Data was analyzed by ANOVA and Tukey tests. The difference was significant in mid apical parts when comparing the three groups. Most transportation was in the furcation area. Race had the most and profiles showed the least transportation in both parts of the roots [P=0.001]. The profile system was found to be the best for preserving the centering position of the root canal among the three rotary systems